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• How to Use USER_DEFINED Activity in OWB Process Flow

  - by Jinggen He

  Process Flow is a very important component of Oracle Warehouse Builder. With Process Flow, we can create and control the ETL process by setting all kinds of activities in a well-constructed flow. In Oracle Warehouse Builder 11gR2, there are 28 kinds of activities, which fall into three categories: Control activities, OWB specific activities and Utility activities. For more information about Process Flow activities, please refer to OWB online doc. Most of those activities are pre-defined for some specific use. For example, the Mapping activity allows execution an OWB mapping in Process Flow and the FTP activity allows an interaction between the local host and a remote FTP server. Besides those activities for specific purposes, the User Defined activity enables you to incorporate into a Process Flow an activity that is not defined within Warehouse Builder. So the User Defined activity brings flexibility and extensibility to Process Flow. In this article, we will take an amazing tour of using the User Defined activity. Let's start. Enable execution of User Defined activity Let's start this section from creating a very simple Process Flow, which contains a Start activity, a User Defined activity and an End Success activity. Leave all parameters of activity USER_DEFINED unchanged except that we enter /tmp/test.sh into the Value column of the COMMAND parameter. Then let's create the shell script test.sh in /tmp directory. Here is the content of /tmp/test.sh (this article is demonstrating a scenario in Linux system, and /tmp/test.sh is a Bash shell script): echo Hello World! > /tmp/test.txt Note: don't forget to grant the execution privilege on /tmp/test.sh to OS Oracle user. For simplicity, we just use the following command. chmod +x /tmp/test.sh OK, it's so simple that we’ve almost done it. Now deploy the Process Flow and run it. For a newly installed OWB, we will come across an error saying "RPE-02248: For security reasons, activity operator Shell has been disabled by the DBA". See below. That's because, by default, the User Defined activity is DISABLED. Configuration about this can be found in <ORACLE_HOME>/owb/bin/admin/Runtime.properties: property.RuntimePlatform.0.NativeExecution.Shell.security_constraint=DISABLED The property can be set to three different values: NATIVE_JAVA, SCHEDULER and DISBALED. Where NATIVE_JAVA uses the Java 'Runtime.exec' interface, SCHEDULER uses a DBMS Scheduler external job submitted by the Control Center repository owner which is executed by the default operating system user configured by the DBA. DISABLED prevents execution via these operators. We enable the execution of User Defined activity by setting: property.RuntimePlatform.0.NativeExecution.Shell.security_constraint= NATIVE_JAVA Restart the Control Center service for the change of setting to take effect. cd <ORACLE_HOME>/owb/rtp/sql sqlplus OWBSYS/<password of OWBSYS> @stop_service.sql sqlplus OWBSYS/<password of OWBSYS> @start_service.sql And then run the Process Flow again. We will see that the Process Flow completes successfully. The execution of /tmp/test.sh successfully generated a file /tmp/test.txt, containing the line Hello World!. Pass parameters to User Defined Activity The Process Flow created in the above section has a drawback: the User Defined activity doesn't accept any information from OWB nor does it give any meaningful results back to OWB. That's to say, it lacks interaction. Maybe, sometimes such a Process Flow can fulfill the business requirement. But for most of the time, we need to get the User Defined activity executed according to some information prior to that step. In this section, we will see how to pass parameters to the User Defined activity and pass them into the to-be-executed shell script. First, let's see how to pass parameters to the script. The User Defined activity has an input parameter named PARAMETER_LIST. This is a list of parameters that will be passed to the command. Parameters are separated from one another by a token. The token is taken as the first character on the PARAMETER_LIST string, and the string must also end in that token. Warehouse Builder recommends the '?' character, but any character can be used. For example, to pass 'abc,' 'def,' and 'ghi' you can use the following equivalent: ?abc?def?ghi? or !abc!def!ghi! or |abc|def|ghi| If the token character or '\' needs to be included as part of the parameter, then it must be preceded with '\'. For example '\\'. If '\' is the token character, then '/' becomes the escape character. Let's configure the PARAMETER_LIST parameter as below: And modify the shell script /tmp/test.sh as below: echo $1 is saying hello to $2! > /tmp/test.txt Re-deploy the Process Flow and run it. We will see that the generated /tmp/test.txt contains the following line: Bob is saying hello to Alice! In the example above, the parameters passed into the shell script are static. This case is not so useful because: instead of passing parameters, we can directly write the value of the parameters in the shell script. To make the case more meaningful, we can pass two dynamic parameters, that are obtained from the previous activity, to the shell script. Prepare the Process Flow as below: The Mapping activity MAPPING_1 has two output parameters: FROM_USER, TO_USER. The User Defined activity has two input parameters: FROM_USER, TO_USER. All the four parameters are of String type. Additionally, the Process Flow has two string variables: VARIABLE_FOR_FROM_USER, VARIABLE_FOR_TO_USER. Through VARIABLE_FOR_FROM_USER, the input parameter FROM_USER of USER_DEFINED gets value from output parameter FROM_USER of MAPPING_1. We achieve this by binding both parameters to VARIABLE_FOR_FROM_USER. See the two figures below. In the same way, through VARIABLE_FOR_TO_USER, the input parameter TO_USER of USER_DEFINED gets value from output parameter TO_USER of MAPPING_1. Also, we need to change the PARAMETER_LIST of the User Defined activity like below: Now, the shell script is getting input from the Mapping activity dynamically. Deploy the Process Flow and all of its necessary dependees then run the Process Flow. We see that the generated /tmp/test.txt contains the following line: USER B is saying hello to USER A! 'USER B' and 'USER A' are two outputs of the Mapping execution. Write the shell script within Oracle Warehouse Builder In the previous section, the shell script is located in the /tmp directory. But sometimes, when the shell script is small, or for the sake of maintaining consistency, you may want to keep the shell script inside Oracle Warehouse Builder. We can achieve this by configuring these three parameters of a User Defined activity properly: COMMAND: Set the path of interpreter, by which the shell script will be interpreted. PARAMETER_LIST: Set it blank. SCRIPT: Enter the shell script content. Note that in Linux the shell script content is passed into the interpreter as standard input at runtime. About how to actually pass parameters to the shell script, we can utilize variable substitutions. As in the following figure, ${FROM_USER} will be replaced by the value of the FROM_USER input parameter of the User Defined activity. So will the ${TO_USER} symbol. Besides the custom substitution variables, OWB also provide some system pre-defined substitution variables. You can refer to the online document for that. Deploy the Process Flow and run it. We see that the generated /tmp/test.txt contains the following line: USER B is saying hello to USER A! Leverage the return value of User Defined activity All of the previous sections are connecting the User Defined activity to END_SUCCESS with an unconditional transition. But what should we do if we want different subsequent activities for different shell script execution results? 1.  The simplest way is to add three simple-conditioned out-going transitions for the User Defined activity just like the figure below. In the figure, to simplify the scenario, we connect the User Defined activity to three End activities. Basically, if the shell script ends successfully, the whole Process Flow will end at END_SUCCESS, otherwise, the whole Process Flow will end at END_ERROR (in our case, ending at END_WARNING seldom happens). In the real world, we can add more complex and meaningful subsequent business logic. 2.  Or we can utilize complex conditions to work with different results of the User Defined activity. Previously, in our script, we only have this line: echo ${FROM_USER} is saying hello to ${TO_USER}! > /tmp/test.txt We can add more logic in it and return different values accordingly. echo ${FROM_USER} is saying hello to ${TO_USER}! > /tmp/test.txt if CONDITION_1 ; then ...... exit 0 fi if CONDITION_2 ; then ...... exit 2 fi if CONDITION_3 ; then ...... exit 3 fi After that we can leverage the result by checking RESULT_CODE in condition expression of those out-going transitions. Let's suppose that we have the Process Flow as the following graph (SUB_PROCESS_n stands for more different further processes): We can set complex condition for the transition from USER_DEFINED to SUB_PROCESS_1 like this: Other transitions can be set in the same way. Note that, in our shell script, we return 0, 2 and 3, but not 1. As in Linux system, if the shell script comes across a system error like IO error, the return value will be 1. We can explicitly handle such a return value. Summary Let's summarize what has been discussed in this article: How to create a Process Flow with a User Defined activity in it How to pass parameters from the prior activity to the User Defined activity and finally into the shell script How to write the shell script within Oracle Warehouse Builder How to do variable substitutions How to let the User Defined activity return different values and in what way can we leverage

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• April 2013 Release of the Ajax Control Toolkit

  - by Stephen.Walther

  I’m excited to announce the April 2013 release of the Ajax Control Toolkit. For this release, we focused on improving two controls: the AjaxFileUpload and the MaskedEdit controls. You can download the latest release from CodePlex at http://AjaxControlToolkit.CodePlex.com or, better yet, you can execute the following NuGet command within Visual Studio 2010/2012: There are three builds of the Ajax Control Toolkit: .NET 3.5, .NET 4.0, and .NET 4.5. A Better AjaxFileUpload Control We completely rewrote the AjaxFileUpload control for this release. We had two primary goals. First, we wanted to support uploading really large files. In particular, we wanted to support uploading multi-gigabyte files such as video files or application files. Second, we wanted to support showing upload progress on as many browsers as possible. The previous version of the AjaxFileUpload could show upload progress when used with Google Chrome or Mozilla Firefox but not when used with Apple Safari or Microsoft Internet Explorer. The new version of the AjaxFileUpload control shows upload progress when used with any browser. Using the AjaxFileUpload Control Let me walk-through using the AjaxFileUpload in the most basic scenario. And then, in following sections, I can explain some of its more advanced features. Here’s how you can declare the AjaxFileUpload control in a page: <ajaxToolkit:ToolkitScriptManager runat="server" /> <ajaxToolkit:AjaxFileUpload ID="AjaxFileUpload1" AllowedFileTypes="mp4" OnUploadComplete="AjaxFileUpload1_UploadComplete" runat="server" /> The exact appearance of the AjaxFileUpload control depends on the features that a browser supports. In the case of Google Chrome, which supports drag-and-drop upload, here’s what the AjaxFileUpload looks like: Notice that the page above includes two Ajax Control Toolkit controls: the AjaxFileUpload and the ToolkitScriptManager control. You always need to include the ToolkitScriptManager with any page which uses Ajax Control Toolkit controls. The AjaxFileUpload control declared in the page above includes an event handler for its UploadComplete event. This event handler is declared in the code-behind page like this: protected void AjaxFileUpload1_UploadComplete(object sender, AjaxControlToolkit.AjaxFileUploadEventArgs e) { // Save uploaded file to App_Data folder AjaxFileUpload1.SaveAs(MapPath("~/App_Data/" + e.FileName)); } This method saves the uploaded file to your website’s App_Data folder. I’m assuming that you have an App_Data folder in your project – if you don’t have one then you need to create one or you will get an error. There is one more thing that you must do in order to get the AjaxFileUpload control to work. The AjaxFileUpload control relies on an HTTP Handler named AjaxFileUploadHandler.axd. You need to declare this handler in your application’s root web.config file like this: <configuration> <system.web> <compilation debug="true" targetFramework="4.5" /> <httpRuntime targetFramework="4.5" maxRequestLength="42949672" /> <httpHandlers> <add verb="*" path="AjaxFileUploadHandler.axd" type="AjaxControlToolkit.AjaxFileUploadHandler, AjaxControlToolkit"/> </httpHandlers> </system.web> <system.webServer> <validation validateIntegratedModeConfiguration="false"/> <handlers> <add name="AjaxFileUploadHandler" verb="*" path="AjaxFileUploadHandler.axd" type="AjaxControlToolkit.AjaxFileUploadHandler, AjaxControlToolkit"/> </handlers> <security> <requestFiltering> <requestLimits maxAllowedContentLength="4294967295"/> </requestFiltering> </security> </system.webServer> </configuration> Notice that the web.config file above also contains configuration settings for the maxRequestLength and maxAllowedContentLength. You need to assign large values to these configuration settings — as I did in the web.config file above — in order to accept large file uploads. Supporting Chunked File Uploads Because one of our primary goals with this release was support for large file uploads, we added support for client-side chunking. When you upload a file using a browser which fully supports the HTML5 File API — such as Google Chrome or Mozilla Firefox — then the file is uploaded in multiple chunks. You can see chunking in action by opening F12 Developer Tools in your browser and observing the Network tab: Notice that there is a crazy number of distinct post requests made (about 360 distinct requests for a 1 gigabyte file). Each post request looks like this: http://localhost:24338/AjaxFileUploadHandler.axd?contextKey={DA8BEDC8-B952-4d5d-8CC2-59FE922E2923}&fileId=B7CCE31C-6AB1-BB28-2940-49E0C9B81C64 &fileName=Sita_Sings_the_Blues_480p_2150kbps.mp4&chunked=true&firstChunk=false Each request posts another chunk of the file being uploaded. Notice that the request URL includes a chunked=true parameter which indicates that the browser is breaking the file being uploaded into multiple chunks. Showing Upload Progress on All Browsers The previous version of the AjaxFileUpload control could display upload progress only in the case of browsers which fully support the HTML5 File API. The new version of the AjaxFileUpload control can display upload progress in the case of all browsers. If a browser does not fully support the HTML5 File API then the browser polls the server every few seconds with an Ajax request to determine the percentage of the file that has been uploaded. This technique of displaying progress works with any browser which supports making Ajax requests. There is one catch. Be warned that this new feature only works with the .NET 4.0 and .NET 4.5 versions of the AjaxControlToolkit. To show upload progress, we are taking advantage of the new ASP.NET HttpRequest.GetBufferedInputStream() and HttpRequest.GetBufferlessInputStream() methods which are not supported by .NET 3.5. For example, here is what the Network tab looks like when you use the AjaxFileUpload with Microsoft Internet Explorer: Here’s what the requests in the Network tab look like: GET /WebForm1.aspx?contextKey={DA8BEDC8-B952-4d5d-8CC2-59FE922E2923}&poll=1&guid=9206FF94-76F9-B197-D1BC-EA9AD282806B HTTP/1.1 Notice that each request includes a poll=1 parameter. This parameter indicates that this is a polling request to get the size of the file buffered on the server. Here’s what the response body of a request looks like when about 20% of a file has been uploaded: Buffering to a Temporary File When you upload a file using the AjaxFileUpload control, the file upload is buffered to a temporary file located at Path.GetTempPath(). When you call the SaveAs() method, as we did in the sample page above, the temporary file is copied to a new file and then the temporary file is deleted. If you don’t call the SaveAs() method, then you must ensure that the temporary file gets deleted yourself. For example, if you want to save the file to a database then you will never call the SaveAs() method and you are responsible for deleting the file. The easiest way to delete the temporary file is to call the AjaxFileUploadEventArgs.DeleteTemporaryData() method in the UploadComplete handler: protected void AjaxFileUpload1_UploadComplete(object sender, AjaxControlToolkit.AjaxFileUploadEventArgs e) { // Save uploaded file to a database table e.DeleteTemporaryData(); } You also can call the static AjaxFileUpload.CleanAllTemporaryData() method to delete all temporary data and not only the temporary data related to the current file upload. For example, you might want to call this method on application start to ensure that all temporary data is removed whenever your application restarts. A Better MaskedEdit Extender This release of the Ajax Control Toolkit contains bug fixes for the top-voted issues related to the MaskedEdit control. We closed over 25 MaskedEdit issues. Here is a complete list of the issues addressed with this release: · 17302 MaskedEditExtender MaskType=Date, Mask=99/99/99 Undefined JS Error · 11758 MaskedEdit causes error in JScript when working with 2-digits year · 18810 Maskededitextender/validator Date validation issue · 23236 MaskEditValidator does not work with date input using format dd/mm/yyyy · 23042 Webkit based browsers (Safari, Chrome) and MaskedEditExtender · 26685 MaskedEditExtender@(ClearMaskOnLostFocus=false) adds a zero character when you each focused to target textbox · 16109 MaskedEditExtender: Negative amount, followed by decimal, sets value to positive · 11522 MaskEditExtender of AjaxtoolKit-1.0.10618.0 does not work properly for Hungarian Culture · 25988 MaskedEditExtender – CultureName (HU-hu) > DateSeparator · 23221 MaskedEditExtender date separator problem · 15233 Day and month swap in Dynamic user control · 15492 MaskedEditExtender with ClearMaskOnLostFocus and with MaskedEditValidator with ClientValidationFunction · 9389 MaskedEditValidator – when on no entry · 11392 MaskedEdit Number format messed up · 11819 MaskedEditExtender erases all values beyond first comma separtor · 13423 MaskedEdit(Extender/Validator) combo problem · 16111 MaskedEditValidator cannot validate date with DayMonthYear in UserDateFormat of MaskedEditExtender · 10901 MaskedEdit: The months and date fields swap values when you hit submit if UserDateFormat is set. · 15190 MaskedEditValidator can’t make use of MaskedEditExtender’s UserDateFormat property · 13898 MaskedEdit Extender with custom date type mask gives javascript error · 14692 MaskedEdit error in “yy/MM/dd” format. · 16186 MaskedEditExtender does not handle century properly in a date mask · 26456 MaskedEditBehavior. ConvFmtTime : function(input,loadFirst) fails if this._CultureAMPMPlaceholder == “” · 21474 Error on MaskedEditExtender working with number format · 23023 MaskedEditExtender’s ClearMaskOnLostFocus property causes problems for MaskedEditValidator when set to false · 13656 MaskedEditValidator Min/Max Date value issue Conclusion This latest release of the Ajax Control Toolkit required many hours of work by a team of talented developers. I want to thank the members of the Superexpert team for the long hours which they put into this release.

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• Project Navigation and File Nesting in ASP.NET MVC Projects

  - by Rick Strahl

  More and more I’m finding myself getting lost in the files in some of my larger Web projects. There’s so much freaking content to deal with – HTML Views, several derived CSS pages, page level CSS, script libraries, application wide scripts and page specific script files etc. etc. Thankfully I use Resharper and the Ctrl-T Go to Anything which autocompletes you to any file, type, member rapidly. Awesome except when I forget – or when I’m not quite sure of the name of what I’m looking for. Project navigation is still important. Sometimes while working on a project I seem to have 30 or more files open and trying to locate another new file to open in the solution often ends up being a mental exercise – “where did I put that thing?” It’s those little hesitations that tend to get in the way of workflow frequently. To make things worse most NuGet packages for client side frameworks and scripts, dump stuff into folders that I generally don’t use. I’ve never been a fan of the ‘Content’ folder in MVC which is just an empty layer that doesn’t serve much of a purpose. It’s usually the first thing I nuke in every MVC project. To me the project root is where the actual content for a site goes – is there really a need to add another folder to force another path into every resource you use? It’s ugly and also inefficient as it adds additional bytes to every resource link you embed into a page. Alternatives I’ve been playing around with different folder layouts recently and found that moving my cheese around has actually made project navigation much easier. In this post I show a couple of things I’ve found useful and maybe you find some of these useful as well or at least get some ideas what can be changed to provide better project flow. The first thing I’ve been doing is add a root Code folder and putting all server code into that. I’m a big fan of treating the Web project root folder as my Web root folder so all content comes from the root without unneeded nesting like the Content folder. By moving all server code out of the root tree (except for Code) the root tree becomes a lot cleaner immediately as you remove Controllers, App_Start, Models etc. and move them underneath Code. Yes this adds another folder level for server code, but it leaves only code related things in one place that’s easier to jump back and forth in. Additionally I find myself doing a lot less with server side code these days, more with client side code so I want the server code separated from that. The root folder itself then serves as the root content folder. Specifically I have the Views folder below it, as well as the Css and Scripts folders which serve to hold only common libraries and global CSS and Scripts code. These days of building SPA style application, I also tend to have an App folder there where I keep my application specific JavaScript files, as well as HTML View templates for client SPA apps like Angular. Here’s an example of what this looks like in a relatively small project: The goal is to keep things that are related together, so I don’t end up jumping around so much in the solution to get to specific project items. The Code folder may irk some of you and hark back to the days of the App_Code folder in non Web-Application projects, but these days I find myself messing with a lot less server side code and much more with client side files – HTML, CSS and JavaScript. Generally I work on a single controller at a time – once that’s open it’s open that’s typically the only server code I work with regularily. Business logic lives in another project altogether, so other than the controller and maybe ViewModels there’s not a lot of code being accessed in the Code folder. So throwing that off the root and isolating seems like an easy win. Nesting Page specific content In a lot of my existing applications that are pure server side MVC application perhaps with some JavaScript associated with them , I tend to have page level javascript and css files. For these types of pages I actually prefer the local files stored in the same folder as the parent view. So typically I have a .css and .js files with the same name as the view in the same folder. This looks something like this: In order for this to work you have to also make a configuration change inside of the /Views/web.config file, as the Views folder is blocked with the BlockViewHandler that prohibits access to content from that folder. It’s easy to fix by changing the path from * to *.cshtml or *.vbhtml so that view retrieval is blocked:<system.webServer> <handlers> <remove name="BlockViewHandler"/> <add name="BlockViewHandler" path="*.cshtml" verb="*" preCondition="integratedMode" type="System.Web.HttpNotFoundHandler" /> </handlers> </system.webServer> With this in place, from inside of your Views you can then reference those same resources like this:<link href="~/Views/Admin/QuizPrognosisItems.css" rel="stylesheet" /> and<script src="~/Views/Admin/QuizPrognosisItems.js"></script> which works fine. JavaScript and CSS files in the Views folder deploy just like the .cshtml files do and can be referenced from this folder as well. Making this happen is not really as straightforward as it should be with just Visual Studio unfortunately, as there’s no easy way to get the file nesting from the VS IDE directly (you have to modify the .csproj file). However, Mads Kristensen has a nice Visual Studio Add-in that provides file nesting via a short cut menu option. Using this you can select each of the ‘child’ files and then nest them under a parent file. In the case above I select the .js and .css files and nest them underneath the .cshtml view. I was even toying with the idea of throwing the controller.cs files into the Views folder, but that’s maybe going a little too far :-) It would work however as Visual Studio doesn’t publish .cs files and the compiler doesn’t care where the files live. There are lots of options and if you think that would make life easier it’s another option to help group related things together. Are there any downside to this? Possibly – if you’re using automated minification/packaging tools like ASP.NET Bundling or Grunt/Gulp with Uglify, it becomes a little harder to group script and css files for minification as you may end up looking in multiple folders instead of a single folder. But – again that’s a one time configuration step that’s easily handled and much less intrusive then constantly having to search for files in your project. Client Side Folders The particular project shown above in the screen shots above is a traditional server side ASP.NET MVC application with most content rendered into server side Razor pages. There’s a fair amount of client side stuff happening on these pages as well – specifically several of these pages are self contained single page Angular applications that deal with 1 or maybe 2 separate views and the layout I’ve shown above really focuses on the server side aspect where there are Razor views with related script and css resources. For applications that are more client centric and have a lot more script and HTML template based content I tend to use the same layout for the server components, but the client side code can often be broken out differently. In SPA type applications I tend to follow the App folder approach where all the application pieces that make the SPA applications end up below the App folder. Here’s what that looks like for me – here this is an AngularJs project: In this case the App folder holds both the application specific js files, and the partial HTML views that get loaded into this single SPA page application. In this particular Angular SPA application that has controllers linked to particular partial views, I prefer to keep the script files that are associated with the views – Angular Js Controllers in this case – with the actual partials. Again I like the proximity of the view with the main code associated with the view, because 90% of the UI application code that gets written is handled between these two files. This approach works well, but only if controllers are fairly closely aligned with the partials. If you have many smaller sub-controllers or lots of directives where the alignment between views and code is more segmented this approach starts falling apart and you’ll probably be better off with separate folders in js folder. Following Angular conventions you’d have controllers/directives/services etc. folders. Please note that I’m not saying any of these ways are right or wrong  – this is just what has worked for me and why! Skipping Project Navigation altogether with Resharper I’ve talked a bit about project navigation in the project tree, which is a common way to navigate and which we all use at least some of the time, but if you use a tool like Resharper – which has Ctrl-T to jump to anything, you can quickly navigate with a shortcut key and autocomplete search. Here’s what Resharper’s jump to anything looks like: Resharper’s Goto Anything box lets you type and quick search over files, classes and members of the entire solution which is a very fast and powerful way to find what you’re looking for in your project, by passing the solution explorer altogether. As long as you remember to use (which I sometimes don’t) and you know what you’re looking for it’s by far the quickest way to find things in a project. It’s a shame that this sort of a simple search interface isn’t part of the native Visual Studio IDE. Work how you like to work Ultimately it all comes down to workflow and how you like to work, and what makes *you* more productive. Following pre-defined patterns is great for consistency, as long as they don’t get in the way you work. A lot of the default folder structures in Visual Studio for ASP.NET MVC were defined when things were done differently. These days we’re dealing with a lot more diverse project content than when ASP.NET MVC was originally introduced and project organization definitely is something that can get in the way if it doesn’t fit your workflow. So take a look and see what works well and what might benefit from organizing files differently. As so many things with ASP.NET, as things evolve and tend to get more complex I’ve found that I end up fighting some of the conventions. The good news is that you don’t have to follow the conventions and you have the freedom to do just about anything that works for you. Even though what I’ve shown here diverges from conventions, I don’t think anybody would stumble over these relatively minor changes and not immediately figure out where things live, even in larger projects. But nevertheless think long and hard before breaking those conventions – if there isn’t a good reason to break them or the changes don’t provide improved workflow then it’s not worth it. Break the rules, but only if there’s a quantifiable benefit. You may not agree with how I’ve chosen to divert from the standard project structures in this article, but maybe it gives you some ideas of how you can mix things up to make your existing project flow a little nicer and make it easier to navigate for your environment. © Rick Strahl, West Wind Technologies, 2005-2014Posted in ASP.NET  MVC   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Understanding LINQ to SQL (11) Performance

  - by Dixin

  [LINQ via C# series] LINQ to SQL has a lot of great features like strong typing query compilation deferred execution declarative paradigm etc., which are very productive. Of course, these cannot be free, and one price is the performance. O/R mapping overhead Because LINQ to SQL is based on O/R mapping, one obvious overhead is, data changing usually requires data retrieving:private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (NorthwindDataContext database = new NorthwindDataContext()) { Product product = database.Products.Single(item => item.ProductID == id); // SELECT... product.UnitPrice = unitPrice; // UPDATE... database.SubmitChanges(); } } Before updating an entity, that entity has to be retrieved by an extra SELECT query. This is slower than direct data update via ADO.NET:private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (SqlConnection connection = new SqlConnection( "Data Source=localhost;Initial Catalog=Northwind;Integrated Security=True")) using (SqlCommand command = new SqlCommand( @"UPDATE [dbo].[Products] SET [UnitPrice] = @UnitPrice WHERE [ProductID] = @ProductID", connection)) { command.Parameters.Add("@ProductID", SqlDbType.Int).Value = id; command.Parameters.Add("@UnitPrice", SqlDbType.Money).Value = unitPrice; connection.Open(); command.Transaction = connection.BeginTransaction(); command.ExecuteNonQuery(); // UPDATE... command.Transaction.Commit(); } } The above imperative code specifies the “how to do” details with better performance. For the same reason, some articles from Internet insist that, when updating data via LINQ to SQL, the above declarative code should be replaced by:private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (NorthwindDataContext database = new NorthwindDataContext()) { database.ExecuteCommand( "UPDATE [dbo].[Products] SET [UnitPrice] = {0} WHERE [ProductID] = {1}", id, unitPrice); } } Or just create a stored procedure:CREATE PROCEDURE [dbo].[UpdateProductUnitPrice] ( @ProductID INT, @UnitPrice MONEY ) AS BEGIN BEGIN TRANSACTION UPDATE [dbo].[Products] SET [UnitPrice] = @UnitPrice WHERE [ProductID] = @ProductID COMMIT TRANSACTION END and map it as a method of NorthwindDataContext (explained in this post):private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (NorthwindDataContext database = new NorthwindDataContext()) { database.UpdateProductUnitPrice(id, unitPrice); } } As a normal trade off for O/R mapping, a decision has to be made between performance overhead and programming productivity according to the case. In a developer’s perspective, if O/R mapping is chosen, I consistently choose the declarative LINQ code, unless this kind of overhead is unacceptable. Data retrieving overhead After talking about the O/R mapping specific issue. Now look into the LINQ to SQL specific issues, for example, performance in the data retrieving process. The previous post has explained that the SQL translating and executing is complex. Actually, the LINQ to SQL pipeline is similar to the compiler pipeline. It consists of about 15 steps to translate an C# expression tree to SQL statement, which can be categorized as: Convert: Invoke SqlProvider.BuildQuery() to convert the tree of Expression nodes into a tree of SqlNode nodes; Bind: Used visitor pattern to figure out the meanings of names according to the mapping info, like a property for a column, etc.; Flatten: Figure out the hierarchy of the query; Rewrite: for SQL Server 2000, if needed Reduce: Remove the unnecessary information from the tree. Parameterize Format: Generate the SQL statement string; Parameterize: Figure out the parameters, for example, a reference to a local variable should be a parameter in SQL; Materialize: Executes the reader and convert the result back into typed objects. So for each data retrieving, even for data retrieving which looks simple: private static Product[] RetrieveProducts(int productId) { using (NorthwindDataContext database = new NorthwindDataContext()) { return database.Products.Where(product => product.ProductID == productId) .ToArray(); } } LINQ to SQL goes through above steps to translate and execute the query. Fortunately, there is a built-in way to cache the translated query. Compiled query When such a LINQ to SQL query is executed repeatedly, The CompiledQuery can be used to translate query for one time, and execute for multiple times:internal static class CompiledQueries { private static readonly Func<NorthwindDataContext, int, Product[]> _retrieveProducts = CompiledQuery.Compile((NorthwindDataContext database, int productId) => database.Products.Where(product => product.ProductID == productId).ToArray()); internal static Product[] RetrieveProducts( this NorthwindDataContext database, int productId) { return _retrieveProducts(database, productId); } } The new version of RetrieveProducts() gets better performance, because only when _retrieveProducts is first time invoked, it internally invokes SqlProvider.Compile() to translate the query expression. And it also uses lock to make sure translating once in multi-threading scenarios. Static SQL / stored procedures without translating Another way to avoid the translating overhead is to use static SQL or stored procedures, just as the above examples. Because this is a functional programming series, this article not dive into. For the details, Scott Guthrie already has some excellent articles: LINQ to SQL (Part 6: Retrieving Data Using Stored Procedures) LINQ to SQL (Part 7: Updating our Database using Stored Procedures) LINQ to SQL (Part 8: Executing Custom SQL Expressions) Data changing overhead By looking into the data updating process, it also needs a lot of work: Begins transaction Processes the changes (ChangeProcessor) Walks through the objects to identify the changes Determines the order of the changes Executes the changings LINQ queries may be needed to execute the changings, like the first example in this article, an object needs to be retrieved before changed, then the above whole process of data retrieving will be went through If there is user customization, it will be executed, for example, a table’s INSERT / UPDATE / DELETE can be customized in the O/R designer It is important to keep these overhead in mind. Bulk deleting / updating Another thing to be aware is the bulk deleting:private static void DeleteProducts(int categoryId) { using (NorthwindDataContext database = new NorthwindDataContext()) { database.Products.DeleteAllOnSubmit( database.Products.Where(product => product.CategoryID == categoryId)); database.SubmitChanges(); } } The expected SQL should be like:BEGIN TRANSACTION exec sp_executesql N'DELETE FROM [dbo].[Products] AS [t0] WHERE [t0].[CategoryID] = @p0',N'@p0 int',@p0=9 COMMIT TRANSACTION Hoverer, as fore mentioned, the actual SQL is to retrieving the entities, and then delete them one by one:-- Retrieves the entities to be deleted: exec sp_executesql N'SELECT [t0].[ProductID], [t0].[ProductName], [t0].[SupplierID], [t0].[CategoryID], [t0].[QuantityPerUnit], [t0].[UnitPrice], [t0].[UnitsInStock], [t0].[UnitsOnOrder], [t0].[ReorderLevel], [t0].[Discontinued] FROM [dbo].[Products] AS [t0] WHERE [t0].[CategoryID] = @p0',N'@p0 int',@p0=9 -- Deletes the retrieved entities one by one: BEGIN TRANSACTION exec sp_executesql N'DELETE FROM [dbo].[Products] WHERE ([ProductID] = @p0) AND ([ProductName] = @p1) AND ([SupplierID] IS NULL) AND ([CategoryID] = @p2) AND ([QuantityPerUnit] IS NULL) AND ([UnitPrice] = @p3) AND ([UnitsInStock] = @p4) AND ([UnitsOnOrder] = @p5) AND ([ReorderLevel] = @p6) AND (NOT ([Discontinued] = 1))',N'@p0 int,@p1 nvarchar(4000),@p2 int,@p3 money,@p4 smallint,@p5 smallint,@p6 smallint',@p0=78,@p1=N'Optimus Prime',@p2=9,@p3=$0.0000,@p4=0,@p5=0,@p6=0 exec sp_executesql N'DELETE FROM [dbo].[Products] WHERE ([ProductID] = @p0) AND ([ProductName] = @p1) AND ([SupplierID] IS NULL) AND ([CategoryID] = @p2) AND ([QuantityPerUnit] IS NULL) AND ([UnitPrice] = @p3) AND ([UnitsInStock] = @p4) AND ([UnitsOnOrder] = @p5) AND ([ReorderLevel] = @p6) AND (NOT ([Discontinued] = 1))',N'@p0 int,@p1 nvarchar(4000),@p2 int,@p3 money,@p4 smallint,@p5 smallint,@p6 smallint',@p0=79,@p1=N'Bumble Bee',@p2=9,@p3=$0.0000,@p4=0,@p5=0,@p6=0 -- ... COMMIT TRANSACTION And the same to the bulk updating. This is really not effective and need to be aware. Here is already some solutions from the Internet, like this one. The idea is wrap the above SELECT statement into a INNER JOIN:exec sp_executesql N'DELETE [dbo].[Products] FROM [dbo].[Products] AS [j0] INNER JOIN ( SELECT [t0].[ProductID], [t0].[ProductName], [t0].[SupplierID], [t0].[CategoryID], [t0].[QuantityPerUnit], [t0].[UnitPrice], [t0].[UnitsInStock], [t0].[UnitsOnOrder], [t0].[ReorderLevel], [t0].[Discontinued] FROM [dbo].[Products] AS [t0] WHERE [t0].[CategoryID] = @p0) AS [j1] ON ([j0].[ProductID] = [j1].[[Products])', -- The Primary Key N'@p0 int',@p0=9 Query plan overhead The last thing is about the SQL Server query plan. Before .NET 4.0, LINQ to SQL has an issue (not sure if it is a bug). LINQ to SQL internally uses ADO.NET, but it does not set the SqlParameter.Size for a variable-length argument, like argument of NVARCHAR type, etc. So for two queries with the same SQL but different argument length:using (NorthwindDataContext database = new NorthwindDataContext()) { database.Products.Where(product => product.ProductName == "A") .Select(product => product.ProductID).ToArray(); // The same SQL and argument type, different argument length. database.Products.Where(product => product.ProductName == "AA") .Select(product => product.ProductID).ToArray(); } Pay attention to the argument length in the translated SQL:exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(1)',@p0=N'A' exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(2)',@p0=N'AA' Here is the overhead: The first query’s query plan cache is not reused by the second one:SELECT sys.syscacheobjects.cacheobjtype, sys.dm_exec_cached_plans.usecounts, sys.syscacheobjects.[sql] FROM sys.syscacheobjects INNER JOIN sys.dm_exec_cached_plans ON sys.syscacheobjects.bucketid = sys.dm_exec_cached_plans.bucketid; They actually use different query plans. Again, pay attention to the argument length in the [sql] column (@p0 nvarchar(2) / @p0 nvarchar(1)). Fortunately, in .NET 4.0 this is fixed:internal static class SqlTypeSystem { private abstract class ProviderBase : TypeSystemProvider { protected int? GetLargestDeclarableSize(SqlType declaredType) { SqlDbType sqlDbType = declaredType.SqlDbType; if (sqlDbType <= SqlDbType.Image) { switch (sqlDbType) { case SqlDbType.Binary: case SqlDbType.Image: return 8000; } return null; } if (sqlDbType == SqlDbType.NVarChar) { return 4000; // Max length for NVARCHAR. } if (sqlDbType != SqlDbType.VarChar) { return null; } return 8000; } } } In this above example, the translated SQL becomes:exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(4000)',@p0=N'A' exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(4000)',@p0=N'AA' So that they reuses the same query plan cache: Now the [usecounts] column is 2.

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• BizTalk 2009 - Naming Guidelines

  - by StuartBrierley

  The following is effectively a repost of the BizTalk 2004 naming guidlines that I have previously detailed.  I have posted these again for completeness under BizTalk 2009 and to allow an element of separation in case I find some reason to amend these for BizTalk 2009. These guidlines should be universal across any version of BizTalk you may wish to apply them to. General Rules All names should be named with a Pascal convention. Project Namespaces For message schemas: [CompanyName].XML.Schemas.[FunctionalName]* Examples:  ABC.XML.Schemas.Underwriting DEF.XML.Schemas.MarshmellowTradingExchange * Donates potential for multiple levels of functional name, such as Underwriting.Dictionary.Valuation For web services: [CompanyName].Web.Services.[FunctionalName] Examples: ABC.Web.Services.OrderJellyBeans For the main BizTalk Projects: [CompanyName].BizTalk.[AssemblyType].[FunctionalName]* Examples: ABC.BizTalk.Mappings.Underwriting ABC.BizTalk.Orchestrations.Underwriting * Donates potential for multiple levels of functional name, such as Mappings.Underwriting.Valuations Assemblies BizTalk Assembly names should match the associated Project Namespace, such as ABC.BizTalk.Mappings.Underwriting. This pertains to the formal assembly name and the DLL name. The Solution name should take the name of the main project within the solution, and also therefore the namespace for that project. Although long names such as this can be unwieldy to work with, the benefits of having the full scope available when the assemblies are installed on the target server are generally judged to outweigh this inconvenience. Messaging Artifacts Artifact Standard Notes Example Schema <DescriptiveName>.xsd   .NET Type name should match, without file extension.    .NET Namespace will likely match assembly name. PurchaseOrderAcknowledge_FF.xsd  or FNMA100330_FF.xsd Property Schema <DescriptiveName>.xsd Should be named to reflect possible common usage across multiple schemas  IspecMessagePropertySchema.xsd UnderwritingOrchestrationKeys.xsd Map <SourceSchema>2<DestinationSchema>.btm Exceptions to this may be made where the source and destination schemas share the majority of the name, such as in mainframe web service maps InstructionResponse2CustomEmailRequest.btm (exception example) AccountCustomerAddressSummaryRequest2MainframeRequest.btm Orchestration <DescriptiveName>.odx   GetValuationReports.odx SendMTEDecisionResponse.odx Send/Receive Pipeline <DescriptiveName>.btp   ValidatingXMLReceivePipeline.btp FlatFileAssembler.btp Receive Port A plainly worded phrase that will clearly explain the function.    FraudPreventionServices LetterProcessing   Receive Location A plainly worded phrase that will clearly explain the function.  ? Do we want to include the transport type here ? Arrears Web Service Send Port Group A plainly worded phrase that will clearly explain the function.   Customer Updates Send Port A plainly worded phrase that will clearly explain the function.    ABCProductUpdater LogLendingPolicyOutput Parties A meaningful name for a Trading Partner. If dealing with multiple entities within a Trading Partner organization, the Organization name could be used as a prefix.   Roles A meaningful name for the role that a Trading Partner plays.     Orchestration Workflow Shapes Shape Standard Notes Example Scopes <DescriptionOfContainedWork> or <DescOfcontainedWork><TxType>   Including info about transaction type may be appropriate in some situations where it adds significant documentation value to the diagram. HandleReportResponse         Receive Receive<MessageName> Typically, MessageName will be the same as the name of the message variable that is being received “into”. ReceiveReportResponse Send Send<MessageName> Typically, MessageName will be the same as the name of the message variable that is being sent. SendValuationDetailsRequest Expression <DescriptionOfEffect> Expression shapes should be named to describe the net effect of the expression, similar to naming a method.  The exception to this is the case where the expression is interacting with an external .NET component to perform a function that overlaps with existing BizTalk functionality – use closest BizTalk shape for this case. CreatePrintXML Decide <DescriptionOfDecision> A description of what will be decided in the “if” branch Report Type? Perform MF Save? If-Branch <DescriptionOfDecision> A (potentially abbreviated) description of what is being decided Mortgage Valuation Yes Else-Branch Else Else-branch shapes should always be named “Else” Else Construct Message (Assign) Create<Message> (for Construct)     <ExpressionDescription> (for expression) If a Construct shape contains a message assignment, it should be prefixed with “Create” followed by an abbreviated name of the message being assigned.    The actual message assignment shape contained should be named to describe the expression that is contained. CreateReportDataMV   which contains expression: ExtractReportData Construct Message (Transform) Create<Message> (for Construct)   <SourceSchema>2<DestSchema> (for transform) If a Construct shape contains a message transform, it should be prefixed with “Create” followed by an abbreviated name of the message being assigned.   The actual message transform shape contained should generally be named the same as the called map.  CreateReportDataMV   which contains transform: ReportDataMV2ReportDataMV                 Construct Message (containing multiple shapes)   If a Construct Message shape uses multiple assignments or transforms, the overall shape should be named to communicate the net effect, using no prefix.     Call/Start Orchestration Call<OrchestrationName>   Start<OrchestrationName>     Throw Throw<ExceptionType> The corresponding variable name for the exception type should (often) be the same name as the exception type, only camel-cased. ThrowRuleException, which references the “ruleException” variable.     Parallel <DescriptionOfParallelWork> Parallel shapes should be named by a description of what work will be done in parallel   Delay <DescriptionOfWhatWaitingFor> Delay shapes should be named by a description of what is being waited for.  POAcknowledgeTimeout Listen <DescriptionOfOutcomes> Listen shapes should be named by a description that captures (to the degree possible) all the branches of the Listen shape POAckOrTimeout FirstShippingBid Loop <DescriptionOfLoop> A (potentially abbreviated) description of what the loop is. ForEachValuationReport WhileErrorFlagTrue Role Link   See “Roles” in messaging naming conventions above.   Suspend <ReasonDescription> Describe what action an administrator must take to resume the orchestration.  More detail can be passed to error property – and should include what should be done by the administrator before resuming the orchestration. ReEstablishCreditLink Terminate <ReasonDescription> Describe why the orchestration terminated.  More detail can be passed to error property. TimeoutsExpired Call Rules Call<PolicyName> The policy name may need to be abbreviated. CallLendingPolicy Compensate Compensate or Compensate<TxName> If the shape compensates nested transactions, names should be suffixed with the name of the nested transaction – otherwise it should simple be Compensate. CompensateTransferFunds Orchestration Types Type Standard Notes Example Multi-Part Message Types <LogicalDocumentType>   Multi-part types encapsulate multiple parts.  The WSDL spec indicates “parts are a flexible mechanism for describing the logical abstract content of a message.”  The name of the multi-part type should correspond to the “logical” document type, i.e. what the sum of the parts describes. InvoiceReceipt   (which might encapsulate an invoice acknowledgement and a payment voucher.) Multi-Part Messsage Part <SchemaNameOfPart> Should be named (most often) simply for the schema (or simple type) associated with the part. InvoiceHeader Messages <SchemaName> or <MuliPartMessageTypeName> Should be named based on the corresponding schema type or multi-part message type.  If there is more than one variable of a type, name for its use within the orchestration. ReportDataMV UpdatedReportDataMV Variables <DescriptiveName>   TargetFilePath StringProcessor Port Types <FunctionDescription>PortType Should be named to suggest the nature of an endpoint, with pascal casing and suffixed with “PortType”.   If there will be more than one Port for a Port Type, the Port Type should be named according to the abstract service supplied.   The WSDL spec indicates port types are “a named set of abstract operations and the abstract messages involved” that also encapsulates the message pattern (i.e. one-way, request-response, solicit-response) that all operations on the port type adhere to. ReceiveReportResponsePortType  or CallEAEPortType (This is a two way port, so Receove or Send alone would not be appropriate.  Could have been ProcessEAERequestPortType etc....) Ports <FunctionDescription>Port Should be named to suggest a grouping of functionality, with pascal casing and suffixed with “Port.”  ReceiveReportResponsePort CallEAEPort Correlation types <DescriptiveName> Should be named based on the logical name of what is being used to correlate.  PurchaseOrderNumber Correlation sets <DescriptiveName> Should be named based on the corresponding correlation type.  If there is more than one, it should be named to reflect its specific purpose within the orchestration.   PurchaseOrderNumber Orchestration parameters <DescriptiveName> Should be named to match the caller’s names for the corresponding variables where appropriate.

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• SQL SERVER – Weekly Series – Memory Lane – #033

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Spatial Database Definition and Research Documents Here is the definition from Wikipedia about spatial database : A spatial database is a database that is optimized to store and query data related to objects in space, including points, lines and polygons. While typical databases can understand various numeric and character types of data, additional functionality needs to be added for databases to process spatial data types. Select Only Date Part From DateTime – Best Practice A very common question which I receive is how to only get Date or Time part from datetime value. In this blog post I explain the same in very simple words. T-SQL Paging Query Technique Comparison (OVER and ROW_NUMBER()) – CTE vs. Derived Table I have received few emails and comments about my post SQL SERVER – T-SQL Paging Query Technique Comparison – SQL 2000 vs SQL 2005. The main question was is this can be done using CTE? Absolutely! What about Performance? It is identical! Please refer above mentioned article for the history of paging. SQL SERVER – Cannot resolve collation conflict for equal to operation One of the very first error I ever encountered in my career was to resolve this conflict. I have blogged about it and I have realized that many others like me who are facing this error. LEN and DATALENGTH of NULL Simple Example Here is the question for you what is the LEN of NULL value? Well it is very easy – just read the blog. Recovery Models and Selection Very simple and easy explanation of the Database Backup Recovery Model and how to select the best option for you. Explanation SQL SERVER Hash Join Hash join gives best performance when two more join tables are joined and at-least one of them have no index or is not sorted. It is also expected that smaller of the either of table can be read in memory completely (though not necessary). Easy Sequence of SELECT FROM JOIN WHERE GROUP BY HAVING ORDER BY SELECT yourcolumns FROM tablenames JOIN tablenames WHERE condition GROUP BY yourcolumns HAVING aggregatecolumn condition ORDER BY yourcolumns NorthWind Database or AdventureWorks Database – Samples Databases In this blog post we learn how to install Northwind database. I also shared the source where one can download this database as that is used in many examples on MSDN help files. sp_HelpText for sp_HelpText – Puzzle A simple quick puzzle – do you know the answer of it? If not, go ahead and read the blog. 2008 SQL SERVER – 2008 – Step By Step Installation Guide With Images When SQL Server 2008 was newly introduced lots of people had no clue how to install SQL Server 2008 and the amount of the question which I used to receive were so much. I wrote this blog post with the spirit that this will help all the newbies to install SQL Server 2008 with the help of images. Still today this blog post has been bible for all of the people who are confused with SQL Server installation. Inline Variable Assignment I loved this feature. I have always wanted this feature to be present in SQL Server. The last time when I met developers from Microsoft SQL Server, I had talked about this feature. I think this feature saves some time but make the code more readable. Introduction to Policy Management – Enforcing Rules on SQL Server If our company policy is to create all the Stored Procedure with prefix ‘usp’ that developers should be just prevented to create Stored Procedure with any other prefix. Let us see a small tutorial how to create conditions and policy which will prevent any future SP to be created with any other prefix. 2009 Performance Counters from System Views – By Kevin Mckenna Many of you are not aware of this fact that access to performance information is readily available in SQL Server and that too without querying performance counters using a custom application or via perfmon. Till now, this fact has remained undisclosed but through this post I would like to explain you can easily access SQL Server performance counter information. Without putting much effort you will come across the system viewsys.dm_os_performance_counters. As the name suggests, this provides you easy access to the SQL Server performance counter information that is passed on to perfmon, but you can get at it via tsql. Customize Toolbar – Remove Debug Button from Toolbar I was fond of SQL Server Debugger feature in SQL Server 2000. To my utter disappointment, this feature was withdrawn from SQL Server 2005. The button of the debugger is similar to a play button and is used to run debugging commands of Visual Studio. Because of this reason, it gets very much infuriating for developers when they are developing on both – Visual Studio and SSMS. Let us now see how we can remove debugging button from SQL Server Management Studio. Effect of Normalization on Index and Performance A very interesting conversation which started from twitter. If you want to read one link this is the link I encourage you to read it. SSMS Feature – Multi-server Queries Using SQL Server Management Studio (SSMS) DBAs can now query multiple servers from one window. It is quite common for DBAs with large amount of servers to maintain and gather information from multiple SQL Servers and create report. This feature is a blessing for the DBAs, as they can now assemble all the information instantaneously without going anywhere. Query Optimizer Hint ROBUST PLAN – Question to You “ROBUST PLAN” is a kind of query hint which works quite differently than other hints. It does not improve join or force any indexes to use; it just makes sure that a query does not crash due to over the limit size of row. Let me elaborate upon it in the blog post. 2010 Do you really know the difference between various date functions available in SQL Server 2012? Here is a three part story where we explored the same with examples: Fastest Way to Restore the Database Difference Between DATETIME and DATETIME2 Difference Between DATETIME and DATETIME2 – WITH GETDATE Shrinking NDF and MDF Files – Readers’ Opinion Shrinking Database always creates performance degradation and increases fragmentation in the database. I suggest that you keep that in mind before you start reading the following comment. If you are going to say Shrinking Database is bad and evil, here I am saying it first and loud. Now, the comment of Imran is written while keeping in mind only the process showing how the Shrinking Database Operation works. Imran has already explained his understanding and requests further explanation. I have removed the Best Practices section from Imran’s comments, as there are a few corrections. 2011 Solution – Puzzle – SELECT * vs SELECT COUNT(*) This is very interesting question and I am very confident that not every one knows the answer to this question. Let me ask you again – Which will be faster SELECT* or SELECT COUNT (*) or do you think this is apples and oranges comparison. 2012 Service Broker and CAP_CPU_PERCENT – Limiting SQL Server Instances to CPU Usage In SQL Server 2012 there are a few enhancements with regards to SQL Server Resource Governor. One of the enhancement is how the resources are allocated. Let me explain you with examples. Let us understand the entire discussion with the help of three different examples. Finding Size of a Columnstore Index Using DMVs One of the very common question I often see is need of the list of columnstore index along with their size and corresponding table name. I quickly re-wrote a script using DMVs sys.indexes and sys.dm_db_partition_stats. This script gives the size of the columnstore index on disk only. I am sure there will be advanced script to retrieve details related to components associated with the columnstore index. However, I believe following script is sufficient to start getting an idea of columnstore index size. Developer Training Resources and Summary Roundup Developer Training - Importance and Significance - Part 1 In this part we discussed the importance of training in the real world. The most important and valuable resource any company is its employee. Employees who have been well-trained will be better at their jobs and produce a better product.  An employee who is well trained obviously knows more about their job and all the technical aspects. I have a very high opinion about training employees and it is the most important task. Developer Training – Employee Morals and Ethics – Part 2 In this part we discussed the most crucial components of training. Often employees are expecting the company to pay for their training and the company expresses no interest in training the employee. Quite often training expenses are the real issue for both the employee and employer. Developer Training – Difficult Questions and Alternative Perspective - Part 3 This part was the most difficult to write as I tried to address a few difficult questions and answers. Training is such a sensitive issue that many developers when not receiving chance for training think about leaving the organization. Developer Training – Various Options for Developer Training – Part 4 In this part I tried to explore a few methods and options for training. The generic feedback I received on this blog post was short and I should have explored each of the subject of the training in details. I believe there are two big buckets of training 1) Instructor Lead Training and 2) Self Lead Training. Developer Training – A Conclusive Summary- Part 5 There is no better motivation than a personal desire to learn new technology. Honestly there is nothing more personal learning. That “change is the only constant” and “adapt & overcome” are the essential lessons of life. One cannot stop the learning and resist the change. In the IT industry “ego of knowing all” and the “resistance to change” are the most challenging issues. A Quick Look at Logging and Ideas around Logging Question: What is the first thing comes to your mind when you hear the word “Logging”? Strange enough I got a different answer every single time. Let me just list what answer I got from my friends. Let us go over them one by one. Beginning Performance Tuning with SQL Server Execution Plan Solution of Puzzle – Swap Value of Column Without Case Statement Earlier this week I asked a question where I asked how to Swap Values of the column without using CASE Statement. Read here: SQL SERVER – A Puzzle – Swap Value of Column Without Case Statement. I have proposed 3 different solutions in the blog posts itself. I had requested the help of the community to come up with alternate solutions and honestly I am stunned and amazed by the qualified entries. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Begin the Clone Wars Have!

  - by Antony Reynolds

  Creating a New Virtual Machine from an Existing Virtual Disk In previous posts I described how I set up an OEL6 machine under VirtualBox that can run an 11gR2 database and FMW 11.1.1.5.  That is great if you want the DB and FMW running in the same virtual image and it has served me well for some proof of concepts and also for some testing of different JVMs.  However I also wanted to run some testing of FMW with the database running on a separate physical machine.  So in this post I will show how to take a VirtualBox image and create a new image based on the disks from that original image. What are my Options? There is more than one way to skin a cat, or in this case to create two separate VMs that can run on different hardware.  Some of the options include: Create new virtual disk images for each new VM. Clone the existing disk images and point the new VM at the cloned images. Point the new VM at the existing snapshots. #1 is too much like hard work, install OEL twice, install a database again, install FMW again, run RCU again!  Life is too short! #2 is probably the safest way of doing things.  VirtualBox allows you to clone a disk image for use in a separate machine.  However this of course duplicates the disk and means that it is now occupying 3 times the space, once for the original disk and twice more for the two clones I would need. #3 is the most space efficient way of doing things.  It does mean however that I can only run the new “cloned” images if I have access to the original image because that is where the base snapshots reside.  However this is not a problem for me as long as I remember to keep all threee images together.  So this is the approach we will follow. Snapshot, What Snapshot? As we are going to create new virtual machines based on existing snapshots we need to figure out which snapshot to use.  We do this by opening the “Media Manager” from within VirtualBox and moving the mouse over the snapshot images until we find the snapshots we want – the snapshot name is identified in the “Attached to:” comment.  In my case I wanted the FMW installed snapshot because that had a database configured for FMW alongside the FMW software.  I made a note of the filename of that snapshot (actually I just noted the first 5 characters as that was all that was needed to uniquely identify the snapshot file). When we create the new machines we will point them at the snapshot filename we have just checked. Network or NotWork? Because we want the two new machines to communicate with each other when hosted in different physical machines we can’t use the default NAT networking mode without a lot of hassle.  But at the same time we need them to have fixed IP addresses relative to each other so that they can see each other whilst also being able to see the outside world. To achieve all these requirements I created two network adapters for each machine.  Adapter 1 was a standard NAT mapping.  This will allow each machine to get a dynamic IP address (10.0.2.15 by default) that can be used to access the external world through the VBox provided NAT gateway.  This is the same as the existing configuration. The second adapter I created as a bridged adapter.  This gives the virtual machine direct access to the host network card and by using fixed IP addresses each machine can see the other.  It is important to choose fixed IP addresses that are not routable across your internal network so you don’t get any clashes with other machines on your network.  Of course you could always get proper fixed IP addresses from your network people, but I have serveral people using my images and as long as I don’t have two instances of the same VM on the same network segment this is easier and avoids reconfiguring the network every time someone wants a copy of my VM.  If it is available I would suggest using the 10.0.3.* network as 10.0.2.* is the default NAT network.  You can check availability by pinging 10.0.3.1 and 10.0.3.2 from your host machine.  If it times out then you are probably safe to use that. Creating the New VMs Now that I had collected the data that I needed I went ahead and created the new VMs. When asked for a “Boot Hard Disk” I used the “Choose a virtual hard disk file…” link to find the snapshot I had previously selected and set that to be the existing hard disk.  I chose the previously existing SOA 11.1.1.5 install for both the new DB and FMW machines because that snapshot had the database with the RCU completed that I wanted for my DB machine and it had the SOA software installed which I wanted for my FMW machine. After the initial creation of the virtual machine go into the network setting section and enable a second adapter which will be bridged.  Make a note of the MAC addresses (the last four digits should be sufficient) of the two adapters so that you can later set the bridged adapter to use fixed IP and the NAT adapter to use DHCP. We are now ready to start the VMs and reconfigure Linux. Reconfiguring Linux Because I now have two new machines I need to change their network configuration.  In particular I need to change the hostname, update the hosts file and change the network settings. Changing the Hostname I renamed both hosts by running the hostname command as root: hostname vboxfmw.oracle.com I also edited the /etc/sysconfig file and set the correct hostname in there. HOSTNAME=vboxfmw.oracle.com Changing the Network Settings I needed to change the network configuration to give the bridged network a fixed IP address.  I first explicitly set the MAC addresses of the two adapters, because the order of the virtual adapters in the VirtualBox Manager is not necessarily the same as the order of the adapters in the guest OS.  So I went in to the System->Preferences->Network Connections screen and explicitly set the “Device MAC address” for the two adapters. Having correctly mapped the Linux adapters to the VirtualBox adapters I then set the Bridged adapter to use fixed IP addressing rather than DHCP.  There is no need for additional routing or default gateways because we expect the two machine to be on the same LAN segment. Updating the Hosts File Having renamed the machines and reconfigured the network I then updated the /etc/hosts file to refer to the new machine name add a new line to the hosts file to provide an additional IP address for my server (the new fixed IP address) add a new line for the fixed IP address of the other virtual machine 10.0.3.101      vboxdb.oracle.com       vboxdb  # Added by NetworkManager 10.0.2.15       vboxdb.oracle.com       vboxdb  # Added by NetworkManager 10.0.3.102      vboxfmw.oracle.com      vboxfmw # Added by NetworkManager 127.0.0.1       localhost.localdomain   localhost ::1     vboxdb.oracle.com       vboxdb  localhost6.localdomain6 localhost6 To make sure everything takes effect I restarted the server. Reconfiguring the Database on the DB Machine Because we changed the hostname the listener and the EM console no longer start so I need to modify the listener.ora to use the new hostname and I also need to rebuild the EM configuration because it also relies on the hostname. I edited the $ORACLE_HOME/network/admin/listener.ora and changed the listening address to the new hostname:       (ADDRESS = (PROTOCOL = TCP)(HOST = vboxdb.oracle.com)(PORT = 1521)) After changing the listener.ora I was able to start the listener using: lsnrctl start I also had to reconfigure the EM database control.  I first deconfigured it using the command: emca -deconfig dbcontrol db -repos drop This drops the repository and removes any existing registered dbcontrols. I then re-configured it using the following command: emca -config dbcontrol db -repos create This creates the EM repository and then configures and starts dbcontrol. Now my database machine is ready so I can close it down and take a snapshot. Disabling the Database on the FMW Machine I set up the database to start automatically by creating a service called “dbora”.  On the FMW machine I do not need the database running so I can prevent it auto-starting by running the following command: chkconfig –del dbora Note that because I am using a snapshot it is not a waste of disk space to have the DB installed but not used.  As long as I don’t run it, it won’t cost me anything. I can now close the FMW machine down and take a snapshot. Creating a New Domain The FMW machine is now ready to create a new domain.  When creating the domain I can point it at the second machine which is running the database.  I can potentially run these machines on two separate physical machines as long as I have the original virtual machine available to both of the physical machines. Gotchas in Snapshotting VirtualBox does not support the concept of linked machines in a network like some virtualization technologies so when creating a snapshot it is a good idea to shut both VMs down and then take a snapshot on both of them.  This is because we want to keep the database in sync with the middleware.  One way to make sure that this happens would be to place all the domain configuration files on the database server via an NFS share, this would mean that all we would need to snapshot would be the database machine because that would hold all the state and configuration. The Sky’s the Limit We have covered a simple case of having just two machines.  I have a more complicated configuration in which two machine run a RAC database off the same base OS image, and two more machines run a SOA cluster based on the same OS image.  Just remember what machine holds state and what are the consequences of taking a snapshot.

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• C#/.NET Little Wonders: The EventHandler and EventHandler&lt;TEventArgs&gt; delegates

  - by James Michael Hare

  Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. In the last two weeks, we examined the Action family of delegates (and delegates in general), and the Func family of delegates and how they can be used to support generic, reusable algorithms and classes. So this week, we are going to look at a handy pair of delegates that can be used to eliminate the need for defining custom delegates when creating events: the EventHandler and EventHandler<TEventArgs> delegates. Events and delegates Before we begin, let’s quickly consider events in .NET.  According to the MSDN: An event in C# is a way for a class to provide notifications to clients of that class when some interesting thing happens to an object. So, basically, you can create an event in a type so that users of that type can subscribe to notifications of things of interest.  How is this different than some of the delegate programming that we talked about in the last two weeks?  Well, you can think of an event as a special access modifier on a delegate.  Some differences between the two are: Events are a special access case of delegates They behave much like delegates instances inside the type they are declared in, but outside of that type they can only be (un)subscribed to. Events can specify add/remove behavior explicitly If you want to do additional work when someone subscribes or unsubscribes to an event, you can specify the add and remove actions explicitly. Events have access modifiers, but these only specify the access level of those who can (un)subscribe A public event, for example, means anyone can (un)subscribe, but it does not mean that anyone can raise (invoke) the event directly.  Events can only be raised by the type that contains them In contrast, if a delegate is visible, it can be invoked outside of the object (not even in a sub-class!). Events tend to be for notifications only, and should be treated as optional Semantically speaking, events typically don’t perform work on the the class directly, but tend to just notify subscribers when something of note occurs. My basic rule-of-thumb is that if you are just wanting to notify any listeners (who may or may not care) that something has happened, use an event.  However, if you want the caller to provide some function to perform to direct the class about how it should perform work, make it a delegate. Declaring events using custom delegates To declare an event in a type, we simply use the event keyword and specify its delegate type.  For example, let’s say you wanted to create a new TimeOfDayTimer that triggers at a given time of the day (as opposed to on an interval).  We could write something like this: 1: public delegate void TimeOfDayHandler(object source, ElapsedEventArgs e); 2:  3: // A timer that will fire at time of day each day. 4: public class TimeOfDayTimer : IDisposable 5: { 6: // Event that is triggered at time of day. 7: public event TimeOfDayHandler Elapsed; 8:  9: // ... 10: } The first thing to note is that the event is a delegate type, which tells us what types of methods may subscribe to it.  The second thing to note is the signature of the event handler delegate, according to the MSDN: The standard signature of an event handler delegate defines a method that does not return a value, whose first parameter is of type Object and refers to the instance that raises the event, and whose second parameter is derived from type EventArgs and holds the event data. If the event does not generate event data, the second parameter is simply an instance of EventArgs. Otherwise, the second parameter is a custom type derived from EventArgs and supplies any fields or properties needed to hold the event data. So, in a nutshell, the event handler delegates should return void and take two parameters: An object reference to the object that raised the event. An EventArgs (or a subclass of EventArgs) reference to event specific information. Even if your event has no additional information to provide, you are still expected to provide an EventArgs instance.  In this case, feel free to pass the EventArgs.Empty singleton instead of creating new instances of EventArgs (to avoid generating unneeded memory garbage). The EventHandler delegate Because many events have no additional information to pass, and thus do not require custom EventArgs, the signature of the delegates for subscribing to these events is typically: 1: // always takes an object and an EventArgs reference 2: public delegate void EventHandler(object sender, EventArgs e) It would be insane to recreate this delegate for every class that had a basic event with no additional event data, so there already exists a delegate for you called EventHandler that has this very definition!  Feel free to use it to define any events which supply no additional event information: 1: public class Cache 2: { 3: // event that is raised whenever the cache performs a cleanup 4: public event EventHandler OnCleanup; 5:  6: // ... 7: } This will handle any event with the standard EventArgs (no additional information).  But what of events that do need to supply additional information?  Does that mean we’re out of luck for subclasses of EventArgs?  That’s where the generic for of EventHandler comes into play… The generic EventHandler<TEventArgs> delegate Starting with the introduction of generics in .NET 2.0, we have a generic delegate called EventHandler<TEventArgs>.  Its signature is as follows: 1: public delegate void EventHandler<TEventArgs>(object sender, TEventArgs e) 2: where TEventArgs : EventArgs This is similar to EventHandler except it has been made generic to support the more general case.  Thus, it will work for any delegate where the first argument is an object (the sender) and the second argument is a class derived from EventArgs (the event data). For example, let’s say we wanted to create a message receiver, and we wanted it to have a few events such as OnConnected that will tell us when a connection is established (probably with no additional information) and OnMessageReceived that will tell us when a new message arrives (probably with a string for the new message text). So for OnMessageReceived, our MessageReceivedEventArgs might look like this: 1: public sealed class MessageReceivedEventArgs : EventArgs 2: { 3: public string Message { get; set; } 4: } And since OnConnected needs no event argument type defined, our class might look something like this: 1: public class MessageReceiver 2: { 3: // event that is called when the receiver connects with sender 4: public event EventHandler OnConnected; 5:  6: // event that is called when a new message is received. 7: public event EventHandler<MessageReceivedEventArgs> OnMessageReceived; 8:  9: // ... 10: } Notice, nowhere did we have to define a delegate to fit our event definition, the EventHandler and generic EventHandler<TEventArgs> delegates fit almost anything we’d need to do with events. Sidebar: Thread-safety and raising an event When the time comes to raise an event, we should always check to make sure there are subscribers, and then only raise the event if anyone is subscribed.  This is important because if no one is subscribed to the event, then the instance will be null and we will get a NullReferenceException if we attempt to raise the event. 1: // This protects against NullReferenceException... or does it? 2: if (OnMessageReceived != null) 3: { 4: OnMessageReceived(this, new MessageReceivedEventArgs(aMessage)); 5: } The above code seems to handle the null reference if no one is subscribed, but there’s a problem if this is being used in multi-threaded environments.  For example, assume we have thread A which is about to raise the event, and it checks and clears the null check and is about to raise the event.  However, before it can do that thread B unsubscribes to the event, which sets the delegate to null.  Now, when thread A attempts to raise the event, this causes the NullReferenceException that we were hoping to avoid! To counter this, the simplest best-practice method is to copy the event (just a multicast delegate) to a temporary local variable just before we raise it.  Since we are inside the class where this event is being raised, we can copy it to a local variable like this, and it will protect us from multi-threading since multicast delegates are immutable and assignments are atomic: 1: // always make copy of the event multi-cast delegate before checking 2: // for null to avoid race-condition between the null-check and raising it. 3: var handler = OnMessageReceived; 4: 5: if (handler != null) 6: { 7: handler(this, new MessageReceivedEventArgs(aMessage)); 8: } The very slight trade-off is that it’s possible a class may get an event after it unsubscribes in a multi-threaded environment, but this is a small risk and classes should be prepared for this possibility anyway.  For a more detailed discussion on this, check out this excellent Eric Lippert blog post on Events and Races. Summary Generic delegates give us a lot of power to make generic algorithms and classes, and the EventHandler delegate family gives us the flexibility to create events easily, without needing to redefine delegates over and over.  Use them whenever you need to define events with or without specialized EventArgs.   Tweet Technorati Tags: .NET, C#, CSharp, Little Wonders, Generics, Delegates, EventHandler

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• What's up with LDoms: Part 1 - Introduction & Basic Concepts

  - by Stefan Hinker

  LDoms - the correct name is Oracle VM Server for SPARC - have been around for quite a while now.  But to my surprise, I get more and more requests to explain how they work or to give advise on how to make good use of them.  This made me think that writing up a few articles discussing the different features would be a good idea.  Now - I don't intend to rewrite the LDoms Admin Guide or to copy and reformat the (hopefully) well known "Beginners Guide to LDoms" by Tony Shoumack from 2007.  Those documents are very recommendable - especially the Beginners Guide, although based on LDoms 1.0, is still a good place to begin with.  However, LDoms have come a long way since then, and I hope to contribute to their adoption by discussing how they work and what features there are today.  In this and the following posts, I will use the term "LDoms" as a common abbreviation for Oracle VM Server for SPARC, just because it's a lot shorter and easier to type (and presumably, read). So, just to get everyone on the same baseline, lets briefly discuss the basic concepts of virtualization with LDoms.  LDoms make use of a hypervisor as a layer of abstraction between real, physical hardware and virtual hardware.  This virtual hardware is then used to create a number of guest systems which each behave very similar to a system running on bare metal:  Each has its own OBP, each will install its own copy of the Solaris OS and each will see a certain amount of CPU, memory, disk and network resources available to it.  Unlike some other type 1 hypervisors running on x86 hardware, the SPARC hypervisor is embedded in the system firmware and makes use both of supporting functions in the sun4v SPARC instruction set as well as the overall CPU architecture to fulfill its function. The CMT architecture of the supporting CPUs (T1 through T4) provide a large number of cores and threads to the OS.  For example, the current T4 CPU has eight cores, each running 8 threads, for a total of 64 threads per socket.  To the OS, this looks like 64 CPUs.  The SPARC hypervisor, when creating guest systems, simply assigns a certain number of these threads exclusively to one guest, thus avoiding the overhead of having to schedule OS threads to CPUs, as do typical x86 hypervisors.  The hypervisor only assigns CPUs and then steps aside.  It is not involved in the actual work being dispatched from the OS to the CPU, all it does is maintain isolation between different guests. Likewise, memory is assigned exclusively to individual guests.  Here,  the hypervisor provides generic mappings between the physical hardware addresses and the guest's views on memory.  Again, the hypervisor is not involved in the actual memory access, it only maintains isolation between guests. During the inital setup of a system with LDoms, you start with one special domain, called the Control Domain.  Initially, this domain owns all the hardware available in the system, including all CPUs, all RAM and all IO resources.  If you'd be running the system un-virtualized, this would be what you'd be working with.  To allow for guests, you first resize this initial domain (also called a primary domain in LDoms speak), assigning it a small amount of CPU and memory.  This frees up most of the available CPU and memory resources for guest domains.  IO is a little more complex, but very straightforward.  When LDoms 1.0 first came out, the only way to provide IO to guest systems was to create virtual disk and network services and attach guests to these services.  In the meantime, several different ways to connect guest domains to IO have been developed, the most recent one being SR-IOV support for network devices released in version 2.2 of Oracle VM Server for SPARC. I will cover these more advanced features in detail later.  For now, lets have a short look at the initial way IO was virtualized in LDoms: For virtualized IO, you create two services, one "Virtual Disk Service" or vds, and one "Virtual Switch" or vswitch.  You can, of course, also create more of these, but that's more advanced than I want to cover in this introduction.  These IO services now connect real, physical IO resources like a disk LUN or a networt port to the virtual devices that are assigned to guest domains.  For disk IO, the normal case would be to connect a physical LUN (or some other storage option that I'll discuss later) to one specific guest.  That guest would be assigned a virtual disk, which would appear to be just like a real LUN to the guest, while the IO is actually routed through the virtual disk service down to the physical device.  For network, the vswitch acts very much like a real, physical ethernet switch - you connect one physical port to it for outside connectivity and define one or more connections per guest, just like you would plug cables between a real switch and a real system. For completeness, there is another service that provides console access to guest domains which mimics the behavior of serial terminal servers. The connections between the virtual devices on the guest's side and the virtual IO services in the primary domain are created by the hypervisor.  It uses so called "Logical Domain Channels" or LDCs to create point-to-point connections between all of these devices and services.  These LDCs work very similar to high speed serial connections and are configured automatically whenever the Control Domain adds or removes virtual IO. To see all this in action, now lets look at a first example.  I will start with a newly installed machine and configure the control domain so that it's ready to create guest systems. In a first step, after we've installed the software, let's start the virtual console service and downsize the primary domain.  root@sun # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-c-- UART 512 261632M 0.3% 2d 13h 58m root@sun # ldm add-vconscon port-range=5000-5100 \ primary-console primary root@sun # svcadm enable vntsd root@sun # svcs vntsd STATE STIME FMRI online 9:53:21 svc:/ldoms/vntsd:default root@sun # ldm set-vcpu 16 primary root@sun # ldm set-mau 1 primary root@sun # ldm start-reconf primary root@sun # ldm set-memory 7680m primary root@sun # ldm add-config initial root@sun # shutdown -y -g0 -i6 So what have I done: I've defined a range of ports (5000-5100) for the virtual network terminal service and then started that service.  The vnts will later provide console connections to guest systems, very much like serial NTS's do in the physical world. Next, I assigned 16 vCPUs (on this platform, a T3-4, that's two cores) to the primary domain, freeing the rest up for future guest systems.  I also assigned one MAU to this domain.  A MAU is a crypto unit in the T3 CPU.  These need to be explicitly assigned to domains, just like CPU or memory.  (This is no longer the case with T4 systems, where crypto is always available everywhere.) Before I reassigned the memory, I started what's called a "delayed reconfiguration" session.  That avoids actually doing the change right away, which would take a considerable amount of time in this case.  Instead, I'll need to reboot once I'm all done.  I've assigned 7680MB of RAM to the primary.  That's 8GB less the 512MB which the hypervisor uses for it's own private purposes.  You can, depending on your needs, work with less.  I'll spend a dedicated article on sizing, discussing the pros and cons in detail. Finally, just before the reboot, I saved my work on the ILOM, to make this configuration available after a powercycle of the box.  (It'll always be available after a simple reboot, but the ILOM needs to know the configuration of the hypervisor after a power-cycle, before the primary domain is booted.) Now, lets create a first disk service and a first virtual switch which is connected to the physical network device igb2. We will later use these to connect virtual disks and virtual network ports of our guest systems to real world storage and network. root@sun # ldm add-vds primary-vds root@sun # ldm add-vswitch net-dev=igb2 switch-primary primary You are free to choose whatever names you like for the virtual disk service and the virtual switch.  I strongly recommend that you choose names that make sense to you and describe the function of each service in the context of your implementation.  For the vswitch, for example, you could choose names like "admin-vswitch" or "production-network" etc. This already concludes the configuration of the control domain.  We've freed up considerable amounts of CPU and RAM for guest systems and created the necessary infrastructure - console, vts and vswitch - so that guests systems can actually interact with the outside world.  The system is now ready to create guests, which I'll describe in the next section. For further reading, here are some recommendable links: The LDoms 2.2 Admin Guide The "Beginners Guide to LDoms" The LDoms Information Center on MOS LDoms on OTN

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• Observable Collections

  - by SGWellens

  I didn't think it was possible, but .NET surprised me yet again with a cool feature I never knew existed: The ObservableCollection. This became available in .NET 3.0. In essence, an ObservableCollection is a collection with an event you can connect to. The event fires when the collection changes. As usual, working with the .NET classes is so ridiculously easy, it feels like cheating. The following is small test program to illustrate how the ObservableCollection works. To start, create an ObservableCollection and then store it in the Session object so it will persist between page post backs. I also added the code to pull it out of Session state when there is a page post back:   public partial class _Default : System.Web.UI.Page{    public ObservableCollection<int> MyInts;     // ---- Page_Load ------------------------------     protected void Page_Load(object sender, EventArgs e)    {        if (IsPostBack == false)        {            MyInts = new ObservableCollection<int>();            MyInts.CollectionChanged += CollectionChangedHandler;             Session["MyInts"] = MyInts;  // store for use between postbacks        }        else        {            MyInts = Session["MyInts"] as ObservableCollection<int>;        }    } Here's the event handler I hooked up to the ObservableCollection, it writes status strings to a ListBox. Note: The event handler fires in a different thread than the IIS process thread.     // ---- CollectionChangedHandler -----------------------------------    //    // Something changed in the Observable collection     public void CollectionChangedHandler(object sender, NotifyCollectionChangedEventArgs e)    {        // need to dig around to get the current page and control to write to:        // (because this is in a separate thread)        Page CurrentPage = System.Web.HttpContext.Current.Handler as Page;        ListBox LB = CurrentPage.FindControl("ListBoxHistory") as ListBox;         switch (e.Action)        {            case NotifyCollectionChangedAction.Add:                LB.Items.Add("Add: " + e.NewItems[0]);                               break;             case NotifyCollectionChangedAction.Remove:                LB.Items.Add("Remove: " + e.OldItems[0]);                break;             case NotifyCollectionChangedAction.Reset:                LB.Items.Add("Reset: ");                break;             default:                LB.Items.Add(e.Action.ToString());                break;                     }    }  Next, add some buttons and code to exercise the ObservableCollection:     <br />    <asp:Button ID="ButtonAdd" runat="server" Text="Add" OnClick="ButtonAdd_Click" />    <asp:Button ID="ButtonRemove" runat="server" Text="Remove" OnClick="ButtonRemove_Click" />    <asp:Button ID="ButtonReset" runat="server" Text="Reset" OnClick="ButtonReset_Click" />    <asp:Button ID="ButtonList" runat="server" Text="List" OnClick="ButtonList_Click" />    <br />    <asp:TextBox ID="TextBoxInt" runat="server" Width="51px"></asp:TextBox>    <br />    <asp:ListBox ID="ListBoxHistory" runat="server" Height="255px" Width="195px">    </asp:ListBox>    // ---- Add Button --------------------------------------     protected void ButtonAdd_Click(object sender, EventArgs e)    {        int Temp;        if (int.TryParse(TextBoxInt.Text, out Temp) == true)            MyInts.Add(Temp);    }     // ---- Remove Button --------------------------------------     protected void ButtonRemove_Click(object sender, EventArgs e)    {        int Temp;        if (int.TryParse(TextBoxInt.Text, out Temp) == true)            MyInts.Remove(Temp);    }     // ---- Button Reset -----------------------------------     protected void ButtonReset_Click(object sender, EventArgs e)    {        MyInts.Clear();    }     // ---- Button List --------------------------------------     protected void ButtonList_Click(object sender, EventArgs e)    {        ListBoxHistory.Items.Add("MyInts:");        foreach (int i in MyInts)        {            // a bit of tweaking to get the text to be indented            ListItem LI = new ListItem("&nbsp;&nbsp;" + i.ToString());            LI.Text = Server.HtmlDecode(LI.Text);            ListBoxHistory.Items.Add(LI);        }    } Here's what it looks like after entering some numbers and clicking some buttons: An interesting note is that I had to use: System.Web.HttpContext.Current.Response to write to a control on the page. As mentioned earlier, this implies that the notification event is in a thread separate from the IIS thread. Another interesting note: From the online help: Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe What does that mean to Asp.Net developers? If you are going to share an ObservableCollection among different sessions, you'd better make it a static object. I hope someone finds this useful. Steve Wellens

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• The Internet of Things & Commerce: Part 2 -- Interview with Brian Celenza, Commerce Innovation Strategist

  - by Katrina Gosek, Director | Commerce Product Strategy-Oracle

  Internet of Things & Commerce Series: Part 2 (of 3) Welcome back to the second installation of my three part series on the Internet of Things & Commerce. A few weeks ago, I wrote “The Next 7,000 Days” about how we’ve become embedded in a digital architecture in the last 7,000 days since the birth of the internet – an architecture that everyday ties the massive expanse of the internet evermore closely with our physical lives. This blog series explores how this new blend of virtual and material will change how we shop and how businesses sell. Now enjoy reading my interview with Brian Celenza, one of the chief strategists in our Oracle Commerce innovation group. He comments on the past, present, and future of the how the growing Internet of Things relates and will relate to the buying and selling of goods on and offline. -------------------------------------------- QUESTION: You probably have one of the coolest jobs on our team, Brian – and frankly, one of the coolest jobs in our industry. As part of the innovation team for Oracle Commerce, you’re regularly working on bold features and groundbreaking commerce-focused experiences for our vision demos. As you look back over the past couple of years, what is the biggest trend (or trends) you’ve seen in digital commerce that started to bring us closer to this idea of what people are calling an “Internet of Things”? Brian: Well as you look back over the last couple of years, the speed at which change in our industry has moved looks like one of those blurred movement photos – you know the ones where the landscape blurs because the observer is moving so quickly your eye focus can’t keep up. But one thing that is absolutely clear is that the biggest catalyst for that speed of change – especially over the last three years – has been mobile. Mobile technology changed everything. Over the last three years the entire thought process of how to sell on (and offline) has shifted because of mobile technology advances. Particularly for eCommerce professionals who have started to move past the notion of “channels” for selling goods to this notion of “Mobile First”… then the Web site. Or more accurately, that everything – smartphones, web, store, tablet – is just one channel or has to act like one singular access point to the same product catalog, information and content. The most innovative eCommerce professionals realized some time ago that it’s not ideal to build an eCommerce Web site and then build everything on top of or off of it. Rather, they want to build an eCommerce API and then integrate it will all other systems. To accomplish this, they are leveraging all the latest mobile technologies or possibilities mobile technology has opened up: 4G and LTE, GPS, bluetooth, touch screens, apps, html5… How has this all started to come together for shopping experiences on and offline? Well to give you a personal example, I remember visiting an Apple store a few years ago and being amazed that I didn’t have to wait in line because a store associate knew everything about me from my ID – right there on the sales floor – and could check me out anywhere. Then just a few months later (when like any good addict) I went back to get the latest and greatest new gadget, I felt like I was stealing it because I could check myself out with my smartphone. I didn’t even need to see a sales associate OR go to a cash register. Amazing. And since then, all sort sorts of companies across all different types of industries – from food service to apparel –  are starting to see mobile payments in the billions of dollars now thanks not only to the convenience factor but to smart loyalty rewards programs as well. These are just some really simple current examples that come to mind. So many different things have happened in the last couple of years, it’s hard to really absorb all of the quickly – because as soon as you do, everything changes again! Just like that blurry speed photo image. For eCommerce, however, this type of new environment underscores the importance of building an eCommerce API – a platform that has services you can tap in to and build on as the landscape changes at a fever pitch. It’s a mobile first perspective. A web service perspective – particularly if you are thinking of how to engage customers across digital and physical spaces. —— QUESTION: Thanks for bringing us into the present – some really great examples you gave there to put things into perspective. So what do you see as the biggest trend right now around the “Internet of Things” – and what’s coming next few years? Brian: Honestly, even sitting where I am in the innovation group – it’s hard to look out even 12 months because, well, I don’t even think we’ve fully caught up with what is possible now. But I can definitely say that in the last 12 months and in the coming 12 months, in the technology and eCommerce world it’s all about iBeacons. iBeacons are awesome tools we have right now to tie together physical and digital shopping experiences. They know exactly where you are as a shopper and can communicate that to businesses. Currently there seem to be two camps of thought around iBeacons. First, many people are thinking of them like an “indoor GPS”, which to be fair they literally are. The use case this first camp envisions for iBeacons is primarily for advertising and marketing. So they use iBeacons to push location-based promotions to customers if they are close to a store or in a store. You may have seen these types of mobile promotions start to pop up occasionally on your smart phone as you pass by a store you’ve bought from in the past. That’s the work of iBeacons. But in my humble opinion, these promotions probably come too early in the customer journey and although they may be well timed and work to “convert” in some cases, I imagine in most they are just eroding customer trust because they are kind of a “one-size-fits-all” solution rather than one that is taking into account what exactly the customer might be looking for in that particular moment. Maybe they just want more information and a promotion is way too soon for that type of customer. The second camp is more in line with where my thinking falls. In this case, businesses take a more sensitive approach with iBeacons to customers’ needs. Instead of throwing out a “one-size-fits-all” to any passer by with iBeacons, the use case is more around looking at the physical proximity of a customer as an opportunity to provide a service: show expert reviews on a product they may be looking at in a particular aisle of a store, offer the opportunity to compare prices (and then offer a promotion), signal an in-store associate if a customer has been in the store for more than 10 minutes in one place. These are all less intrusive more value-driven uses of iBeacons. And they are more about building customer trust through service. To take this example a bit further into the future realm of “Big Data” and “Internet of Things” businesses could actually use the Oracle Commerce Platform and iBeacons to “silently” track customer movement w/in the store to provide higher quality service. And this doesn’t have to be creepy or intrusive. Simply if a customer has been in a particular department or aisle for more than a 5 or 10 minutes, an in-store associate could come over an offer some assistance already knowing customer preferences from their online profile and maybe even seeing the items in a shopping cart they started at home. None of this has to be revealed to the customer, but it certainly could boost the level of service an in-store sales associate could provide. Or, in another futuristic example, stores could use the digital footprint of the physical store transmitted by iBeacons to generate heat maps of the store that could be tracked over time. Imagine how much you could find out about which parts of the store are more busy during certain parts of the day or seasons. This could completely revolutionize how physical merchandising is deployed or where certain high value / new items are placed. And / or this use of iBeacons could also help businesses figure out if customers are getting held up in certain parts of the store during busy days like Black Friday. If long lines are causing customers to bounce from a physical store and leave those holiday gifts behind, maybe having employees with mobile check as an option could remove the cash register bottleneck. But going to back to my original statement, it’s all still very early in the story for iBeacons. The hardware manufacturers are still very new and there is still not one clear standard.  Honestly, it all goes back to building and maintaining an extensible and flexible platform for anywhere engagement. What you’re building today should allow you to rapidly take advantage of whatever unimaginable use cases wait around the corner. ------------------------------------------------------ I hope you enjoyed the brief interview with Brian. It’s really awesome to have such smart and innovation-minded individuals on our Oracle Commerce innovation team. Please join me again in a few weeks for Part 3 of this series where I interview one of the product managers on our team about how the blending of digital and in-store selling in influencing our product development and vision.

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• CodePlex Daily Summary for Sunday, October 06, 2013

  CodePlex Daily Summary for Sunday, October 06, 2013Popular ReleasesMedia Companion: Media Companion MC3.580b: Fixed IMDB Actor names and Actor Roles, empty <actor> entries in movie nfo, and actor scraping during initial movie scrape. Revision HistoryEvent-Based Components AppBuilder: AB3.Iteration.53: Iteration 53 (Feature): Allow drag&drop of existing component (flow, step) from component list to chart. Duplicate names are automatically recognized and solved. By the color of the draged component you can see what kind of component (flow or step) is currently draged. New: AddExistingComponentFlow, PartDragDropEventHandler, ExistingStepPreparerPulse: Pulse 0.6.7.3: Pulse is now accepting donations. To donate by Bitcoin or PayPal see https://pulse.codeplex.com/wikipage?title=Donations Lots of updates in v0.6.7.3: (Feature) New option allows you to disable wallpaper changing when a full screen application is running. This way Pulse doesn't slow down/lag your videos and games :) (Fix) Some users were getting Wallbase errors when logging in. This has been fixed. (Feature) Right click a provider and you can now make a copy of it by selecting the "Dupl...MoreTerra (Terraria World Viewer): MoreTerra 1.11.1: Release 1.11.1 =========== =Bug Fixes= =========== Added more tile blocks (Clouds, crimstone) Added items (binoculars, rope, Pirahna Gun) Added ores (Lead, Tin) Chests now work, I broke them yesterday. =============== =Known Issues= =============== I am having trouble with new background walls. So you will see a red outline for crimson then a pink inside. Same with where I think the queen bee lives.VG-Ripper & PG-Ripper: PG-Ripper 1.4.19: NEW: Added Option to login as Guest NEW: Added Menu Option to delete an Forum Account NEW: Added Support for "ImageTeam.org links FIXED: Fixed Ripping of http://forum.babeunion.com ForumsSimpleExcelReportMaker: Serm 0.03: SourceCode and Sample .Net Framework 3.5 AnyCPU compile.Application Architecture Guidelines: App Architecture Guidelines 3.0.8: This document is an overview of software qualities, principles, patterns, practices, tools and libraries.fastJSON: v2.0.22: 2.0.22 - added .net 3.5 project - now compiling to 'output' directory - added signed assembly - version numbers will stay at 2.0.0.0 for drop in compatibility - file version will reflect the build number - bug fix deserializing to dictionaries instead of dataset when type is not definedResponsive SharePoint: Bootstrap 3 for SharePoint 2013 - Alpha 0.1: Bootstrap 3 for SharePoint 2013 Alpha version 0.1 NOTE - This is an alpha version, there are bound to be issues. Please help us solve them by contributing in our Discussion. Publishing - The source for Twitter Bootstrap 3.0.0 integrated into SharePoint 2013 for a site with Publishing enabled. Non-Publishing - A master page and branding assets for Twitter Bootstrap 3.0.0 integrated into SharePoint 2013 without Publishing enabled. PageLayoutSampleContent - Sample content for included page l...C++ AMP Conformance Test Suite: C++ AMP Conformance Test Suite 1.0.0: This release contains following changes from previous release: Removed the tests that were testing Microsoft specific behavior not part of open specification. The test suite now contains two folders, containing set of test cases, named ‘Tests’ and ‘TestsWithProp'. The set of tests under these two folders are identical except one difference. The set of test cases under directory ‘TestsWithProp’ makes use of ‘properties’ (which the compiler being tested should handle as mentioned in the open ...ASP.NET dhtmxGantt Class: dhtmlxGantt2.vb class: This is the latest class based on work performed. For more information read the project description and get the source files from dhtmlx.comExpressiveDataGenerators: Alpha 2: Fix serveral bugs, more testsQuickTestsFramework: 1.0.0: First release with stable API.VS Tiny Extension for TortoiseGit: 0.1c: + Icons revised + Push button disappeared when IDE loads the menu instead of toolbar. + Detected twice loading and prevented. + About box deprecated. + Next version will have major improvements. NEW: Visual Studio 2013 Support!BlackJumboDog: Ver5.9.6: 2013.09.30 Ver5.9.6 (1)SMTP???????、???????????????? (2)WinAPI??????? (3)Web???????CGI???????????????????????PayBox payment gateway provider for NB_Store: NB_Store_Gateway_01.00.02_PayBox: Paybox DNN module installMicrosoft Ajax Minifier: Microsoft Ajax Minifier 5.2: Mostly internal code tweaks. added -nosize switch to turn off the size- and gzip-calculations done after minification. removed the comments in the build targets script for the old AjaxMin build task (discussion #458831). Fixed an issue with extended Unicode characters encoded inside a string literal with adjacent \uHHHH\uHHHH sequences. Fixed an IndexOutOfRange exception when encountering a CSS identifier that's a single underscore character (_). In previous builds, the net35 and net20...AJAX Control Toolkit: September 2013 Release: AJAX Control Toolkit Release Notes - September 2013 Release (Updated) Version 7.1005September 2013 release of the AJAX Control Toolkit. AJAX Control Toolkit .NET 4.5 – AJAX Control Toolkit for .NET 4.5 and sample site (Recommended). AJAX Control Toolkit .NET 4 – AJAX Control Toolkit for .NET 4 and sample site (Recommended). AJAX Control Toolkit .NET 3.5 – AJAX Control Toolkit for .NET 3.5 and sample site (Recommended). Important UpdateThis release has been updated to fix three issues: Up...WDTVHubGen - Adds Metadata, thumbnails and subtitles to WDTV Live Hubs: WDTVHubGen.v2.1.4.apifix-alpha: WDTVHubGen.v2.1.4.apifix-alpha is for testers to figure out if we got the NEW api plugged in ok. thanksVisual Log Parser: VisualLogParser: Portable Visual Log Parser for Dotnet 4.0New ProjectsBasic4Android (B4A) Charting Framework: dhtlmxCharts, GoogleCharts etc: Basic4Android (B4A) mobile charting framework.Client Meeting Tool: This site facilitate users to create and schedule meetings for an event.FoodScan: This app focuses on implementing diet monitoring application for Malaysian overweight and obese adolescents using AR technique on Windows Phone 8.Hello Team foundation server: Try to use team foundation server and compare it with GitKDG C# Password Generator: C# password generator developed by KDG.KDG's C# Password Generator: C# password generator that uses Random to create strong passwords based on user input.Meta: Meta is the EECS 111 programming language at Northwestern University. Meta is a dynamically-typed scheme-like language built on .NET. This is its home.Monoscript: Allows using Mono and C# for scripting on Unix. Source files are automatically compiled and executed. Caching is employed to avoid recompiling unchanged files.mtdsharp: Developed by Chris Hyndman, Alec KC, Lu Huang and Merrill Huang for CS 196 at the University of Illinois.Planr.me: Planr is a time management website currently in the early development stageProject Hermes: This very project is currently closed door and under core development. The project description and other works would be published soon.Remindme for Windows Phone 8: Simple, open source Pocket client for Windows Phone 8Remindme for WinRT: Simple, open source Pocket client for WinRT and Windows 8.SQL Server Periodic Table with Molecules: This a SQL Server Database intended to be used by students and researchers for Chemistry and Physics projects. Tesseract: The Tesseract Project aims to easily display and rotate 4 Dimensional Objects in 3D Test Case Manager: A Windows Application which extends Microsoft Test Manager. Features: * one click search * test case export * better test case reader * extended edit modeTest Project for Assignment 1: This is a test ProjectTorah File: Torah File is an project that allow you to use Torah Bible and Mishneh for the computer by type of the programming languages that will be able to use the ToUSAePay nopCommerce Payment Plugin: A simple plugin for nopCommerce to use the USAePay SOAP API interface for processing credit cards.Veterinaria Dr Leo: Este es nuestro Proyecto del curso Calidad y Pruebas de Software 2013-2 Arevalo Ticlla, Susan. Chalán Malca, Elvis. Cruzado Asencio, Gustavo.Visual Studio Test Extensions: The Visual Studio Test Extensions provides extensions and tools for the Visual Studio MSTest engine. It allows to execute unit tests in a separate AppDomain.WSAAD7COM1052: Central repository for 7COM1052 - Web Scripting & Application Development (COM)wscc2013online: this is a project related to Web Application Development at the University of Hertfordshire

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• Routing to a Controller with no View in Angular

  - by Rick Strahl

  I've finally had some time to put Angular to use this week in a small project I'm working on for fun. Angular's routing is great and makes it real easy to map URL routes to controllers and model data into views. But what if you don't actually need a view, if you effectively need a headless controller that just runs code, but doesn't render a view?Preserve the ViewWhen Angular navigates a route and and presents a new view, it loads the controller and then renders the view from scratch. Views are not cached or stored, but displayed and then removed. So if you have routes configured like this:'use strict'; // Declare app level module which depends on filters, and services window.myApp = angular.module('myApp', ['myApp.filters', 'myApp.services', 'myApp.directives', 'myApp.controllers']). config(['$routeProvider', function($routeProvider) { $routeProvider.when('/map', { template: "partials/map.html ", controller: 'mapController', reloadOnSearch: false, animation: 'slide' }); … $routeProvider.otherwise({redirectTo: '/map'}); }]); Angular routes to the mapController and then re-renders the map.html template with the new data from the $scope filled in.But, but… I don't want a new View!Now in most cases this works just fine. If I'm rendering plain DOM content, or textboxes in a form interface that is all fine and dandy - it's perfectly fine to completely re-render the UI.But in some cases, the UI that's being managed has state and shouldn't be redrawn. In this case the main page in question has a Google Map on it. The map is  going to be manipulated throughout the lifetime of the application and the rest of the pages. In my application I have a toolbar on the bottom and the rest of the content is replaced/switched out by the Angular Views:The problem is that the map shouldn't be redrawn each time the Location view is activated. It should maintain its state, such as the current position selected (which can move), and shouldn't redraw due to the overhead of re-rendering the initial map.Originally I set up the map, exactly like all my other views - as a partial, that is rendered with a separate file, but that didn't work.The Workaround - Controller Only RoutesThe workaround for this goes decidedly against Angular's way of doing things:Setting up a Template-less RouteIn-lining the map view directly into the main pageHiding and showing the map view manuallyLet's see how this works.Controller Only RouteThe template-less route is basically a route that doesn't have any template to render. This is not directly supported by Angular, but thankfully easy to fake. The end goal here is that I want to simply have the Controller fire and then have the controller manage the display of the already active view by hiding and showing the map and any other view content, in effect bypassing Angular's view display management.In short - I want a controller action, but no view rendering.The controller-only or template-less route looks like this: $routeProvider.when('/map', { template: " ", // just fire controller controller: 'mapController', animation: 'slide' });Notice I'm using the template property rather than templateUrl (used in the first example above), which allows specifying a string template, and leaving it blank. The template property basically allows you to provide a templated string using Angular's HandleBar like binding syntax which can be useful at times. You can use plain strings or strings with template code in the template, or as I'm doing here a blank string to essentially fake 'just clear the view'. In-lined ViewSo if there's no view where does the HTML go? Because I don't want Angular to manage the view the map markup is in-lined directly into the page. So instead of rendering the map into the Angular view container, the content is simply set up as inline HTML to display as a sibling to the view container.<div id="MapContent" data-icon="LocationIcon" ng-controller="mapController" style="display:none"> <div class="headerbar"> <div class="right-header" style="float:right"> <a id="btnShowSaveLocationDialog" class="iconbutton btn btn-sm" href="#/saveLocation" style="margin-right: 2px;"> <i class="icon-ok icon-2x" style="color: lightgreen; "></i> Save Location </a> </div> <div class="left-header">GeoCrumbs</div> </div> <div class="clearfix"></div> <div id="Message"> <i id="MessageIcon"></i> <span id="MessageText"></span> </div> <div id="Map" class="content-area"> </div> </div> <div id="ViewPlaceholder" ng-view></div>Note that there's the #MapContent element and the #ViewPlaceHolder. The #MapContent is my static map view that is always 'live' and is initially hidden. It is initially hidden and doesn't get made visible until the MapController controller activates it which does the initial rendering of the map. After that the element is persisted with the map data already loaded and any future access only updates the map with new locations/pins etc.Note that default route is assigned to the mapController, which means that the mapController is fired right as the page loads, which is actually a good thing in this case, as the map is the cornerstone of this app that is manipulated by some of the other controllers/views.The Controller handles some UISince there's effectively no view activation with the template-less route, the controller unfortunately has to take over some UI interaction directly. Specifically it has to swap the hidden state between the map and any of the other views.Here's what the controller looks like:myApp.controller('mapController', ["$scope", "$routeParams", "locationData", function($scope, $routeParams, locationData) { $scope.locationData = locationData.location; $scope.locationHistory = locationData.locationHistory; if ($routeParams.mode == "currentLocation") { bc.getCurrentLocation(false); } bc.showMap(false,"#LocationIcon"); }]);bc.showMap is responsible for a couple of display tasks that hide/show the views/map and for activating/deactivating icons. The code looks like this:this.showMap = function (hide,selActiveIcon) { if (!hide) $("#MapContent").show(); else { $("#MapContent").hide(); } self.fitContent(); if (selActiveIcon) { $(".iconbutton").removeClass("active"); $(selActiveIcon).addClass("active"); } };Each of the other controllers in the app also call this function when they are activated to basically hide the map and make the View Content area visible. The map controller makes the map.This is UI code and calling this sort of thing from controllers is generally not recommended, but I couldn't figure out a way using directives to make this work any more easily than this. It'd be easy to hide and show the map and view container using a flag an ng-show, but it gets tricky because of scoping of the $scope. I would have to resort to storing this setting on the $rootscope which I try to avoid. The same issues exists with the icons.It sure would be nice if Angular had a way to explicitly specify that a View shouldn't be destroyed when another view is activated, so currently this workaround is required. Searching around, I saw a number of whacky hacks to get around this, but this solution I'm using here seems much easier than any of that I could dig up even if it doesn't quite fit the 'Angular way'.Angular nice, until it's notOverall I really like Angular and the way it works although it took me a bit of time to get my head around how all the pieces fit together. Once I got the idea how the app/routes, the controllers and views snap together, putting together Angular pages becomes fairly straightforward. You can get quite a bit done never going beyond those basics. For most common things Angular's default routing and view presentation works very well.But, when you do something a bit more complex, where there are multiple dependencies or as in this case where Angular doesn't appear to support a feature that's absolutely necessary, you're on your own. Finding information on more advanced topics is not trivial especially since versions are changing so rapidly and the low level behaviors are changing frequently so finding something that works is often an exercise in trial and error. Not that this is surprising. Angular is a complex piece of kit as are all the frameworks that try to hack JavaScript into submission to do something that it was really never designed to. After all everything about a framework like Angular is an elaborate hack. A lot of shit has to happen to make this all work together and at that Angular (and Ember, Durandel etc.) are pretty amazing pieces of JavaScript code. So no harm, no foul, but I just can't help feeling like working in toy sandbox at times :-)© Rick Strahl, West Wind Technologies, 2005-2013Posted in Angular  JavaScript   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• EM12c Release 4: Cloud Control to Major Tom...

  - by abulloch

  With the latest release of Enterprise Manager 12c, Release 4 (12.1.0.4) the EM development team has added new functionality to assist the EM Administrator to monitor the health of the EM infrastructure.   Taking feedback delivered from customers directly and through customer advisory boards some nice enhancements have been made to the “Manage Cloud Control” sections of the UI, commonly known in the EM community as “the MTM pages” (MTM stands for Monitor the Monitor).  This part of the EM Cloud Control UI is viewed by many as the mission control for EM Administrators. In this post we’ll highlight some of the new information that’s on display in these redesigned pages and explain how the information they present can help EM administrators identify potential bottlenecks or issues with the EM infrastructure. The first page we’ll take a look at is the newly designed Repository information page.  You can get to this from the main Setup menu, through Manage Cloud Control, then Repository.  Once this page loads you’ll see the new layout that includes 3 tabs containing more drill-down information. The Repository Tab The first tab, Repository, gives you a series of 6 panels or regions on screen that display key information that the EM Administrator needs to review from time to time to ensure that their infrastructure is in good health. Rather than go through every panel let’s call out a few and let you explore the others later yourself on your own EM site.  Firstly, we have the Repository Details panel. At a glance the EM Administrator can see the current version of the EM repository database and more critically, three important elements of information relating to availability and reliability :- Is the database in Archive Log mode ? Is the database using Flashback ? When was the last database backup taken ? In this test environment above the answers are not too worrying, however, Production environments should have at least Archivelog mode enabled, Flashback is a nice feature to enable prior to upgrades (for fast rollback) and all Production sites should have a backup.  In this case the backup information in the Control file indicates there’s been no recorded backups taken. The next region of interest to note on this page shows key information around the Repository configuration, specifically, the initialisation parameters (from the spfile). If you’re storing your EM Repository in a Cluster Database you can view the parameters on each individual instance using the Instance Name drop-down selector in the top right of the region. Additionally, you’ll note there is now a check performed on the active configuration to ensure that you’re using, at the very least, Oracle minimum recommended values.  Should the values in your EM Repository not meet these requirements it will be flagged in this table with a red X for non-compliance.  You can of-course change these values within EM by selecting the Database target and modifying the parameters in the spfile (and optionally, the run-time values if the parameter allows dynamic changes). The last region to call out on this page before moving on is the new look Repository Scheduler Job Status region. This region is an update of a similar region seen on previous releases of the MTM pages in Cloud Control but there’s some important new functionality that’s been added that customers have requested. First-up - Restarting Repository Jobs.  As you can see from the graphic, you can now optionally select a job (by selecting the row in the UI table element) and click on the Restart Job button to take care of any jobs which have stopped or stalled for any reason.  Previously this needed to be done at the command line using EMDIAG or through a PL/SQL package invocation.  You can now take care of this directly from within the UI. Next, you’ll see that a feature has been added to allow the EM administrator to customise the run-time for some of the background jobs that run in the Repository.  We heard from some customers that ensuring these jobs don’t clash with Production backups, etc is a key requirement.  This new functionality allows you to select the pencil icon to edit the schedule time for these more resource intensive background jobs and modify the schedule to avoid clashes like this. Moving onto the next tab, let’s select the Metrics tab. The Metrics Tab There’s some big changes here, this page contains new information regions that help the Administrator understand the direct impact the in-bound metric flows are having on the EM Repository.  Many customers have provided feedback that they are in the dark about the impact of adding new targets or large numbers of new hosts or new target types into EM and the impact this has on the Repository.  This page helps the EM Administrator get to grips with this.  Let’s take a quick look at two regions on this page. First-up there’s a bubble chart showing a comprehensive view of the top resource consumers of metric data, over the last 30 days, charted as the number of rows loaded against the number of collections for the metric.  The size of the bubble indicates a relative volume.  You can see from this example above that a quick glance shows that Host metrics are the largest inbound flow into the repository when measured by number of rows.  Closely following behind this though are a large number of collections for Oracle Weblogic Server and Application Deployment.  Taken together the Host Collections is around 0.7Mb of data.  The total information collection for Weblogic Server and Application Deployments is 0.38Mb and 0.37Mb respectively. If you want to get this information breakdown on the volume of data collected simply hover over the bubble in the chart and you’ll get a floating tooltip showing the information. Clicking on any bubble in the chart takes you one level deeper into a drill-down of the Metric collection. Doing this reveals the individual metric elements for these target types and again shows a representation of the relative cost - in terms of Number of Rows, Number of Collections and Storage cost of data for each Metric type. Looking at another panel on this page we can see a different view on this data. This view shows a view of the Top N metrics (the drop down allows you to select 10, 15 or 20) and sort them by volume of data.  In the case above we can see the largest metric collection (by volume) in this case (over the last 30 days) is the information about OS Registered Software on a Host target. Taken together, these two regions provide a powerful tool for the EM Administrator to understand the potential impact of any new targets that have been discovered and promoted into management by EM12c.  It’s a great tool for identifying the cause of a sudden increase in Repository storage consumption or Redo log and Archive log generation. Using the information on this page EM Administrators can take action to mitigate any load impact by deploying monitoring templates to the targets causing most load if appropriate.   The last tab we’ll look at on this page is the Schema tab. The Schema Tab Selecting this tab brings up a window onto the SYSMAN schema with a focus on Space usage in the EM Repository.  Understanding what tablespaces are growing, at what rate, is essential information for the EM Administrator to stay on top of managing space allocations for the EM Repository so that it works as efficiently as possible and performs well for the users.  Not least because ensuring storage is managed well ensures continued availability of EM for monitoring purposes. The first region to highlight here shows the trend of space usage for the tablespaces in the EM Repository over time.  You can see the upward trend here showing that storage in the EM Repository is being consumed on an upward trend over the last few days here. This is normal as this EM being used here is brand new with Agents being added daily to bring targets into monitoring.  If your Enterprise Manager configuration has reached a steady state over a period of time where the number of new inbound targets is relatively small, the metric collection settings are fairly uniform and standardised (using Templates and Template Collections) you’re likely to see a trend of space allocation that plateau’s. The table below the trend chart shows the Top 20 Tables/Indexes sorted descending by order of space consumed.  You can switch the trend view chart and corresponding detail table by choosing a different tablespace in the EM Repository using the drop-down picker on the top right of this region. The last region to highlight on this page is the region showing information about the Purge policies in effect in the EM Repository. This information is useful to illustrate to EM Administrators the default purge policies in effect for the different categories of information available in the EM Repository.  Of course, it’s also been a long requested feature to have the ability to modify these default retention periods.  You can also do this using this screen.  As there are interdependencies between some data elements you can’t modify retention policies on a feature by feature basis.  Instead, retention policies take categories of information and bundles them together in Groups.  Retention policies are modified at the Group Level.  Understanding the impact of this really deserves a blog post all on it’s own as modifying these can have a significant impact on both the EM Repository’s storage footprint and it’s performance.  For now, we’re just highlighting the features visibility on these new pages. As a user of EM12c we hope the new features you see here address some of the feedback that’s been given on these pages over the past few releases.  We’ll look out for any comments or feedback you have on these pages ! 

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• Craftsmanship is ALL that Matters

  - by Wayne Molina

  Today, I'm going to talk about a touchy subject: the notion of working in a company that doesn't use the prescribed "best practices" in its software development endeavours.  Over the years I have, using a variety of pseudonyms, asked this question on popular programming forums.  Although I always add in some minor variation of the story to avoid suspicion that it's the same person posting, the crux of the tale remains the same: A Programmer’s Tale A junior software developer has just started a new job at an average company, creating average line-of-business applications for internal use (the most typical scenario programmers find themselves in).  This hypothetical newbie has spent a lot of time reading up on the "theory" of software development, devouring books, blogs and screencasts from well-known and respected software developers in the community in order to broaden his knowledge and "do what the pros do".  He begins his new job, eager to apply what he's learned on a real-world project only to discover that his new teammates doesn't use any of those concepts and techniques.  They hack their way through development, or in a best-case scenario use some homebrew, thrown-together semblance of a framework for their applications that follows not one of the best practices suggested by the “elite” in the software community - things like TDD (TDD as a "best practice" is the only subjective part of this post, but it's included here due to a very large following of respected developers who consider it one), the SOLID principles, well-known and venerable tools, even version control in a worst case and truly nightmarish scenario.  Our protagonist is frustrated that he isn't doing things the "proper" way - a way he's spent personal time digesting and learning about and, more importantly, a way that some of the top developers in the industry advocate - and turns to a forum to ask the advice of his peers. Invariably the answer I, in the guise of the concerned newbie, will receive is that A) I don't know anything and should just shut my mouth and sling code the bad way like everybody else on the team, and B) These "best practices" are fade or a joke, and the only thing that matters is shipping software to your customers. I am here today to say that anyone who says this, or anything like it, is not only full of crap but indicative of exactly the type of “developer” that has helped to give our industry a bad name.  Here is why: One Who Knows Nothing, Understands Nothing On one hand, you have the cognoscenti of the .NET development world.  Guys like James Avery, Jeremy Miller, Ayende Rahien and Rob Conery; all well-respected and noted programmers that are pretty much our version of celebrities.  These guys write blogs, books, and post videos outlining the "correct" way of writing software to make sure it not only works but is maintainable and extensible and a joy to work with.  They tout the virtues of the SOLID principles, or of using TDD/BDD, or using a mature ORM like NHibernate, Subsonic or even Entity Framework. On the other hand, you have Joe Everyman, Lead Software Developer at Initrode Corporation - in our hypothetical story Joe is the junior developer's new boss.  Joe's been with Initrode for 10 years, starting as the company’s very first programmer and over the years building up a little fiefdom of his own until at the present he’s in charge of all Initrode’s software development.  Joe writes code the same way he always has, without bothering to learn much, if anything.  He looked at NHibernate once and found it was "too hard", so he uses a primitive implementation of the TableDataGateway pattern as a wrapper around SqlClient.SqlConnection and SqlClient.SqlCommand instead of an actual ORM (or, in a better case scenario, has created his own ORM); the thought of using LINQ or Entity Framework or really anything other than his own hastily homebrew solution has never occurred to him.  He doesn't understand TDD and considers “testing” to be using the .NET debugger to step through code, or simply loading up an app and entering some values to see if it works.  He doesn't really understand SOLID, and he doesn't care to.  He's worked as a programmer for years, and that's all that counts.  Right?  WRONG. Who would you rather trust?  Someone with years of experience and who writes books, creates well-known software and is akin to a celebrity, or someone with no credibility outside their own minute environment who throws around their clout and company seniority as the "proof" of their ability?  Joe Everyman may have years of experience at Initrode as a programmer, and says to do things "his way" but someone like Jeremy Miller or Ayende Rahien have years of experience at companies just like Initrode, THEY know ten times more than Joe Everyman knows or could ever hope to know, and THEY say to do things "this way". Here's another way of thinking about it: If you wanted to get into politics and needed advice on the best way to do it, would you rather listen to the mayor of Hicktown, USA or Barack Obama?  One is a small-time nobody while the other is very well-known and, as such, would probably have much more accurate and beneficial advice. NOTE: The selection of Barack Obama as an example in no way, shape, or form suggests a political affiliation or political bent to this post or blog, and no political innuendo should be mistakenly read from it; the intent was merely to compare a small-time persona with a well-known persona in a non-software field.  Feel free to replace the name "Barack Obama" with any well-known Congressman, Senator or US President of your choice. DIY Considered Harmful I will say right now that the homebrew development environment is the WORST one for an aspiring programmer, because it relies on nothing outside it's own little box - no useful skill outside of the small pond.  If you are forced to use some half-baked, homebrew ORM created by your Director of Software, you are not learning anything valuable you can take with you in the future; now, if you plan to stay at Initrode for 10 years like Joe Everyman, this is fine and dandy.  However if, like most of us, you want to advance your career outside a very narrow space you will do more harm than good by sticking it out in an environment where you, to be frank, know better than everybody else because you are aware of alternative and, in almost most cases, better tools for the job.  A junior developer who understands why the SOLID principles are good to follow, or why TDD is beneficial, or who knows that it's better to use NHibernate/Subsonic/EF/LINQ/well-known ORM versus some in-house one knows better than a senior developer with 20 years experience who doesn't understand any of that, plain and simple.  Anyone who disagrees is either a liar, or someone who, just like Joe Everyman, Lead Developer, relies on seniority and tenure rather than adapting their knowledge as things evolve. In many cases, the Joe Everymans of the world act this way out of fear - they cannot possibly fathom that a “junior” could know more than them; after all, they’ve spent 10 or more years in the same company, doing the same job, cranking out the same shoddy software.  And here comes a newbie who hasn’t spent 10+ years doing the same things, with a fresh and often radical take on the craft, and Joe Everyman is afraid he might have to put some real effort into his career again instead of just pointing to his 10 years of service at Initrode as “proof” that he’s good, or that he might have to learn something new to improve; in most cases the problem is Joe Everyman, and by extension Initrode itself, has a mentality of just being “good enough”, and mediocrity is the rule of the day. A Thorn Bush is No Place for a Phoenix My advice is that if you work on a team where they don't use the best practices that some of the most famous developers in our field say is the "right" way to do things (and have legions of people who agree), and YOU are aware of these practices and can see why they work, then LEAVE the company.  Find a company where they DO care about quality, and craftsmanship, otherwise you will never be happy.  There is no point in "dumbing" yourself down to the level of your co-workers and slinging code without care to craftsmanship.  In 95% of these situations there will be no point in bringing it to the attention of Joe Everyman because he won't listen; he might even get upset that someone is trying to "upstage" him and fire the newbie, and replace someone with loads of untapped potential with a drone that will just nod affirmatively and grind out the tasks assigned without question. Find a company that has people smart enough to listen to the "best and brightest", and be happy.  Do not, I repeat, DO NOT waste away in a job working for ignorant people.  At the end of the day software development IS a craft, and a level of craftsmanship is REQUIRED for any serious professional.  When you have knowledgeable people with the credibility to back it up saying one thing, and small-time people who are, to put it bluntly, nobodies in the field saying and doing something totally different because they can't comprehend it, leave the nobodies to their own devices to fade into obscurity.  Work for a company that uses REAL software engineering techniques and really cares about craftsmanship.  The biggest issue affecting our career, and the reason software development has never been the respected, white-collar career it was meant to be, is because hacks and charlatans can pass themselves off as professional programmers without following a lick of good advice from programmers much better at the craft than they are.  These modern day snake-oil salesmen entrench themselves in companies by hoodwinking non-technical businesspeople and customers with their shoddy wares, end up in senior/lead/executive positions, and push their lack of knowledge on everybody unfortunate enough to work with/for/under them, crushing any dissent or voices of reason and change under their tyrannical heel and leaving behind a trail of dismayed and, often, unemployed junior developers who were made examples of to keep up the facade and avoid the shadow of doubt being cast upon them. To sum this up another way: If you surround yourself with learned people, you will learn.  Surround yourself with ignorant people who can't, as the saying goes, see the forest through the trees, and you'll learn nothing of any real value.  There is more to software development than just writing code, and the end goal should not be just "shipping software", it should be shipping software that is extensible, maintainable, and above all else software whose creation has broadened your knowledge in some capacity, even if a minor one.  An eager newbie who knows theory and thirsts for knowledge can easily be moulded and taught the advanced topics, but the same can't be said of someone who only cares about the finish line.  This industry needs more people espousing the benefits of software craftsmanship and proper software engineering techniques, and less Joe Everymans who are unwilling to adapt or foster new ways of thinking. Conclusion - I Cast “Protection from Fire” I am fairly certain this post will spark some controversy and might even invite the flames.  Please keep in mind these are opinions and nothing more.  A little healthy rant and subsequent flamewar can be good for the soul once in a while.  To paraphrase The Godfather: It helps to get rid of the bad blood.

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• Investigation: Can different combinations of components effect Dataflow performance?

  - by jamiet

  Introduction The Dataflow task is one of the core components (if not the core component) of SQL Server Integration Services (SSIS) and often the most misunderstood. This is not surprising, its an incredibly complicated beast and we’re abstracted away from that complexity via some boxes that go yellow red or green and that have some lines drawn between them. Example dataflow In this blog post I intend to look under that facade and get into some of the nuts and bolts of the Dataflow Task by investigating how the decisions we make when building our packages can affect performance. I will do this by comparing the performance of three dataflows that all have the same input, all produce the same output, but which all operate slightly differently by way of having different transformation components. I also want to use this blog post to challenge a common held opinion that I see perpetuated over and over again on the SSIS forum. That is, that people assume adding components to a dataflow will be detrimental to overall performance. Its not surprising that people think this –it is intuitive to think that more components means more work- however this is not a view that I share. I have always been of the opinion that there are many factors affecting dataflow duration and the number of components is actually one of the less important ones; having said that I have never proven that assertion and that is one reason for this investigation. I have actually seen evidence that some people think dataflow duration is simply a function of number of rows and number of components. I’ll happily call that one out as a myth even without any investigation!  The Setup I have a 2GB datafile which is a list of 4731904 (~4.7million) customer records with various attributes against them and it contains 2 columns that I am going to use for categorisation: [YearlyIncome] [BirthDate] The data file is a SSIS raw format file which I chose to use because it is the quickest way of getting data into a dataflow and given that I am testing the transformations, not the source or destination adapters, I want to minimise external influences as much as possible. In the test I will split the customers according to month of birth (12 of those) and whether or not their yearly income is above or below 50000 (2 of those); in other words I will be splitting them into 24 discrete categories and in order to do it I shall be using different combinations of SSIS’ Conditional Split and Derived Column transformation components. The 24 datapaths that occur will each input to a rowcount component, again because this is the least resource intensive means of terminating a datapath. The test is being carried out on a Dell XPS Studio laptop with a quad core (8 logical Procs) Intel Core i7 at 1.73GHz and Samsung SSD hard drive. Its running SQL Server 2008 R2 on Windows 7. The Variables Here are the three combinations of components that I am going to test:     One Conditional Split - A single Conditional Split component CSPL Split by Month of Birth and income category that will use expressions on [YearlyIncome] & [BirthDate] to send each row to one of 24 outputs. This next screenshot displays the expression logic in use: Derived Column & Conditional Split - A Derived Column component DER Income Category that adds a new column [IncomeCategory] which will contain one of two possible text values {“LessThan50000”,”GreaterThan50000”} and uses [YearlyIncome] to determine which value each row should get. A Conditional Split component CSPL Split by Month of Birth and Income Category then uses that new column in conjunction with [BirthDate] to determine which of the same 24 outputs to send each row to. Put more simply, I am separating the Conditional Split of #1 into a Derived Column and a Conditional Split. The next screenshots display the expression logic in use: DER Income Category         CSPL Split by Month of Birth and Income Category       Three Conditional Splits - A Conditional Split component that produces two outputs based on [YearlyIncome], one for each Income Category. Each of those outputs will go to a further Conditional Split that splits the input into 12 outputs, one for each month of birth (identical logic in each). In this case then I am separating the single Conditional Split of #1 into three Conditional Split components. The next screenshots display the expression logic in use: CSPL Split by Income Category         CSPL Split by Month of Birth 1& 2       Each of these combinations will provide an input to one of the 24 rowcount components, just the same as before. For illustration here is a screenshot of the dataflow containing three Conditional Split components: As you can these dataflows have a fair bit of work to do and remember that they’re doing that work for 4.7million rows. I will execute each dataflow 10 times and use the average for comparison. I foresee three possible outcomes: The dataflow containing just one Conditional Split (i.e. #1) will be quicker There is no significant difference between any of them One of the two dataflows containing multiple transformation components will be quicker Regardless of which of those outcomes come to pass we will have learnt something and that makes this an interesting test to carry out. Note that I will be executing the dataflows using dtexec.exe rather than hitting F5 within BIDS. The Results and Analysis The table below shows all of the executions, 10 for each dataflow. It also shows the average for each along with a standard deviation. All durations are in seconds. I’m pasting a screenshot because I frankly can’t be bothered with the faffing about needed to make a presentable HTML table. It is plain to see from the average that the dataflow containing three conditional splits is significantly faster, the other two taking 43% and 52% longer respectively. This seems strange though, right? Why does the dataflow containing the most components outperform the other two by such a big margin? The answer is actually quite logical when you put some thought into it and I’ll explain that below. Before progressing, a side note. The standard deviation for the “Three Conditional Splits” dataflow is orders of magnitude smaller – indicating that performance for this dataflow can be predicted with much greater confidence too. The Explanation I refer you to the screenshot above that shows how CSPL Split by Month of Birth and salary category in the first dataflow is setup. Observe that there is a case for each combination of Month Of Date and Income Category – 24 in total. These expressions get evaluated in the order that they appear and hence if we assume that Month of Date and Income Category are uniformly distributed in the dataset we can deduce that the expected number of expression evaluations for each row is 12.5 i.e. 1 (the minimum) + 24 (the maximum) divided by 2 = 12.5. Now take a look at the screenshots for the second dataflow. We are doing one expression evaluation in DER Income Category and we have the same 24 cases in CSPL Split by Month of Birth and Income Category as we had before, only the expression differs slightly. In this case then we have 1 + 12.5 = 13.5 expected evaluations for each row – that would account for the slightly longer average execution time for this dataflow. Now onto the third dataflow, the quick one. CSPL Split by Income Category does a maximum of 2 expression evaluations thus the expected number of evaluations per row is 1.5. CSPL Split by Month of Birth 1 & CSPL Split by Month of Birth 2 both have less work to do than the previous Conditional Split components because they only have 12 cases to test for thus the expected number of expression evaluations is 6.5 There are two of them so total expected number of expression evaluations for this dataflow is 6.5 + 6.5 + 1.5 = 14.5. 14.5 is still more than 12.5 & 13.5 though so why is the third dataflow so much quicker? Simple, the conditional expressions in the first two dataflows have two boolean predicates to evaluate – one for Income Category and one for Month of Birth; the expressions in the Conditional Split in the third dataflow however only have one predicate thus they are doing a lot less work. To sum up, the difference in execution times can be attributed to the difference between: MONTH(BirthDate) == 1 && YearlyIncome <= 50000 and MONTH(BirthDate) == 1 In the first two dataflows YearlyIncome <= 50000 gets evaluated an average of 12.5 times for every row whereas in the third dataflow it is evaluated once and once only. Multiply those 11.5 extra operations by 4.7million rows and you get a significant amount of extra CPU cycles – that’s where our duration difference comes from. The Wrap-up The obvious point here is that adding new components to a dataflow isn’t necessarily going to make it go any slower, moreover you may be able to achieve significant improvements by splitting logic over multiple components rather than one. Performance tuning is all about reducing the amount of work that needs to be done and that doesn’t necessarily mean use less components, indeed sometimes you may be able to reduce workload in ways that aren’t immediately obvious as I think I have proven here. Of course there are many variables in play here and your mileage will most definitely vary. I encourage you to download the package and see if you get similar results – let me know in the comments. The package contains all three dataflows plus a fourth dataflow that will create the 2GB raw file for you (you will also need the [AdventureWorksDW2008] sample database from which to source the data); simply disable all dataflows except the one you want to test before executing the package and remember, execute using dtexec, not within BIDS. If you want to explore dataflow performance tuning in more detail then here are some links you might want to check out: Inequality joins, Asynchronous transformations and Lookups Destination Adapter Comparison Don’t turn the dataflow into a cursor SSIS Dataflow – Designing for performance (webinar) Any comments? Let me know! @Jamiet

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• Glassfish alive or dead? WebLogic SE cost is less than Glassfish!

  - by JuergenKress

  Is a hot discussion in the community in the last few days! Send us your opinion on tiwtter @wlscommunity #Glassfish #WebLogicCommunity We posted theGlassFishStrategy.pptx at our WebLogic Community Workspace (WebLogic Community membership required). Please read also the Java EE and GlassFish Server Roadmap Update Bruno Borges ?Another great article covering story about #GlassFish. Comments starting to be reasonable ;-) 6 facts helped a lot http://adtmag.com/articles/2013/11/08/oracle-drops-glassfish.aspx … Adam Bien ?What Oracle Could Do For GlassFish Now: Move the sources to GitHub (GitHub is the most popular collaboration p... http://bit.ly/1d1uo24 JAXenter.com ?Oracle evangelist: “GlassFish Open Source Edition is not dead” http://jaxenter.com/oracle-evangelist-glassfish-open-source-edition-is-not-dead-48830.html … GlassFish 6 Facts About #GlassFish Announcement and the Future of #JavaEE http://bit.ly/1bbSVPf via @brunoborges David Blevins ?In support of our #GlassFish friends and open source in general: Feed the Fish http://www.tomitribe.com/blog/2013/11/feed-the-fish/ … #JavaEE #opensource #manifesto GlassFish ?GlassFish Server Open Source Edition 4.1 is scheduled for 2014. Version 5.0 as impl for #JavaEE8 https://blogs.oracle.com/theaquarium/entry/java_ee_and_glassfish_server … #Community focused C2B2 Consulting ?C2B2 continues to offer support for your operational #JEE applications running on #GlassFish http://blog.c2b2.co.uk/2013/11/oracle-dropping-commercial-support-of.html … #Java Markus Eisele ?RT @InfoQ: #GlassFish Commercial Edition is Dead http://bit.ly/17eFB0Z < at least they agree to my points... Adam Bien suggests: Move the sources to GitHub (GitHub is the most popular collaboration platform). It is more likely for an individual to contribute via GitHub, than the current infrastructure. Introduce a business friendlier license like e.g. the Apache license. Companies interesting in providing added value (and commercial support) on top of existing sources would appreciate it. Implement GitHub-based, open source, CI system with nightly builds. Introduce a transparent voting process / pull-request acceptance process. Release more frequently. Keep https://glassfish.java.net as the main hub. C2B2 offers Glassfish support by Steve Millidge Oracle have just announced that commercial support for GlassFish 4 will not be available from Oracle. In light of this announcement I thought I would put together some thoughts about how I see this development. I think the key word in this announcement is "commercial", nowhere does Oracle announce the "death of GlassFish" in contrary Oracle reaffirm; GlassFish Server Open Source Edition continues to be the strategic foundation for Java EE reference implementation going forward. And for developers, updates will be delivered as needed to continue to deliver a great developer experience for GlassFish Server Open Source Edition so GlassFish is not about to go away soon. In a similar fashion RedHat do not provide commercial support for WildFly and only provide commercial support for JBoss EAP. Admittedly JBoss EAP and WildFly are much closer together than GlassFish and WebLogic but WildFly and JBoss EAP are absolutely NOT the same thing. The key going forward to the viability of GlassFish as a production platform is how the GlassFish community develops; How often does the community release binary builds? How open is the community to bug fixes? How much engineering resource does Oracle commit to GlassFish? At this stage we just don't know the answers to these questions. If the GlassFish open source project continues on it's current trajectory without a commercial support offering then I don't see much of a problem. Oracle just have to work harder to sell migration paths to WebLogic in the same way as RedHat have to sell migration paths from WildFly to JBoss EAP. In the meantime C2B2 continues to offer support for your operational JEE applications running on GlassFish and we will endeavour to work with the community to get any bugs fixed. The key difference is we can no longer back our Expert Support with a support contract from Oracle for patches and fixes for any release greater than 3.x. Read the complete article here. 6 Facts About GlassFish Announcement By Bruno.Borges Fact #1 - GlassFish Open Source Edition is not dead GlassFish Server Open Source Edition will remain the reference implementation of Java EE. The current trunk is where an implementation for Java EE 8 will flourish, and this will become the future GlassFish 5.0. Calling "GlassFish is dead" does no good to the Java EE ecosystem. The GlassFish Community will remain strong towards the future of Java EE. Without revenue-focused mind, this might actually help the GlassFish community to shape the next version, and set free from any ties with commercial decisions. Fact #2 - OGS support is not over As I said before, GlassFish Server Open Source Edition will continue. Main change is that there will be no more future commercial releases of Oracle GlassFish Server. New and existing OGS 2.1.x and 3.1.x commercial customers will continue to be supported according to the Oracle Lifetime Support Policy. In parallel, I believe there's no other company in the Java EE business that offers commercial support to more than one build of a Java EE application server. This new direction can actually help customers and partners, simplifying decision through commercial negotiations. Fact #3 - WebLogic is not always more expensive than OGS Oracle GlassFish Server ("OGS") is a build of GlassFish Server Open Source Edition bundled with a set of commercial features called GlassFish Server Control and license bundles such as Java SE Support. OGS has at the moment of this writing the pricelist of U$ 5,000 / processor. One information that some bloggers are mentioning is that WebLogic is more expensive than this. Fact 3.1: it is not necessarily the case. The initial edition of WebLogic is called "Standard Edition" and falls into a policy where some “Standard Edition” products are licensed on a per socket basis. As of current pricelist, US$ 10,000 / socket. If you do the math, you will realize that WebLogic SE can actually be significantly more cost effective than OGS, and a customer can save money if running on a CPU with 4 cores or more for example. Quote from the price list: “When licensing Oracle programs with Standard Edition One or Standard Edition in the product name (with the exception of Java SE Support, Java SE Advanced, and Java SE Suite), a processor is counted equivalent to an occupied socket; however, in the case of multi-chip modules, each chip in the multi-chip module is counted as one occupied socket.” For more details speak to your Oracle sales representative - this is clearly at list price and every customer typically has a relationship with Oracle (like they do with other vendors) and different contractual details may apply. And although OGS has always been production-ready for Java EE applications, it is no secret that WebLogic has always been more enterprise, mission critical application server than OGS since BEA. Different editions of WLS provide features and upgrade irons like the WebLogic Diagnostic Framework, Work Managers, Side by Side Deployment, ADF and TopLink bundled license, Web Tier (Oracle HTTP Server) bundled licensed, Fusion Middleware stack support, Oracle DB integration features, Oracle RAC features (such as GridLink), Coherence Management capabilities, Advanced HA (Whole Service Migration and Server Migration), Java Mission Control, Flight Recorder, Oracle JDK support, etc. Fact #4 - There’s no major vendor supporting community builds of Java EE app servers There are no major vendors providing support for community builds of any Open Source application server. For example, IBM used to provide community support for builds of Apache Geronimo, not anymore. Red Hat does not commercially support builds of WildFly and if I remember correctly, never supported community builds of former JBoss AS. Oracle has never commercially supported GlassFish Server Open Source Edition builds. Tomitribe appears to be the exception to the rule, offering commercial support for Apache TomEE. Fact #5 - WebLogic and GlassFish share several Java EE implementations It has been no secret that although GlassFish and WebLogic share some JSR implementations (as stated in the The Aquarium announcement: JPA, JSF, WebSockets, CDI, Bean Validation, JAX-WS, JAXB, and WS-AT) and WebLogic understands GlassFish deployment descriptors, they are not from the same codebase. Fact #6 - WebLogic is not for GlassFish what JBoss EAP is for WildFly WebLogic is closed-source offering. It is commercialized through a license-based plus support fee model. OGS although from an Open Source code, has had the same commercial model as WebLogic. Still, one cannot compare GlassFish/WebLogic to WildFly/JBoss EAP. It is simply not the same case, since Oracle has had two different products from different codebases. The comparison should be limited to GlassFish Open Source / Oracle GlassFish Server versus WildFly / JBoss EAP. Read the complete article here WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: Glassfish,training,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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• Understanding C# async / await (2) Awaitable / Awaiter Pattern

  - by Dixin

  What is awaitable Part 1 shows that any Task is awaitable. Actually there are other awaitable types. Here is an example: Task<int> task = new Task<int>(() => 0); int result = await task.ConfigureAwait(false); // Returns a ConfiguredTaskAwaitable<TResult>. The returned ConfiguredTaskAwaitable<TResult> struct is awaitable. And it is not Task at all: public struct ConfiguredTaskAwaitable<TResult> { private readonly ConfiguredTaskAwaiter m_configuredTaskAwaiter; internal ConfiguredTaskAwaitable(Task<TResult> task, bool continueOnCapturedContext) { this.m_configuredTaskAwaiter = new ConfiguredTaskAwaiter(task, continueOnCapturedContext); } public ConfiguredTaskAwaiter GetAwaiter() { return this.m_configuredTaskAwaiter; } } It has one GetAwaiter() method. Actually in part 1 we have seen that Task has GetAwaiter() method too: public class Task { public TaskAwaiter GetAwaiter() { return new TaskAwaiter(this); } } public class Task<TResult> : Task { public new TaskAwaiter<TResult> GetAwaiter() { return new TaskAwaiter<TResult>(this); } } Task.Yield() is a another example: await Task.Yield(); // Returns a YieldAwaitable. The returned YieldAwaitable is not Task either: public struct YieldAwaitable { public YieldAwaiter GetAwaiter() { return default(YieldAwaiter); } } Again, it just has one GetAwaiter() method. In this article, we will look at what is awaitable. The awaitable / awaiter pattern By observing different awaitable / awaiter types, we can tell that an object is awaitable if It has a GetAwaiter() method (instance method or extension method); Its GetAwaiter() method returns an awaiter. An object is an awaiter if: It implements INotifyCompletion or ICriticalNotifyCompletion interface; It has an IsCompleted, which has a getter and returns a Boolean; it has a GetResult() method, which returns void, or a result. This awaitable / awaiter pattern is very similar to the iteratable / iterator pattern. Here is the interface definitions of iteratable / iterator: public interface IEnumerable { IEnumerator GetEnumerator(); } public interface IEnumerator { object Current { get; } bool MoveNext(); void Reset(); } public interface IEnumerable<out T> : IEnumerable { IEnumerator<T> GetEnumerator(); } public interface IEnumerator<out T> : IDisposable, IEnumerator { T Current { get; } } In case you are not familiar with the out keyword, please find out the explanation in Understanding C# Covariance And Contravariance (2) Interfaces. The “missing” IAwaitable / IAwaiter interfaces Similar to IEnumerable and IEnumerator interfaces, awaitable / awaiter can be visualized by IAwaitable / IAwaiter interfaces too. This is the non-generic version: public interface IAwaitable { IAwaiter GetAwaiter(); } public interface IAwaiter : INotifyCompletion // or ICriticalNotifyCompletion { // INotifyCompletion has one method: void OnCompleted(Action continuation); // ICriticalNotifyCompletion implements INotifyCompletion, // also has this method: void UnsafeOnCompleted(Action continuation); bool IsCompleted { get; } void GetResult(); } Please notice GetResult() returns void here. Task.GetAwaiter() / TaskAwaiter.GetResult() is of such case. And this is the generic version: public interface IAwaitable<out TResult> { IAwaiter<TResult> GetAwaiter(); } public interface IAwaiter<out TResult> : INotifyCompletion // or ICriticalNotifyCompletion { bool IsCompleted { get; } TResult GetResult(); } Here the only difference is, GetResult() return a result. Task<TResult>.GetAwaiter() / TaskAwaiter<TResult>.GetResult() is of this case. Please notice .NET does not define these IAwaitable / IAwaiter interfaces at all. As an UI designer, I guess the reason is, IAwaitable interface will constraint GetAwaiter() to be instance method. Actually C# supports both GetAwaiter() instance method and GetAwaiter() extension method. Here I use these interfaces only for better visualizing what is awaitable / awaiter. Now, if looking at above ConfiguredTaskAwaitable / ConfiguredTaskAwaiter, YieldAwaitable / YieldAwaiter, Task / TaskAwaiter pairs again, they all “implicitly” implement these “missing” IAwaitable / IAwaiter interfaces. In the next part, we will see how to implement awaitable / awaiter. Await any function / action In C# await cannot be used with lambda. This code: int result = await (() => 0); will cause a compiler error: Cannot await 'lambda expression' This is easy to understand because this lambda expression (() => 0) may be a function or a expression tree. Obviously we mean function here, and we can tell compiler in this way: int result = await new Func<int>(() => 0); It causes an different error: Cannot await 'System.Func<int>' OK, now the compiler is complaining the type instead of syntax. With the understanding of the awaitable / awaiter pattern, Func<TResult> type can be easily made into awaitable. GetAwaiter() instance method, using IAwaitable / IAwaiter interfaces First, similar to above ConfiguredTaskAwaitable<TResult>, a FuncAwaitable<TResult> can be implemented to wrap Func<TResult>: internal struct FuncAwaitable<TResult> : IAwaitable<TResult> { private readonly Func<TResult> function; public FuncAwaitable(Func<TResult> function) { this.function = function; } public IAwaiter<TResult> GetAwaiter() { return new FuncAwaiter<TResult>(this.function); } } FuncAwaitable<TResult> wrapper is used to implement IAwaitable<TResult>, so it has one instance method, GetAwaiter(), which returns a IAwaiter<TResult>, which wraps that Func<TResult> too. FuncAwaiter<TResult> is used to implement IAwaiter<TResult>: public struct FuncAwaiter<TResult> : IAwaiter<TResult> { private readonly Task<TResult> task; public FuncAwaiter(Func<TResult> function) { this.task = new Task<TResult>(function); this.task.Start(); } bool IAwaiter<TResult>.IsCompleted { get { return this.task.IsCompleted; } } TResult IAwaiter<TResult>.GetResult() { return this.task.Result; } void INotifyCompletion.OnCompleted(Action continuation) { new Task(continuation).Start(); } } Now a function can be awaited in this way: int result = await new FuncAwaitable<int>(() => 0); GetAwaiter() extension method As IAwaitable shows, all that an awaitable needs is just a GetAwaiter() method. In above code, FuncAwaitable<TResult> is created as a wrapper of Func<TResult> and implements IAwaitable<TResult>, so that there is a  GetAwaiter() instance method. If a GetAwaiter() extension method  can be defined for Func<TResult>, then FuncAwaitable<TResult> is no longer needed: public static class FuncExtensions { public static IAwaiter<TResult> GetAwaiter<TResult>(this Func<TResult> function) { return new FuncAwaiter<TResult>(function); } } So a Func<TResult> function can be directly awaited: int result = await new Func<int>(() => 0); Using the existing awaitable / awaiter - Task / TaskAwaiter Remember the most frequently used awaitable / awaiter - Task / TaskAwaiter. With Task / TaskAwaiter, FuncAwaitable / FuncAwaiter are no longer needed: public static class FuncExtensions { public static TaskAwaiter<TResult> GetAwaiter<TResult>(this Func<TResult> function) { Task<TResult> task = new Task<TResult>(function); task.Start(); return task.GetAwaiter(); // Returns a TaskAwaiter<TResult>. } } Similarly, with this extension method: public static class ActionExtensions { public static TaskAwaiter GetAwaiter(this Action action) { Task task = new Task(action); task.Start(); return task.GetAwaiter(); // Returns a TaskAwaiter. } } an action can be awaited as well: await new Action(() => { }); Now any function / action can be awaited: await new Action(() => HelperMethods.IO()); // or: await new Action(HelperMethods.IO); If function / action has parameter(s), closure can be used: int arg0 = 0; int arg1 = 1; int result = await new Action(() => HelperMethods.IO(arg0, arg1)); Using Task.Run() The above code is used to demonstrate how awaitable / awaiter can be implemented. Because it is a common scenario to await a function / action, so .NET provides a built-in API: Task.Run(): public class Task2 { public static Task Run(Action action) { // The implementation is similar to: Task task = new Task(action); task.Start(); return task; } public static Task<TResult> Run<TResult>(Func<TResult> function) { // The implementation is similar to: Task<TResult> task = new Task<TResult>(function); task.Start(); return task; } } In reality, this is how we await a function: int result = await Task.Run(() => HelperMethods.IO(arg0, arg1)); and await a action: await Task.Run(() => HelperMethods.IO());

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• The UIManager Pattern

  - by Duncan Mills

  One of the most common mistakes that I see when reviewing ADF application code, is the sin of storing UI component references, most commonly things like table or tree components in Session or PageFlow scope. The reasons why this is bad are simple; firstly, these UI object references are not serializable so would not survive a session migration between servers and secondly there is no guarantee that the framework will re-use the same component tree from request to request, although in practice it generally does do so. So there danger here is, that at best you end up with an NPE after you session has migrated, and at worse, you end up pinning old generations of the component tree happily eating up your precious memory. So that's clear, we should never. ever, be storing references to components anywhere other than request scope (or maybe backing bean scope). So double check the scope of those binding attributes that map component references into a managed bean in your applications.  Why is it Such a Common Mistake?  At this point I want to examine why there is this urge to hold onto these references anyway? After all, JSF will obligingly populate your backing beans with the fresh and correct reference when needed.   In most cases, it seems that the rational is down to a lack of distinction within the application between what is data and what is presentation. I think perhaps, a cause of this is the logical separation between business data behind the ADF data binding (#{bindings}) façade and the UI components themselves. Developers tend to think, OK this is my data layer behind the bindings object and everything else is just UI.  Of course that's not the case.  The UI layer itself will have state which is intrinsically linked to the UI presentation rather than the business model, but at the same time should not be tighly bound to a specific instance of any single UI component. So here's the problem.  I think developers try and use the UI components as state-holders for this kind of data, rather than using them to represent that state. An example of this might be something like the selection state of a tabset (panelTabbed), you might be interested in knowing what the currently disclosed tab is. The temptation that leads to the component reference sin is to go and ask the tabset what the selection is.  That of course is fine in context - e.g. a handler within the same request scoped bean that's got the binding to the tabset. However, it leads to problems when you subsequently want the same information outside of the immediate scope.  The simple solution seems to be to chuck that component reference into session scope and then you can simply re-check in the same way, leading of course to this mistake. Turn it on its Head  So the correct solution to this is to turn the problem on its head. If you are going to be interested in the value or state of some component outside of the immediate request context then it becomes persistent state (persistent in the sense that it extends beyond the lifespan of a single request). So you need to externalize that state outside of the component and have the component reference and manipulate that state as needed rather than owning it. This is what I call the UIManager pattern.  Defining the Pattern The  UIManager pattern really is very simple. The premise is that every application should define a session scoped managed bean, appropriately named UIManger, which is specifically responsible for holding this persistent UI component related state.  The actual makeup of the UIManger class varies depending on a needs of the application and the amount of state that needs to be stored. Generally I'll start off with a Map in which individual flags can be created as required, although you could opt for a more formal set of typed member variables with getters and setters, or indeed a mix. This UIManager class is defined as a session scoped managed bean (#{uiManager}) in the faces-config.xml.  The pattern is to then inject this instance of the class into any other managed bean (usually request scope) that needs it using a managed property.  So typically you'll have something like this:   <managed-bean>     <managed-bean-name>uiManager</managed-bean-name>     <managed-bean-class>oracle.demo.view.state.UIManager</managed-bean-class>     <managed-bean-scope>session</managed-bean-scope>   </managed-bean>  When is then injected into any backing bean that needs it:    <managed-bean>     <managed-bean-name>mainPageBB</managed-bean-name>     <managed-bean-class>oracle.demo.view.MainBacking</managed-bean-class>     <managed-bean-scope>request</managed-bean-scope>     <managed-property>       <property-name>uiManager</property-name>       <property-class>oracle.demo.view.state.UIManager</property-class>       <value>#{uiManager}</value>     </managed-property>   </managed-bean> In this case the backing bean in question needs a member variable to hold and reference the UIManager: private UIManager _uiManager;  Which should be exposed via a getter and setter pair with names that match the managed property name (e.g. setUiManager(UIManager _uiManager), getUiManager()).  This will then give your code within the backing bean full access to the UI state. UI components in the page can, of course, directly reference the uiManager bean in their properties, for example, going back to the tab-set example you might have something like this: <af:paneltabbed>   <af:showDetailItem text="First"                disclosed="#{uiManager.settings['MAIN_TABSET_STATE'].['FIRST']}"> ...   </af:showDetailItem>   <af:showDetailItem text="Second"                      disclosed="#{uiManager.settings['MAIN_TABSET_STATE'].['SECOND']}">     ...   </af:showDetailItem>   ... </af:panelTabbed> Where in this case the settings member within the UI Manger is a Map which contains a Map of Booleans for each tab under the MAIN_TABSET_STATE key. (Just an example you could choose to store just an identifier for the selected tab or whatever, how you choose to store the state within UI Manger is up to you.) Get into the Habit So we can see that the UIManager pattern is not great strain to implement for an application and can even be retrofitted to an existing application with ease. The point is, however, that you should always take this approach rather than committing the sin of persistent component references which will bite you in the future or shotgun scattered UI flags on the session which are hard to maintain.  If you take the approach of always accessing all UI state via the uiManager, or perhaps a pageScope focused variant of it, you'll find your applications much easier to understand and maintain. Do it today!

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• Game Over function is not working Starling

  - by aNgeLyN omar

  I've been following a tutorial over the web but it somehow did not show something about creating a game over function. I am new to the Starling framework and Actionscript so I'm kind of still trying to find a way to make it work. Here's the complete snippet of the code. package screens { import flash.geom.Rectangle; import flash.utils.getTimer; import events.NavigationEvent; import objects.GameBackground; import objects.Hero; import objects.Item; import objects.Obstacle; import starling.display.Button; import starling.display.Image; import starling.display.Sprite; import starling.events.Event; import starling.events.Touch; import starling.events.TouchEvent; import starling.text.TextField; import starling.utils.deg2rad; public class InGame extends Sprite { private var screenInGame:InGame; private var screenWelcome:Welcome; private var startButton:Button; private var playAgain:Button; private var bg:GameBackground; private var hero:Hero; private var timePrevious:Number; private var timeCurrent:Number; private var elapsed:Number; private var gameState:String; private var playerSpeed:Number = 0; private var hitObstacle:Number = 0; private const MIN_SPEED:Number = 650; private var scoreDistance:int; private var obstacleGapCount:int; private var gameArea:Rectangle; private var touch:Touch; private var touchX:Number; private var touchY:Number; private var obstaclesToAnimate:Vector.<Obstacle>; private var itemsToAnimate:Vector.<Item>; private var scoreText:TextField; private var remainingLives:TextField; private var gameOverText:TextField; private var iconSmall:Image; static private var lives:Number = 2; public function InGame() { super(); this.addEventListener(starling.events.Event.ADDED_TO_STAGE, onAddedToStage); } private function onAddedToStage(event:Event):void { this.removeEventListener(Event.ADDED_TO_STAGE, onAddedToStage); drawGame(); scoreText = new TextField(300, 100, "Score: 0", "MyFontName", 35, 0xD9D919, true); remainingLives = new TextField(600, 100, "Lives: " + lives +" X ", "MyFontName", 35, 0xD9D919, true); iconSmall = new Image(Assets.getAtlas().getTexture("darnahead1")); iconSmall.x = 360; iconSmall.y = 40; this.addChild(iconSmall); this.addChild(scoreText); this.addChild(remainingLives); } private function drawGame():void { bg = new GameBackground(); this.addChild(bg); hero = new Hero(); hero.x = stage.stageHeight / 2; hero.y = stage.stageWidth / 2; this.addChild(hero); startButton = new Button(Assets.getAtlas().getTexture("startButton")); startButton.x = stage.stageWidth * 0.5 - startButton.width * 0.5; startButton.y = stage.stageHeight * 0.5 - startButton.height * 0.5; this.addChild(startButton); gameArea = new Rectangle(0, 100, stage.stageWidth, stage.stageHeight - 250); } public function disposeTemporarily():void { this.visible = false; } public function initialize():void { this.visible = true; this.addEventListener(Event.ENTER_FRAME, checkElapsed); hero.x = -stage.stageWidth; hero.y = stage.stageHeight * 0.5; gameState ="idle"; playerSpeed = 0; hitObstacle = 0; bg.speed = 0; scoreDistance = 0; obstacleGapCount = 0; obstaclesToAnimate = new Vector.<Obstacle>(); itemsToAnimate = new Vector.<Item>(); startButton.addEventListener(Event.TRIGGERED, onStartButtonClick); //var mainStage:InGame =InGame.current.nativeStage; //mainStage.dispatchEvent(new Event(Event.COMPLETE)); //playAgain.addEventListener(Event.TRIGGERED, onRetry); } private function onStartButtonClick(event:Event):void { startButton.visible = false; startButton.removeEventListener(Event.TRIGGERED, onStartButtonClick); launchHero(); } private function launchHero():void { this.addEventListener(TouchEvent.TOUCH, onTouch); this.addEventListener(Event.ENTER_FRAME, onGameTick); } private function onTouch(event:TouchEvent):void { touch = event.getTouch(stage); touchX = touch.globalX; touchY = touch.globalY; } private function onGameTick(event:Event):void { switch(gameState) { case "idle": if(hero.x < stage.stageWidth * 0.5 * 0.5) { hero.x += ((stage.stageWidth * 0.5 * 0.5 + 10) - hero.x) * 0.05; hero.y = stage.stageHeight * 0.5; playerSpeed += (MIN_SPEED - playerSpeed) * 0.05; bg.speed = playerSpeed * elapsed; } else { gameState = "flying"; } break; case "flying": if(hitObstacle <= 0) { hero.y -= (hero.y - touchY) * 0.1; if(-(hero.y - touchY) < 150 && -(hero.y - touchY) > -150) { hero.rotation = deg2rad(-(hero.y - touchY) * 0.2); } if(hero.y > gameArea.bottom - hero.height * 0.5) { hero.y = gameArea.bottom - hero.height * 0.5; hero.rotation = deg2rad(0); } if(hero.y < gameArea.top + hero.height * 0.5) { hero.y = gameArea.top + hero.height * 0.5; hero.rotation = deg2rad(0); } } else { hitObstacle-- cameraShake(); } playerSpeed -= (playerSpeed - MIN_SPEED) * 0.01; bg.speed = playerSpeed * elapsed; scoreDistance += (playerSpeed * elapsed) * 0.1; scoreText.text = "Score: " + scoreDistance; initObstacle(); animateObstacles(); createEggItems(); animateItems(); remainingLives.text = "Lives: "+lives + " X "; if(lives == 0) { gameState = "over"; } break; case "over": gameOver(); break; } } private function gameOver():void { gameOverText = new TextField(800, 400, "Hero WAS KILLED!!!", "MyFontName", 50, 0xD9D919, true); scoreText = new TextField(800, 600, "Score: "+scoreDistance, "MyFontName", 30, 0xFFFFFF, true); this.addChild(scoreText); this.addChild(gameOverText); playAgain = new Button(Assets.getAtlas().getTexture("button_tryAgain")); playAgain.x = stage.stageWidth * 0.5 - startButton.width * 0.5; playAgain.y = stage.stageHeight * 0.75 - startButton.height * 0.75; this.addChild(playAgain); playAgain.addEventListener(Event.TRIGGERED, onRetry); } private function onRetry(event:Event):void { playAgain.visible = false; gameOverText.visible = false; scoreText.visible = false; var btnClicked:Button = event.target as Button; if((btnClicked as Button) == playAgain) { this.dispatchEvent(new NavigationEvent(NavigationEvent.CHANGE_SCREEN, {id: "playnow"}, true)); } disposeTemporarily(); } private function animateItems():void { var itemToTrack:Item; for(var i:uint = 0; i < itemsToAnimate.length; i++) { itemToTrack = itemsToAnimate[i]; itemToTrack.x -= playerSpeed * elapsed; if(itemToTrack.bounds.intersects(hero.bounds)) { itemsToAnimate.splice(i, 1); this.removeChild(itemToTrack); } if(itemToTrack.x < -50) { itemsToAnimate.splice(i, 1); this.removeChild(itemToTrack); } } } private function createEggItems():void { if(Math.random() > 0.95){ var itemToTrack:Item = new Item(Math.ceil(Math.random() * 10)); itemToTrack.x = stage.stageWidth + 50; itemToTrack.y = int(Math.random() * (gameArea.bottom - gameArea.top)) + gameArea.top; this.addChild(itemToTrack); itemsToAnimate.push(itemToTrack); } } private function cameraShake():void { if(hitObstacle > 0) { this.x = Math.random() * hitObstacle; this.y = Math.random() * hitObstacle; } else if(x != 0) { this.x = 0; this.y = 0; lives--; } } private function initObstacle():void { if(obstacleGapCount < 1200) { obstacleGapCount += playerSpeed * elapsed; } else if(obstacleGapCount !=0) { obstacleGapCount = 0; createObstacle(Math.ceil(Math.random() * 5), Math.random() * 1000 + 1000); } } private function animateObstacles():void { var obstacleToTrack:Obstacle; for(var i:uint = 0; i<obstaclesToAnimate.length; i++) { obstacleToTrack = obstaclesToAnimate[i]; if(obstacleToTrack.alreadyHit == false && obstacleToTrack.bounds.intersects(hero.bounds)) { obstacleToTrack.alreadyHit = true; obstacleToTrack.rotation = deg2rad(70); hitObstacle = 30; playerSpeed *= 0.5; } if(obstacleToTrack.distance > 0) { obstacleToTrack.distance -= playerSpeed * elapsed; } else { if(obstacleToTrack.watchOut) { obstacleToTrack.watchOut = false; } obstacleToTrack.x -= (playerSpeed + obstacleToTrack.speed) * elapsed; } if(obstacleToTrack.x < -obstacleToTrack.width || gameState == "over") { obstaclesToAnimate.splice(i, 1); this.removeChild(obstacleToTrack); } } } private function checkElapsed(event:Event):void { timePrevious = timeCurrent; timeCurrent = getTimer(); elapsed = (timeCurrent - timePrevious) * 0.001; } private function createObstacle(type:Number, distance:Number):void{ var obstacle:Obstacle = new Obstacle(type, distance, true, 300); obstacle.x = stage.stageWidth; this.addChild(obstacle); if(type >= 4) { if(Math.random() > 0.5) { obstacle.y = gameArea.top; obstacle.position = "top" } else { obstacle.y = gameArea.bottom - obstacle.height; obstacle.position = "bottom"; } } else { obstacle.y = int(Math.random() * (gameArea.bottom - obstacle.height - gameArea.top)) + gameArea.top; obstacle.position = "middle"; } obstaclesToAnimate.push(obstacle); } } }

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• Code Reuse is (Damn) Hard

  - by James Michael Hare

  Being a development team lead, the task of interviewing new candidates was part of my job.  Like any typical interview, we started with some easy questions to get them warmed up and help calm their nerves before hitting the hard stuff. One of those easier questions was almost always: “Name some benefits of object-oriented development.”  Nearly every time, the candidate would chime in with a plethora of canned answers which typically included: “it helps ease code reuse.”  Of course, this is a gross oversimplification.  Tools only ease reuse, its developers that ultimately can cause code to be reusable or not, regardless of the language or methodology. But it did get me thinking…  we always used to say that as part of our mantra as to why Object-Oriented Programming was so great.  With polymorphism, inheritance, encapsulation, etc. we in essence set up the concepts to help facilitate reuse as much as possible.  And yes, as a developer now of many years, I unquestionably held that belief for ages before it really struck me how my views on reuse have jaded over the years.  In fact, in many ways Agile rightly eschews reuse as taking a backseat to developing what's needed for the here and now.  It used to be I was in complete opposition to that view, but more and more I've come to see the logic in it.  Too many times I've seen developers (myself included) get lost in design paralysis trying to come up with the perfect abstraction that would stand all time.  Nearly without fail, all of these pieces of code become obsolete in a matter of months or years. It’s not that I don’t like reuse – it’s just that reuse is hard.  In fact, reuse is DAMN hard.  Many times it is just a distraction that eats up architect and developer time, and worse yet can be counter-productive and force wrong decisions.  Now don’t get me wrong, I love the idea of reusable code when it makes sense.  These are in the few cases where you are designing something that is inherently reusable.  The problem is, most business-class code is inherently unfit for reuse! Furthermore, the code that is reusable will often fail to be reused if you don’t have the proper framework in place for effective reuse that includes standardized versioning, building, releasing, and documenting the components.  That should always be standard across the board when promoting reusable code.  All of this is hard, and it should only be done when you have code that is truly reusable or you will be exerting a large amount of development effort for very little bang for your buck. But my goal here is not to get into how to reuse (that is a topic unto itself) but what should be reused.  First, let’s look at an extension method.  There’s many times where I want to kick off a thread to handle a task, then when I want to reign that thread in of course I want to do a Join on it.  But what if I only want to wait a limited amount of time and then Abort?  Well, I could of course write that logic out by hand each time, but it seemed like a great extension method: 1: public static class ThreadExtensions 2: { 3: public static bool JoinOrAbort(this Thread thread, TimeSpan timeToWait) 4: { 5: bool isJoined = false; 6:  7: if (thread != null) 8: { 9: isJoined = thread.Join(timeToWait); 10:  11: if (!isJoined) 12: { 13: thread.Abort(); 14: } 15: } 16: return isJoined; 17: } 18: } 19:  When I look at this code, I can immediately see things that jump out at me as reasons why this code is very reusable.  Some of them are standard OO principles, and some are kind-of home grown litmus tests: Single Responsibility Principle (SRP) – The only reason this extension method need change is if the Thread class itself changes (one responsibility). Stable Dependencies Principle (SDP) – This method only depends on classes that are more stable than it is (System.Threading.Thread), and in itself is very stable, hence other classes may safely depend on it. It is also not dependent on any business domain, and thus isn't subject to changes as the business itself changes. Open-Closed Principle (OCP) – This class is inherently closed to change. Small and Stable Problem Domain – This method only cares about System.Threading.Thread. All-or-None Usage – A user of a reusable class should want the functionality of that class, not parts of that functionality.  That’s not to say they most use every method, but they shouldn’t be using a method just to get half of its result. Cost of Reuse vs. Cost to Recreate – since this class is highly stable and minimally complex, we can offer it up for reuse very cheaply by promoting it as “ready-to-go” and already unit tested (important!) and available through a standard release cycle (very important!). Okay, all seems good there, now lets look at an entity and DAO.  I don’t know about you all, but there have been times I’ve been in organizations that get the grand idea that all DAOs and entities should be standardized and shared.  While this may work for small or static organizations, it’s near ludicrous for anything large or volatile. 1: namespace Shared.Entities 2: { 3: public class Account 4: { 5: public int Id { get; set; } 6:  7: public string Name { get; set; } 8:  9: public Address HomeAddress { get; set; } 10:  11: public int Age { get; set;} 12:  13: public DateTime LastUsed { get; set; } 14:  15: // etc, etc, etc... 16: } 17: } 18:  19: ... 20:  21: namespace Shared.DataAccess 22: { 23: public class AccountDao 24: { 25: public Account FindAccount(int id) 26: { 27: // dao logic to query and return account 28: } 29:  30: ... 31:  32: } 33: } Now to be fair, I’m not saying there doesn’t exist an organization where some entites may be extremely static and unchanging.  But at best such entities and DAOs will be problematic cases of reuse.  Let’s examine those same tests: Single Responsibility Principle (SRP) – The reasons to change for these classes will be strongly dependent on what the definition of the account is which can change over time and may have multiple influences depending on the number of systems an account can cover. Stable Dependencies Principle (SDP) – This method depends on the data model beneath itself which also is largely dependent on the business definition of an account which can be very inherently unstable. Open-Closed Principle (OCP) – This class is not really closed for modification.  Every time the account definition may change, you’d need to modify this class. Small and Stable Problem Domain – The definition of an account is inherently unstable and in fact may be very large.  What if you are designing a system that aggregates account information from several sources? All-or-None Usage – What if your view of the account encompasses data from 3 different sources but you only care about one of those sources or one piece of data?  Should you have to take the hit of looking up all the other data?  On the other hand, should you have ten different methods returning portions of data in chunks people tend to ask for?  Neither is really a great solution. Cost of Reuse vs. Cost to Recreate – DAOs are really trivial to rewrite, and unless your definition of an account is EXTREMELY stable, the cost to promote, support, and release a reusable account entity and DAO are usually far higher than the cost to recreate as needed. It’s no accident that my case for reuse was a utility class and my case for non-reuse was an entity/DAO.  In general, the smaller and more stable an abstraction is, the higher its level of reuse.  When I became the lead of the Shared Components Committee at my workplace, one of the original goals we looked at satisfying was to find (or create), version, release, and promote a shared library of common utility classes, frameworks, and data access objects.  Now, of course, many of you will point to nHibernate and Entity for the latter, but we were looking at larger, macro collections of data that span multiple data sources of varying types (databases, web services, etc). As we got deeper and deeper in the details of how to manage and release these items, it quickly became apparent that while the case for reuse was typically a slam dunk for utilities and frameworks, the data access objects just didn’t “smell” right.  We ended up having session after session of design meetings to try and find the right way to share these data access components. When someone asked me why it was taking so long to iron out the shared entities, my response was quite simple, “Reuse is hard...”  And that’s when I realized, that while reuse is an awesome goal and we should strive to make code maintainable, often times you end up creating far more work for yourself than necessary by trying to force code to be reusable that inherently isn’t. Think about classes the times you’ve worked in a company where in the design session people fight over the best way to implement a class to make it maximally reusable, extensible, and any other buzzwordable.  Then think about how quickly that design became obsolete.  Many times I set out to do a project and think, “yes, this is the best design, I can extend it easily!” only to find out the business requirements change COMPLETELY in such a way that the design is rendered invalid.  Code, in general, tends to rust and age over time.  As such, writing reusable code can often be difficult and many times ends up being a futile exercise and worse yet, sometimes makes the code harder to maintain because it obfuscates the design in the name of extensibility or reusability. So what do I think are reusable components? Generic Utility classes – these tend to be small classes that assist in a task and have no business context whatsoever. Implementation Abstraction Frameworks – home-grown frameworks that try to isolate changes to third party products you may be depending on (like writing a messaging abstraction layer for publishing/subscribing that is independent of whether you use JMS, MSMQ, etc). Simplification and Uniformity Frameworks – To some extent this is similar to an abstraction framework, but there may be one chosen provider but a development shop mandate to perform certain complex items in a certain way.  Or, perhaps to simplify and dumb-down a complex task for the average developer (such as implementing a particular development-shop’s method of encryption). And what are less reusable? Application and Business Layers – tend to fluctuate a lot as requirements change and new features are added, so tend to be an unstable dependency.  May be reused across applications but also very volatile. Entities and Data Access Layers – these tend to be tuned to the scope of the application, so reusing them can be hard unless the abstract is very stable. So what’s the big lesson?  Reuse is hard.  In fact it’s damn hard.  And much of the time I’m not convinced we should focus too hard on it. If you’re designing a utility or framework, then by all means design it for reuse.  But you most also really set down a good versioning, release, and documentation process to maximize your chances.  For anything else, design it to be maintainable and extendable, but don’t waste the effort on reusability for something that most likely will be obsolete in a year or two anyway.

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• Taking web sites offline for demonstration

  While working in software development in general, and in web development for a couple of customers it is quite common that it is necessary to provide a test bed where the client is able to get an image, or better said, a feeling for the visions and ideas you are talking about. Usually here at IOS Indian Ocean Software Ltd. we set up a demo web site on one of our staging servers, and provide credentials to the customer to access and review our progress and work ad hoc. This gives us the highest flexibility on both sides, as the test bed is simply online and available 24/7. We can update the structure, the UI and data at any time, and the client is able to view it as it suits best for her/him. Limited or lack of online connectivity But what is going to happen when your client is not capable to be online - no matter for what reasons; here are some more obvious ones: No internet connection (permanently or temporarily) Expensive connection, ie. mobile data package, stay at a hotel, etc. Presentation devices at an exhibition, ie. using tablets or iPads Being abroad for a certain time, and only occasionally online No network coverage, especially on mobile Bad infrastructure, like ie. in Third World countries Providing a catalogue on CD or USB pen drive Anyway, it doesn't matter really. We should be able to provide a solution for the circumstances of our customers. Presentation during an exhibition Recently, we had the following request from a customer: Is it possible to let us have a desktop version of ResortWork.co.uk that we can use for demo purposes at the forthcoming Ski Shows? It would allow us to let stand visitors browse the sites on an iPad to view jobs and training directory course listings. Yes, sure we can do that. Eventually, you might think why don't they simply use 3G enabled iPads for that purpose? As stated above, there might be several reasons for that - low coverage, expensive data packages, etc. Anyway, it is not a question on how to circumvent the request but to deliver a solution to that. Possible solutions... or not? We already did offline websites earlier, and even established complete mirrors of one or two web sites on our systems. There are actually several possibilities to handle this kind of request, and it mainly depends on the system or device where the offline site should be available on. Here, it is clearly expressed that we have to address this on an Apple iPad, well actually, I think that they'd like to use multiple devices during their exhibitions. Following is an overview of possible solutions depending on the technology or device in use, and how it can be done: Replication of source files and database The above mentioned web site is running on ASP.NET, IIS and SQL Server. In case that a laptop or slate runs a Windows OS, the easiest way would be to take a snapshot of the source files and database, and transfer them as local installation to those Windows machines. This approach would be fully operational on the local machine. Saving pages for offline usage This is actually a quite tedious job but still practicable for small web sites Tool based approach to 'harvest' the web site There quite some tools in the wild that could handle this job, namely wget, httrack, web copier, etc. Screenshots bundled as PDF document Not really... ;-) Creating screencast or video Simply navigate through your website and record your desktop session. Actually, we are using this kind of approach to track down difficult problems in order to see and understand exactly what the user was doing to cause an error. Of course, this list isn't complete and I'd love to get more of your ideas in the comments section below the article. Preparations for offline browsing The original website is dynamically and data-driven by ASP.NET, and looks like this: As we have to put the result onto iPads we are going to choose the tool-based approach to 'download' the whole web site for offline usage. Again, depending on the complexity of your web site you might have to check which of the applications produces the best results for you. My usual choice is to use wget but in this case, we run into problems related to the rewriting of hyperlinks. As a consequence of that we opted for using HTTrack. HTTrack comes in different flavours, like console application but also as either GUI (WinHTTrack on Windows) or Web client (WebHTTrack on Linux/Unix/BSD). Here's a brief description taken from the original website about HTTrack: HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility. It allows you to download a World Wide Web site from the Internet to a local directory, building recursively all directories, getting HTML, images, and other files from the server to your computer. HTTrack arranges the original site's relative link-structure. Simply open a page of the "mirrored" website in your browser, and you can browse the site from link to link, as if you were viewing it online. And there is an extensive documentation for all options and switches online. General recommendation is to go through the HTTrack Users Guide By Fred Cohen. It covers all the initial steps you need to get up and running. Be aware that it will take quite some time to get all the necessary resources down to your machine. Actually, for our customer we run the tool directly on their web server to avoid unnecessary traffic and bandwidth. After a couple of runs and some additional fine-tuning - explicit inclusion or exclusion of various external linked web sites - we finally had a more or less complete offline version available. A very handsome feature of HTTrack is the error/warning log after completing the download. It contains some detailed information about errors that appeared on the pages and the links within the pages that have been processed. Error: "Bad Request" (400) at link www.resortwork.co.uk/job-details_Ski_hire:tech_or_mgr_or_driver_37854.aspx (from www.resortwork.co.uk/Jobs_A_to_Z.aspx)Error: "Not Found" (404) at link www.247recruit.net/images/applynow.png (from www.247recruit.net/css/global.css)Error: "Not Found" (404) at link www.247recruit.net/activate.html (from www.247recruit.net/247recruit_tefl_jobs_network.html) In our situation, we took the records of HTTP 400/404 errors and passed them to the web development department. Improvements are to be expected soon. ;-) Quality assurance on the full-featured desktop Unfortunately, the generated output of HTTrack was still incomplete but luckily there were only images missing. Being directly on the web server we simply copied the missing images from the original source folder into our offline version. After that, we created an archive and transferred the file securely to our local workspace for further review and checks. From that point on, it wasn't necessary to get any more files from the original web server, and we could focus ourselves completely on the process of browsing and navigating through the offline version to isolate visual differences and functional problems. As said, the original web site runs on ASP.NET Web Forms and uses Postback calls for interaction like search, pagination and partly for navigation. This is the main field of improving the offline experience. Of course, same as for standard web development it is advised to test with various browsers, and strangely we discovered that the offline version looked pretty good on Firefox, Chrome and Safari, but not in Internet Explorer. A quick look at the HTML source shed some light on this, and there are conditional CSS inclusions based on the user agent. HTTrack is not acting as Internet Explorer and so we didn't have the necessary overrides for this browser. Not problematic after all in our case, but you might have to pay attention to this and get the IE-specific files explicitly. And while having a view at the source code, we also found out that HTTrack actually modifies the generated HTML output. In several occasions we discovered that <div> elements were converted into <table> constructs for no obvious reason; even nested structures. Search 'e'nd destroy - sed (or Notepad++) to the rescue During our intensive root cause analysis for a couple of HTML/CSS problems that needed some extra attention it is very helpful to be familiar with any editor that allows search and replace over multiple files like, ie. sed - stream editor for filtering and transforming text on Linux or my personal favourite Notepad++ on Windows. This allowed us to quickly fix a lot of anchors with onclick attributes and Javascript code that was addressed to ASP.NET files instead of their generated HTML counterparts, like so: grep -lr -e '.aspx' * | xargs sed -e 's/.aspx/.html?/g' The additional question mark after the HTML extension helps to separate the query string from the actual target and solved all our missing hyperlinks very fast. The same can be done in Notepad++ on Windows, too. Just use the 'Replace in files' feature and you are settled. Especially, in combination with Regular Expressions (regex). Landscape of browsers Okay, after several runs of HTML/CSS code analysis, searching and replacing some strings in a pool of more than 4.000 files, we finally had a very good match of an offline browsing experience in Firefox and Chrome on Linux. Next, we transferred that modified set of files to a Windows 8 machine for review on Firefox, Chrome and Internet Explorer 7 to 10, and a Mac mini running Mac OS X 10.7 to check the output on Safari and again on Chrome. Besides IE, for reasons already mentioned above, the results were identical. And last but not least it was about to check web site on tablets. Please continue to read on the following articles: Taking web sites offline for demonstration on Galaxy Tablet Taking web sites offline for demonstration on iPad

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• Developing a SQL Server Function in a Test-Harness.

  - by Phil Factor

  /* Many times, it is a lot quicker to take some pain up-front and make a proper development/test harness for a routine (function or procedure) rather than think ‘I’m feeling lucky today!’. Then, you keep code and harness together from then on. Every time you run the build script, it runs the test harness too.  The advantage is that, if the test harness persists, then it is much less likely that someone, probably ‘you-in-the-future’  unintentionally breaks the code. If you store the actual code for the procedure as well as the test harness, then it is likely that any bugs in functionality will break the build rather than to introduce subtle bugs later on that could even slip through testing and get into production.   This is just an example of what I mean.   Imagine we had a database that was storing addresses with embedded UK postcodes. We really wouldn’t want that. Instead, we might want the postcode in one column and the address in another. In effect, we’d want to extract the entire postcode string and place it in another column. This might be part of a table refactoring or int could easily be part of a process of importing addresses from another system. We could easily decide to do this with a function that takes in a table as its parameter, and produces a table as its output. This is all very well, but we’d need to work on it, and test it when you make an alteration. By its very nature, a routine like this either works very well or horribly, but there is every chance that you might introduce subtle errors by fidding with it, and if young Thomas, the rather cocky developer who has just joined touches it, it is bound to break.     right, we drop the function we’re developing and re-create it. This is so we avoid the problem of having to change CREATE to ALTER when working on it. */ IF EXISTS(SELECT * FROM sys.objects WHERE name LIKE ‘ExtractPostcode’                                      and schema_name(schema_ID)=‘Dbo’)     DROP FUNCTION dbo.ExtractPostcode GO   /* we drop the user-defined table type and recreate it */ IF EXISTS(SELECT * FROM sys.types WHERE name LIKE ‘AddressesWithPostCodes’                                    and schema_name(schema_ID)=‘Dbo’)   DROP TYPE dbo.AddressesWithPostCodes GO /* we drop the user defined table type and recreate it */ IF EXISTS(SELECT * FROM sys.types WHERE name LIKE ‘OutputFormat’                                    and schema_name(schema_ID)=‘Dbo’)   DROP TYPE dbo.OutputFormat GO   /* and now create the table type that we can use to pass the addresses to the function */ CREATE TYPE AddressesWithPostCodes AS TABLE ( AddressWithPostcode_ID INT IDENTITY PRIMARY KEY, –because they work better that way! Address_ID INT NOT NULL, –the address we are fixing TheAddress VARCHAR(100) NOT NULL –The actual address ) GO CREATE TYPE OutputFormat AS TABLE (   Address_ID INT PRIMARY KEY, –the address we are fixing   TheAddress VARCHAR(1000) NULL, –The actual address   ThePostCode VARCHAR(105) NOT NULL – The Postcode )   GO CREATE FUNCTION ExtractPostcode(@AddressesWithPostCodes AddressesWithPostCodes READONLY)  /** summary:   > This Table-valued function takes a table type as a parameter, containing a table of addresses along with their integer IDs. Each address has an embedded postcode somewhere in it but not consistently in a particular place. The routine takes out the postcode and puts it in its own column, passing back a table where theinteger key is accompanied by the address without the (first) postcode and the postcode. If no postcode, then the address is returned unchanged and the postcode will be a blank string Author: Phil Factor Revision: 1.3 date: 20 May 2014 example:      – code: returns:   > Table of  Address_ID, TheAddress and ThePostCode. **/     RETURNS @FixedAddresses TABLE   (   Address_ID INT, –the address we are fixing   TheAddress VARCHAR(1000) NULL, –The actual address   ThePostCode VARCHAR(105) NOT NULL – The Postcode   ) AS – body of the function BEGIN DECLARE @BlankRange VARCHAR(10) SELECT  @BlankRange = CHAR(0)+‘- ‘+CHAR(160) INSERT INTO @FixedAddresses(Address_ID, TheAddress, ThePostCode) SELECT Address_ID,          CASE WHEN start>0 THEN REPLACE(STUFF([Theaddress],start,matchlength,”),‘  ‘,‘ ‘)             ELSE TheAddress END            AS TheAddress,        CASE WHEN Start>0 THEN SUBSTRING([Theaddress],start,matchlength-1) ELSE ” END AS ThePostCode FROM (–we have a derived table with the results we need for the chopping SELECT MAX(PATINDEX([matched],‘ ‘+[Theaddress] collate SQL_Latin1_General_CP850_Bin)) AS start,         MAX( CASE WHEN PATINDEX([matched],‘ ‘+[Theaddress] collate SQL_Latin1_General_CP850_Bin)>0 THEN TheLength ELSE 0 END) AS matchlength,        MAX(TheAddress) AS TheAddress,        Address_ID FROM (SELECT –first the match, then the length. There are three possible valid matches         ‘%['+@BlankRange+'][A-Z][0-9] [0-9][A-Z][A-Z]%’, 7 –seven character postcode       UNION ALL SELECT ‘%['+@BlankRange+'][A-Z][A-Z0-9][A-Z0-9] [0-9][A-Z][A-Z]%’, 8       UNION ALL SELECT ‘%['+@BlankRange+'][A-Z][A-Z][A-Z0-9][A-Z0-9] [0-9][A-Z][A-Z]%’, 9)      AS f(Matched,TheLength) CROSS JOIN  @AddressesWithPostCodes GROUP BY [address_ID] ) WORK; RETURN END GO ——————————-end of the function————————   IF NOT EXISTS (SELECT * FROM sys.objects WHERE name LIKE ‘ExtractPostcode’)   BEGIN   RAISERROR (‘There was an error creating the function.’,16,1)   RETURN   END   /* now the job is only half done because we need to make sure that it works. So we now load our sample data, making sure that for each Sample, we have what we actually think the output should be. */ DECLARE @InputTable AddressesWithPostCodes INSERT INTO  @InputTable(Address_ID,TheAddress) VALUES(1,’14 Mason mews, Awkward Hill, Bibury, Cirencester, GL7 5NH’), (2,’5 Binney St      Abbey Ward    Buckinghamshire      HP11 2AX UK’), (3,‘BH6 3BE 8 Moor street, East Southbourne and Tuckton W     Bournemouth UK’), (4,’505 Exeter Rd,   DN36 5RP Hawerby cum BeesbyLincolnshire UK’), (5,”), (6,’9472 Lind St,    Desborough    Northamptonshire NN14 2GH  NN14 3GH UK’), (7,’7457 Cowl St, #70      Bargate Ward  Southampton   SO14 3TY UK’), (8,”’The Pippins”, 20 Gloucester Pl, Chirton Ward,   Tyne & Wear   NE29 7AD UK’), (9,’929 Augustine lane,    Staple Hill Ward     South Gloucestershire      BS16 4LL UK’), (10,’45 Bradfield road, Parwich   Derbyshire    DE6 1QN UK’), (11,’63A Northampton St,   Wilmington    Kent   DA2 7PP UK’), (12,’5 Hygeia avenue,      Loundsley Green WardDerbyshire    S40 4LY UK’), (13,’2150 Morley St,Dee Ward      Dumfries and Galloway      DG8 7DE UK’), (14,’24 Bolton St,   Broxburn, Uphall and Winchburg    West Lothian  EH52 5TL UK’), (15,’4 Forrest St,   Weston-Super-Mare    North Somerset       BS23 3HG UK’), (16,’89 Noon St,     Carbrooke     Norfolk       IP25 6JQ UK’), (17,’99 Guthrie St,  New Milton    Hampshire     BH25 5DF UK’), (18,’7 Richmond St,  Parkham       Devon  EX39 5DJ UK’), (19,’9165 laburnum St,     Darnall Ward  Yorkshire, South     S4 7WN UK’)   Declare @OutputTable  OutputFormat  –the table of what we think the correct results should be Declare @IncorrectRows OutputFormat –done for error reporting   –here is the table of what we think the output should be, along with a few edge cases. INSERT INTO  @OutputTable(Address_ID,TheAddress, ThePostcode)     VALUES         (1, ’14 Mason mews, Awkward Hill, Bibury, Cirencester, ‘,‘GL7 5NH’),         (2, ’5 Binney St   Abbey Ward    Buckinghamshire      UK’,‘HP11 2AX’),         (3, ’8 Moor street, East Southbourne and Tuckton W    Bournemouth UK’,‘BH6 3BE’),         (4, ’505 Exeter Rd,Hawerby cum Beesby   Lincolnshire UK’,‘DN36 5RP’),         (5, ”,”),         (6, ’9472 Lind St,Desborough    Northamptonshire NN14 3GH UK’,‘NN14 2GH’),         (7, ’7457 Cowl St, #70    Bargate Ward  Southampton   UK’,‘SO14 3TY’),         (8, ”’The Pippins”, 20 Gloucester Pl, Chirton Ward,Tyne & Wear   UK’,‘NE29 7AD’),         (9, ’929 Augustine lane,  Staple Hill Ward     South Gloucestershire      UK’,‘BS16 4LL’),         (10, ’45 Bradfield road, ParwichDerbyshire    UK’,‘DE6 1QN’),         (11, ’63A Northampton St,Wilmington    Kent   UK’,‘DA2 7PP’),         (12, ’5 Hygeia avenue,    Loundsley Green WardDerbyshire    UK’,‘S40 4LY’),         (13, ’2150 Morley St,     Dee Ward      Dumfries and Galloway      UK’,‘DG8 7DE’),         (14, ’24 Bolton St,Broxburn, Uphall and Winchburg    West Lothian  UK’,‘EH52 5TL’),         (15, ’4 Forrest St,Weston-Super-Mare    North Somerset       UK’,‘BS23 3HG’),         (16, ’89 Noon St,  Carbrooke     Norfolk       UK’,‘IP25 6JQ’),         (17, ’99 Guthrie St,      New Milton    Hampshire     UK’,‘BH25 5DF’),         (18, ’7 Richmond St,      Parkham       Devon  UK’,‘EX39 5DJ’),         (19, ’9165 laburnum St,   Darnall Ward  Yorkshire, South     UK’,‘S4 7WN’)       insert into @IncorrectRows(Address_ID,TheAddress, ThePostcode)        SELECT Address_ID,TheAddress,ThePostCode FROM dbo.ExtractPostcode(@InputTable)       EXCEPT     SELECT Address_ID,TheAddress,ThePostCode FROM @outputTable; If @@RowCount>0        Begin        PRINT ‘The following rows gave ‘;     SELECT Address_ID,TheAddress,ThePostCode FROM @IncorrectRows        RAISERROR (‘These rows gave unexpected results.’,16,1);     end   /* For tear-down, we drop the user defined table type */ IF EXISTS(SELECT * FROM sys.types WHERE name LIKE ‘OutputFormat’                                    and schema_name(schema_ID)=‘Dbo’)   DROP TYPE dbo.OutputFormat GO /* once this is working, the development work turns from a chore into a delight and one ends up hitting execute so much more often to catch mistakes as soon as possible. It also prevents a wildly-broken routine getting into a build! */

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• BizTalk: History of one project architecture

  - by Leonid Ganeline

  "In the beginning God made heaven and earth. Then he started to integrate." At the very start was the requirement: integrate two working systems. Small digging up: It was one system. It was good but IT guys want to change it to the new one, much better, chipper, more flexible, and more progressive in technologies, more suitable for the future, for the faster world and hungry competitors. One thing. One small, little thing. We cannot turn off the old system (call it A, because it was the first), turn on the new one (call it B, because it is second but not the last one). The A has a hundreds users all across a country, they must study B. A still has a lot nice custom features, home-made features that cannot disappear. These features have to be moved to the B and it is a long process, months and months of redevelopment. So, the decision was simple. Let’s move not jump, let’s both systems working side-by-side several months. In this time we could teach the users and move all custom A’s special functionality to B. That automatically means both systems should work side-by-side all these months and use the same data. Data in A and B must be in sync. That’s how the integration projects get birth. Moreover, the specific of the user tasks requires the both systems must be in sync in real-time. Nightly synchronization is not working, absolutely.   First draft The first draft seems simple. Both systems keep data in SQL databases. When data changes, the Create, Update, Delete operations performed on the data, and the sync process could be started. The obvious decision is to use triggers on tables. When we are talking about data, we are talking about several entities. For example, Orders and Items [in Orders]. We decided to use the BizTalk Server to synchronize systems. Why it was chosen is another story. Second draft   Let’s take an example how it works in more details. 1.       User creates a new entity in the A system. This fires an insert trigger on the entity table. Trigger has to pass the message “Entity created”. This message includes all attributes of the new entity, but I focused on the Id of this entity in the A system. Notation for this message is id.A. System A sends id.A to the BizTalk Server. 2.       BizTalk transforms id.A to the format of the system B. This is easiest part and I will not focus on this kind of transformations in the following text. The message on the picture is still id.A but it is in slightly different format, that’s why it is changing in color. BizTalk sends id.A to the system B. 3.       The system B creates the entity on its side. But it uses different id-s for entities, these id-s are id.B. System B saves id.A+id.B. System B sends the message id.A+id.B back to the BizTalk. 4.       BizTalk sends the message id.A+id.B to the system A. 5.       System A saves id.A+id.B. Why both id-s should be saved on both systems? It was one of the next requirements. Users of both systems have to know the systems are in sync or not in sync. Users working with the entity on the system A can see the id.B and use it to switch to the system B and work there with the copy of the same entity. The decision was to store the pairs of entity id-s on both sides. If there is only one id, the entities are not in sync yet (for the Create operation). Third draft Next problem was the reliability of the synchronization. The synchronizing process can be interrupted on each step, when message goes through the wires. It can be communication problem, timeout, temporary shutdown one of the systems, the second system cannot be synchronized by some internal reason. There were several potential problems that prevented from enclosing the whole synchronization process in one transaction. Decision was to restart the whole sync process if it was not finished (in case of the error). For this purpose was created an additional service. Let’s call it the Resync service. We still keep the id pairs in both systems, but only for the fast access not for the synchronization process. For the synchronizing these id-s now are kept in one main place, in the Resync service database. The Resync service keeps record as: ·       Id.A ·       Id.B ·       Entity.Type ·       Operation (Create, Update, Delete) ·       IsSyncStarted (true/false) ·       IsSyncFinished (true/false0 The example now looks like: 1.       System A creates id.A. id.A is saved on the A. Id.A is sent to the BizTalk. 2.       BizTalk sends id.A to the Resync and to the B. id.A is saved on the Resync. 3.       System B creates id.B. id.A+id.B are saved on the B. id.A+id.B are sent to the BizTalk. 4.       BizTalk sends id.A+id.B to the Resync and to the A. id.A+id.B are saved on the Resync. 5.       id.A+id.B are saved on the B. Resync changes the IsSyncStarted and IsSyncFinished flags accordingly. The Resync service implements three main methods: ·       Save (id.A, Entity.Type, Operation) ·       Save (id.A, id.B, Entity.Type, Operation) ·       Resync () Two Save() are used to save id-s to the service storage. See in the above example, in 2 and 4 steps. What about the Resync()? It is the method that finishes the interrupted synchronization processes. If Save() is started by the trigger event, the Resync() is working as an independent process. It periodically scans the Resync storage to find out “unfinished” records. Then it restarts the synchronization processes. It tries to synchronize them several times then gives up.     One more thing, both systems A and B must tolerate duplicates of one synchronizing process. Say on the step 3 the system B was not able to send id.A+id.B back. The Resync service must restart the synchronization process that will send the id.A to B second time. In this case system B must just send back again also created id.A+id.B pair without errors. That means “tolerate duplicates”. Fourth draft Next draft was created only because of the aesthetics. As it always happens, aesthetics gave significant performance gain to the whole system. First was the stupid question. Why do we need this additional service with special database? Can we just master the BizTalk to do something like this Resync() does? So the Resync orchestration is doing the same thing as the Resync service. It is started by the Id.A and finished by the id.A+id.B message. The first works as a Start message, the second works as a Finish message.     Here is a diagram the whole process without errors. It is pretty straightforward. The Resync orchestration is waiting for the Finish message specific period of time then resubmits the Id.A message. It resubmits the Id.A message specific number of times then gives up and gets suspended. It can be resubmitted then it starts the whole process again: waiting [, resubmitting [, get suspended]], finishing. Tuning up The Resync orchestration resubmits the id.A message with special “Resubmitted” flag. The subscription filter on the Resync orchestration includes predicate as (Resubmit_Flag != “Resubmitted”). That means only the first Sync orchestration starts the Resync orchestration. Other Sync orchestration instantiated by the resubmitting can finish this Resync orchestration but cannot start another instance of the Resync   Here is a diagram where system B was inaccessible for some period of time. The Resync orchestration resubmitted the id.A two times. Then system B got the response the id.A+id.B and this finished the Resync service execution. What is interesting about this, there were submitted several identical id.A messages and only one id.A+id.B message. Because of this, the system B and the Resync must tolerate the duplicate messages. We also told about this requirement for the system B. Now the same requirement is for the Resunc. Let’s assume the system B was very slow in the first response and the Resync service had time to resubmit two id.A messages. System B responded not, as it was in previous case, with one id.A+id.B but with two id.A+id.B messages. First of them finished the Resync execution for the id.A. What about the second id.A+id.B? Where it goes? So, we have to add one more internal requirement. The whole solution must tolerate many identical id.A+id.B messages. It is easy task with the BizTalk. I added the “SinkExtraMessages” subscriber (orchestration with one receive shape), that just get these messages and do nothing. Real design Real architecture is much more complex and interesting. In reality each system can submit several id.A almost simultaneously and completely unordered. There are not only the “Create entity” operation but the Update and Delete operations. And these operations relate each other. Say the Update operation after Delete means not the same as Update after Create. In reality there are entities related each other. Say the Order and Order Items. Change on one of it could start the series of the operations on another. Moreover, the system internals are the “black boxes” and we cannot predict the exact content and order of the operation series. It worth to say, I had to spend a time to manage the zombie message problems. The zombies are still here, but this is not a problem now. And this is another story. What is interesting in the last design? One orchestration works to help another to be more reliable. Why two orchestration design is more reliable, isn’t it something strange? The Synch orchestration takes all the message exchange between systems, here is the area where most of the errors could happen. The Resync orchestration sends and receives messages only within the BizTalk server. Is there another design? Sure. All Resync functionality could be implemented inside the Sync orchestration. Hey guys, some other ideas?

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• Maintaining State in Mud Engine

  - by Johnathon Sullinger

  I am currently working on a Mud Engine and have started implementing my state engine. One of the things that has me troubled is maintaining different states at once. For instance, lets say that the user has started a tutorial, which requires specific input. If the user types "help" I want to switch in to a help state, so they can get the help they need, then return them to the original state once exiting the help. my state system uses a State Manager to manage the state per user: public class StateManager { /// <summary> /// Gets the current state. /// </summary> public IState CurrentState { get; private set; } /// <summary> /// Gets the states available for use. /// </summary> /// <value> public List<IState> States { get; private set; } /// <summary> /// Gets the commands available. /// </summary> public List<ICommand> Commands { get; private set; } /// <summary> /// Gets the mob that this manager controls the state of. /// </summary> public IMob Mob { get; private set; } public void Initialize(IMob mob, IState initialState = null) { this.Mob = mob; if (initialState != null) { this.SwitchState(initialState); } } /// <summary> /// Performs the command. /// </summary> /// <param name="message">The message.</param> public void PerformCommand(IMessage message) { if (this.CurrentState != null) { ICommand command = this.CurrentState.GetCommand(message); if (command is NoOpCommand) { // NoOperation commands indicate that the current state is not finished yet. this.CurrentState.Render(this.Mob); } else if (command != null) { command.Execute(this.Mob); } else if (command == null) { new InvalidCommand().Execute(this.Mob); } } } /// <summary> /// Switches the state. /// </summary> /// <param name="state">The state.</param> public void SwitchState(IState state) { if (this.CurrentState != null) { this.CurrentState.Cleanup(); } this.CurrentState = state; if (state != null) { this.CurrentState.Render(this.Mob); } } } Each of the different states that the user can be in, is a Type implementing IState. public interface IState { /// <summary> /// Renders the current state to the players terminal. /// </summary> /// <param name="player">The player to render to</param> void Render(IMob mob); /// <summary> /// Gets the Command that the player entered and preps it for execution. /// </summary> /// <returns></returns> ICommand GetCommand(IMessage command); /// <summary> /// Cleanups this instance during a state change. /// </summary> void Cleanup(); } Example state: public class ConnectState : IState { /// <summary> /// The connected player /// </summary> private IMob connectedPlayer; public void Render(IMob mob) { if (!(mob is IPlayer)) { throw new NullReferenceException("ConnectState can only be used with a player object implementing IPlayer"); } //Store a reference for the GetCommand() method to use. this.connectedPlayer = mob as IPlayer; var server = mob.Game as IServer; var game = mob.Game as IGame; // It is not guaranteed that mob.Game will implement IServer. We are only guaranteed that it will implement IGame. if (server == null) { throw new NullReferenceException("LoginState can only be set to a player object that is part of a server."); } //Output the game information mob.Send(new InformationalMessage(game.Name)); mob.Send(new InformationalMessage(game.Description)); mob.Send(new InformationalMessage(string.Empty)); //blank line //Output the server MOTD information mob.Send(new InformationalMessage(string.Join("\n", server.MessageOfTheDay))); mob.Send(new InformationalMessage(string.Empty)); //blank line mob.StateManager.SwitchState(new LoginState()); } /// <summary> /// Gets the command. /// </summary> /// <param name="message">The message.</param> /// <returns>Returns no operation required.</returns> public Commands.ICommand GetCommand(IMessage message) { return new NoOpCommand(); } /// <summary> /// Cleanups this instance during a state change. /// </summary> public void Cleanup() { // We have nothing to clean up. return; } } With the way that I have my FSM set up at the moment, the user can only ever have one state at a time. I read a few different posts on here about state management but nothing regarding keeping a stack history. I thought about using a Stack collection, and just pushing new states on to the stack then popping them off as the user moves out from one. It seems like it would work, but I'm not sure if it is the best approach to take. I'm looking for recommendations on this. I'm currently swapping state from within the individual states themselves as well which I'm on the fence about if it makes sense to do there or not. The user enters a command, the StateManager passes the command to the current State and lets it determine if it needs it (like passing in a password after entering a user name), if the state doesn't need any further commands, it returns null. If it does need to continue doing work, it returns a No Operation to let the state manager know that the state still requires further input from the user. If null is returned, the state manager will then go find the appropriate state for the command entered by the user. Example state requiring additional input from the user public class LoginState : IState { /// <summary> /// The connected player /// </summary> private IPlayer connectedPlayer; private enum CurrentState { FetchUserName, FetchPassword, InvalidUser, } private CurrentState currentState; /// <summary> /// Renders the current state to the players terminal. /// </summary> /// <param name="mob"></param> /// <exception cref="System.NullReferenceException"> /// ConnectState can only be used with a player object implementing IPlayer /// or /// LoginState can only be set to a player object that is part of a server. /// </exception> public void Render(IMob mob) { if (!(mob is IPlayer)) { throw new NullReferenceException("ConnectState can only be used with a player object implementing IPlayer"); } //Store a reference for the GetCommand() method to use. this.connectedPlayer = mob as IPlayer; var server = mob.Game as IServer; // Register to receive new input from the user. mob.ReceivedMessage += connectedPlayer_ReceivedMessage; if (server == null) { throw new NullReferenceException("LoginState can only be set to a player object that is part of a server."); } this.currentState = CurrentState.FetchUserName; switch (this.currentState) { case CurrentState.FetchUserName: mob.Send(new InputMessage("Please enter your user name")); break; case CurrentState.FetchPassword: mob.Send(new InputMessage("Please enter your password")); break; case CurrentState.InvalidUser: mob.Send(new InformationalMessage("Invalid username/password specified.")); this.currentState = CurrentState.FetchUserName; mob.Send(new InputMessage("Please enter your user name")); break; } } /// <summary> /// Receives the players input. /// </summary> /// <param name="sender">The sender.</param> /// <param name="e">The e.</param> void connectedPlayer_ReceivedMessage(object sender, IMessage e) { // Be good memory citizens and clean ourself up after receiving a message. // Not doing this results in duplicate events being registered and memory leaks. this.connectedPlayer.ReceivedMessage -= connectedPlayer_ReceivedMessage; ICommand command = this.GetCommand(e); } /// <summary> /// Gets the Command that the player entered and preps it for execution. /// </summary> /// <param name="command"></param> /// <returns>Returns the ICommand specified.</returns> public Commands.ICommand GetCommand(IMessage command) { if (this.currentState == CurrentState.FetchUserName) { this.connectedPlayer.Name = command.Message; this.currentState = CurrentState.FetchPassword; } else if (this.currentState == CurrentState.FetchPassword) { // find user } return new NoOpCommand(); } /// <summary> /// Cleanups this instance during a state change. /// </summary> public void Cleanup() { // If we have a player instance, we clean up the registered event. if (this.connectedPlayer != null) { this.connectedPlayer.ReceivedMessage -= this.connectedPlayer_ReceivedMessage; } } Maybe my entire FSM isn't wired up in the best way, but I would appreciate input on what would be the best to maintain a stack of state in a MUD game engine, and if my states should be allowed to receive the input from the user or not to check what command was entered before allowing the state manager to switch states. Thanks in advance.

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