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• T-SQL Tuesday #34: Help! I Need Somebody!

  - by Most Valuable Yak (Rob Volk)

  Welcome everyone to T-SQL Tuesday Episode 34!  When last we tuned in, Mike Fal (b|t) hosted Trick Shots.  These highlighted techniques or tricks that you figured out on your own which helped you understand SQL Server better. This month, I'm asking you to look back this past week, year, century, or hour...to a time when you COULDN'T figure it out.  When you were stuck on a SQL Server problem and you had to seek help. In the beginning... SQL Server has changed a lot since I started with it.  <Cranky Old Guy> Back in my day, Books Online was neither.  There were no blogs. Google was the third-place search site. There were perhaps two or three community forums where you could ask questions.  (Besides the Microsoft newsgroups...which you had to access with Usenet.  And endure the wrath of...Celko.)  Your "training" was reading a book, made from real dead trees, that you bought from your choice of brick-and-mortar bookstore. And except for your local user groups, there were no conferences, seminars, SQL Saturdays, or any online video hookups where you could interact with a person. You'd have to call Microsoft Support...on the phone...a LANDLINE phone.  And none of this "SQL Family" business!</Cranky Old Guy> Even now, with all these excellent resources available, it's still daunting for a beginner to seek help for SQL Server.  The product is roughly 1247.4523 times larger than it was 15 years ago, and it's simply impossible to know everything about it.*  So whether you are a beginner, or a seasoned pro of over a decade's experience, what do you do when you need help on SQL Server? That's so meta... In the spirit of offering help, here are some suggestions for your topic: Tell us about a person or SQL Server community who have been helpful to you.  It can be about a technical problem, or not, e.g. someone who volunteered for your local SQL Saturday.  Sing their praises!  Let the world know who they are! Do you have any tricks for using Books Online?  Do you use the locally installed product, or are you completely online with BOL/MSDN/Technet, and why? If you've been using SQL Server for over 10 years, how has your help-seeking changed? Are you using Twitter, StackOverflow, MSDN Forums, or another resource that didn't exist when you started? What made you switch? Do you spend more time helping others than seeking help? What motivates you to help, and how do you contribute? Structure your post along the lyrics to The Beatles song Help! Audio or video renditions are particularly welcome! Lyrics must include reference to SQL Server terminology or community, and performances must be in your voice or include you playing an instrument. These are just suggestions, you are free to write whatever you like.  Bonus points if you can incorporate ALL of these into a single post.  (Or you can do multiple posts, we're flexible like that.)  Help us help others by showing how others helped you! Legalese, Your Rights, Yada yada... If you would like to participate in T-SQL Tuesday please be sure to follow the rules below: Your blog post must be published between Tuesday, September 11, 2012 00:00:00 GMT and Wednesday, September 12, 2012 00:00:00 GMT. Include the T-SQL Tuesday logo (above) and hyperlink it back to this post. If you don’t see your post in trackbacks, add the link to the comments below. If you are on Twitter please tweet your blog using the #TSQL2sDay hashtag.  I can be contacted there as @sql_r, in case you have questions or problems with comments/trackback.  I'll have a follow-up post listing all the contributions as soon as I can. Thank you all for participating, and special thanks to Adam Machanic (b|t) for all his help and for continuing this series!

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• How do I cleanly design a central render/animation loop?

  - by mtoast

  I'm learning some graphics programming, and am in the midst of my first such project of any substance. But, I am really struggling at the moment with how to architect it cleanly. Let me explain. To display complicated graphics in my current language of choice (JavaScript -- have you heard of it?), you have to draw graphical content onto a <canvas> element. And to do animation, you must clear the <canvas> after every frame (unless you want previous graphics to remain). Thus, most canvas-related JavaScript demos I've seen have a function like this: function render() { clearCanvas(); // draw stuff here requestAnimationFrame(render); } render, as you may surmise, encapsulates the drawing of a single frame. What a single frame contains at a specific point in time, well... that is determined by the program state. So, in order for my program to do its thing, I just need to look at the state, and decide what to render. Right? Right. But that is more complicated than it seems. My program is called "Critter Clicker". In my program, you see several cute critters bouncing around the screen. Clicking on one of them agitates it, making it bounce around even more. There is also a start screen, which says "Click to start!" prior to the critters being displayed. Here are a few of the objects I'm working with in my program: StartScreenView // represents the start screen CritterTubView // represents the area in which the critters live CritterList // a collection of all the critters Critter // a single critter model CritterView // view of a single critter Nothing too egregious with this, I think. Yet, when I set out to flesh out my render function, I get stuck, because everything I write seems utterly ugly and reminiscent of a certain popular Italian dish. Here are a couple of approaches I've attempted, with my internal thought process included, and unrelated bits excluded for clarity. Approach 1: "It's conditions all the way down" // "I'll just write the program as I think it, one frame at a time." if (assetsLoaded) { if (userClickedToStart) { if (critterTubDisplayed) { if (crittersDisplayed) { forEach(crittersList, function(c) { if (c.wasClickedRecently) { c.getAgitated(); } }); } else { displayCritters(); } } else { displayCritterTub(); } } else { displayStartScreen(); } } That's a very much simplified example. Yet even with only a fraction of all the rendering conditions visible, render is already starting to get out of hand. So, I dispense with that and try another idea: Approach 2: Under the Rug // "Each view object shall be responsible for its own rendering. // "I'll pass each object the program state, and each can render itself." startScreen.render(state); critterTub.render(state); critterList.render(state); In this setup, I've essentially just pushed those crazy nested conditions to a deeper level in the code, hiding them from view. In other words, startScreen.render would check state to see if it needed actually to be drawn or not, and take the correct action. But this seems more like it only solves a code-aesthetic problem. The third and final approach I'm considering that I'll share is the idea that I could invent my own "wheel" to take care of this. I'm envisioning a function that takes a data structure that defines what should happen at any given point in the render call -- revealing the conditions and dependencies as a kind of tree. Approach 3: Mad Scientist renderTree({ phases: ['startScreen', 'critterTub', 'endCredits'], dependencies: { startScreen: ['assetsLoaded'], critterTub: ['startScreenClicked'], critterList ['critterTubDisplayed'] // etc. }, exclusions: { startScreen: ['startScreenClicked'], // etc. } }); That seems kind of cool. I'm not exactly sure how it would actually work, but I can see it being a rather nifty way to express things, especially if I flex some of JavaScript's events. In any case, I'm a little bit stumped because I don't see an obvious way to do this. If you couldn't tell, I'm coming to this from the web development world, and finding that doing animation is a bit more exotic than arranging an MVC application for handling simple requests - responses. What is the clean, established solution to this common-I-would-think problem?

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• Jersey 2 in GlassFish 4 - First Java EE 7 Implementation Now Integrated (TOTD #182)

  - by arungupta

  The JAX-RS 2.0 specification released their Early Draft 3 recently. One of my earlier blogs explained as the features were first introduced in the very first draft of the JAX-RS 2.0 specification. Last week was another milestone when the first Java EE 7 specification implementation was added to GlassFish 4 builds. Jakub blogged about Jersey 2 integration in GlassFish 4 builds. Most of the basic functionality is working but EJB, CDI, and Validation are still a TBD. Here is a simple Tip Of The Day (TOTD) sample to get you started with using that functionality. Create a Java EE 6-style Maven project mvn archetype:generate -DarchetypeGroupId=org.codehaus.mojo.archetypes -DarchetypeArtifactId=webapp-javaee6 -DgroupId=example -DartifactId=jersey2-helloworld -DarchetypeVersion=1.5 -DinteractiveMode=false Note, this is still a Java EE 6 archetype, at least for now. Open the project in NetBeans IDE as it makes it much easier to edit/add the files. Add the following <respositories> <repositories> <repository> <id>snapshot-repository.java.net</id> <name>Java.net Snapshot Repository for Maven</name> <url>https://maven.java.net/content/repositories/snapshots/</url> <layout>default</layout> </repository></repositories> Add the following <dependency>s <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.10</version> <scope>test</scope></dependency><dependency> <groupId>javax.ws.rs</groupId> <artifactId>javax.ws.rs-api</artifactId> <version>2.0-m09</version> <scope>test</scope></dependency><dependency> <groupId>org.glassfish.jersey.core</groupId> <artifactId>jersey-client</artifactId> <version>2.0-m05</version> <scope>test</scope></dependency> The complete list of Maven coordinates for Jersey2 are available here. An up-to-date status of Jersey 2 can always be obtained from here. Here is a simple resource class: @Path("movies")public class MoviesResource { @GET @Path("list") public List<Movie> getMovies() { List<Movie> movies = new ArrayList<Movie>(); movies.add(new Movie("Million Dollar Baby", "Hillary Swank")); movies.add(new Movie("Toy Story", "Buzz Light Year")); movies.add(new Movie("Hunger Games", "Jennifer Lawrence")); return movies; }} This resource publishes a list of movies and is accessible at "movies/list" path with HTTP GET. The project is using the standard JAX-RS APIs. Of course, you need the trivial "Movie" and the "Application" class as well. They are available in the downloadable project anyway. Build the project mvn package And deploy to GlassFish 4.0 promoted build 43 (download, unzip, and start as "bin/asadmin start-domain") as asadmin deploy --force=true target/jersey2-helloworld.war Add a simple test case by right-clicking on the MoviesResource class, select "Tools", "Create Tests", and take defaults. Replace the function "testGetMovies" to @Testpublic void testGetMovies() { System.out.println("getMovies"); Client client = ClientFactory.newClient(); List<Movie> movieList = client.target("http://localhost:8080/jersey2-helloworld/webresources/movies/list") .request() .get(new GenericType<List<Movie>>() {}); assertEquals(3, movieList.size());} This test uses the newly defined JAX-RS 2 client APIs to access the RESTful resource. Run the test by giving the command "mvn test" and see the output as ------------------------------------------------------- T E S T S-------------------------------------------------------Running example.MoviesResourceTestgetMoviesTests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.561 secResults :Tests run: 1, Failures: 0, Errors: 0, Skipped: 0 GlassFish 4 contains Jersey 2 as the JAX-RS implementation. If you want to use Jersey 1.1 functionality, then Martin's blog provide more details on that. All JAX-RS 1.x functionality will be supported using standard APIs anyway. This workaround is only required if Jersey 1.x functionality needs to be accessed. The complete source code explained in this project can be downloaded from here. Here are some pointers to follow JAX-RS 2 Specification Early Draft 3 Latest status on specification (jax-rs-spec.java.net) Latest JAX-RS 2.0 Javadocs Latest status on Jersey (Reference Implementation of JAX-RS 2 - jersey.java.net) Latest Jersey API Javadocs Latest GlassFish 4.0 Promoted Build Follow @gf_jersey Provide feedback on Jersey 2 to [email protected] and JAX-RS specification to [email protected].

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• Centered Content using panelGridLayout

  - by Duncan Mills

  A classic layout conundrum,  which I think pretty much every ADF developer may have faced at some time or other, is that of truly centered (centred) layout. Typically this requirement comes up in relation to say displaying a login type screen or similar. Superficially the  problem seems easy, but as my buddy Eduardo explained when discussing this subject a couple of years ago it's actually a little more complex than you might have thought. If fact, even the "solution" provided in that posting is not perfect and suffers from a several issues (not Eduardo's fault, just limitations of panelStretch!) The top, bottom, end and start facets all need something in them The percentages you apply to the topHeight, startWidth etc. are calculated as part of the whole width.  This means that you have to guestimate the correct percentage based on your typical screen size and the sizing of the centered content. So, at best, you will in fact only get approximate centering, and the more you tune that centering for a particular browser size the more it will fail if the user resizes. You can't attach styles to the panelStretchLayout facets so to provide things like background color or fixed sizing you need to embed another container that you can apply styles to, typically a panelgroupLayout   For reference here's the code to print a simple 100px x 100px red centered square  using the panelStretchLayout solution, approximately tuned to a 1980 x 1080 maximized browser (IDs omitted for brevity): <af:panelStretchLayout startWidth="45%" endWidth="45%"                        topHeight="45%"  bottomHeight="45%" >   <f:facet name="center">     <af:panelGroupLayout inlineStyle="height:100px;width:100px;background-color:red;"                          layout="vertical"/>   </f:facet>   <f:facet name="top">     <af:spacer height="1" width="1"/>   </f:facet>   <f:facet name="bottom">     <af:spacer height="1" width="1"/>   </f:facet>   <f:facet name="start">     <af:spacer height="1" width="1"/>   </f:facet>   <f:facet name="end">     <af:spacer height="1" width="1"/>    </f:facet> </af:panelStretchLayout>  And so to panelGridLayout  So here's the  good news, panelGridLayout makes this really easy and it works without the caveats above.  The key point is that percentages used in the grid definition are evaluated after the fixed sizes are taken into account, so rather than having to guestimate what percentage will "more, or less", center the content you can just say "allocate half of what's left" to the flexible content and you're done. Here's the same example using panelGridLayout: <af:panelGridLayout> <af:gridRow height="50%"/> <af:gridRow height="100px"> <af:gridCell width="50%" /> <af:gridCell width="100px" halign="stretch" valign="stretch"  inlineStyle="background-color:red;"> <af:spacer width="1" height="1"/> </af:gridCell> <af:gridCell width="50%" /> </af:gridRow> <af:gridRow height="50%"/> </af:panelGridLayout>  So you can see that the amount of markup is somewhat smaller (as is, I should mention, the generated DOM structure in the browser), mainly because we don't need to introduce artificial components to ensure that facets are actually observed in the final result.  But the key thing here is that the centering is no longer approximate and it will work as expected as the user resizes the browser screen.  By far this is a more satisfactory solution and although it's only a simple example, it will hopefully open your eyes to the potential of panelGridLayout as your number one, go-to layout container. Just a reminder though, right now, panelGridLayout is only available in 11.1.2.2 and above.

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• Code refactoring with Visual Studio 2010 Part-4

  - by Jalpesh P. Vadgama

  I have been writing few post with code refactoring features in Visual Studio 2010. This post also will be part of series and this post will be last of the series. In this post I am going explain two features 1) Encapsulate Field and 2) Extract Interface. Let’s explore both features in details. Encapsulate Field: This is a nice code refactoring feature provides by Visual Studio 2010. With help of this feature we can create properties from the existing private field of the class. Let’s take a simple example of Customer Class. In that I there are two private field called firstName and lastName. Below is the code for the class. public class Customer { private string firstName; private string lastName; public string Address { get; set; } public string City { get; set; } } Now lets encapsulate first field firstName with Encapsulate feature. So first select that field and goto refactor menu in Visual Studio 2010 and click on Encapsulate Field. Once you click that a dialog box will appear like following. Now once you click OK a preview dialog box will open as we have selected preview reference changes. I think its a good options to check that option to preview code that is being changed by IDE itself. Dialog will look like following. Once you click apply it create a new property called FirstName. Same way I have done for the lastName and now my customer class code look like following. public class Customer { private string firstName; public string FirstName { get { return firstName; } set { firstName = value; } } private string lastName; public string LastName { get { return lastName; } set { lastName = value; } } public string Address { get; set; } public string City { get; set; } } So you can see that its very easy to create properties with existing fields and you don’t have to change anything there in code it will change all the stuff itself. Extract Interface: When you are writing software prototype and You don’t know the future implementation of that then its a good practice to use interface there. I am going to explain here that How we can extract interface from the existing code without writing a single line of code with the help of code refactoring feature of Visual Studio 2010. For that I have create a Simple Repository class called CustomerRepository with three methods like following. public class CustomerRespository { public void Add() { // Some code to add customer } public void Update() { //some code to update customer } public void Delete() { //some code delete customer } } In above class there are three method Add,Update and Delete where we are going to implement some code for each one. Now I want to create a interface which I can use for my other entities in project. So let’s create a interface from the above class with the help of Visual Studio 2010. So first select class and goto refactor menu and click Extract Interface. It will open up dialog box like following. Here I have selected all the method for interface and Once I click OK then it will create a new file called ICustomerRespository where it has created a interface. Just like following. Here is a code for that interface. using System; namespace CodeRefractoring { interface ICustomerRespository { void Add(); void Delete(); void Update(); } } Now let's see the code for the our class. It will also changed like following to implement the interface. public class CustomerRespository : ICustomerRespository { public void Add() { // Some code to add customer } public void Update() { //some code to update customer } public void Delete() { //some code delete customer } } Isn't that great we have created a interface and implemented it without writing a single line of code. Hope you liked it. Stay tuned for more.. Till that Happy Programming.

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• Existential CAML - does an item exist?

  - by PointsToShare

  © 2011 By: Dov Trietsch. All rights reserved More CAML and existence. In “SharePoint List Issues” and “Passing the CAML thru the EY of the NEEDL we saw how to use CAML to return a subset of a list and also how to check the existence of lists, fields, defaults, and values.   Here is a general function that may be used to get a subset of a list by comparing a “text” type field to a given value.  The function is pretty smart. It can be used to check existence or to return a collection of items that may be further processed. It handles non existing fields and replaces them with the ubiquitous “Title”, but only once!  /// Build an SPQuery that returns a selected set of columns from a List /// titleField must be a "Text" type field /// When the titleField parameter is empty ("") "Title" is assumed /// When the title parameter is empty ("") All is assumed /// When the columnNames parameter is null, the query returns all the fields /// When the rowLimit parameter is 0, the query return all the items. /// with a non-zero, the query returns at most rowLimits /// /// usage: to check if an item titled "Blah" exists in your list, do: /// colNames = {"Title"} /// col = GetListItemColumnByTitle(myList, "", "Blah", colNames, 1) /// Check the col.Count. if > 0 the item exists and is in the collection private static SPListItemCollection GetListItemColumnByTitle(SPList list, string titleField, string title, string[] columnNames, uint rowLimit) {   try   {     char QT = Convert.ToChar((int)34);     SPQuery query = new SPQuery();     if (title != "")     {       string tf = titleField;       if (titleField == "") tf = "Title";       tf = CAMLThisName(list, tf, "Title");        StringBuilder titleQuery = new StringBuilder  ("<Where><Eq><FieldRef Name=");       titleQuery.Append(QT);       titleQuery.Append(tf);       titleQuery.Append(QT);       titleQuery.Append("/><Value Type=");       titleQuery.Append(QT);       titleQuery.Append("Text");       titleQuery.Append(QT);       titleQuery.Append(">");       titleQuery.Append(title);       titleQuery.Append("</Value></Eq></Where>");       query.Query = titleQuery.ToString();     }     if (columnNames.Length != 0)     {       StringBuilder sb = new StringBuilder("");       bool TitleAlreadyIncluded = false;       foreach (string columnName in columnNames)       {         string tst = CAMLThisName(list, columnName, "Title");         //Allow Title only once         if (tst != "Title" || !TitleAlreadyIncluded)         {           sb.Append("<FieldRef Name=");           sb.Append(QT);           sb.Append(tst);           sb.Append(QT);           sb.Append("/>");           if (tst == "Title") TitleAlreadyIncluded = true;         }       }       query.ViewFields = sb.ToString();     }     if (rowLimit > 0)     {        query.RowLimit = rowLimit;     }     SPListItemCollection col = list.GetItems(query);     return col;   }   catch (Exception ex)   {     //Console.WriteLine("GetListItemColumnByTitle" + ex.ToString());     //sw.WriteLine("GetListItemColumnByTitle" + ex.ToString());     return null;   } } Here I called it for a list in which “Author” (it is the internal name for “Created”) and “Blah” do not exist. The list of column names is:  string[] columnNames = {"Test Column1", "Title", "Author", "Allow Multiple Ratings", "Blah"};  So if I use this call, I get all the items for which “01-STD MIL_some” has the value of 1. the fields returned are: “Test Column1”, “Title”, and “Allow Multiple Ratings”. Because “Title” was already included and the default for non exixsting is “Title”, it was not replicated for the 2 non-existing fields.  SPListItemCollection col = GetListItemColumnByTitle(masterList, "01-STD MIL_some", "1", columnNames, 0); The following call checks if there are any items where “01-STD MIL_some” has the value of “1”. Note that I limited the number of returned items to 1.  SPListItemCollection col = GetListItemColumnByTitle(masterList, "01-STD MIL_some", "1", columnNames, 1); The code also uses the CAMLThisName function that checks for an existence of a field and returns its InternalName. This is yet another useful function that I use again and again.  /// <summary> /// return a fields internal name (CAMLName)  /// or the "default" name that you passed. /// To check existence pass "" or some funny name like "mud in your eye" /// </summary> public static string CAMLThisName(SPList list, string name, string def) {   String CAMLName = def;   SPField fld = GetFieldByName(list, name);   if (fld != null)   {      CAMLName = fld.InternalName;   }   return CAMLName; } That’s all folks?!

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• Breaking 1NF to model subset constraints. Does this sound sane?

  - by Chris Travers

  My first question here. Appologize if it is in the wrong forum but this seems pretty conceptual. I am looking at doing something that goes against conventional wisdom and want to get some feedback as to whether this is totally insane or will result in problems, so critique away! I am on PostgreSQL 9.1 but may be moving to 9.2 for this part of this project. To re-iterate: Does it seem sane to break 1NF in this way? I am not looking for debugging code so much as where people see problems that this might lead. The Problem In double entry accounting, financial transactions are journal entries with an arbitrary number of lines. Each line has either a left value (debit) or a right value (credit) which can be modelled as a single value with negatives as debits and positives as credits or vice versa. The sum of all debits and credits must equal zero (so if we go with a single amount field, sum(amount) must equal zero for each financial journal entry). SQL-based databases, pretty much required for this sort of work, have no way to express this sort of constraint natively and so any approach to enforcing it in the database seems rather complex. The Write Model The journal entries are append only. There is a possibility we will add a delete model but it will be subject to a different set of restrictions and so is not applicable here. If and when we allow deletes, we will probably do them using a simple ON DELETE CASCADE designation on the foreign key, and require that deletes go through a dedicated stored procedure which can enforce the other constraints. So inserts and selects have to be accommodated but updates and deletes do not for this task. My Proposed Solution My proposed solution is to break first normal form and model constraints on arrays of tuples, with a trigger that breaks the rows out into another table. CREATE TABLE journal_line ( entry_id bigserial primary key, account_id int not null references account(id), journal_entry_id bigint not null, -- adding references later amount numeric not null ); I would then add "table methods" to extract debits and credits for reporting purposes: CREATE OR REPLACE FUNCTION debits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount < 0 THEN $1.amount * -1 ELSE NULL END; $$; CREATE OR REPLACE FUNCTION credits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount > 0 THEN $1.amount ELSE NULL END; $$; Then the journal entry table (simplified for this example): CREATE TABLE journal_entry ( entry_id bigserial primary key, -- no natural keys :-( journal_id int not null references journal(id), date_posted date not null, reference text not null, description text not null, journal_lines journal_line[] not null ); Then a table method and and check constraints: CREATE OR REPLACE FUNCTION running_total(journal_entry) returns numeric language sql immutable as $$ SELECT sum(amount) FROM unnest($1.journal_lines); $$; ALTER TABLE journal_entry ADD CONSTRAINT CHECK (((journal_entry.running_total) = 0)); ALTER TABLE journal_line ADD FOREIGN KEY journal_entry_id REFERENCES journal_entry(entry_id); And finally we'd have a breakout trigger: CREATE OR REPLACE FUNCTION je_breakout() RETURNS TRIGGER LANGUAGE PLPGSQL AS $$ BEGIN IF TG_OP = 'INSERT' THEN INSERT INTO journal_line (journal_entry_id, account_id, amount) SELECT NEW.id, account_id, amount FROM unnest(NEW.journal_lines); RETURN NEW; ELSE RAISE EXCEPTION 'Operation Not Allowed'; END IF; END; $$; And finally CREATE TRIGGER AFTER INSERT OR UPDATE OR DELETE ON journal_entry FOR EACH ROW EXECUTE_PROCEDURE je_breaout(); Of course the example above is simplified. There will be a status table that will track approval status allowing for separation of duties, etc. However the goal here is to prevent unbalanced transactions. Any feedback? Does this sound entirely insane? Standard Solutions? In getting to this point I have to say I have looked at four different current ERP solutions to this problems: Represent every line item as a debit and a credit against different accounts. Use of foreign keys against the line item table to enforce an eventual running total of 0 Use of constraint triggers in PostgreSQL Forcing all validation here solely through the app logic. My concerns are that #1 is pretty limiting and very hard to audit internally. It's not programmer transparent and so it strikes me as being difficult to work with in the future. The second strikes me as being very complex and required a series of contraints and foreign keys against self to make work, and therefore it strikes me as complex, hard to sort out at least in my mind, and thus hard to work with. The fourth could be done as we force all access through stored procedures anyway and this is the most common solution (have the app total things up and throw an error otherwise). However, I think proof that a constraint is followed is superior to test cases, and so the question becomes whether this in fact generates insert anomilies rather than solving them. If this is a solved problem it isn't the case that everyone agrees on the solution....

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• Upgrading to Code Based Migrations EF 4.3.1 with Connector/Net 6.6

  - by GABMARTINEZ

  Entity Framework 4.3.1 includes a new feature called code first migrations.  We are adding support for this feature in our upcoming 6.6 release of Connector/Net.  In this walk-through we'll see the workflow of code-based migrations when you have an existing application and you would like to upgrade to this EF 4.3.1 version and use this approach, so you can keep track of the changes that you do to your database.   The first thing we need to do is add the new Entity Framework 4.3.1 package to our application. This should via the NuGet package manager.  You can read more about why EF is not part of the .NET framework here. Adding EF 4.3.1 to our existing application  Inside VS 2010 go to Tools -> Library Package Manager -> Package Manager Console, this will open the Power Shell Host Window where we can work with all the EF commands. In order to install this library to your existing application you should type Install-Package EntityFramework This will make some changes to your application. So Let's check them. In your .config file you'll see a  <configSections> which contains the version you have from EntityFramework and also was added the <entityFramework> section as shown below. This section is by default configured to use SQL Express which won't be necesary for this case. So you can comment it out or leave it empty. Also please make sure you're using the Connector/Net 6.6.x version which is the one that has this support as is shown in the previous image. At this point we face one issue; in order to be able to work with Migrations we need the __MigrationHistory table that we don't have yet since our Database was created with an older version. This table is used to keep track of the changes in our model. So we need to get it in our existing Database. Getting a Migration-History table into an existing database First thing we need to do to enable migrations in our existing application is to create our configuration class which will set up the MySqlClient Provider as our SQL Generator. So we have to add it with the following code: using System.Data.Entity.Migrations;     //add this at the top of your cs file public class Configuration : DbMigrationsConfiguration<NameOfYourDbContext>  //Make sure to use the name of your existing DBContext { public Configuration() { this.AutomaticMigrationsEnabled = false; //Set Automatic migrations to false since we'll be applying the migrations manually for this case. SetSqlGenerator("MySql.Data.MySqlClient", new MySql.Data.Entity.MySqlMigrationSqlGenerator());     }   }  This code will set up our configuration that we'll be using when executing all the migrations for our application. Once we have done this we can Build our application so we can check that everything is fine. Creating our Initial Migration Now let's add our Initial Migration. In Package Manager Console, execute "add-migration InitialCreate", you can use any other name but I like to set this as our initial create for future reference. After we run this command, some changes were done in our application: A new Migrations Folder was created. A new class migration call InitialCreate which in most of the cases should have empty Up and Down methods as long as your database is up to date with your Model. Since all your entities already exists, delete all duplicated code to create any entity which exists already in your Database if there is any. I found this easier when you don't have any pending updates to do to your database. Now we have our empty migration that will make no changes in our database and represents how are all the things at the begining of our migrations.  Finally, let's create our MigrationsHistory table. Optionally you can add SQL code to delete the edmdata table which is not needed anymore. public override void Up() { // Just make sure that you used 4.1 or later version         Sql("DROP TABLE EdmMetadata"); } From our Package Manager Console let's type: Update-database; If you like to see the operations made on each Update-database command you can use the flag -verbose after the Update-database. This will make two important changes.  It will execute the Up method in the initial migration which has no changes in the database. And second, and very important,  it will create the __MigrationHistory table necessary to keep track of your changes. And next time you make a change to your database it will compare the current model to the one stored in the Model Column of this table. Conclusion The important thing of this walk through is that we must create our initial migration before we start doing any changes to our model. This way we'll be adding the necessary __MigrationsHistory table to our existing database, so we can keep our database up to date with all the changes we do in our context model using migrations. Hope you have found this information useful. Please let us know if you have any questions or comments, also please check our forums here where we keep answering questions in general for the community.  Happy MySQL/Net Coding!

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• What Counts For a DBA: Fitness

  - by Louis Davidson

  If you know me, you can probably guess that physical exercise is not really my thing. There was a time in my past when it a larger part of my life, but even then never in the same sort of passionate way as a number of our SQL friends.  For me, I find that mental exercise satisfies what I believe to be the same inner need that drives people to run farther than I like to drive on most Saturday mornings, and it is certainly just as addictive. Mental fitness shares many common traits with physical fitness, especially the need to attain it through repetitive training. I only wish that mental training burned off a bacon cheeseburger in the same manner as does jogging around a dewy park on Saturday morning. In physical training, there are at least two goals, the first of which is to be physically able to do a task. The second is to train the brain to perform the task without thinking too hard about it. No matter how long it has been since you last rode a bike, you will be almost certainly be able to hop on and start riding without thinking about the process of pedaling or balancing. If you’ve never ridden a bike, you could be a physics professor /Olympic athlete and still crash the first few times you try, even though you are as strong as an ox and your knowledge of the physics of bicycle riding makes the concept child’s play. For programming tasks, the process is very similar. As a DBA, you will come to know intuitively how to backup, optimize, and secure database systems. As a data programmer, you will work to instinctively use the clauses of Transact-SQL DML so that, when you need to group data three ways (and not four), you will know to use the GROUP BY clause with GROUPING SETS without resorting to a search engine.  You have the skill. Making it naturally then requires repetition and experience is the primary requirement, not just simply learning about a topic. The hardest part of being really good at something is this difference between knowledge and skill. I have recently taken several informative training classes with Kimball University on data warehousing and ETL. Now I have a lot more knowledge about designing data warehouses than before. I have also done a good bit of data warehouse designing of late and have started to improve to some level of proficiency with the theory. Yet, for all of this head knowledge, it is still a struggle to take what I have learned and apply it to the designs I am working on.  Data warehousing is still a task that is not yet deeply ingrained in my brain muscle memory. On the other hand, relational database design is something that no matter how much or how little I may get to do it, I am comfortable doing it. I have done it as a profession now for well over a decade, I teach classes on it, and I also have done (and continue to do) a lot of mental training beyond the work day. Sometimes the training is just basic education, some reading blogs and attending sessions at PASS events.  My best training comes from spending time working on other people’s design issues in forums (though not nearly as much as I would like to lately). Working through other people’s problems is a great way to exercise your brain on problems with which you’re not immediately familiar. The final bit of exercise I find useful for cultivating mental fitness for a data professional is also probably the nerdiest thing that I will ever suggest you do.  Akin to running in place, the idea is to work through designs in your head. I have designed more than one database system that would revolutionize grocery store operations, sales at my local Target store, the ordering process at Amazon, and ways to improve Disney World operations to get me through a line faster (some of which they are starting to implement without any of my help.) Never are the designs truly fleshed out, but enough to work through structures and processes.  On “paper”, I have designed database systems to catalog things as trivial as my Lego creations, rental car companies and my audio and video collections. Once I get the database designed mentally, sometimes I will create the database, add some data (often using Red-Gate’s Data Generator), and write a few queries to see if a concept was realistic, but I will rarely fully flesh out the database since I have no desire to do any user interface programming anymore.  The mental training allows me to keep in practice for when the time comes to do the work I love the most for real…even if I have been spending most of my work time lately building data warehouses.  If you are really strong of mind and body, perhaps you can mix a mental run with a physical run; though don’t run off of a cliff while contemplating how you might design a database to catalog the trees on a mountain…that would be contradictory to the purpose of both types of exercise.

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• Rebuilding CoasterBuzz, Part II: Hot data objects

  - by Jeff

  This is the second post, originally from my personal blog, in a series about rebuilding one of my Web sites, which has been around for 12 years. More: Part I: Evolution, and death to WCF After the rush to get moving on stuff, I temporarily lost interest. I went almost two weeks without touching the project, in part because the next thing on my backlog was doing up a bunch of administrative pages. So boring. Unfortunately, because most of the site's content is user-generated, you need some facilities for editing data. CoasterBuzz has a database full of amusement parks and roller coasters. The entities enjoy the relationships that you would expect, though they're further defined by "instances" of a coaster, to define one that has moved between parks as one, with different names and operational dates. And of course, there are pictures and news items, too. It's not horribly complex, except when you have to account for a name change and display just the newest name. In all previous versions, data access was straight SQL. As so much of the old code was rooted in 2003, with some changes in 2008, there wasn't much in the way of ORM frameworks going on then. Let me rephrase that, I mostly wasn't interested in ORM's. Since that time, I used a little LINQ to SQL in some projects, and a whole bunch of nHibernate while at Microsoft. Through all of that experience, I have to admit that these frameworks are often a bigger pain in the ass than not. They're great for basic crud operations, but when you start having all kinds of exotic relationships, they get difficult, and generate all kinds of weird SQL under the covers. The black box can quickly turn into a black hole. Sometimes you end up having to build all kinds of new expertise to do things "right" with a framework. Still, despite my reservations, I used the newer version of Entity Framework, with the "code first" modeling, in a science project and I really liked it. Since it's just a right-click away with NuGet, I figured I'd give it a shot here. My initial effort was spent defining the context class, which requires a bit of work because I deviate quite a bit from the conventions that EF uses, starting with table names. Then throw some partial querying of certain tables (where you'll find image data), and you're splitting tables across several objects (navigation properties). I won't go into the details, because these are all things that are well documented around the Internet, but there was a minor learning curve there. The basics of reading data using EF are fantastic. For example, a roller coaster object has a park associated with it, as well as a number of instances (if it was ever relocated), and there also might be a big banner image for it. This is stupid easy to use because it takes one line of code in your repository class, and by the time you pass it to the view, you have a rich object graph that has everything you need to display stuff. Likewise, editing simple data is also, well, simple. For this goodness, thank the ASP.NET MVC framework. The UpdateModel() method on the controllers is very elegant. Remember the old days of assigning all kinds of properties to objects in your Webforms code-behind? What a time consuming mess that used to be. Even if you're not using an ORM tool, having hydrated objects come off the wire is such a time saver. Not everything is easy, though. When you have to persist a complex graph of objects, particularly if they were composed in the user interface with all kinds of AJAX elements and list boxes, it's not just a simple matter of submitting the form. There were a few instances where I ended up going back to "old-fashioned" SQL just in the interest of time. It's not that I couldn't do what I needed with EF, it's just that the efficiency, both my own and that of the generated SQL, wasn't good. Since EF context objects expose a database connection object, you can use that to do the old school ADO.NET stuff you've done for a decade. Using various extension methods from POP Forums' data project, it was a breeze. You just have to stick to your decision, in this case. When you start messing with SQL directly, you can't go back in the same code to messing with entities because EF doesn't know what you're changing. Not really a big deal. There are a number of take-aways from using EF. The first is that you write a lot less code, which has always been a desired outcome of ORM's. The other lesson, and I particularly learned this the hard way working on the MSDN forums back in the day, is that trying to retrofit an ORM framework into an existing schema isn't fun at all. The CoasterBuzz database isn't bad, but there are design decisions I'd make differently if I were starting from scratch. Now that I have some of this stuff done, I feel like I can start to move on to the more interesting things on the backlog. There's a lot to do, but at least it's fun stuff, and not more forms that will be used infrequently.

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• SQL SERVER – Backing Up and Recovering the Tail End of a Transaction Log – Notes from the Field #042

  - by Pinal Dave

  [Notes from Pinal]: The biggest challenge which people face is not taking backup, but the biggest challenge is to restore a backup successfully. I have seen so many different examples where users have failed to restore their database because they made some mistake while they take backup and were not aware of the same. Tail Log backup was such an issue in earlier version of SQL Server but in the latest version of SQL Server, Microsoft team has fixed the confusion with additional information on the backup and restore screen itself. Now they have additional information, there are a few more people confused as they have no clue about this. Previously they did not find this as a issue and now they are finding tail log as a new learning. Linchpin People are database coaches and wellness experts for a data driven world. In this 42nd episode of the Notes from the Fields series database expert Tim Radney (partner at Linchpin People) explains in a very simple words, Backing Up and Recovering the Tail End of a Transaction Log. Many times when restoring a database over an existing database SQL Server will warn you about needing to make a tail end of the log backup. This might be your reminder that you have to choose to overwrite the database or could be your reminder that you are about to write over and lose any transactions since the last transaction log backup. You might be asking yourself “What is the tail end of the transaction log”. The tail end of the transaction log is simply any committed transactions that have occurred since the last transaction log backup. This is a very crucial part of a recovery strategy if you are lucky enough to be able to capture this part of the log. Most organizations have chosen to accept some amount of data loss. You might be shaking your head at this statement however if your organization is taking transaction logs backup every 15 minutes, then your potential risk of data loss is up to 15 minutes. Depending on the extent of the issue causing you to have to perform a restore, you may or may not have access to the transaction log (LDF) to be able to back up those vital transactions. For example, if the storage array or disk that holds your transaction log file becomes corrupt or damaged then you wouldn’t be able to recover the tail end of the log. If you do have access to the physical log file then you can still back up the tail end of the log. In 2013 I presented a session at the PASS Summit called “The Ultimate Tail Log Backup and Restore” and have been invited back this year to present it again. During this session I demonstrate how you can back up the tail end of the log even after the data file becomes corrupt. In my demonstration I set my database offline and then delete the data file (MDF). The database can’t become more corrupt than that. I attempt to bring the database back online to change the state to RECOVERY PENDING and then backup the tail end of the log. I can do this by specifying WITH NO_TRUNCATE. Using NO_TRUNCATE is equivalent to specifying both COPY_ONLY and CONTINUE_AFTER_ERROR. It as its name says, does not try to truncate the log. This is a great demo however how could I achieve backing up the tail end of the log if the failure destroys my entire instance of SQL and all I had was the LDF file? During my demonstration I also demonstrate that I can attach the log file to a database on another instance and then back up the tail end of the log. If I am performing proper backups then my most recent full, differential and log files should be on a server other than the one that crashed. I am able to achieve this task by creating new database with the same name as the failed database. I then set the database offline, delete my data file and overwrite the log with my good log file. I attempt to bring the database back online and then backup the log with NO_TRUNCATE just like in the first example. I encourage each of you to view my blog post and watch the video demonstration on how to perform these tasks. I really hope that none of you ever have to perform this in production, however it is a really good idea to know how to do this just in case. It really isn’t a matter of “IF” you will have to perform a restore of a production system but more of a “WHEN”. Being able to recover the tail end of the log in these sever cases could be the difference of having to notify all your business customers of data loss or not. If you want me to take a look at your server and its settings, or if your server is facing any issue we can Fix Your SQL Server. Note: Tim has also written an excellent book on SQL Backup and Recovery, a must have for everyone. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• "Imprinting" as a language feature?

  - by MKO

  Idea I had this idea for a language feature that I think would be useful, does anyone know of a language that implements something like this? The idea is that besides inheritance a class can also use something called "imprinting" (for lack of better term). A class can imprint one or several (non-abstract) classes. When a class imprints another class it gets all it's properties and all it's methods. It's like the class storing an instance of the imprinted class and redirecting it's methods/properties to it. A class that imprints another class therefore by definition also implements all it's interfaces and it's abstract class. So what's the point? Well, inheritance and polymorphism is hard to get right. Often composition gives far more flexibility. Multiple inheritance offers a slew of different problems without much benefits (IMO). I often write adapter classes (in C#) by implementing some interface and passing along the actual methods/properties to an encapsulated object. The downside to that approach is that if the interface changes the class breaks. You also you have to put in a lot of code that does nothing but pass things along to the encapsulated object. A classic example is that you have some class that implements IEnumerable or IList and contains an internal class it uses. With this technique things would be much easier Example (c#) [imprint List<Person> as peopleList] public class People : PersonBase { public void SomeMethod() { DoSomething(this.Count); //Count is from List } } //Now People can be treated as an List<Person> People people = new People(); foreach(Person person in people) { ... } peopleList is an alias/variablename (of your choice)used internally to alias the instance but can be skipped if not needed. One thing that's useful is to override an imprinted method, that could be achieved with the ordinary override syntax public override void Add(Person person) { DoSomething(); personList.Add(person); } note that the above is functional equivalent (and could be rewritten by the compiler) to: public class People : PersonBase , IList<Person> { private List<Person> personList = new List<Person>(); public override void Add(object obj) { this.personList.Add(obj) } public override int IndexOf(object obj) { return personList.IndexOf(obj) } //etc etc for each signature in the interface } only if IList changes your class will break. IList won't change but an interface that you, someone in your team, or a thirdparty has designed might just change. Also this saves you writing a whole lot of code for some interfaces/abstract classes. Caveats There's a couple of gotchas. First we, syntax must be added to call the imprinted classes's constructors from the imprinting class constructor. Also, what happends if a class imprints two classes which have the same method? In that case the compiler would detect it and force the class to define an override of that method (where you could chose if you wanted to call either imprinted class or both) So what do you think, would it be useful, any caveats? It seems it would be pretty straightforward to implement something like that in the C# language but I might be missing something :) Sidenote - Why is this different from multiple inheritance Ok, so some people have asked about this. Why is this different from multiple inheritance and why not multiple inheritance. In C# methods are either virtual or not. Say that we have ClassB who inherits from ClassA. ClassA has the methods MethodA and MethodB. ClassB overrides MethodA but not MethodB. Now say that MethodB has a call to MethodA. if MethodA is virtual it will call the implementation that ClassB has, if not it will use the base class, ClassA's MethodA and you'll end up wondering why your class doesn't work as it should. By the terminology sofar you might already confused. So what happens if ClassB inherits both from ClassA and another ClassC. I bet both programmers and compilers will be scratching their heads. The benefit of this approach IMO is that the imprinting classes are totally encapsulated and need not be designed with multiple inheritance in mind. You can basically imprint anything.

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• Data Source Security Part 5

  - by Steve Felts

  If you read through the first four parts of this series on data source security, you should be an expert on this focus area.  There is one more small topic to cover related to WebLogic Resource permissions.  After that comes the test, I mean example, to see with a real set of configuration parameters what the results are with some concrete values. WebLogic Resource Permissions All of the discussion so far has been about database credentials that are (eventually) used on the database side.  WLS has resource credentials to control what WLS users are allowed to access JDBC resources.  These can be defined on the Policies tab on the Security tab associated with the data source.  There are four permissions: “reserve” (get a new connection), “admin”, “shrink”, and reset (plus the all-inclusive “ALL”); we will focus on “reserve” here because we are talking about getting connections.  By default, JDBC resource permissions are completely open – anyone can do anything.  As soon as you add one policy for a permission, then all other users are restricted.  For example, if I add a policy so that “weblogic” can reserve a connection, then all other users will fail to reserve connections unless they are also explicitly added.  The validation is done for WLS user credentials only, not database user credentials.  Configuration of resources in general is described at “Create policies for resource instances” http://docs.oracle.com/cd/E24329_01/apirefs.1211/e24401/taskhelp/security/CreatePoliciesForResourceInstances.html.  This feature can be very useful to restrict what code and users can get to your database. There are the three use cases: API Use database credentials User for permission checking getConnection() True or false Current WLS user getConnection(user,password) False User/password from API getConnection(user,password) True Current WLS user If a simple getConnection() is used or database credentials are enabled, the current user that is authenticated to the WLS system is checked. If database credentials are not enabled, then the user and password on the API are used. Example The following is an actual example of the interactions between identity-based-connection-pooling-enabled, oracle-proxy-session, and use-database-credentials. On the database side, the following objects are configured.- Database users scott; jdbcqa; jdbcqa3- Permission for proxy: alter user jdbcqa3 grant connect through jdbcqa;- Permission for proxy: alter user jdbcqa grant connect through jdbcqa; The following WebLogic Data Source objects are configured.- Users weblogic, wluser- Credential mapping “weblogic” to “scott”- Credential mapping "wluser" to "jdbcqa3"- Data source descriptor configured with user “jdbcqa”- All tests are run with Set Client ID set to true (more about that below).- All tests are run with oracle-proxy-session set to false (more about that below). The test program:- Runs in servlet- Authenticates to WLS as user “weblogic” Use DB Credentials Identity based getConnection(scott,***) getConnection(weblogic,***) getConnection(jdbcqa3,***) getConnection()  true  true Identity scottClient weblogicProxy null weblogic fails - not a db user User jdbcqa3Client weblogicProxy null Default user jdbcqaClient weblogicProxy null  false  true scott fails - not a WLS user User scottClient scottProxy null jdbcqa3 fails - not a WLS user User scottClient scottProxy null  true  false Proxy for scott fails weblogic fails - not a db user User jdbcqa3Client weblogicProxy jdbcqa Default user jdbcqaClient weblogicProxy null  false  false scott fails - not a WLS user Default user jdbcqaClient scottProxy null jdbcqa3 fails - not a WLS user Default user jdbcqaClient scottProxy null If Set Client ID is set to false, all cases would have Client set to null. If this was not an Oracle thin driver, the one case with the non-null Proxy in the above table would throw an exception because proxy session is only supported, implicitly or explicitly, with the Oracle thin driver. When oracle-proxy-session is set to true, the only cases that will pass (with a proxy of "jdbcqa") are the following.1. Setting use-database-credentials to true and doing getConnection(jdbcqa3,…) or getConnection().2. Setting use-database-credentials to false and doing getConnection(wluser, …) or getConnection(). Summary There are many options to choose from for data source security.  Considerations include the number and volatility of WLS and Database users, the granularity of data access, the depth of the security identity (property on the connection or a real user), performance, coordination of various components in the software stack, and driver capabilities.  Now that you have the big picture (remember that table in part 1), you can make a more informed choice.

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• Web Services Example - Part 2: Programmatic

  - by Denis T

  In this edition of the ADF Mobile blog we'll tackle part 2 of our Web Service examples.  In this posting we'll take a look at using a SOAP Web Service but calling it programmatically in code and parsing the return into a bean. Getting the sample code: Just click here to download a zip of the entire project.  You can unzip it and load it into JDeveloper and deploy it either to iOS or Android.  Please follow the previous blog posts if you need help getting JDeveloper or ADF Mobile installed.  Note: This is a different workspace than WS-Part1 Defining our Web Service: Just like our first installment, we are using the same public weather forecast web service provided free by CDYNE Corporation.  Sometimes this service goes down so please ensure you know it's up before reporting this example isn't working. We're going to concentrate on the same two web service methods, GetCityForecastByZIP and GetWeatherInformation. Defing the Application: The application setup is identical to the Weather1 version.  There are some improvements to the data that is displayed as part of this example though.  Now we are able to show the associated image along with each forecast line when using the Forecast By Zip feature.  We've also added the temperature Hi/Low values into the UI. Summary of Fundamental Changes In This Application The most fundamental change is that we're binding the UI to the Bean Data Controls instead of directly to the Web Service Data Controls.  This gives us much more flexibility to control the shape of the data and allows us to do caching of the data outside of the Web Service.  This way if your application is, say offline, your bean could still populate with data from a local cache and still show you some UI as opposed to completely failing because you don't have any connectivity. In general we promote this type of programming technique with ADF Mobile to insulate your application from any issues with network connectivity. What's different with this example? We have setup the Web Service DC the same way but now we have managed beans to process the data.  The following classes define the "Model" of our application:  CityInformation-CityForecast-Forecast, WeatherInformation-WeatherDescription.  We use WeatherBean for UI interaction to the model layer.  If you look through this example, we don't really do that much with the java code except use it to grab the image URL from the weather description.  In a more realistic example, you might be using some JDBC classes to persist the data to a local database. To have a good architecture it is always good to keep your model and UI layers separate.  This gets muddied if you start to use bindings on a page invoked from Java code and this java code starts to become your "model" layer.  Since bindings are page specific, your model layer starts to become entwined with your UI.  Not good!  To help with this, we've added some utility functions that let you invoke DC methods without having a binding and thus execute methods from your "model" layer without requiring a binding in your page definition.  We do this with the invokeDataControlMethod of the AdfmfJavaUtilities class.  An example of this method call is available in line 95 of WeatherInformation.java and line 93 of CityInformation.Java. What's a GenericType? Because Web Service Data Controls (and also URL Data Controls AKA REST) use generic name/value pairs to define their structure and don't have strongly typed objects, these are actually stored internally as GenericType objects.  The GenericType class is simply a property map of name/value pairs that can be hierarchical.  There are methods like getAttribute where you supply the index of the attribute or it's string property name.  Why is this important to know?  Because invokeDataControlMethod returns GenericType objects and developers either need to parse these GenericType objects themselves or use one of our helper functions. GenericTypeBeanSerializationHelper This class does exactly what it's name implies.  It's a helper class for developers to aid in serialization of GenericTypes to/from java objects.  This is extremely handy if you have a large GenericType object with many attributes (or you're just lazy like me!) and you just want to parse it out into a real java object you can use more easily.  Here you would use the fromGenericType method.  This method takes the class of the Java object you wish to return and the GenericType as parameters.  The method then parses through each attribute in the GenericType and uses reflection to set that same attribute in the Java class.  Then the method returns that new object of the class you specified.  This is obviously very handy to avoid a lot of shuffling code between GenericType and your own Java classes.  The reverse method, toGenericType is also available when you want to go the other way.  In this case you supply the string that represents the package location in the DataControl definition (Example: "MyDC.myParams.MyCollection") and then pass in the Java object you have that holds the data and a GenericType is returned to you.  Again, it will use reflection to calculate the attributes that match between the java class and the GenericType and call the getters/setters on those. Issues and Possible Improvements: In the next installment we'll show you how to make your web service calls asynchronously so your UI will fill dynamically when the service call returns but in the meantime you show the data you have locally in your bean fed from some local cache.  This gives your users instant delivery of some data while you fetch other data in the background.

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• Right-Time Retail Part 2

  - by David Dorf

  This is part two of the three-part series. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Right-Time Integration Of course these real-time enabling technologies are only as good as the systems that utilize them, and it only takes one bottleneck to slow everyone else down. What good is an immediate stock-out notification if the supply chain can’t react until tomorrow? Since being formed in 2006, Oracle Retail has been not only adding more integrations between systems, but also modernizing integrations for appropriate speed. Notice I tossed in the word “appropriate.” Not everything needs to be real-time – again, we’re talking about Right-Time Retail. The speed of data capture, analysis, and execution must be synchronized or you’re wasting effort. Unfortunately, there isn’t an enterprise-wide dial that you can crank-up for your estate. You’ll need to improve things piecemeal, with people and processes as limiting factors while choosing the appropriate types of integrations. There are three integration styles we see in the retail industry. First is batch. I know, the word “batch” just sounds slow, but this pattern is less about velocity and more about volume. When there are large amounts of data to be moved, you’ll want to use batch processes. Our technology of choice here is Oracle Data Integrator (ODI), which provides a fast version of Extract-Transform-Load (ETL). Instead of the three-step process, the load and transform steps are combined to save time. ODI is a key technology for moving data into Retail Analytics where we can apply science. Performing analytics on each sale as it occurs doesn’t make any sense, so we batch up a statistically significant amount and submit all at once. The second style is fire-and-forget. For some types of data, we want the data to arrive ASAP but immediacy is not necessary. Speed is less important than guaranteed delivery, so we use message-oriented middleware available in both Weblogic and the Oracle database. For example, Point-of-Service transactions are queued for delivery to Central Office at corporate. If the network is offline, those transactions remain in the queue and will be delivered when the network returns. Transactions cannot be lost and they must be delivered in order. (Ever tried processing a return before the sale?) To enhance the standard queues, we offer the Retail Integration Bus (RIB) to help the management and monitoring of fire-and-forget messaging in the enterprise. The third style is request-response and is most commonly implemented as Web services. This is a synchronous message where the sender waits for a response. In this situation, the volume of data is small, guaranteed delivery is not necessary, but speed is very important. Examples include the website checking inventory, a price lookup, or processing a credit card authorization. The Oracle Service Bus (OSB) typically handles the routing of such messages, and we’ve enhanced its abilities with the Retail Service Backbone (RSB). To better understand these integration patterns and where they apply within the retail enterprise, we’re providing the Retail Reference Library (RRL) at no charge to Oracle Retail customers. The library is composed of a large number of industry business processes, including those necessary to support Commerce Anywhere, as well as detailed architectural diagrams. These diagrams allow implementers to understand the systems involved in integrations and the specific data payloads. Furthermore, with our upcoming release we’ll be providing a new tool called the Retail Integration Console (RIC) that allows IT to monitor and manage integrations from a single point. Using RIC, retailers can quickly discern where integration activity is occurring, volume statistics, average response times, and errors. The dashboards provide the ability to dive down into the architecture documentation to gather information all the way down to the specific payload. Retailers that want real-time integrations will also need real-time monitoring of those integrations to ensure service-level agreements are maintained. Part 3 looks at marketing.

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• Clone a VirtualBox Machine

  I just installed VirtualBox, which I want to try out based on recommendations from peers for running a server from within my Windows 7 x64 OS.  Ive never used VirtualBox, so Im certainly no expert at it, but I did want to share my experience with it thus far.  Specifically, my intention is to create a couple of virtual machines.  One I intend to use as a build server, for which a virtual machine makes sense because I can easily move it around as needed if there are hardware issues (its worth noting my need for setting up a build server at the moment is a result of a disk failure on the old build server).  The other VM I want to set up will act as a proxy server for the issue tracking system were using at Code Project, Axosoft OnTime.  They have a Remote Server application for this purpose, and since the OnTime install is 300 miles away from my location, the Remote Server should speed up my use of the OnTime client by limiting the chattiness with the database (at least, thats the hope). So, I need two VMs, and Im lazy.  I dont want to have to install the OS and such twice.  No problem, it should be simple to clone a virtualbox machine, or clone a virtualbox hard drive, right?  Well unfortunately, if you look at the UI for VirtualBox, theres no such command.  Youre left wondering How do I clone a VirtualBox machine? or the slightly related How do I clone a VirtualBox hard drive? If youve used VirtualPC, then you know that its actually pretty easy to copy and move around those VMs.  Not quite so easy with VirtualBox.  Finding the files is easy, theyre located in your user folder within the .VirtualBox folder (possibly within a HardDisks folder).  The disks have a .vdi extension and will be pretty large if youve installed anything.  The one shown here has just Windows Server 2008 R2 installed on it nothing else. If you copy the .vdi file and rename it, you can use the Virtual Media Manager to view it and you can create a new machine and choose the new drive to attach to.  Unfortunately, if you simply make a copy of the drive, this wont work and youll get an error that says something to the effect of: Cannot register the hard disk PATH with UUID {id goes here} because a hard disk PATH2 with UUID {same id goes here} already exists in the media registry (PATH to XML file). There are command line tools you can use to do this in a way that avoids this error.  Specifically, the c:\Program File\Sun\VirtualBox\VBoxManage.exe program is used for all command line access to VirtualBox, and to copy a virtual disk (.vdi file) you would call something like this: VBoxManage clonehd Disk1.vdi Disk1_Copy.vdi However, in my case this didnt work.  I got basically the same error I showed above, along with some debug information for line 628 of VBoxManageDisk.cpp.  As my main task was not to debug the C++ code used to write VirtualBox, I continued looking for a simple way to clone a virtual drive.  I found it in this blog post. The Secret setvdiuuid Command VBoxManage has a whole bunch of commands you can use with it just pass it /? to see the list.  However, it also has a special command called internalcommands that opens up access to even more commands.  The one thats interesting for us here is the setvdiuuid command.  By calling this command and passing in the file path to your vdi file, it will reset the UUID to a new (random, apparently) UUID.  This then allows the virtual media manager to cope with the file, and lets you set up new machines that reference the newly UUIDd virtual drive.  The full command line would be: VBoxManage internalcommands setvdiuuid MyCopy.vdi The following screenshot shows the error when trying clonehd as well as the successful use of setvdiuuid. Summary Now that I can clone machines easily, its a simple matter to set up base builds of any OS I might need, and then fork from there as needed.  Hopefully the GUI for VirtualBox will be improved to include better support for copying machines/disks, as this is Im sure a very common scenario. Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• ADF Reusable Artefacts

  - by Arda Eralp

  Primary reusable ADF Business Component: Entity Objects (EOs) View Objects (VOs) Application Modules (AMs) Framework Extensions Classes Primary reusable ADF Controller: Bounded Task Flows (BTFs) Task Flow Templates Primary reusable ADF Faces: Page Templates Skins Declarative Components Utility Classes Certain components will often be used more than once. Whether the reuse happens within the same application, or across different applications, it is often advantageous to package these reusable components into a library that can be shared between different developers, across different teams, and even across departments within an organization. In the world of Java object-oriented programming, reusing classes and objects is just standard procedure. With the introduction of the model-view-controller (MVC) architecture, applications can be further modularized into separate model, view, and controller layers. By separating the data (model and business services layers) from the presentation (view and controller layers), you ensure that changes to any one layer do not affect the integrity of the other layers. You can change business logic without having to change the UI, or redesign the web pages or front end without having to recode domain logic. Oracle ADF and JDeveloper support the MVC design pattern. When you create an application in JDeveloper, you can choose many application templates that automatically set up data model and user interface projects. Because the different MVC layers are decoupled from each other, development can proceed on different projects in parallel and with a certain amount of independence. ADF Library further extends this modularity of design by providing a convenient and practical way to create, deploy, and reuse high-level components. When you first design your application, you design it with component reusability in mind. If you created components that can be reused, you can package them into JAR files and add them to a reusable component repository. If you need a component, you may look into the repository for those components and then add them into your project or application. For example, you can create an application module for a domain and package it to be used as the data model project in several different applications. Or, if your application will be consuming components, you may be able to load a page template component from a repository of ADF Library JARs to create common look and feel pages. Then you can put your page flow together by stringing together several task flow components pulled from the library. An ADF Library JAR contains ADF components and does not, and cannot, contain other JARs. It should not be confused with the JDeveloper library, Java EE library, or Oracle WebLogic shared library. Reusable Component Description Data Control Any data control can be packaged into an ADF Library JAR. Some of the data controls supported by Oracle ADF include application modules, Enterprise JavaBeans, web services, URL services, JavaBeans, and placeholder data controls. Application Module When you are using ADF Business Components and you generate an application module, an associated application module data control is also generated. When you package an application module data control, you also package up the ADF Business Components associated with that application module. The relevant entity objects, view objects, and associations will be a part of the ADF Library JAR and available for reuse. Business Components Business components are the entity objects, view objects, and associations used in the ADF Business Components data model project. You can package business components by themselves or together with an application module. Task Flows & Task Flow Templates Task flows can be packaged into an ADF Library JAR for reuse. If you drop a bounded task flow that uses page fragments, JDeveloper adds a region to the page and binds it to the dropped task flow. ADF bounded task flows built using pages can be dropped onto pages. The drop will create a link to call the bounded task flow. A task flow call activity and control flow will automatically be added to the task flow, with the view activity referencing the page. If there is more than one existing task flow with a view activity referencing the page, it will prompt you to select the one to automatically add a task flow call activity and control flow. If an ADF task flow template was created in the same project as the task flow, the ADF task flow template will be included in the ADF Library JAR and will be reusable. Page Templates You can package a page template and its artifacts into an ADF Library JAR. If the template uses image files and they are included in a directory within your project, these files will also be available for the template during reuse. Declarative Components You can create declarative components and package them for reuse. The tag libraries associated with the component will be included and loaded into the consuming project. You can also package up projects that have several different reusable components if you expect that more than one component will be consumed. For example, you can create a project that has both an application module and a bounded task flow. When this ADF Library JAR file is consumed, the application will have both the application module and the task flow available for use. You can package multiple components into one JAR file, or you can package a single component into a JAR file. Oracle ADF and JDeveloper give you the option and flexibility to create reusable components that best suit you and your organization. You create a reusable component by using JDeveloper to package and deploy the project that contains the components into a ADF Library JAR file. You use the components by adding that JAR to the consuming project. At design time, the JAR is added to the consuming project's class path and so is available for reuse. At runtime, the reused component runs from the JAR file by reference.

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• What is Happening vs. What is Interesting

  - by Geertjan

  Devoxx 2011 was yet another confirmation that all development everywhere is either on the web or on mobile phones. Whether you looked at the conference schedule or attended sessions or talked to speakers at any point at all, it was very clear that no development whatsoever is done anymore on the desktop. In fact, that's something Tim Bray himself told me to my face at the speakers dinner. No new developments of any kind are happening on the desktop. Everyone who is currently on the desktop is working overtime to move all of their applications to the web. They're probably also creating a small subset of their application on an Android tablet, with an even smaller subset on their Android phone. Then you scratch that monolithic surface and find some interesting results. Without naming any names, I asked one of these prominent "ah, forget about the desktop" people at the Devoxx speakers dinner (and I have a witness): "Yes, the desktop is dead, but what about air traffic control, stock trading, oil analysis, risk management applications? In fact, what about any back office application that needs to be usable across all operating systems? Here there is no concern whatsoever with 100% accessibility which is, after all, the only thing that the web has over the desktop, (except when there's a network failure, of course, or when you find yourself in the 3/4 of the world where there's bandwidth problems)? There are 1000's of hidden applications out there that have processing requirements, security requirements, and the requirement that they'll be available even when the network is down or even completely unavailable. Isn't that a valid use case and aren't there 1000's of applications that fall into this so-called niche category? Are you not, in fact, confusing consumer applications, which are increasingly web-based and mobile-based, with high-end corporate applications, which typically need to do massive processing, of one kind or another, for which the web and mobile worlds are completely unsuited?" And you will not believe what the reply to the above question was. (Again, I have a witness to this discussion.) But here it is: "Yes. But those applications are not interesting. I do not want to spend any of my time or work in any way on those applications. They are boring." I'm sad to say that the leaders of the software development community, including those in the Java world, either share the above opinion or are led by it. Because they find something that is not new to be boring, they move on to what is interesting and start talking like the supposedly-boring developments don't even exist. (Kind of like a rapper pretending classical music doesn't exist.) Time and time again I find myself giving Java desktop development courses (at companies, i.e., not hobbyists, or students, but companies, i.e., the places where dollars are earned), where developers say to me: "The course you're giving about creating cross-platform, loosely coupled, and highly cohesive applications is really useful to us. Why do we never find information about this topic at conferences? Why can we never attend a session at a conference where the story about pluggable cross-platform Java is told? Why do we get the impression that we are uncool because we're not on the web and because we're not on a mobile phone, while the reason for that is because we're creating $1000,000 simulation software which has nothing to gain from being on the web or on the mobile phone?" And then I say: "Because nobody knows you exist. Because you're not submitting abstracts to conferences about your very interesting use cases. And because conferences tend to focus on what is new, which tends to be web related (especially HTML 5) or mobile related (especially Android). Because you're not taking the responsibility on yourself to tell the real stories about the real applications being developed all the time and every day. Because you yourself think your work is boring, while in fact it is fascinating. Because desktop developers are working from 9 to 5 on the desktop, in secure environments, such as banks and defense, where you can't spend time, nor have the interest in, blogging your latest tip or trick, as opposed to web developers, who tend to spend a lot of time on the web anyway and are therefore much more inclined to create buzz about the kind of work they're doing." So, next time you look at a conference program and wonder why there's no stories about large desktop development projects in the program, here's the short answer: "No one is going to put those items on the program until you start submitting those kinds of sessions. And until you start blogging. Until you start creating the buzz that the web developers have been creating around their work for the past 10 years or so. And, yes, indeed, programmers get the conference they deserve." And what about Tim Bray? Ask yourself, as Google's lead web technology evangelist, how many desktop developers do you think he talks to and, more generally, what his frame of reference is and what, clearly, he considers to be most interesting.

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• ADF Business Components

  - by Arda Eralp

  ADF Business Components and JDeveloper simplify the development, delivery, and customization of business applications for the Java EE platform. With ADF Business Components, developers aren't required to write the application infrastructure code required by the typical Java EE application to: Connect to the database Retrieve data Lock database records Manage transactions   ADF Business Components addresses these tasks through its library of reusable software components and through the supporting design time facilities in JDeveloper. Most importantly, developers save time using ADF Business Components since the JDeveloper design time makes typical development tasks entirely declarative. In particular, JDeveloper supports declarative development with ADF Business Components to: Author and test business logic in components which automatically integrate with databases Reuse business logic through multiple SQL-based views of data, supporting different application tasks Access and update the views from browser, desktop, mobile, and web service clients Customize application functionality in layers without requiring modification of the delivered application The goal of ADF Business Components is to make the business services developer more productive.   ADF Business Components provides a foundation of Java classes that allow your business-tier application components to leverage the functionality provided in the following areas: Simplifying Data Access Design a data model for client displays, including only necessary data Include master-detail hierarchies of any complexity as part of the data model Implement end-user Query-by-Example data filtering without code Automatically coordinate data model changes with business services layer Automatically validate and save any changes to the database   Enforcing Business Domain Validation and Business Logic Declaratively enforce required fields, primary key uniqueness, data precision-scale, and foreign key references Easily capture and enforce both simple and complex business rules, programmatically or declaratively, with multilevel validation support Navigate relationships between business domain objects and enforce constraints related to compound components   Supporting Sophisticated UIs with Multipage Units of Work Automatically reflect changes made by business service application logic in the user interface Retrieve reference information from related tables, and automatically maintain the information when the user changes foreign-key values Simplify multistep web-based business transactions with automatic web-tier state management Handle images, video, sound, and documents without having to use code Synchronize pending data changes across multiple views of data Consistently apply prompts, tooltips, format masks, and error messages in any application Define custom metadata for any business components to support metadata-driven user interface or application functionality Add dynamic attributes at runtime to simplify per-row state management   Implementing High-Performance Service-Oriented Architecture Support highly functional web service interfaces for business integration without writing code Enforce best-practice interface-based programming style Simplify application security with automatic JAAS integration and audit maintenance "Write once, run anywhere": use the same business service as plain Java class, EJB session bean, or web service   Streamlining Application Customization Extend component functionality after delivery without modifying source code Globally substitute delivered components with extended ones without modifying the application   ADF Business Components implements the business service through the following set of cooperating components: Entity object An entity object represents a row in a database table and simplifies modifying its data by handling all data manipulation language (DML) operations for you. These are basically your 1 to 1 representation of a database table. Each table in the database will have 1 and only 1 EO. The EO contains the mapping between columns and attributes. EO's also contain the business logic and validation. These are you core data services. They are responsible for updating, inserting and deleting records. The Attributes tab displays the actual mapping between attributes and columns, the mapping has following fields: Name : contains the name of the attribute we expose in our data model. Type : defines the data type of the attribute in our application. Column : specifies the column to which we want to map the attribute with Column Type : contains the type of the column in the database   View object A view object represents a SQL query. You use the full power of the familiar SQL language to join, filter, sort, and aggregate data into exactly the shape required by the end-user task. The attributes in the View Objects are actually coming from the Entity Object. In the end the VO will generate a query but you basically build a VO by selecting which EO need to participate in the VO and which attributes of those EO you want to use. That's why you have the Entity Usage column so you can see the relation between VO and EO. In the query tab you can clearly see the query that will be generated for the VO. At this stage we don't need it and just use it for information purpose. In later stages we might use it. Application module An application module is the controller of your data layer. It is responsible for keeping hold of the transaction. It exposes the data model to the view layer. You expose the VO's through the Application Module. This is the abstraction of your data layer which you want to show to the outside word.It defines an updatable data model and top-level procedures and functions (called service methods) related to a logical unit of work related to an end-user task. While the base components handle all the common cases through built-in behavior, customization is always possible and the default behavior provided by the base components can be easily overridden or augmented. When you create EO's, a foreign key will be translated into an association in our model. It defines the type of relation and who is the master and child as well as how the visibility of the association looks like. A similar concept exists to identify relations between view objects. These are called view links. These are almost identical as association except that a view link is based upon attributes defined in the view object. It can also be based upon an association. Here's a short summary: Entity Objects: representations of tables Association: Relations between EO's. Representations of foreign keys View Objects: Logical model View Links: Relationships between view objects Application Model: interface to your application  

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• "Guiding" a Domain Expert to Retire from Programming

  - by James Kolpack

  I've got a friend who does IT at a local non-profit where they're using a custom web application which is no longer supported by the company who built it. (out of business, support was too expensive, I'm not sure...) Development on this app started around 10+ years ago so the technologies being harnessed are pretty out of date now - classic asp using vbscript and SQL Server 2000. The application domain is in the realm of government bookkeeping - so even though the development team is long gone, there are often new requirements of this software. Enter the... The domain expert. This is an middle aged accounting whiz without much (or any?) prior development experience. He studied the pages, code and queries and learned how to ape the style of the original team which, believe me, is mediocre at best. He's very clever and very tenacious but has no experience in software beyond what he's picked up from this app. Otherwise, he's a pleasant guy to talk to and definitely knows his domain. My friend in IT, and probably his superiors in the company, want him out of the code. They view him as wasting his expertise on coding tasks he shouldn't be doing. My friend got me involved with a few small contracts which I handled without much problem - other than somewhat of a communication barrier with the domain expert. He explained the requirements very quickly, assuming prior knowledge of the domain which I do not have. This is partially his normal style, and I think maybe a bit of resentment from my involvement. So, I think he feels like the owner of the code and has entrenched himself in a development position. So... his coding technique. One of his latest endeavors was to make a page that only he could reach (theoretically - the security model for the system is wretched) where he can enter a raw SQL query, run it, and save the query to run again later. A report that I worked on had been originally implemented by him using 6 distinct queries, 3 or 4 temp tables to coordinate the data between the queries, and the final result obtained by importing the data from the final query into Access and doing a pivot and some formatting. It worked - well, some of the results were incorrect - but at what a cost! (I implemented the report in a single query with at least 1/10th the amount of code.) He edits code in notepad. He doesn't seem to know about online reference material for the languages. I recently read an article on Dr. Dobbs titled "What Makes Bad Programmers Different" - and instantly thought of our domain expert. From the article: Their code is large, messy, and bug laden. They have very superficial knowledge of their problem domain and their tools. Their code has a lot of copy/paste and they have very little interest in techniques that reduce it. The fail to account for edge cases, while inefficiently dealing with the general case. They never have time to comment their code or break it into smaller pieces. Empirical evidence plays no little role in their decisions. 5.5 out of 6. My friend is wanting me to argue the case to their management - specifically, I got this email from their manager to respond to: ...Also, I need to talk to you about what effect there is from Domain Expert continuing to make edits to the live environment. If that is a problem for you I need to know so I can have his access blocked. Some examples would help. In my opinion, from a technical standpoint, it's dangerous to have him making changes without any oversight. On the other hand, I'm just doing one-off contracts at this point and don't have much desire to get involved deeply enough that I'm essentially arguing as one of the Bobs from Office Space. I'd like to help my friend out - but I feel like I'm getting in the middle of a political battle. More importantly - if I do get involved and suggest that his editing privileges be removed, it needs to be handled carefully so that doesn't feel belittled. He is beyond a doubt the foremost expert on this system. I'm hoping this is familiar territory for some other stackechangers, because I'm feeling a little bewildered. How should I respond? Should I argue that he shouldn't be allowed to touch the code? Should I phrase it as "no single developer, no matter how experienced, should be working on production code unchecked"? Should I argue to keep him involved with the code, but with a review process? Should I say "glad I could help, but uh, I'm busy now!" Other options? Thanks a bunch!

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• Extending Expression Blend 4 &amp; Blend for Visual Studio 2012

  - by Chris Skardon

  Just getting this off the bat, I presume this will also work for Blend 5, but I can’t confirm it… Anyhews, I imagine you’re here because you want to know how to create an addin for Blend, so let’s jump right in there! First, and foremost, we’re going to need to ensure our development environment has the right setup, so the checklist: Visual Studio 2012 Blend for Visual Studio 2012 OK, let’s create a new project (class library, .NET 4.5): Hello.Extension The ‘.Extension’ bit is very very important. The addin will not work unless it is named in this way. You can put whatever you want at the front, but it has to have the extension bit. OK, so now we have a solution with one project. To this project we need to add references to the following things: Microsoft.Expression.Extensibility (from c:\program files\Microsoft Visual Studio 11.0\Blend\   -- x86 folder if you are on an x64 windows install) Microsoft.Expression.Framework (same location as above) PresentationCore PresentationFramework WindowsBase System.ComponentModel.Composition Got them? ACE. Let’s now add a project to contain our control, so, create a new WPF Application project, cunningly named something like ‘Hello.Control’… (I’m creating a WPF application here, because I’m too lazy to dig up the correct references, and this will add all the ones I need ) Once that is created, delete the App.xaml and MainWindow.xaml files, we won’t be needing them. You will also need to change the properties of the project itself, so it is only a class library. Once that is done, let’s add a new UserControl, which will be this: <UserControl x:Class="Hello.Control.HelloControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300"> <Grid> <TextBlock Text="HELLO!!!"/> </Grid> </UserControl> Impressive eh? Now, let’s reference the WPF project from the Extension library. All that’s left now is to code up our extension… So, add a class to the Extension project (name wise doesn’t matter), and make it implement the IPackage interface from the Microsoft.Expression.Extensibility library: public class HelloExtension : IPackage { /**/ } We’ll implement the two methods we need to: public class HelloExtension : IPackage { public void Load(IServices services) { } public void Unload() { } } We’re only really concerned about the Load method in this case, as let’s face it, the extension we have doesn’t need to do a lot to bog off. The interesting thing about the Load method is that it receives an IServices instance. This allows us to get access to all the services that Expression provides, in this case we’re interested in one in particular, the ‘IWindowService’ So, let’s get that bad boy… private IWindowService _windowService; public void Load(IServices services) { _windowService = services.GetService<IWindowService>(); } Nailed it… But why? The WindowService allows us to register our UserControl with Blend, which in turn allows people to activate and see it, which is a big plus point. So, let’s do that… We’ll create an ‘Initialize’ method to create our new control, and add it to the WindowService: private HelloControl _helloControl; public void Initialize() { _helloControl = new HelloControl(); if (_windowService.PaletteRegistry["HelloPanel"] == null) _windowService.RegisterPalette("HelloPanel", _helloControl, "Hello Window"); } First we check that we’re not already registered, and if we’re not we register, the first argument is the identifier used by the service to, well, identify your extension. The second argument is the actual control, the third argument is the name that people will see in the ‘Windows’ menu of Blend itself (so important note here – don’t put anything embarrassing or (need I say it?) sweary…) There are only two things to do now - Call ‘Initialize()’ from our Load method, and Export the class This is easy money – add [Export(typeof(IPackage))] to the top of our class… The full code will (should) look like this: [Export(typeof (IPackage))] public class HelloExtension : IPackage { private HelloControl _helloControl; private IWindowService _windowService; public void Load(IServices services) { _windowService = services.GetService<IWindowService>(); Initialize(); } public void Unload() { } public void Initialize() { _helloControl = new HelloControl(); if (_windowService.PaletteRegistry["HelloControl"] == null) _windowService.RegisterPalette("HelloControl", _helloControl, "Hello Window"); } } If you build this and copy it to your ‘Extensions’ folder in Blend (c:\program files\microsoft visual studio 11.0\blend\) and start Blend, you should see ‘Hello Window’ listed in the Window menu: That as they say is it!

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• Context is Everything

  - by Angus Graham

  Normal 0 false false false EN-CA X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Context is Everything How many times have you have you asked a question only to hear an answer like “Well, it depends. What exactly are you trying to do?”.  There are times that raw information can’t tell us what we need to know without putting it in a larger context. Let's take a real world example.  If I'm a maintenance planner trying to figure out which assets should be replaced during my next maintenance window, I'm going to go to my Asset Management System.  I can get it to spit out a list of assets that have failed several times over the last year.  But what are these assets connected to?  Is there any safety consequences to shutting off this pipeline to do the work?  Is some other work that's planned going to conflict with replacing this asset?  Several of these questions can't be answered by simply spitting out a list of asset IDs.  The maintenance planner will have to reference a diagram of the plant to answer several of these questions. This is precisely the idea behind Augmented Business Visualization. An Augmented Business Visualization (ABV) solution is one where your structured data (enterprise application data) and your unstructured data (documents, contracts, floor plans, designs, etc.) come together to allow you to make better decisions.  Essentially we're showing your business data into its context. AutoVue allows you to create ABV solutions by integrating your enterprise application with AutoVue’s hotspot framework. Hotspots can be defined for your document. Users can click these hotspots to trigger actions in your enterprise app. Similarly, the enterprise app can highlight the hotspots in your document based on its business data, creating a visual dashboard of your business data in the context of your document. ABV is not new. We introduced the hotspot framework in AutoVue 20.1 with text hotspots. Any text in a PDF or 2D CAD drawing could be turned into a hotspot. In 20.2 we have enhanced this to include 2 new types of hotspots: 3D and regional hotspots. 3D hotspots allow you to turn 3D parts into hotspots. Hotspots can be defined based on the attributes of the part, so you can create hotspots based on part numbers, material, date of delivery, etc.  Regional hotspots allow an administrator to define rectangular regions on any PDF, image, or 2D CAD drawing. This is perfect for cases where the document you’re using either doesn’t have text in it (a JPG or TIFF for example) or if you want to define hotspots that don’t correspond to the text in the document. There are lots of possible uses for AutoVue hotspots.  A great demonstration of how our hotspot capabilities can help add context to enterprise data in the Energy sector can be found in the following AutoVue movies: Maintenance Planning in the Energy Sector - Watch it Now Capital Construction Project Management in the Energy Sector  -  Watch it Now Commissioning and Handover Process for the Energy Sector  -  Watch it Now

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• iOS Support with Windows Azure Mobile Services – now with Push Notifications

  - by ScottGu

  A few weeks ago I posted about a number of improvements to Windows Azure Mobile Services. One of these was the addition of an Objective-C client SDK that allows iOS developers to easily use Mobile Services for data and authentication.  Today I'm excited to announce a number of improvement to our iOS SDK and, most significantly, our new support for Push Notifications via APNS (Apple Push Notification Services).  This makes it incredibly easy to fire push notifications to your iOS users from Windows Azure Mobile Service scripts. Push Notifications via APNS We've provided two complete tutorials that take you step-by-step through the provisioning and setup process to enable your Windows Azure Mobile Service application with APNS (Apple Push Notification Services), including all of the steps required to configure your application for push in the Apple iOS provisioning portal: Getting started with Push Notifications - iOS Push notifications to users by using Mobile Services - iOS Once you've configured your application in the Apple iOS provisioning portal and uploaded the APNS push certificate to the Apple provisioning portal, it's just a matter of uploading your APNS push certificate to Mobile Services using the Windows Azure admin portal: Clicking the “upload” within the “Push” tab of your Mobile Service allows you to browse your local file-system and locate/upload your exported certificate.  As part of this you can also select whether you want to use the sandbox (dev) or production (prod) Apple service: Now, the code to send a push notification to your clients from within a Windows Azure Mobile Service is as easy as the code below: push.apns.send(deviceToken, {      alert: 'Toast: A new Mobile Services task.',      sound: 'default' }); This will cause Windows Azure Mobile Services to connect to APNS (Apple Push Notification Service) and send a notification to the iOS device you specified via the deviceToken: Check out our reference documentation for full details on how to use the new Windows Azure Mobile Services apns object to send your push notifications. Feedback Scripts An important part of working with any PNS (Push Notification Service) is handling feedback for expired device tokens and channels. This typically happens when your application is uninstalled from a particular device and can no longer receive your notifications. With Windows Notification Services you get an instant response from the HTTP server.  Apple’s Notification Services works in a slightly different way and provides an additional endpoint you can connect to poll for a list of expired tokens. As with all of the capabilities we integrate with Mobile Services, our goal is to allow developers to focus more on building their app and less on building infrastructure to support their ideas. Therefore we knew we had to provide a simple way for developers to integrate feedback from APNS on a regular basis.  This week’s update now includes a new screen in the portal that allows you to optionally provide a script to process your APNS feedback – and it will be executed by Mobile Services on an ongoing basis: This script is invoked periodically while your service is active. To poll the feedback endpoint you can simply call the apns object's getFeedback method from within this script: push.apns.getFeedback({       success: function(results) {           // results is an array of objects with a deviceToken and time properties      } }); This returns you a list of invalid tokens that can now be removed from your database. iOS Client SDK improvements Over the last month we've continued to work with a number of iOS advisors to make improvements to our Objective-C SDK. The SDK is being developed under an open source license (Apache 2.0) and is available on github. Many of the improvements are behind the scenes to improve performance and memory usage. However, one of the biggest improvements to our iOS Client API is the addition of an even easier login method.  Below is the Objective-C code you can now write to invoke it: [client loginWithProvider:@"twitter"                     onController:self                        animated:YES                      completion:^(MSUser *user, NSError *error) {      // if no error, you are now logged in via twitter }]; This code will automatically present and dismiss our login view controller as a modal dialog on the specified controller.  This does all the hard work for you and makes login via Twitter, Google, Facebook and Microsoft Account identities just a single line of code. My colleague Josh just posted a short video demonstrating these new features which I'd recommend checking out: Summary The above features are all now live in production and are available to use immediately.  If you don’t already have a Windows Azure account, you can sign-up for a free trial and start using Mobile Services today. Visit the Windows Azure Mobile Developer Center to learn more about how to build apps with Mobile Services. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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• Pirates, Treasure Chests and Architectural Mapping

  Pirate 1: Why do pirates create treasure maps? Pirate 2: I do not know.Pirate 1: So they can find their gold. Yes, that was a bad joke, but it does illustrate a point. Pirates are known for drawing treasure maps to their most prized possession. These documents detail the decisions pirates made in order to hide and find their chests of gold. The map allows them to trace the steps they took originally to hide their treasure so that they may return. As software engineers, programmers, and architects we need to treat software implementations much like our treasure chest. Why is software like a treasure chest? It cost money, time,  and resources to develop (Usually) It can make or save money, time, and resources (Hopefully) If we operate under the assumption that software is like a treasure chest then wouldn’t make sense to document the steps, rationale, concerns, and decisions about how it was designed? Pirates are notorious for documenting where they hide their treasure.  Shouldn’t we as creators of software do the same? By documenting our design decisions and rationale behind them will help others be able to understand and maintain implemented systems. This can only be done if the design decisions are correctly mapped to its corresponding implementation. This allows for architectural decisions to be traced from the conceptual model, architectural design and finally to the implementation. Mapping gives software professional a method to trace the reason why specific areas of code were developed verses other options. Just like the pirates we need to able to trace our steps from the start of a project to its implementation,  so that we will understand why specific choices were chosen. The traceability of a software implementation that actually maps back to its originating design decisions is invaluable for ensuring that architectural drifting and erosion does not take place. The drifting and erosion is prevented by allowing others to understand the rational of why an implementation was created in a specific manor or methodology The process of mapping distinct design concerns/decisions to the location of its implemented is called traceability. In this context traceability is defined as method for connecting distinctive software artifacts. This process allows architectural design models and decisions to be directly connected with its physical implementation. The process of mapping architectural design concerns to a software implementation can be very complex. However, most design decision can be placed in  a few generalized categories. Commonly Mapped Design Decisions Design Rationale Components and Connectors Interfaces Behaviors/Properties Design rational is one of the hardest categories to map directly to an implementation. Typically this rational is mapped or document in code via comments. These comments consist of general design decisions and reasoning because they do not directly refer to a specific part of an application. They typically focus more on the higher level concerns. Components and connectors can directly be mapped to architectural concerns. Typically concerns subdivide an application in to distinct functional areas. These functional areas then can map directly back to their originating concerns.Interfaces can be mapped back to design concerns in one of two ways. Interfaces that pertain to specific function definitions can be directly mapped back to its originating concern(s). However, more complicated interfaces require additional analysis to ensure that the proper mappings are created. Depending on the complexity some Behaviors\Properties can be translated directly into a generic implementation structure that is ready for business logic. In addition, some behaviors can be translated directly in to an actual implementation depending on the complexity and architectural tools used. Mapping design concerns to an implementation is a lot of work to maintain, but is doable. In order to ensure that concerns are mapped correctly and that an implementation correctly reflects its design concerns then one of two standard approaches are usually used. All Changes Come From ArchitectureBy forcing all application changes to come through the architectural model prior to implementation then the existing mappings will be used to locate where in the implementation changes need to occur. Allow Changes From Implementation Or Architecture By allowing changes to come from the implementation and/or the architecture then the other area must be kept in sync. This methodology is more complex compared to the previous approach.  One reason to justify the added complexity for an application is due to the fact that this approach tends to detect and prevent architectural drift and erosion. Additionally, this approach is usually maintained via software because of the complexity. Reference:Taylor, R. N., Medvidovic, N., & Dashofy, E. M. (2009). Software architecture: Foundations, theory, and practice Hoboken, NJ: John Wiley & Sons  

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• Styling ASP.NET MVC Error Messages

  - by MightyZot

  Originally posted on: http://geekswithblogs.net/MightyZot/archive/2013/11/11/styling-asp.net-mvc-error-messages.aspxOff the cuff, it may look like you’re stuck with the presentation of your error messages (model errors) in ASP.NET MVC. That’s not the case, though. You actually have quite a number of options with regard to styling those boogers. Like many of the helpers in MVC, the Html.ValidationMessageFor helper has multiple prototypes. One of those prototypes lets you pass a dictionary, or anonymous object, representing attribute values for the resulting markup. @Html.ValidationMessageFor( m => Model.Whatever, null, new { @class = “my-error” }) By passing the htmlAttributes parameter, which is the last parameter in the call to the prototype of Html.ValidationMessageFor shown above, I can style the resulting markup by associating styles to the my-error css class.  When you run your MVC project and view the source, you’ll notice that MVC adds the class field-validation-valid or field-validation-error to a span created by the helper. You could actually just style those classes instead of adding your own…it’s really up to you. Now, what if you wanted to move that error message around? Maybe you want to put that error message in a box or a callout. How do you do that? When I first started using MVC, it didn’t occur to me that the Html.ValidationMessageFor helper just spits out a little bit of markup. I wanted to put the error messages in boxes with white backgrounds, our site originally had a black background, and show a little nib on the side to make them look like callouts or conversation bubbles. Not realizing how much freedom there is in the styling and markup, and after reading someone else’s post, I created my own version of the ValidationMessageFor helper that took out the span and replaced it with divs. I styled the divs to produce the effect of a popup box and had a lot of trouble with sizing and such. That’s a really silly and unnecessary way to solve this problem. If you want to move your error messages around, all you have to do is move the helper. MVC doesn’t appear to care where you put it, which makes total sense when you think about it. Html.ValidationMessageFor is just spitting out a little markup using a little bit of reflection on the name you’re passing it. All you’ve got to do to style it the way you want it is to put it in whatever markup you desire. Take a look at this, for example… <div class=”my-anchor”>@Html.ValidationMessageFor( m => Model.Whatever )</div> @Html.TextBoxFor(m => Model.Whatever) Now, given that bit of HTML, consider the following CSS… <style> .my-anchor { position:relative; } .field-validation-error {    background-color:white;    border-radius:4px;    border: solid 1px #333;    display: block;    position: absolute;    top:0; right:0; left:0;    text-align:right; } </style> The my-anchor class establishes an anchor for the absolutely positioned error message. Now you can move the error message wherever you want it relative to the anchor. Using css3, there are some other tricks. For example, you can use the :not(:empty) selector to select the span and apply styles based upon whether or not the span has text in it. Keep it simple, though. Moving your elements around using absolute positioning may cause you issues on devices with screens smaller than your standard laptop or PC. While looking for something else recently, I saw someone asking how to style the output for Html.ValidationSummary.  Html.ValidationSummery is the helper that will spit out a list of property errors, general model errors, or both. Html.ValidationSummary spits out fairly simple markup as well, so you can use the techniques described above with it also. The resulting markup is a <ul><li></li></ul> unordered list of error messages that carries the class validation-summary-errors In the forum question, the user was asking how to hide the error summary when there are no errors. Their errors were in a red box and they didn’t want to show an empty red box when there aren’t any errors. Obviously, you can use the css3 selectors to apply different styles to the list when it’s empty and when it’s not empty; however, that’s not support in all browsers. Well, it just so happens that the unordered list carries the style validation-summary-valid when the list is empty. While the div rendered by the Html.ValidationSummary helper renders a visible div, containing one invisible listitem, you can always just style the whole div with “display:none” when the validation-summary-valid class is applied and make it visible when the validation-summary-errors class is applied. Or, if you don’t like that solution, which I like quite well, you can also check the model state for errors with something like this… int errors = ViewData.ModelState.Sum(ms => ms.Value.Errors.Count); That’ll give you a count of the errors that have been added to ModelState. You can check that and conditionally include markup in your page if you want to. The choice is yours. Obviously, doing most everything you can with styles increases the flexibility of the presentation of your solution, so I recommend going that route when you can. That picture of the fat guy jumping has nothing to do with the article. That’s just a picture of me on the roof and I thought it was funny. Doesn’t every post need a picture?

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