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• Visual Web Developer 2008 Express and XHTML 1.1 (not applying)

  - by Mike Valeriano

  Hello. I may be missing something since I'm not used to work with IDEs for web development, so please understand if I'm doing something stupid. I've picked a copy of Beginning ASP.NET 3.5 in C# and VB to try and learn this thing quickly. I'm no HTML guru, but I know something about the DTDs and I want to either use XHTML 1.0 Strict or XHTML 1.1 while learning the ins and outs of ASP.NET. Following the book (just started actually), I'm not having any trouble understanding the concepts, since I have a C# background, but what I don't understand is how VWD goes about applying the schema you select for validation. The book explains that the drop-down list on the toolbar is enough to set this, so that's what I did: I've selected XHTML 1.1 (since there is no 1.0 strict option, what I find really odd) and then started the project. The thing is that the code generated automatically for the Default page had the XHTML 1.0 transitional DTD. Every other page added had the same DTD, even though XHTML 1.1 is still the selected schema in the drop-down list. I decided to test it out and there it was: inserting some text in the design view and then applying a bold formatting just inserted < b tags on the code. Changing color does add a span tag with added CSS though. What I want to know is: if I want strict XHTML (or 1.1) should I just code it manually? Or is there a "fix" for this problem (having a schema selected but not applied by the IDE)? Am I missing something really easy and dumb? I have no problem with coding it manually - I actually prefer doing that. The thing is that I really wanna try this WYSIWYG approach for once, since some developers swear by it. Plus I don't know yet if I'll need special tags for ASP.NET, so I think having them inserted automatically should be the best practice. I couldn't find any similar problems around (MSDN, Google, here), and as far as the book goes (up to the point I've read), this is the expected VWD behavior, which I find suspect at least. Sorry for the long text (and poor English - not my primary language). Thanks in advance for any help/tips.

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• .NET SerialPort DataReceived event thread interference with main thread

  - by Kiran

  I am writing a serial communication program using the SerialPort class in C# to interact with a strip machine connected via a RS232 cable. When i send the command to the machine it responds with some bytes depending on the command. Like when i send a "\D" command, i am expecting to download the machine program data of 180 bytes as a continous string. As per the machine's manual, it suggests as a best practice to send an unreognized characters like comma (,) character to make sure the machine is initialized before sending the first command in the cycle. My serial communication code is as follows: public class SerialHelper { SerialPort commPort = null; string currentReceived = string.Empty; string receivedStr = string.Empty; private bool CommInitialized() { try { commPort = new SerialPort(); commPort.PortName = "COM1"; if (!commPort.IsOpen) commPort.Open(); commPort.BaudRate = 9600; commPort.Parity = System.IO.Ports.Parity.None; commPort.StopBits = StopBits.One; commPort.DataBits = 8; commPort.RtsEnable = true; commPort.DtrEnable = true; commPort.DataReceived += new SerialDataReceivedEventHandler(commPort_DataReceived); return true; } catch (Exception ex) { return false; } } void commPort_DataReceived(object sender, SerialDataReceivedEventArgs e) { SerialPort currentPort = (SerialPort)sender; currentReceived = currentPort.ReadExisting(); receivedStr += currentReceived; } internal int CommIO(string outString, int outLen, ref string inBuffer, int inLen) { receivedStr = string.Empty; inBuffer = string.Empty; if (CommInitialized()) { commPort.Write(outString); } System.Threading.Thread.Sleep(1500); int i = 0; while ((receivedStr.Length < inLen) && i < 10) { System.Threading.Thread.Sleep(500); i += 1; } if (!string.IsNullOrEmpty(receivedStr)) { inBuffer = receivedStr; } commPort.Close(); return inBuffer.Length; } } I am calling this code from a windows form as follows: len = SerialHelperObj.CommIO(",",1,ref inBuffer, 4) len = SerialHelperObj.CommIO(",",1,ref inBuffer, 4) If(inBuffer == "!?*O") { len = SerialHelperObj.CommIO("\D",2,ref inBuffer, 180) } A valid return value from the serial port looks like this: \D00000010000000000010 550 3250 0000256000 and so on ... I am getting some thing like this: \D00000010D,, 000 550 D,, and so on... I feel that my comm calls are getting interferred with the one when i send commands. But i am trying to make sure the result of the comma command then initiating the actual command. but the received thread is inserting the bytes from the previous communication cycle. Can any one please shed some light into this...? I lost quite some hair just trying to get this work. I am not sure where i am doing wrong

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• Does my fat-client application belong in the MVC pattern?

  - by boatingcow

  The web-based application I’m currently working on is growing arms and legs! It’s basically an administration system which helps users to keep track of bookings, user accounts, invoicing etc. It can also be accessed via a couple of different websites using a fairly crude API. The fat-client design loosely follows the MVC pattern (or perhaps MVP) with a php/MySQL backend, Front Controller, several dissimilar Page Controllers, a liberal smattering of object-oriented and procedural Models, a confusing bunch of Views and templates, some JavaScripts, CSS files and Flash objects. The programmer in me is a big fan of the principle of “Separation of Concerns” and on that note, I’m currently trying to figure out the best way to separate and combine the various concerns as the project grows and more people contribute to it. The problem we’re facing is that although JavaScript (or Flash with ActionScript) is normally written with the template, hence part of the View and decoupled from the Controller and Model, we find that it actually encompasses the entire MVC pattern... Swap an image with an onmouseover event - that’s Behaviour. Render a datagrid - we’re manipulating the View. Send the result of reordering a list via AJAX - now we’re in Control. Check a form field to see if an email address is in a valid format - we’re consulting the Model. Is it wise to let the database people write up the validation Model with jQuery? Can the php programmers write the necessary Control structures in JavaScript? Can the web designers really write a functional AJAX form for their View? Should there be a JavaScript overlord for every project? If the MVC pattern could be applied to the people instead of the code, we would end up with this: Model - the database boffins - “SELECT * FROM mind WHERE interested IS NULL” Control - pesky programmers - “class Something extends NothingAbstractClass{…}” View - traditionally the domain of the graphic/web designer - “” …and a new layer: Behaviour - interaction and feedback designer - “CSS3 is the new black…” So, we’re refactoring and I’d like to stick to best practice design, but I’m not sure how to proceed. I don’t want to reinvent the wheel, so would anyone have any hints or tips as to what pattern I should be looking at or any code samples from someone who’s already done the dirty work? As the programmer guy, how can I rewrite the app for backend and front end whilst keeping the two separate? And before you ask, yes I’ve looked at Zend, CodeIgnitor, Symfony, etc., and no, they don’t seem to cross the boundary between server logic and client logic!

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• NHibernate, transactions and TransactionScope

  - by Erik

  I'm trying to find the best solution to handle transaction in a web application that uses NHibernate. We use a IHttpModule and at HttpApplication.BeginRequest we open a new session and we bind it to the HttpContext with ManagedWebSessionContext.Bind(context, session); We close and unbind the session on HttpApplication.EndRequest. In our Repository base class, we always wrapped a transaction around our SaveOrUpdate, Delete, Get methods like, according to best practice: public virtual void Save(T entity) { var session = DependencyManager.Resolve<ISession>(); using (var transaction = session.BeginTransaction()) { session.SaveOrUpdate(entity); transaction.Commit(); } } But then this doesn't work, if you need to put a transaction somewhere in e.g. a Application service to include several repository calls to Save, Delete, etc.. So what we tried is to use TransactionScope (I didn't want to write my own transactionmanager). To test that this worked, I use an outer TransactionScope that doesn't call .Complete() to force a rollback: Repository Save(): public virtual void Save(T entity) { using (TransactionScope scope = new TransactionScope()) { var session = Depe.ndencyManager.Resolve<ISession>(); session.SaveOrUpdate(entity); scope.Complete(); } } The block that uses the repository: TestEntity testEntity = new TestEntity { Text = "Test1" }; ITestRepository testRepository = DependencyManager.Resolve<ITestRepository>(); testRepository.Save(testEntity); using (var scope = new TransactionScope()) { TestEntity entityToChange = testRepository.GetById(testEntity.Id); entityToChange.Text = "TestChanged"; testRepository.Save(entityToChange); } TestEntity entityChanged = testRepository.GetById(testEntity.Id); Assert.That(entityChanged.Text, Is.EqualTo("Test1")); This doesn't work. But to me if NHibernate supports TransactionScope it would! What happens is that there is no ROLLBACK at all in the database but when the testRepository.GetById(testEntity.Id); statement is executed a UPDATE with SET Text = "TestCahgned" is fired instead (It should have been fired between BEGIN TRAN and ROLLBACK TRAN). NHibernate reads the value from the level1 cache and fires a UPDATE to the database. Not expected behaviour!? From what I understand whenever a rollback is done in the scope of NHibernate you also need to close and unbind the current session. My question is: Does anyone know of a good way to do this using TransactionScope and ManagedWebSessionContext?

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• Wiki-fying a text using LPeg

  - by Stigma

  Long story coming up, but I'll try to keep it brief. I have many pure-text paragraphs which I extract from a system and re-output in wiki format so that the copying of said data is not such an arduous task. This all goes really well, except that there are no automatic references being generated for the 'topics' we have pages for, which end up needing to be added by reading through all the text and adding it in manually by changing Topic to [[Topic]]. First requirement: each topic is only to be made clickable once, which is the first occurrence. Otherwise, it would become a really spammy linkfest, which would detract from readability. To avoid issues with topics that start with the same words Second requirement: overlapping topic names should be handled in such a way that the most 'precise' topic gets the link, and in later occurrences, the less precise topics do not get linked, since they're likely not correct. Example: topics = { "Project", "Mary", "Mr. Moore", "Project Omega"} input = "Mary and Mr. Moore work together on Project Omega. Mr. Moore hates both Mary and Project Omega, but Mary simply loves the Project." output = function_to_be_written(input) -- "[[Mary]] and [[Mr. Moore]] work together on [[Project Omega]]. Mr. Moore hates both Mary and Project Omega, but Mary simply loves the [[Project]]." Now, I quickly figured out a simple or complicated string.gsub() could not get me what I need to satisfy the second requirement, as it provides no way to say 'Consider this match as if it did not happen - I want you to backtrack further'. I need the engine to do something akin to: input = "abc def ghi" -- Looping over the input would, in this order, match the following strings: -- 1) abc def ghi -- 2) abc def -- 3) abc -- 4) def ghi -- 5) def -- 6) ghi Once a string matches an actual topic and has not been replaced before by its wikified version, it is replaced. If this topic has been replaced by a wikified version before, don't replace, but simply continue the matching at the end of the topic. (So for a topic "abc def", it would test "ghi" next in both cases.) Thus I arrive at LPeg. I have read up on it, played with it, but it is considerably complex, and while I think I need to use lpeg.Cmt and lpeg.Cs somehow, I am unable to mix the two properly to make what I want to do work. I am refraining from posting my practice attempts as they are of miserable quality and probably more likely to confuse anyone than assist in clarifying my problem. (Why do I want to use a PEG instead of writing a triple-nested loop myself? Because I don't want to, and it is a great excuse to learn PEGs.. except that I am in over my head a bit. Unless it is not possible with LPeg, the first is not an option.)

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• Windows Service HTTPListener Memory Issue

  - by crawshaws

  Hi all, Im a complete novice to the "best practices" etc of writing in any code. I tend to just write it an if it works, why fix it. Well, this way of working is landing me in some hot water. I am writing a simple windows service to server a single webpage. (This service will be incorperated in to another project which monitors the services and some folders on a group of servers.) My problem is that whenever a request is recieved, the memory usage jumps up by a few K per request and keeps qoing up on every request. Now ive found that by putting GC.Collect in the mix it stops at a certain number but im sure its not meant to be used this way. I was wondering if i am missing something or not doing something i should to free up memory. Here is the code: Public Class SimpleWebService : Inherits ServiceBase 'Set the values for the different event log types. Public Const EVENT_ERROR As Integer = 1 Public Const EVENT_WARNING As Integer = 2 Public Const EVENT_INFORMATION As Integer = 4 Public listenerThread As Thread Dim HTTPListner As HttpListener Dim blnKeepAlive As Boolean = True Shared Sub Main() Dim ServicesToRun As ServiceBase() ServicesToRun = New ServiceBase() {New SimpleWebService()} ServiceBase.Run(ServicesToRun) End Sub Protected Overrides Sub OnStart(ByVal args As String()) If Not HttpListener.IsSupported Then CreateEventLogEntry("Windows XP SP2, Server 2003, or higher is required to " & "use the HttpListener class.") Me.Stop() End If Try listenerThread = New Thread(AddressOf ListenForConnections) listenerThread.Start() Catch ex As Exception CreateEventLogEntry(ex.Message) End Try End Sub Protected Overrides Sub OnStop() blnKeepAlive = False End Sub Private Sub CreateEventLogEntry(ByRef strEventContent As String) Dim sSource As String Dim sLog As String sSource = "Service1" sLog = "Application" If Not EventLog.SourceExists(sSource) Then EventLog.CreateEventSource(sSource, sLog) End If Dim ELog As New EventLog(sLog, ".", sSource) ELog.WriteEntry(strEventContent) End Sub Public Sub ListenForConnections() HTTPListner = New HttpListener HTTPListner.Prefixes.Add("http://*:1986/") HTTPListner.Start() Do While blnKeepAlive Dim ctx As HttpListenerContext = HTTPListner.GetContext() Dim HandlerThread As Thread = New Thread(AddressOf ProcessRequest) HandlerThread.Start(ctx) HandlerThread = Nothing Loop HTTPListner.Stop() End Sub Private Sub ProcessRequest(ByVal ctx As HttpListenerContext) Dim sb As StringBuilder = New StringBuilder sb.Append("<html><body><h1>Test My Service</h1>") sb.Append("</body></html>") Dim buffer() As Byte = Encoding.UTF8.GetBytes(sb.ToString) ctx.Response.ContentLength64 = buffer.Length ctx.Response.OutputStream.Write(buffer, 0, buffer.Length) ctx.Response.OutputStream.Close() ctx.Response.Close() sb = Nothing buffer = Nothing ctx = Nothing 'This line seems to keep the mem leak down 'System.GC.Collect() End Sub End Class Please feel free to critisise and tear the code apart but please BE KIND. I have admitted I dont tend to follow the best practice when it comes to coding.

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• Advice on displaying and allowing editing of data using ASP.NET MVC?

  - by Remnant

  I am embarking upon my first ASP.NET MVC project and I would like to get some input on possible ways to display database data and general best practice. In short, the body of my webpage will show data from my database in a table like format, with each table row showing similar data. For example: Name Age Position Date Joined Jon Smith 23 Striker 18th Mar 2005 John Doe 38 Defender 3rd Jan 1988 In terms of functionality, primarily I’d like to give the user the ability to edit the data and, after the edit, commit the edit to the database and refresh the view.The reason I want to refresh the view is because the data is date ordered and I will need to re-sort if the user edits a date field. My main question is what architecture / tools would be best suited to this fulfil my requirements at a high level? From the research I have done so far my initial conclusions were: ADO.NET for data retrieval. This is something I have used before and feel comfortable with. I like the look of LINQ to SQL but don’t want to make the learning curve any steeper for my first outing into MVC land just yet. Partial Views to create a template and then iterate through a datatable that I have pulled back from my database model. jQuery to allow the user to edit data in the table, error check edited data entries etc. Also, my intial view was that caching the data would not be a key requirement here. The only field a user will be able to update is the field and, if they do, I will need to commit that data to the database immediately and then refresh the view (as the data is date sorted). Any thoughts on this? Alternatively, I have seen some jQuery plug-ins that emulate a datagrid and provide associated functionality. My first thoughts are that I do not need all the functionality that comes with these plug-ins (e.g. zebra striping, ability to sort by column using sort glyph in column headers etc .) and I don’t really see any benefit to this over and above the solution I have outlined above. Again, is there reason to reconsider this view? Finally, when a user edits a date , I will need to refresh the view. In order to do this I had been reading about Html.RenderAction and this seemed like it may be a better option than using Partial Views as I can incorporate application logic into the action method. Am I right to consider Html.RenderAction or have I misunderstood its usage? Hope this post is clear and not too long. I did consider separate posts for each topic (e.g. Partial View vs. Html.RenderAction, when to use jQury datagrid plug-in) but it feels like these issues are so intertwined that they need to be dealt with in contect of each other. Thanks

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• EXT-GWT Portal: How to get all Portlets?

  - by Lars

  Hi all this is my first Question here! Im just making my first steps with (Ext-) GWT. I´m testing the Ext-GWT libraries and really: These are absolute great! Now my question: Is it possible to make a kind of "clear-Portal" or "hide all portles" for a defined Portal? Or have i always manually clear the portal like in my example code above? My sample code looks like this: //define the Portal, 2 columns, each 50% auf width, with borders and Backgroundcolor portal = new Portal(2); portal.setBorders(true); portal.setStyleAttribute("backgroundColor", "white"); portal.setColumnWidth(0, .50); portal.setColumnWidth(1, .50); //define a Portlet for showing all Users portletUser = new Portlet(); portletUser.setHeading("Benutzer"); configPanel(portletUser); portletUser.setLayout(new FitLayout()); CompUserList compUserList = new CompUserList(); portletUser.add(compUserList); portletUser.setHeight(250); //define a Portlet for showing all Vehicles portletVehicles = new Portlet(); portletVehicles.setHeading("Fahrzeuge"); configPanel(portletVehicles); portletVehicles.setLayout(new FitLayout()); CompVehicleList compVehicleList = new CompVehicleList(); portletVehicles.add(compVehicleList); portletVehicles.setHeight(250); //define a portlet for showing all countries portletCountries = new Portlet(); portletCountries.setHeading("Länder"); configPanel(portletCountries); portletCountries.setLayout(new FitLayout()); CompCountryList compCountryList = new CompCountryList(); portletCountries.add(compCountryList); portletCountries.setHeight(250); //add both Portlets to Portal portal.add(portletUser, 0); portal.add(portletVehicles, 1); So first of all this works fine and looks great :-) Now i have a a button in a accordeon menu. The Listener on this button should hide all portlets in the portal (at this time its the portletUser and portletVehicles) and then add another portlet (for example the portletCountries): portletUser.hide(); portletVehicles.hide(); portal.add(portletCountries, 0) Question from above again ;-) Is it possible to make a kind of "clear-Portal" or "hide all portles" for a defined Portal? Or have i always manually clear the portal like in my example code above? What is the best practice for this functionallity? Thanks all for your tips! Lars.

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• do you want try ? [closed]

  - by gemxia

  Only with time and hard work, that can you get an IT certification. Although there are hundreds of certifications for you to pick from, the basic steps to get certified are the same. The following steps are certain to clear your puzzles about the preparation process of your <. The first step to take is choosing a certification. It is simple but at the same time very important. Make sure to choose the certifications that are respected in your industries. The second step you should take is to evaluate your experience. Find out what skills and experience the IBM certification is expecting. Then, decide what type of training is suitable for you. Preparation books will certainly not make you an expert in subjects you’re not already an expert in. But, for the subject areas you know little or nothing about, a study guide provides you clues and guidance about what the important information from those subjects is when it comes to passing the Examkiller IBM examination exam. Visit certification forums during your 000-M62 certification exam preparation. In this way, you can learn from others’ mistakes and example, meanwhile help your own studies. Achieving your goals without proper training is a sure road to failure. Knowing about a topic and having special expertise in it are completely different. One cannot be an expert in the IT industry without the proper foundation. Taking a training class for Examkiller IBM exam might be a guaranteed way. When the economy dips and budgets get tightened, one of the first things to go from corporate spending is training. There are plenty of courses, boot camps and cram sessions that promise to prepare you for the IBM exam, but they are exceptionally expensive. As much as possible, for your own benefit, you should look for resources that are free. Vendor of IBM offers free resource in their sites. These practice exams are the closest to the real exams. If you think that you have got ready for the exam, you can take the fourth now, which is registering your exam. Even if you have passed your <, yet you can’t relax, since there are still so many certifications ahead. If you have just memorized some questions and answers, excepting a fluke, then, don’t take the IBM test exam, until you really have the experience and skills the certification requires.

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• Looking for efficient scaling patterns for Silverlight application with distributed text-file data s

  - by Edward Tanguay

  I'm designing a Silverlight software solution for students and teachers to record flashcards, e.g. words and phrases that students find while reading and errors that teachers notice while teaching. Requirements are: each person publishes his own flashcards in a file on a web server, e.g. http://:www.mywebserver.com/flashcards.txt other people subscribe to that person's flashcards by using a Silverlight flashcard reader that I have developed and entering the URLs of flashcard files they want to subscribe to, URLs and imported flashcards being saved in IsolatedStorage the flashcards.txt file has the following simple format: title, then blocks of question/answers: Jim Smith's flashcards from English class 53-222, winter semester 2009 ==fla Das kann nicht sein. That can't be. ==fla Es sei denn, er kommt nicht. Unless he doesn't come. The user then makes public the URL to his flashcard file and other readers begin reading in his flashcards. In order to lower the bar for non-technical users to contribute, it will even be possible for them to save this text in a Google Document, which they publish and distribute the URL. The flashcard readers will then recognize it is a google document and perform the necessary screen scraping to get at the raw text. I have two technical questions about this approach: What is a best way to plan now for scalability issues: e.g. if your reader is subscribed to 10 flashcard files that are each 200K, it will have to download 2MB of text just to find out if any new flashcards are available. Or can I somehow accurately and consistently get at the last update date/time of text files on servers and published google docs? Each reader will have the ability to allow the person to test himself on imported flashcards and add meta information to them, e.g. categorize them, edit them, etc. This information will be stored in IsolatedStorage along with the important flashcards themselves. What is a good pattern to allow these readers to share and synchronize this meta data, e.g. so when you are looking at a flashcard you can see that 5 other people have made corrections to it. The best solution I can think of now is that the Silverlight readers will have to republish their data to a central database, but then there is the problem of uniquely identifying each flashcard, the best approach seems to be URL + position-in-file, or even better URL + original text of both question and answer fields, but both of these have their obvious drawbacks. The main requirement is that the bar for participation is kept as low as possible, i.e. type text in a google document, publish it, distribute the URL, and you're publishing within the flashcard community. So I want to come up with the most efficient technical solutions in order to compensate for the lack of database, lack of unique ids, etc. For those who have designed or developed similar non-traditional, distributed database projects like this, what advice, experience or best-practice tips you can share on the above two points?

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• Would Ruby on Rails be appropriate for this Foreign Language project?

  - by Lynne Overesch-Maister

  I'm a Spanish professor & computer groupie. About 15 years ago, I authored in HyperCard a series of verb conjugation programs that are now completely out of date with respect to System OS X. I would like to redo these programs myself because I had a lot of fun doing them last time (mostly I coded while my son played in Leaps and Bounds, you know, one of those places where parents take their kids & let them run wild through the tubes...). Colleagues have mentioned using Flash, Director, and various other solutions, but I saw a presentation on RoR at our SIDLIT conference today, and was inspired. I will be parsing and comparing strings (and there are other features on top of that, but that is the main one), "adding" strings relationally indexed in some kind of database(s). It will also have to handle various foreign characters (accents, upside down question marks, etc.). On top of the main process of the program, it will have to provide a practice vs. test mode, keep track of specific answers as well as totals right/wrong, and print a report. Would this be either easier and/or more efficiently done in RoR than in other languages. I am pretty sure that it will work on a Microsoft server, right? Because I think that is where most of our stuff is. I would be programming either on a Mac or a PC, whichever you think is easier. So, in summary, is RoR the way for me to go with this project? If I have some (little) experience programming in Hypercard and C, should I be able to pick RoR up fairly quickly? What things will I need to start (I already saw something called Redhills foreign key migration plugin, which I assume would be beneficial)? I still have my old scripts from hypercard, however what I would really like to do is to combine all six of my former tense-specific programs into one larger program. I figure that it wouldn't be too hard to reference the individual tenses in some way--could that be a class? Many thanks for any help you can give me on this forum.

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• How should I provide access to this custom DAL?

  - by Casey

  I'm writing a custom DAL (VB.NET) for an ordering system project. I'd like to explain how it is coded now, and receive some alternate ideas to make coding against the DAL easier/more readable. The DAL is part of an n-tier (not n-layer) application, where each tier is in it's own assembly/DLL. The DAL consists of several classes that have specific behavior. For instance, there is an Order class that is responsible for retrieving and saving orders. Most of the classes have only two methods, a "Get" and a "Save," with multiple overloads for each. These classes are marked as Friend and are only visible to the DAL (which is in it's own assembly). In most cases, the DAL returns what I will call a "Data Object." This object is a class that contains only data and validation, and is located in a common assembly that both the BLL and DAL can read. To provide public access to the DAL, I currently have a static (module) class that has many shared members. A simplified version looks something like this: Public Class DAL Private Sub New End Sub Public Shared Function GetOrder(OrderID as String) as OrderData Dim OrderGetter as New OrderClass Return OrderGetter.GetOrder(OrderID) End Function End Class Friend Class OrderClass Friend Function GetOrder(OrderID as string) as OrderData End Function End Class The BLL would call for an order like this: DAL.GetOrder("123456") As you can imagine, this gets cumbersome very quickly. I'm mainly interested in structuring access to the DAL so that Intellisense is very intuitive. As it stands now, there are too many methods/functions in the DAL class with similar names. One idea I had is to break down the DAL into nested classes: Public Class DAL Private Sub New End Sub Public Class Orders Private Sub New End Sub Public Shared Function Get(OrderID as string) as OrderData End Function End Class End Class So the BLL would call like this: DAL.Orders.Get("12345") This cleans it up a bit, but it leaves a lot of classes that only have references to other classes, which I don't like for some reason. Without resorting to passing DB specific instructions (like where clauses) from BLL to DAL, what is the best or most common practice for providing a single point of access for the DAL?

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• Is this good code? Linked List Stack Implementation

  - by Quik Tester

  I have used the following code for a stack implementation. The top keeps track of the topmost node of the stack. Now since top is a data member of the node function, each node created will have a top member, which ideally we wouldn't want. Firstly, is this good approach to coding? Secondly, will making top as static make it a better coding practice? Or should I have a global declaration of top? #include<iostream> using namespace std; class node { int data; node *top; node *link; public: node() { top=NULL; link=NULL; } void push(int x) { node *n=new node; n->data=x; n->link=top; top=n; cout<<"Pushed "<<n->data<<endl; } void pop() { node *n=new node; n=top; top=top->link; n->link=NULL; cout<<"Popped "<<n->data<<endl; delete n; } void print() { node *n=new node; n=top; while(n!=NULL) { cout<<n->data<<endl; n=n->link; } delete n; } }; int main() { node stack; stack.push(5); stack.push(7); stack.push(9); stack.pop(); stack.print(); } Any other suggestions welcome. I have also seen codes where there are two classes, where the second one has the top member. What about this? Thanks. :)

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• How to make efficient code emerge through unit testing

  - by Jean

  Hi, I participate in a TDD Coding Dojo, where we try to practice pure TDD on simple problems. It occured to me however that the code which emerges from the unit tests isn't the most efficient. Now this is fine most of the time, but what if the code usage grows so that efficiency becomes a problem. I love the way the code emerges from unit testing, but is it possible to make the efficiency property emerge through further tests ? Here is a trivial example in ruby: prime factorization. I followed a pure TDD approach making the tests pass one after the other validating my original acceptance test (commented at the bottom). What further steps could I take, if I wanted to make one of the generic prime factorization algorithms emerge ? To reduce the problem domain, let's say I want to get a quadratic sieve implementation ... Now in this precise case I know the "optimal algorithm, but in most cases, the client will simply add a requirement that the feature runs in less than "x" time for a given environment. require 'shoulda' require 'lib/prime' class MathTest < Test::Unit::TestCase context "The math module" do should "have a method to get primes" do assert Math.respond_to? 'primes' end end context "The primes method of Math" do should "return [] for 0" do assert_equal [], Math.primes(0) end should "return [1] for 1 " do assert_equal [1], Math.primes(1) end should "return [1,2] for 2" do assert_equal [1,2], Math.primes(2) end should "return [1,3] for 3" do assert_equal [1,3], Math.primes(3) end should "return [1,2] for 4" do assert_equal [1,2,2], Math.primes(4) end should "return [1,5] for 5" do assert_equal [1,5], Math.primes(5) end should "return [1,2,3] for 6" do assert_equal [1,2,3], Math.primes(6) end should "return [1,3] for 9" do assert_equal [1,3,3], Math.primes(9) end should "return [1,2,5] for 10" do assert_equal [1,2,5], Math.primes(10) end end # context "Functionnal Acceptance test 1" do # context "the prime factors of 14101980 are 1,2,2,3,5,61,3853"do # should "return [1,2,3,5,61,3853] for ${14101980*14101980}" do # assert_equal [1,2,2,3,5,61,3853], Math.primes(14101980*14101980) # end # end # end end and the naive algorithm I created by this approach module Math def self.primes(n) if n==0 return [] else primes=[1] for i in 2..n do if n%i==0 while(n%i==0) primes<<i n=n/i end end end primes end end end

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• Why is my javascript function sometimes "not defined"?

  - by harpo

  Problem: I call my javascript function, and sometimes I get the error 'myFunction is not defined'. But it is defined. For example. I'll occasionally get 'copyArray is not defined' even in this example: function copyArray( pa ) { var la = []; for (var i=0; i < pa.length; i++) la.push( pa[i] ); return la; } Function.prototype.bind = function( po ) { var __method = this; var __args = []; // sometimes errors -- in practice I inline the function as a workaround __args = copyArray( arguments ); return function() { /* bind logic omitted for brevity */ } } As you can see, copyArray is defined right there, so this can't be about the order in which script files load. I've been getting this in situations that are harder to work around, where the calling function is located in another file that should be loaded after the called function. But this was the simplest case I could present, and appears to be the same problem. It doesn't happen 100% of the time, so I do suspect some kind of load-timing-related problem. But I have no idea what. @Hojou: That's part of the problem. The function in which I'm now getting this error is itself my addLoadEvent, which is basically a standard version of the common library function. @James: I understand that, and there is no syntax error in the function. When that is the case, the syntax error is reported as well. In this case, I am getting only the 'not defined' error. @David: The script in this case resides in an external file that is referenced using the normal <script src="file.js"></script> method in the page's head section. @Douglas: Interesting idea, but if this were the case, how could we ever call a user-defined function with confidence? In any event, I tried this and it didn't work. @sk: This technique has been tested across browsers and is basically copied from the prototype library.

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• Advice on logic circuits and serial communications

  - by Spencer Ruport

  As far as I understand the serial port so far, transferring data is done over pin 3. As shown here: There are two things that make me uncomfortable about this. The first is that it seems to imply that the two connected devices agree on a signal speed and the second is that even if they are configured to run at the same speed you run into possible synchronization issues... right? Such things can be handled I suppose but it seems like there must be a simpler method. What seems like a better approach to me would be to have one of the serial port pins send a pulse that indicates that the next bit is ready to be stored. So if we're hooking these pins up to a shift register we basically have: (some pulse pin)-clk, tx-d Is this a common practice? Is there some reason not to do this? EDIT Mike shouldn't have deleted his answer. This I2C (2 pin serial) approach seems fairly close to what I did. The serial port doesn't have a clock you're right nobugz but that's basically what I've done. See here: private void SendBytes(byte[] data) { int baudRate = 0; int byteToSend = 0; int bitToSend = 0; byte bitmask = 0; byte[] trigger = new byte[1]; trigger[0] = 0; SerialPort p; try { p = new SerialPort(cmbPorts.Text); } catch { return; } if (!int.TryParse(txtBaudRate.Text, out baudRate)) return; if (baudRate < 100) return; p.BaudRate = baudRate; for (int index = 0; index < data.Length * 8; index++) { byteToSend = (int)(index / 8); bitToSend = index - (byteToSend * 8); bitmask = (byte)System.Math.Pow(2, bitToSend); p.Open(); p.Parity = Parity.Space; p.RtsEnable = (byte)(data[byteToSend] & bitmask) > 0; s = p.BaseStream; s.WriteByte(trigger[0]); p.Close(); } } Before anyone tells me how ugly this is or how I'm destroying my transfer speeds my quick answer is I don't care about that. My point is this seems much much simpler than the method you described in your answer nobugz. And it wouldn't be as ugly if the .Net SerialPort class gave me more control over the pin signals. Are there other serial port APIs that do?

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• redoing object model construction to fit with asynchronous data fetching

  - by Andrew Patterson

  I have a modeled a set of objects that correspond with some real world concepts. TradeDrug, GenericDrug, TradePackage, DrugForm Underlying the simple object model I am trying to provide is a complex medical terminology that uses numeric codes to represent relationships and concepts, all accessible via a REST service - I am trying to hide away some of that complexity with an object wrapper. To give a concrete example I can call TradeDrug d = Searcher.FindTradeDrug("Zoloft") or TradeDrug d = new TradeDrug(34) where 34 might be the code for Zoloft. This will consult a remote server to find out some details about Zoloft. I might then call GenericDrug generic = d.EquivalentGeneric() System.Out.WriteLine(generic.ActiveIngredient().Name) in order to get back the generic drug sertraline as an object (again via a background REST call to the remote server that has all these drug details), and then perhaps find its ingredient. This model works fine and is being used in some applications that involve data processing. Recently however I wanted to do a silverlight application that used and displayed these objects. The silverlight environment only allows asynchronous REST/web service calls. I have no problems with how to make the asychhronous calls - but I am having trouble with what the design should be for my object construction. Currently the constructors for my objects do some REST calls sychronously. public TradeDrug(int code) { form = restclient.FetchForm(code) name = restclient.FetchName(code) etc.. } If I have to use async 'events' or 'actions' in order to use the Silverlight web client (I know silverlight can be forced to be a synchronous client but I am interested in asychronous approaches), does anyone have an guidance or best practice for how to structure my objects. I can pass in an action callback to the constructor public TradeDrug(int code, Action<TradeDrug> constructCompleted) { } but this then allows the user to have a TradeDrug object instance before what I want to construct is actually finished. It also doesn't support an 'event' async pattern because the object doesn't exist to add the event to until it is constructed. Extending that approach might be a factory object that itself has an asynchronous interface to objects factory.GetTradeDrugAsync(code, completedaction) or with a GetTradeDrugCompleted event? Does anyone have any recommendations?

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• How can I easily maintain a cross-file JavaScript Library Development Environment

  - by John

  I have been developing a new JavaScript application which is rapidly growing in size. My entire JavaScript Application has been encapsulated inside a single function, in a single file, in a way like this: (function(){ var uniqueApplication = window.uniqueApplication = function(opts){ if (opts.featureOne) { this.featureOne = new featureOne(opts.featureOne); } if (opts.featureTwo) { this.featureTwo = new featureTwo(opts.featureTwo); } if (opts.featureThree) { this.featureThree = new featureThree(opts.featureThree); } }; var featureOne = function(options) { this.options = options; }; featureOne.prototype.myFeatureBehavior = function() { //Lots of Behaviors }; var featureTwo = function(options) { this.options = options; }; featureTwo.prototype.myFeatureBehavior = function() { //Lots of Behaviors }; var featureThree = function(options) { this.options = options; }; featureThree.prototype.myFeatureBehavior = function() { //Lots of Behaviors }; })(); In the same file after the anonymous function and execution I do something like this: (function(){ var instanceOfApplication = new uniqueApplication({ featureOne:"dataSource", featureTwo:"drawingCanvas", featureThree:3540 }); })(); Before uploading this software online I pass my JavaScript file, and all it's dependencies, into Google Closure Compiler, using just the default Compression, and then I have one nice JavaScript file ready to go online for production. This technique has worked marvelously for me - as it has created only one global footprint in the DOM and has given me a very flexible framework to grow each additional feature of the application. However - I am reaching the point where I'd really rather not keep this entire application inside one JavaScript file. I'd like to move from having one large uniqueApplication.js file during development to having a separate file for each feature in the application, featureOne.js - featureTwo.js - featureThree.js Once I have completed offline development testing, I would then like to use something, perhaps Google Closure Compiler, to combine all of these files together - however I want these files to all be compiled inside of that scope, as they are when I have them inside one file - and I would like for them to remain in the same scope during offline testing too. I see that Google Closure Compiler supports an argument for passing in modules but I haven't really been able to find a whole lot of information on doing something like this. Anybody have any idea how this could be accomplished - or any suggestions on a development practice for writing a single JavaScript Library across multiple files that still only leaves one footprint on the DOM?

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• SSIS DTS Package flat file error - "The file name specified in the connection was not valid"

  - by MisterZimbu

  I have a pretty basic SSIS package that is attempting to read a file hosted on a share, and import its contents to a database table. The package runs fine when I run it manually within SSIS. However, when I set up a SQL Agent job and attempt to execute it, I get the following error: Executed as user: DOMAIN\UserName. Microsoft (R) SQL Server Execute Package Utility Version 9.00.3042.00 for 64-bit Copyright (C) Microsoft Corp 1984-2005. All rights reserved. Started: 10:14:17 AM Error: 2010-05-03 10:14:17.75 Code: 0xC001401E Source: DataImport Connection manager "Data File Local" Description: The file name "\10.1.1.159\llpf\datafile.dat" specified in the connection was not valid. End Error Error: 2010-05-03 10:14:17.75 Code: 0xC001401D Source: DataAnimalImport Description: Connection "Data File Local" failed validation. End Error DTExec: The package execution returned DTSER_FAILURE (1). Started: 10:14:17 AM Finished: 10:14:17 AM Elapsed: 0.594 seconds. The package execution failed. The step failed. This leads me to believe it's a permissions issue, but every attempt I've made to fix it has failed. What I've tried so far: Run as the SQL Agent account (DOMAIN\SqlAgent) - yields same error. DOMAIN\SqlAgent has "Full Control" permissions on both the share and the uploaded file. Set up a proxy account with a different account's credentials (DOMAIN\Account) - yields same error. Like above, "Full Control" permissions were given over the share to that account. Gave "Everyone" full control permissions over the share (temporarily!). Yielded same error. Manually copied the file to a local path and tested with the SQL Agent account. Worked properly. Added an ActiveX script task that would first copy the remotely hosted file to a local path, and then have the DTS package reference the local file. Gave a completely nondescriptive (even by SSIS standards) error when trying to run the script. Set up a proxy account, using my own personal account's credentials - worked correctly. However, this is not an acceptable solution as there are password policies in place on my account, as well as being a bad practice to set things up this way in general. Any ideas? I'm still convinced it's a permissions issue. However, what I've read from various searches more or less says giving the executing account permissions on the share should work. However, this is not the case here (unless I'm missing something obscure when I'm setting up permissions on the share).

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• CSS selectors : should I make my CSS easier to read or optimise the speed

  - by Laurent Bourgault-Roy

  As I was working on a small website, I decided to use the PageSpeed extension to check if their was some improvement I could do to make the site load faster. However I was quite surprise when it told me that my use of CSS selector was "inefficient". I was always told that you should keep the usage of the class attribute in the HTML to a minimum, but if I understand correctly what PageSpeed tell me, it's much more efficient for the browser to match directly against a class name. It make sense to me, but it also mean that I need to put more CSS classes in my HTML. It make my .css file harder to read. I usually tend to mark my CSS like this : #mainContent p.productDescription em.priceTag { ... } Which make it easy to read : I know this will affect the main content and that it affect something in a paragraph tag (so I wont start to put all sort of layout code in it) that describe a product and its something that need emphasis. However it seem I should rewrite it as .priceTag { ... } Which remove all context information about the style. And if I want to use differently formatted price tag (for example, one in a list on the sidebar and one in a paragraph), I need to use something like that .paragraphPriceTag { ... } .listPriceTag { ... } Which really annoy me since I seem to duplicate the semantic of the HTML in my classes. And that mean I can't put common style in an unqualified .priceTag { ... } and thus I need to replicate the style in both CSS rule, making it harder to make change. (Altough for that I could use multiple class selector, but IE6 dont support them) I believe making code harder to read for the sake of speed has never been really considered a very good practice . Except where it is critical, of course. This is why people use PHP/Ruby/C# etc. instead of C/assembly to code their site. It's easier to write and debug. So I was wondering if I should stick with few CSS classes and complex selector or if I should go the optimisation route and remove my fancy CSS selectors for the sake of speed? Does PageSpeed make over the top recommandation? On most modern computer, will it even make a difference?

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• Java Hardware Acceleration

  - by Freezerburn

  I have been spending some time looking into the hardware acceleration features of Java, and I am still a bit confused as none of the sites that I found online directly and clearly answered some of the questions I have. So here are the questions I have for hardware acceleration in Java: 1) In Eclipse version 3.6.0, with the most recent Java update for Mac OS X (1.6u10 I think), is hardware acceleration enabled by default? I read somewhere that someCanvas.getGraphicsConfiguration().getBufferCapabilities().isPageFlipping() is supposed to give an indication of whether or not hardware acceleration is enabled, and my program reports back true when that is run on my main Canvas instance for drawing to. If my hardware acceleration is not enabled now, or by default, what would I have to do to enable it? 2) I have seen a couple articles here and there about the difference between a BufferedImage and VolatileImage, mainly saying that VolatileImage is the hardware accelerated image and is stored in VRAM for fast copy-from operations. However, I have also found some instances where BufferedImage is said to be hardware accelerated as well. Is BufferedImage hardware accelerated as well in my environment? What would be the advantage of using a VolatileImage if both types are hardware accelerated? My main assumption for the advantage of having a VolatileImage in the case of both having acceleration is that VolatileImage is able to detect when its VRAM has been dumped. But if BufferedImage also support acceleration now, would it not have the same kind of detection built into it as well, just hidden from the user, in case that the memory is dumped? 3) Is there any advantage to using someGraphicsConfiguration.getCompatibleImage/getCompatibleVolatileImage() as opposed to ImageIO.read() In a tutorial I have been reading for some general concepts about setting up the rendering window properly (tutorial) it uses the getCompatibleImage method, which I believe returns a BufferedImage, to get their "hardware accelerated" images for fast drawing, which ties into question 2 about if it is hardware accelerated. 4) This is less hardware acceleration, but it is something I have been curious about: do I need to order which graphics get drawn? I know that when using OpenGL via C/C++ it is best to make sure that the same graphic is drawn in all the locations it needs to be drawn at once to reduce the number of times the current texture needs to be switch. From what I have read, it seems as if Java will take care of this for me and make sure things are drawn in the most optimal fashion, but again, nothing has ever said anything like this clearly. 5) What AWT/Swing classes support hardware acceleration, and which ones should be used? I am currently using a class that extends JFrame to create a window, and adding a Canvas to it from which I create a BufferStrategy. Is this good practice, or is there some other type of way I should be implementing this? Thank you very much for your time, and I hope I provided clear questions and enough information for you to answer my several questions.

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• Using Hibernate to do a query involving two tables

  - by Nathan Spears

  I'm inexperienced with sql in general, so using Hibernate is like looking for an answer before I know exactly what the question is. Please feel free to correct any misunderstandings I have. I am on a project where I have to use Hibernate. Most of what I am doing is pretty basic and I could copy and modify. Now I would like to do something different and I'm not sure how configuration and syntax need to come together. Let's say I have two tables. Table A has two (relevant) columns, user GUID and manager GUID. Obviously managers can have more than one user under them, so queries on manager can return more than one row. Additionally, a manager can be managing the same user on multiple projects, so the same user can be returned multiple times for the same manager query. Table B has two columns, user GUID and user full name. One-to-one mapping there. I want to do a query on manager GUID from Table A, group them by unique User GUID (so the same User isn't in the results twice), then return those users' full names from Table B. I could do this in sql without too much trouble but I want to use Hibernate so I don't have to parse the sql results by hand. That's one of the points of using Hibernate, isn't it? Right now I have Hibernate mappings that map each column in Table A to a field (well the get/set methods I guess) in a DAO object that I wrote just to hold that Table's data. I could also use the Hibernate DAOs I have to access each table separately and do each of the things I mentioned above in separate steps, but that would be less efficient (I assume) that doing one query. I wrote a Service object to hold the data that gets returned from the query (my example is simplified - I'm going to keep some other data from Table A and get multiple columns from Table B) but I'm at a loss for how to write a DAO that can do the join, or use the DAOs I have to do the join. FYI, here is a sample of my hibernate config file (simplified to match my example): <hibernate-mapping package="com.my.dao"> <class name="TableA" table="table_a"> <id name="pkIndex" column="pk_index" /> <property name="userGuid" column="user_guid" /> <property name="managerGuid" column="manager_guid" /> </class> </hibernate-mapping> So then I have a DAOImplementation class that does queries and returns lists like public List<TableA> findByHQL(String hql, Map<String, String> params) etc. I'm not sure how "best practice" that is either.

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• Swiping Images with Page Control in Iphone

  - by lakesh

  I am trying to make practice app where i can scroll images with page control. I am able to scroll images and able to include the page control. But the problem i face is i am not able to interlink the two. Meaning to say when I scroll the images, the page control is not affected and when i change the page control, the scrolling of the images is unaffected. I have referred to this: http://www.iosdevnotes.com/2011/03/uiscrollview-paging/ for the scrolling with page control. Viewcontroller.h #import <UIKit/UIKit.h> @interface ViewController : UIViewController <UIScrollViewDelegate>{ UIScrollView *scrollView; UIPageControl *pageControl; BOOL pageControlBeingUsed; } @property (nonatomic, retain) IBOutlet UIScrollView *scrollView; @property (nonatomic, retain) IBOutlet UIPageControl *pageControl; - (IBAction)changePage; @end Viewcontroller.m #import "ViewController.h" @interface ViewController () @end @implementation ViewController @synthesize scrollView,pageControl; - (void)viewDidLoad { [super viewDidLoad]; NSArray *images = [[NSArray alloc] initWithObjects:[UIImage imageNamed:@"1.jpeg"],[UIImage imageNamed:@"2.jpeg"],[UIImage imageNamed:@"3.jpeg" ], nil]; self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * images.count, self.scrollView.frame.size.height); for (int i = 0; i < images.count; i++) { CGRect frame; frame.origin.x = self.scrollView.frame.size.width * i; frame.origin.y = 0; frame.size = self.scrollView.frame.size; UIImageView* imgView = [[UIImageView alloc] init]; imgView.image = [images objectAtIndex:i]; imgView.frame = frame; [scrollView addSubview:imgView]; } } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } - (void)viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; self.scrollView = nil; } - (void)scrollViewDidScroll:(UIScrollView *)sender { // Update the page when more than 50% of the previous/next page is visible CGFloat pageWidth = self.scrollView.frame.size.width; int page = floor((self.scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1; self.pageControl.currentPage = page; } - (IBAction)changePage{ // update the scroll view to the appropriate page CGRect frame; frame.origin.x = self.scrollView.frame.size.width * self.pageControl.currentPage; frame.origin.y = 0; frame.size = self.scrollView.frame.size; [self.scrollView scrollRectToVisible:frame animated:YES]; pageControlBeingUsed = YES; } - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView { pageControlBeingUsed = NO; } - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { pageControlBeingUsed = NO; } @end Need some guidance on this... Thanks..

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• In GWT I'd like to load the main page on www.domain.com and a dynamic page on www.domain.com/xyz - I

  - by Mike Brecht

  Hi, I have a question for which I'm sure there must a simple solution. I'm writing a small GWT application where I want to achieve this: www.domain.com : should serve the welcome page www.domain.com/xyz : should serve page xyz, where xyz is just a key for an item in a database. If there is an item associated with key xyz, I'll load that and show a page, otherwise I'll show a 404 error page. I was trying to modify the web.xml file accordingly but I just couldn't make it work. I could make it work with an url-pattern if the key in question is after another /, for example: www.domain.com/search/xyz. However, I'd like to have the key xyz directly following the root / (http://www.domain.com/xyz). Something like <servlet-mapping> <servlet-name>main</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> doesn't seem to work as I don't know how to address the main page index.html (as it's not an actual servlet) which will then load my main GWT module. I could make it work with a bad work around (see below): Redirecting a 404 exception to index.html and then doing the look up in the main entry point, but I'm sure that's not the best practice, also for SEO purposes. Can anyone give me a hint on how to configure the web.xml with GWT for my purpose? Thanks a lot. Mike Work-around via 404: Web.xml: <web-app> <error-page> <exception-type>404</exception-type> <location>/index.html</location> </error-page> <welcome-file-list> <welcome-file>index.html</welcome-file> </welcome-file-list> </web-app> index.html -- Main Entry point -- onModuleLoad(): String path = Window.Location.getPath(); if (path == null || path.length() == 0 || path.equalsIgnoreCase("/") || path.equalsIgnoreCase("/index.html")) { ... // load main page } else { lookup(path.substring(1)); // that's key xyz

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• Button.MouseDown

  - by Gilad

  Hi Guys, I'm relatively new with WPF. I'm trying to understand the difference between MouseDownEvent and PreviewMouseDownEvent. I understand the WPF event strategies and i understand that the MouseDown event is a bubbling event and the PreviewMouseDown is a tunneling event. I also understand the order of which these events are being fired - according to this MSDN overview http://msdn.microsoft.com/en-us/library/ms742806.aspx#routing (there is a diagram with example there). So i tried to code some my self, check this for example: <Grid x:Name="grid" Width="250"> <StackPanel Mouse.MouseDown="StackPanel_MouseDown" PreviewMouseDown="StackPanel_PreviewMouseDown"> <WPFVisualizerExample:MyButton x:Name="B1" PreviewMouseDown="B1_PreviewMouseDown" MouseDown="B1_MouseDown" Margin="5,5,5,5"> <WPFVisualizerExample:MyButton x:Name="B2" PreviewMouseDown="B2_PreviewMouseDown" MouseDown="B2_MouseDown" Margin="5,5,5,5"> <WPFVisualizerExample:MyButton x:Name="B3" PreviewMouseDown="B3_PreviewMouseDown" MouseDown="B3_MouseDown" Margin="5,5,5,5">Click Me</WPFVisualizerExample:MyButton> </WPFVisualizerExample:MyButton> </WPFVisualizerExample:MyButton> </StackPanel> </Grid> I have an event handler for each of the events (the preview and non-preview) and i wanted to see what is happening, which of the event is being thrown (i have a message box shown for each event). The 'MyButton' user control simply extends the base Button and override the OnMouseDown and OnPreviewMouseDown to set the e.Handled false: protected override void OnMouseDown(System.Windows.Input.MouseButtonEventArgs e) { base.OnMouseDown(e); e.Handled = false; } protected override void OnPreviewMouseDown(System.Windows.Input.MouseButtonEventArgs e) { base.OnPreviewMouseDown(e); e.Handled = false; } (tried with this and without this). According to the MSDN overview (in the link above), if i have 3 elements then the events route should be as follows: PreviewMouseDown (tunnel) on root element. PreviewMouseDown (tunnel) on intermediate element #1. PreviewMouseDown (tunnel) on source element #2. MouseDown (bubble) on source element #2. MouseDown (bubble) on intermediate element #1. MouseDown (bubble) on root element. So I expected the the message boxes to be shown according to the above. From some reason - which I don't understand only the preview events are being thrown (according to what the MSDN says Preview_B1=Preview_B2=Preview_B3). My expectations were: Preview_B1=Preview_B2=Preview_B3=NonPreview_B3=NonPreview_B2=NonPreview_B1. But the non-preview events are not being thrown at all. So basically I don't understand the route of the events, from MSDN overview I understood that the route starts from the root element, goes down (tunnel) to the source element and then back up (bubble) to the root element, but this is not what happening in practice. It is really important for me to understand how this events are working, i probably miss-understand something basic here, your help will be appreciated. THANX!! -Gili

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