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  • ASP.NET MVC CRUD PartialView Popup Issue

    - by Smiley Face
    I am creating an MVC website which makes use of Partial Views on Popups to handle all my CRUD transactions. Please note that my application can already handle these CRUD operations perfectly (LINQ-To-Entity). However, I have a problem with my popup forms. Below is the code from my _Add.cshtml: @model MyStore.Models.MyModels.ProductsModel @{ Layout = null; } @using (Ajax.BeginForm("_Add", "Products", new AjaxOptions { InsertionMode = InsertionMode.Replace, HttpMethod = "POST", OnSuccess = "addSuccess" }, new { @id = "addForm" })) { @Html.ValidationSummary(true) <div id="add-message" class="error invisible"></div> <fieldset> <legend>Products</legend> @Html.HiddenFor(m => Model.ProductCode) <div class="editor-label"> @Html.LabelFor(model => model.ProductName) </div> <div class="editor-field"> @Html.EditorFor(model => model.ProductName) @Html.ValidationMessageFor(model => model.ProductName) </div> <div class="editor-label"> @Html.LabelFor(model => model.Price) </div> <div class="editor-field"> @Html.TextBoxFor(model => model.Price) @Html.ValidationMessageFor(model => model.Price) </div> </fieldset> } Below is the code from my Controller: [HttpGet] public ActionResult _Add(string productCode) { ProductsModel model = newProductsModel(); model.ProductCode = ProductCode ; return PartialView(model); } [HttpPost] public JsonResult _Add(ProductsModel model) { if (ModelState.IsValid) { ProductsManager prod = new ProductsManager(); Products pa = new Products(); pa.ProductCode = model.ProductCode; pa.ProductName = model.ProductName; pa.Price = model.Price; prod.AddProduct(pa); return Json(HelperClass.SuccessResponse(pa), JsonRequestBehavior.AllowGet); } else { return Json(HelperClass.ErrorResponse("Please review your form"), JsonRequestBehavior.DenyGet); } } Please note that the _Add.cshtml is a partial view which is being rendered through a Popup.js which I found on the internet. It is rendered through this code: @Html.ActionLink("[Add Product]", "_Add", new { ProductCode = @ViewData["ProductCode"] }, new { @class = "editLink" }) This works okay. I mean it adds product to my database. But my problem is upon clicking the Proceed button, I get this pop-up download dialog from the page: Can somebody please help me with this? I have a hunch it's because of the HttpMethod i'm using (POST, PUT, GET, DELETE) but i'm not really sure which one is right to use or if it really is the problem in the first place. Any help would be greatly appreciated! PS. Sorry for the long post.

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  • Ruby on Rails - Create Entity with Relationship

    - by SooDesuNe
    I'm new to rails, so be nice. I'm building a "rolodex" type application, and this question is about the best way to handle creating an entity along with several relationship entities at the same time. For (a contrived) example: My application will have a Person model, which has_one Contact_Info model. On the create.html.erb page for Person it makes sense for the user of my appliction to create the person, and the contact_info at the same time. It doesn't seem right to include details for creating a contact directly in the create view/controller for person. What's the rails way to handle this?

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  • Cnoverting application to MVC architecture

    - by terence6
    I'm practicing writing MVC applications. I have a Mastermind game, that I would like to rewrite as MVC app. I have divided my code to parts, but instead of working game I'm getting empty Frame and an error in "public void paint( Graphics g )". Error comes from calling this method in my view with null argument. But how to overcome this ? MVC was quite simple with swing but awt and it's paint methods are much more complicated. Code of working app : http://paste.pocoo.org/show/224982/ App divided to MVC : Main : public class Main { public static void main(String[] args){ Model model = new Model(); View view = new View("Mastermind", 400, 590, model); Controller controller = new Controller(model, view); view.setVisible(true); } } Controller : import java.awt.*; import java.awt.event.*; public class Controller implements MouseListener, ActionListener { private Model model; private View view; public Controller(Model m, View v){ model = m; view = v; view.addWindowListener( new WindowAdapter(){ public void windowClosing(WindowEvent e){ System.exit(0); } }); view.addMouseListener(this); } public void actionPerformed( ActionEvent e ) { if(e.getSource() == view.checkAnswer){ if(model.isRowFull){ model.check(); } } } public void mousePressed(MouseEvent e) { Point mouse = new Point(); mouse = e.getPoint(); if (model.isPlaying){ if (mouse.x > 350) { int button = 1 + (int)((mouse.y - 32) / 50); if ((button >= 1) && (button <= 5)){ model.fillHole(button); } } } } public void mouseClicked(MouseEvent e) {} public void mouseReleased(MouseEvent e){} public void mouseEntered(MouseEvent e) {} public void mouseExited(MouseEvent e) {} } View : import java.awt.*; import javax.swing.*; import java.awt.event.*; public class View extends Frame implements ActionListener { Model model; JButton checkAnswer; private JPanel button; static final int HIT_X[] = {270,290,310,290,310}, HIT_Y[] = {506,496,496,516,516}; public View(String name, int w, int h, Model m){ model = m; setTitle( name ); setSize( w,h ); setResizable( false ); this.setLayout(new BorderLayout()); button = new JPanel(); button.setSize( new Dimension(400, 100)); button.setVisible(true); checkAnswer = new JButton("Check"); checkAnswer.addActionListener(this); checkAnswer.setSize( new Dimension(200, 30)); button.add( checkAnswer ); this.add( button, BorderLayout.SOUTH); button.setVisible(true); for ( int i=0; i < model.SCORE; i++ ){ for ( int j = 0; j < model.LINE; j++ ){ model.pins[i][j] = new Pin(20,0); model.pins[i][j].setPosition(j*50+30,510-i*50); model.pins[i+model.SCORE][j] = new Pin(8,0); model.pins[i+model.SCORE][j].setPosition(HIT_X[j],HIT_Y[j]-i*50); } } for ( int i=0; i < model.LINE; i++ ){ model.pins[model.OPTIONS][i] = new Pin( 20, i+2 ); model.pins[model.OPTIONS][i].setPosition( 370,i * 50 + 56); } model.combination(); model.paint(null); } public void actionPerformed( ActionEvent e ) { } } Model: import java.awt.*; public class Model extends Frame{ static final int LINE = 5, SCORE = 10, OPTIONS = 20; Pin pins[][] = new Pin[21][LINE]; int combination[] = new int[LINE]; int curPin = 0; int turn = 1; int repaintPin; boolean isUpdate = true, isPlaying = true, isRowFull = false; public Model(){ } void fillHole(int color) { pins[turn-1][curPin].setColor(color+1); repaintPins( turn ); curPin = (curPin+1) % LINE; if (curPin == 0){ isRowFull = true; } } public void paint( Graphics g ) { g.setColor( new Color(238, 238, 238)); g.fillRect( 0,0,400,590); for ( int i=0; i < pins.length; i++ ) { pins[i][0].paint(g); pins[i][1].paint(g); pins[i][2].paint(g); pins[i][3].paint(g); pins[i][4].paint(g); } } public void update( Graphics g ) { if ( isUpdate ) { paint(g); } else { isUpdate = true; pins[repaintPin-1][0].paint(g); pins[repaintPin-1][1].paint(g); pins[repaintPin-1][2].paint(g); pins[repaintPin-1][3].paint(g); pins[repaintPin-1][4].paint(g); } } void repaintPins( int pin ) { repaintPin = pin; isUpdate = false; repaint(); } void check() { int junkPegs[] = new int[LINE], junkCode[] = new int[LINE]; int pegCount = 0, pico = 0; for ( int i = 0; i < LINE; i++ ) { junkPegs[i] = pins[turn-1][i].getColor(); junkCode[i] = combination[i]; } for ( int i = 0; i < LINE; i++ ){ if (junkPegs[i]==junkCode[i]) { pins[turn+SCORE][pegCount].setColor(1); pegCount++; pico++; junkPegs[i] = 98; junkCode[i] = 99; } } for ( int i = 0; i < LINE; i++ ){ for ( int j = 0; j < LINE; j++ ) if (junkPegs[i]==junkCode[j]) { pins[turn+SCORE][pegCount].setColor(2); pegCount++; junkPegs[i] = 98; junkCode[j] = 99; j = LINE; } } repaintPins( turn+SCORE ); if ( pico == LINE ){ isPlaying = false; } else if ( turn >= 10 ){ isPlaying = false; } else{ curPin = 0; isRowFull = false; turn++; } } void combination() { for ( int i = 0; i < LINE; i++ ){ combination[i] = 1 + (int)(Math.random()*5); System.out.print(i+","); } } } class Pin{ private int color, X, Y, radius; private static final Color COLORS[] = { Color.black, Color.white, Color.red, Color.yellow, Color.green, Color.blue, new Color(7, 254, 250)}; public Pin(){ X = 0; Y = 0; radius = 0; color = 0; } public Pin( int r,int c ){ X = 0; Y = 0; radius = r; color = c; } public void paint( Graphics g ){ int x = X-radius; int y = Y-radius; if (color > 0){ g.setColor( COLORS[color]); g.fillOval( x,y,2*radius,2*radius ); } else{ g.setColor( new Color(238, 238, 238) ); g.drawOval( x,y,2*radius-1,2*radius-1 ); } g.setColor( Color.black ); g.drawOval( x,y,2*radius,2*radius ); } public void setPosition( int x,int y ){ this.X = x ; this.Y = y ; } public void setColor( int c ){ color = c; } public int getColor() { return color; } } Any clues on how to overcome this would be great. Have I divided my code improperly ?

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  • why does backbone not send the delete?

    - by Nippysaurus
    I have a very basic backbone (sample) application which just creates and destroys model items. When the model is created the object is persisted with a POST to the web server, but when the model is destroyed there is no DELETE sent to the server? Any idea why this might be? very basic model: window.User = Backbone.Model.extend({ urlRoot: 'users' }); my test code just to create and delete the model: var model = null; $(".add").click(function(){ if (model == null) { model = new window.User; model.set({name: 'meeee'}); model.save(); } }); $(".remove").click(function(){ if (model != null) { model.destroy(); } }); The JSON response when creating the model seems good too:

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  • EntityFramework gives IDisposable error

    - by Snoop Dogg
    I use EF for the back-end DataLayer in my asp.net websites. I create a class library and add the Model in it, reference it and use it from the ASP.NET Website. But this time, I generated the model from database but it seems does not implement IDisposable, and the methods I used to see are not there. DeleteObject , SaveChanges etc. There are only Two tables in the DB and the Model was generated with only the TableSets and two methods AddToTableSet ... Had anybody encountered such a problem?

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  • EntityFramework: Access dabase-column using user defined Type

    - by Nils
    I "inherited" an old Database where dates are stored as Int32 values (times too, but dates shall suffice for this example) i.e. 20090101 for Jan. 1st 2009. I can not change the schema of this database because it is still accessed by the old programs. However I want to write a new program using EF as the O/R-M. Now I'd love to have DateTime-Values in my Model. Is there a way to write a custom type and use this as a Type in the EF-Model. Something like a Type "OldDate" with properties: DatabaseValue : Int23 Value : DateTime (specifying the date-part whereas the time-part is always 0:00:00) Is something like this possible with the EF-Model ?

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  • Converting application to MVC architecture

    - by terence6
    I'm practicing writing MVC applications. I have a Mastermind game, that I would like to rewrite as MVC app. I have divided my code to parts, but instead of working game I'm getting empty Frame and an error in "public void paint( Graphics g )". Error comes from calling this method in my view with null argument. But how to overcome this ? MVC was quite simple with swing but awt and it's paint methods are much more complicated. Code of working app : http://paste.pocoo.org/show/224982/ App divided to MVC : Main : public class Main { public static void main(String[] args){ Model model = new Model(); View view = new View("Mastermind", 400, 590, model); Controller controller = new Controller(model, view); view.setVisible(true); } } Controller : import java.awt.*; import java.awt.event.*; public class Controller implements MouseListener, ActionListener { private Model model; private View view; public Controller(Model m, View v){ model = m; view = v; view.addWindowListener( new WindowAdapter(){ public void windowClosing(WindowEvent e){ System.exit(0); } }); view.addMouseListener(this); } public void actionPerformed( ActionEvent e ) { if(e.getSource() == view.checkAnswer){ if(model.isRowFull){ model.check(); } } } public void mousePressed(MouseEvent e) { Point mouse = new Point(); mouse = e.getPoint(); if (model.isPlaying){ if (mouse.x > 350) { int button = 1 + (int)((mouse.y - 32) / 50); if ((button >= 1) && (button <= 5)){ model.fillHole(button); } } } } public void mouseClicked(MouseEvent e) {} public void mouseReleased(MouseEvent e){} public void mouseEntered(MouseEvent e) {} public void mouseExited(MouseEvent e) {} } View : import java.awt.*; import javax.swing.*; import java.awt.event.*; public class View extends Frame implements ActionListener { Model model; JButton checkAnswer; private JPanel button; static final int HIT_X[] = {270,290,310,290,310}, HIT_Y[] = {506,496,496,516,516}; public View(String name, int w, int h, Model m){ model = m; setTitle( name ); setSize( w,h ); setResizable( false ); this.setLayout(new BorderLayout()); button = new JPanel(); button.setSize( new Dimension(400, 100)); button.setVisible(true); checkAnswer = new JButton("Check"); checkAnswer.addActionListener(this); checkAnswer.setSize( new Dimension(200, 30)); button.add( checkAnswer ); this.add( button, BorderLayout.SOUTH); button.setVisible(true); for ( int i=0; i < model.SCORE; i++ ){ for ( int j = 0; j < model.LINE; j++ ){ model.pins[i][j] = new Pin(20,0); model.pins[i][j].setPosition(j*50+30,510-i*50); model.pins[i+model.SCORE][j] = new Pin(8,0); model.pins[i+model.SCORE][j].setPosition(HIT_X[j],HIT_Y[j]-i*50); } } for ( int i=0; i < model.LINE; i++ ){ model.pins[model.OPTIONS][i] = new Pin( 20, i+2 ); model.pins[model.OPTIONS][i].setPosition( 370,i * 50 + 56); } model.combination(); model.paint(null); } public void actionPerformed( ActionEvent e ) { } } Model: import java.awt.*; public class Model extends Frame{ static final int LINE = 5, SCORE = 10, OPTIONS = 20; Pin pins[][] = new Pin[21][LINE]; int combination[] = new int[LINE]; int curPin = 0; int turn = 1; int repaintPin; boolean isUpdate = true, isPlaying = true, isRowFull = false; public Model(){ } void fillHole(int color) { pins[turn-1][curPin].setColor(color+1); repaintPins( turn ); curPin = (curPin+1) % LINE; if (curPin == 0){ isRowFull = true; } } public void paint( Graphics g ) { g.setColor( new Color(238, 238, 238)); g.fillRect( 0,0,400,590); for ( int i=0; i < pins.length; i++ ) { pins[i][0].paint(g); pins[i][1].paint(g); pins[i][2].paint(g); pins[i][3].paint(g); pins[i][4].paint(g); } } public void update( Graphics g ) { if ( isUpdate ) { paint(g); } else { isUpdate = true; pins[repaintPin-1][0].paint(g); pins[repaintPin-1][1].paint(g); pins[repaintPin-1][2].paint(g); pins[repaintPin-1][3].paint(g); pins[repaintPin-1][4].paint(g); } } void repaintPins( int pin ) { repaintPin = pin; isUpdate = false; repaint(); } void check() { int junkPegs[] = new int[LINE], junkCode[] = new int[LINE]; int pegCount = 0, pico = 0; for ( int i = 0; i < LINE; i++ ) { junkPegs[i] = pins[turn-1][i].getColor(); junkCode[i] = combination[i]; } for ( int i = 0; i < LINE; i++ ){ if (junkPegs[i]==junkCode[i]) { pins[turn+SCORE][pegCount].setColor(1); pegCount++; pico++; junkPegs[i] = 98; junkCode[i] = 99; } } for ( int i = 0; i < LINE; i++ ){ for ( int j = 0; j < LINE; j++ ) if (junkPegs[i]==junkCode[j]) { pins[turn+SCORE][pegCount].setColor(2); pegCount++; junkPegs[i] = 98; junkCode[j] = 99; j = LINE; } } repaintPins( turn+SCORE ); if ( pico == LINE ){ isPlaying = false; } else if ( turn >= 10 ){ isPlaying = false; } else{ curPin = 0; isRowFull = false; turn++; } } void combination() { for ( int i = 0; i < LINE; i++ ){ combination[i] = 1 + (int)(Math.random()*5); System.out.print(i+","); } } } class Pin{ private int color, X, Y, radius; private static final Color COLORS[] = { Color.black, Color.white, Color.red, Color.yellow, Color.green, Color.blue, new Color(7, 254, 250)}; public Pin(){ X = 0; Y = 0; radius = 0; color = 0; } public Pin( int r,int c ){ X = 0; Y = 0; radius = r; color = c; } public void paint( Graphics g ){ int x = X-radius; int y = Y-radius; if (color > 0){ g.setColor( COLORS[color]); g.fillOval( x,y,2*radius,2*radius ); } else{ g.setColor( new Color(238, 238, 238) ); g.drawOval( x,y,2*radius-1,2*radius-1 ); } g.setColor( Color.black ); g.drawOval( x,y,2*radius,2*radius ); } public void setPosition( int x,int y ){ this.X = x ; this.Y = y ; } public void setColor( int c ){ color = c; } public int getColor() { return color; } } Any clues on how to overcome this would be great. Have I divided my code improperly ?

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  • remove the blank rows after i removed xml elements?

    - by fayer
    i removed some elements from a xml file with simpledom. the code: $this->xmlDocument->removeNodes("//entity[name='mac']"); here is the initial file: <entity id="1000070"> <name>apple</name> <type>category</type> <entities> <entity id="7002870"> <name>mac</name> <type>category</type> </entity> <entity id="7024080"> <name>iphone</name> <type>category</type> </entity> <entity id="7024080"> <name>ipad</name> <type>category</type> </entity> </entities> </entity> the file afterwards: <entity id="1000070"> <name>apple</name> <type>category</type> <entities> <entity id="7024080"> <name>iphone</name> <type>category</type> </entity> <entity id="7024080"> <name>ipad</name> <type>category</type> </entity> </entities> </entity> i wonder how i could also remove the blank lines that are left after i ran the removal code? thanks!

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  • How do I combine similar method calls into a delegate pattern?

    - by Daniel T.
    I have three methods: public void Save<T>(T entity) { using (new Transaction()) { Session.Save(entity); } } public void Create<T>(T entity) { using (new Transaction()) { Session.Create(entity); } } public void Delete<T>(T entity) { using (new Transaction()) { Session.Delete(entity); } } As you can see, the only thing that differs is the method call inside the using block. How can I rewrite this so it's something like this instead: public void Save<T>(T entity) { TransactionWrapper(Session.Save(entity)); } public void Create<T>(T entity) { TransactionWrapper(Session.Create(entity)); } public void Save<T>(T entity) { TransactionWrapper(Session.Save(entity)); } So in other words, I pass a method call as a parameter, and the TransactionWrapper method wraps a transaction around the method call.

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  • What is the best way to add attributes to auto-generated entities (using VS2010 and EF4)

    - by Dani
    ASP.NET MVC2 has strong support for using attributes on entities (validation, and extending Html helper class and more). If I generated my Model from the Database using VS2010 EF4 Entity Data Model (edmx and it's cs class), And I want to add attributes on some of the entities. what would be the best practice ? how should I cope with updating the model (adding more fields / tables to the database and merging them into the edmx) - will it keep my attributes or generate a new cs file erasing everything ? (Manual changes to this file may cause unexpected behavior in your application.) (Manual changes to this file will be overwritten if the code is regenerated.)

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  • How to start MSSQL Server with corrupt model db

    - by Jordan McGuigan
    After moving some databases around (restoring, deleting, etc) we experienced an issue creating new databases. Specifically, When trying to create a new database MSSQL Server it failed because the "The database 'model' is marked RESTORING and is in a state that does not allow recovery to be run". As some online solutions suggested, we tried to Start and Stop the MSSQL Service. Service would not restart because "Could not create tempdb. You may not have enough disk space available. Free additional disk space by deleting other files on the tempdb drive" (FYI: the drive has 100gb of free space). Tried restarting the machine the MSSQL Server is running on. When the server came back online, we received the same error. We have tried deleting tempdb.mdf and restoring the modeldb from the templates folder, but neither of these solved the issue. We are unable to connect to the database, even in single user mode. Many of the online solutions have us running SQL commands against the server, but we are unable to connect (even in single user mode) to the DB to run commands against the server. Specific error messages: Database 'model' cannot be opened. It is in the middle of a restore. (Microsoft SQL Server, Error: 927) The SQL Server (MSSQLSERVER) service is starting. The SQL Server (MSSQLSERVER) service could not be started. A service specific error occurred: 1814. We need the server up and running again ASAP.

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  • PC doesn't POST with a certain model of PSU

    - by Core Xii
    I have this PC with an Asus P5N32-E SLI motherboard and an Intel Q6600 CPU. I got a new RX-5300 PSU, but it didn't work. The motherboard power LED is on fine When I switch power on, the PC powers up briefly (0.5-1 sec) then shuts down From there on out when I switch power on, it stays on, all fans and components seem to be receiving power, but the motherboard won't POST. No video output, no PC speaker beeps, nothing If I turn the hard switch on the PSU off and then back on again, go to step 2; The PC turns on and then off immediately again, and on subsequent power-ups it stays on but won't POST I disconnected every component but the motherboard, CPU and PSU. Still nothing. I tried three other models of PSU on this PC, both of higher (600) and lower (<300) wattage than the 530 on the RX-5300 and they all work fine. At this point I was convinced the PSU was faulty so I returned it. When the replacement arrived, it behaved exactly the same. So two different units of RX-5300 both with the same symptoms, neither working with this motherboard + CPU. Yet, three other models of PSU work perfectly fine. The PC store couldn't reproduce my problem with the returned PSU. I tried resetting the CMOS with the jumper. I tried with both the 4 and 4+4 (with and without the extra +4 connected) CPU connectors (curiously the RX-5300 comes equipped with both). Could it be a statistical probability that I get two units of the same model of PSU that are faulty in the exact same manner? Could the RX-5300 model itself be somehow incompatible with this motherboard? I was under the impression that PSUs were pretty much universal so long as you have the wattage. Could the motherboard be broken in some such a way as to work with certain PSUs but not others? What's going on here?

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  • MVC - Sanitizing data, where?

    - by dierre
    I'm using CakePHP but it's a question about the MVC pattern. I have in my form the input-text for the tags (separated by commas). To add the tags I've created a Tag model method that basically check if the tag exists and then add the new tag or just a new unit in the tag counter (the Tag model has these fields: id, name, slug, count). In the controller I explode the tags field and pass one tag at a time. The question is: where do I sanitize data? In the controller or in the model method? I think it should be in the controller because that's where I explode but in term of reusability I think I should sanitize data in the model. What do you think?

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  • Rails has_one vs belongs_to semantics

    - by Anurag
    I have a model representing a Content item that contains some images. The number of images are fixed as these image references are very specific to the content. For example, the Content model refers to the Image model twice (profile image, and background image). I am trying to avoid a generic has_many, and sticking to multiple has_one's. The current database structure looks like: contents - id:integer - integer:profile_image_id - integer:background_image_id images - integer:id - string:filename - integer:content_id I just can't figure out how to setup the associations correctly here. The Content model could contain two belongs_to references to an Image, but that doesn't seem semantically right cause ideally an image belongs to the content, or in other words, the content has two images. This is the best I could think of (by breaking the semantics): class Content belongs_to :profile_image, :class_name => 'Image', :foreign_key => 'profile_image_id' belongs_to :background_image, :class_name => 'Image', :foreign_key => 'background_image_id' end Am I way off, and there a better way to achieve this association?

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  • Best way to attach row from datagrid to EF.

    - by AKoran
    Using MVVM and EF...I have a datagrid binding to a View Model (using ObservableCollection). The view model has a save command which simply calls the SaveChanges command of the Data Context. However, when a user adds a new row to the datagrid, the new entity is detached. Is there any easy way to automatically attach it when it gets created. Currently, I'm having to do this in the Save command of my View Model and it seems a bit clunky: foreach (var dataItem in _DataList) // where _DataList is the ObservableCollection { if (dataItem.EntityState == EntityState.Detached) { _DataContext.AddToTestTables(dataItem); } } _DataContext.SaveChanges();

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  • Instantiating and referencing models in MVC

    - by fig-gnuton
    In MVC, should each model be a globally accessible singleton accessible to any view/controller? Or should the models be singletons that are dependency injected into any component that requires them? Or should a new model instance be created for each component that needs one, in which case events would be used to propagate changes across model instances of the same class?

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  • Accessing two sides of a user-user relationship in rails

    - by Lowgain
    Basically, I have a users model in my rails app, and a fanship model, to facilitate the ability for users to become 'fans' of each other. In my user model, I have: has_many :fanships has_many :fanofs, :through => :fanships In my fanship model, I have: belongs_to :user belongs_to :fanof, :class_name => "User", :foreign_key => "fanof_id" My fanship table basically consists of :id, :user_id and :fanof_id. This all works fine, and I can see what users a specific user is a fan of like: <% @user.fanofs.each do |fan| %> #things <% end %> My question is, how can I get a list of the users that are a fan of this specific user? I'd like it if I could just have something like @user.fans, but if that isn't possible what is the most efficient way of going about this? Thanks!

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  • how to print not mapped value

    - by IcanMakeIt
    I am using complicated SQL queries, i have to use SqlQuery ... in simple way: MODEL: public class C { public int ID { get; set; } [NotMapped] public float Value { get; set; } } CONTROLLER: IEnumerable<C> results = db.C.SqlQuery(@"SELECT ID, ATAN(-45.01) as Value from C); return View(results.ToList()); VIEW: @model IEnumerable<C> @foreach (var item in Model) { @Html.DisplayFor(modelItem => item.Value) } and the result for item.Value is NULL. So my question is , how can i print the computed value from SQL Query ? Thank you for help.

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  • Joining the same model twice in a clean way, but making the code reusable

    - by Shako
    I have a model Painting which has a Paintingtitle in each language and a Paintingdescription in each language: class Painting < ActiveRecord::Base has_many :paintingtitles, :dependent => :destroy has_many :paintingdescriptions, :dependent => :destroy end class Paintingtitle < ActiveRecord::Base belongs_to :painting belongs_to :language end class Paintingdescription < ActiveRecord::Base belongs_to :painting belongs_to :language end class Language < ActiveRecord::Base has_many :paintingtitles, :dependent => :nullify has_many :paintingdescriptions, :dependent => :nullify has_many :paintings, :through => :paintingtitles end As you might notice, I reference the Language model from my Painting model via both the Paintingtitle model and Paintingdescription model. This works for me when getting a list of paintings with their title and description in a specific language: cond = {"paintingdescription_languages.code" => language_code, "paintingtitle_languages.code" => language_code} cond['paintings.publish'] = 1 unless admin paginate( :all, :select => ["paintings.id, paintings.publish, paintings.photo_file_name, paintingtitles.title, paintingdescriptions.description"], :joins => " INNER JOIN paintingdescriptions ON (paintings.id = paintingdescriptions.painting_id) INNER JOIN paintingtitles ON (paintings.id = paintingtitles.painting_id) INNER JOIN languages paintingdescription_languages ON (paintingdescription_languages.id = paintingdescriptions.language_id) INNER JOIN languages paintingtitle_languages ON (paintingtitle_languages.id = paintingtitles.language_id) ", :conditions => cond, :page => page, :per_page => APP_CONFIG['per_page'], :order => "id DESC" ) Now I wonder if this is a correct way of doing this. I need to fetch paintings with their title and description in different functions, but I don't want to specify this long join statement each time. Is there a cleaner way, for instance making use of the has_many through? e.g. has_many :paintingdescription_languages, :through => :paintingdescriptions, :source => :language has_many :paintingtitle_languages, :through => :paintingtitles, :source => :language But if I implement above 2 lines together with the following ones, then only paintingtitles are filtered by language, and not the paintingdescriptions: cond = {"languages.code" => language_code} cond['paintings.publish'] = 1 unless admin paginate( :all, :select => ["paintings.id, paintings.publish, paintings.photo_file_name, paintingtitles.title, paintingdescriptions.description"], :joins => [:paintingdescription_languages, :paintingtitle_languages], :conditions => cond, :page => page, :per_page => APP_CONFIG['per_page'], :order => "id DESC" )

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  • Implementing a generic repository for WCF data services

    - by cibrax
    The repository implementation I am going to discuss here is not exactly what someone would call repository in terms of DDD, but it is an abstraction layer that becomes handy at the moment of unit testing the code around this repository. In other words, you can easily create a mock to replace the real repository implementation. The WCF Data Services update for .NET 3.5 introduced a nice feature to support two way data bindings, which is very helpful for developing WPF or Silverlight based application but also for implementing the repository I am going to talk about. As part of this feature, the WCF Data Services Client library introduced a new collection DataServiceCollection<T> that implements INotifyPropertyChanged to notify the data context (DataServiceContext) about any change in the association links. This means that it is not longer necessary to manually set or remove the links in the data context when an item is added or removed from a collection. Before having this new collection, you basically used the following code to add a new item to a collection. Order order = new Order {   Name = "Foo" }; OrderItem item = new OrderItem {   Name = "bar",   UnitPrice = 10,   Qty = 1 }; var context = new OrderContext(); context.AddToOrders(order); context.AddToOrderItems(item); context.SetLink(item, "Order", order); context.SaveChanges(); Now, thanks to this new collection, everything is much simpler and similar to what you have in other ORMs like Entity Framework or L2S. Order order = new Order {   Name = "Foo" }; OrderItem item = new OrderItem {   Name = "bar",   UnitPrice = 10,   Qty = 1 }; order.Items.Add(item); var context = new OrderContext(); context.AddToOrders(order); context.SaveChanges(); In order to use this new feature, you first need to enable V2 in the data service, and then use some specific arguments in the datasvcutil tool (You can find more information about this new feature and how to use it in this post). DataSvcUtil /uri:"http://localhost:3655/MyDataService.svc/" /out:Reference.cs /dataservicecollection /version:2.0 Once you use those two arguments, the generated proxy classes will use DataServiceCollection<T> rather than a simple ObjectCollection<T>, which was the default collection in V1. There are some aspects that you need to know to use this feature correctly. 1. All the entities retrieved directly from the data context with a query track the changes and report those to the data context automatically. 2. A entity created with “new” does not track any change in the properties or associations. In order to enable change tracking in this entity, you need to do the following trick. public Order CreateOrder() {   var collection = new DataServiceCollection<Order>(this.context);   var order = new Order();   collection.Add(order);   return order; } You basically need to create a collection, and add the entity to that collection with the “Add” method to enable change tracking on that entity. 3. If you need to attach an existing entity (For example, if you created the entity with the “new” operator rather than retrieving it from the data context with a query) to a data context for tracking changes, you can use the “Load” method in the DataServiceCollection. var order = new Order {   Id = 1 }; var collection = new DataServiceCollection<Order>(this.context); collection.Load(order); In this case, the order with Id = 1 must exist on the data source exposed by the Data service. Otherwise, you will get an error because the entity did not exist. These cool extensions methods discussed by Stuart Leeks in this post to replace all the magic strings in the “Expand” operation with Expression Trees represent another feature I am going to use to implement this generic repository. Thanks to these extension methods, you could replace the following query with magic strings by a piece of code that only uses expressions. Magic strings, var customers = dataContext.Customers .Expand("Orders")         .Expand("Orders/Items") Expressions, var customers = dataContext.Customers .Expand(c => c.Orders.SubExpand(o => o.Items)) That query basically returns all the customers with their orders and order items. Ok, now that we have the automatic change tracking support and the expression support for explicitly loading entity associations, we are ready to create the repository. The interface for this repository looks like this,public interface IRepository { T Create<T>() where T : new(); void Update<T>(T entity); void Delete<T>(T entity); IQueryable<T> RetrieveAll<T>(params Expression<Func<T, object>>[] eagerProperties); IQueryable<T> Retrieve<T>(Expression<Func<T, bool>> predicate, params Expression<Func<T, object>>[] eagerProperties); void Attach<T>(T entity); void SaveChanges(); } The Retrieve and RetrieveAll methods are used to execute queries against the data service context. While both methods receive an array of expressions to load associations explicitly, only the Retrieve method receives a predicate representing the “where” clause. The following code represents the final implementation of this repository.public class DataServiceRepository: IRepository { ResourceRepositoryContext context; public DataServiceRepository() : this (new DataServiceContext()) { } public DataServiceRepository(DataServiceContext context) { this.context = context; } private static string ResolveEntitySet(Type type) { var entitySetAttribute = (EntitySetAttribute)type.GetCustomAttributes(typeof(EntitySetAttribute), true).FirstOrDefault(); if (entitySetAttribute != null) return entitySetAttribute.EntitySet; return null; } public T Create<T>() where T : new() { var collection = new DataServiceCollection<T>(this.context); var entity = new T(); collection.Add(entity); return entity; } public void Update<T>(T entity) { this.context.UpdateObject(entity); } public void Delete<T>(T entity) { this.context.DeleteObject(entity); } public void Attach<T>(T entity) { var collection = new DataServiceCollection<T>(this.context); collection.Load(entity); } public IQueryable<T> Retrieve<T>(Expression<Func<T, bool>> predicate, params Expression<Func<T, object>>[] eagerProperties) { var entitySet = ResolveEntitySet(typeof(T)); var query = context.CreateQuery<T>(entitySet); foreach (var e in eagerProperties) { query = query.Expand(e); } return query.Where(predicate); } public IQueryable<T> RetrieveAll<T>(params Expression<Func<T, object>>[] eagerProperties) { var entitySet = ResolveEntitySet(typeof(T)); var query = context.CreateQuery<T>(entitySet); foreach (var e in eagerProperties) { query = query.Expand(e); } return query; } public void SaveChanges() { this.context.SaveChanges(SaveChangesOptions.Batch); } } For instance, you can use the following code to retrieve customers with First name equal to “John”, and all their orders in a single call. repository.Retrieve<Customer>(    c => c.FirstName == “John”, //Where    c => c.Orders.SubExpand(o => o.Items)); In case, you want to have some pre-defined queries that you are going to use across several places, you can put them in an specific class. public static class CustomerQueries {   public static Expression<Func<Customer, bool>> LastNameEqualsTo(string lastName)   {     return c => c.LastName == lastName;   } } And then, use it with the repository. repository.Retrieve<Customer>(    CustomerQueries.LastNameEqualsTo("foo"),    c => c.Orders.SubExpand(o => o.Items));

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  • How do I set up MVP for a Winforms solution?

    - by JonWillis
    Question moved from Stackoverflow - http://stackoverflow.com/questions/4971048/how-do-i-set-up-mvp-for-a-winforms-solution I have used MVP and MVC in the past, and I prefer MVP as it controls the flow of execution so much better in my opinion. I have created my infrastructure (datastore/repository classes) and use them without issue when hard coding sample data, so now I am moving onto the GUI and preparing my MVP. Section A I have seen MVP using the view as the entry point, that is in the views constructor method it creates the presenter, which in turn creates the model, wiring up events as needed. I have also seen the presenter as the entry point, where a view, model and presenter are created, this presenter is then given a view and model object in its constructor to wire up the events. As in 2, but the model is not passed to the presenter. Instead the model is a static class where methods are called and responses returned directly. Section B In terms of keeping the view and model in sync I have seen. Whenever a value in the view in changed, i.e. TextChanged event in .Net/C#. This fires a DataChangedEvent which is passed through into the model, to keep it in sync at all times. And where the model changes, i.e. a background event it listens to, then the view is updated via the same idea of raising a DataChangedEvent. When a user wants to commit changes a SaveEvent it fires, passing through into the model to make the save. In this case the model mimics the view's data and processes actions. Similar to #b1, however the view does not sync with the model all the time. Instead when the user wants to commit changes, SaveEvent is fired and the presenter grabs the latest details and passes them into the model. in this case the model does not know about the views data until it is required to act upon it, in which case it is passed all the needed details. Section C Displaying of business objects in the view, i.e. a object (MyClass) not primitive data (int, double) The view has property fields for all its data that it will display as domain/business objects. Such as view.Animals exposes a IEnumerable<IAnimal> property, even though the view processes these into Nodes in a TreeView. Then for the selected animal it would expose SelectedAnimal as IAnimal property. The view has no knowledge of domain objects, it exposes property for primitive/framework (.Net/Java) included objects types only. In this instance the presenter will pass an adapter object the domain object, the adapter will then translate a given business object into the controls visible on the view. In this instance the adapter must have access to the actual controls on the view, not just any view so becomes more tightly coupled. Section D Multiple views used to create a single control. i.e. You have a complex view with a simple model like saving objects of different types. You could have a menu system at the side with each click on an item the appropriate controls are shown. You create one huge view, that contains all of the individual controls which are exposed via the views interface. You have several views. You have one view for the menu and a blank panel. This view creates the other views required but does not display them (visible = false), this view also implements the interface for each view it contains (i.e. child views) so it can expose to one presenter. The blank panel is filled with other views (Controls.Add(myview)) and ((myview.visible = true). The events raised in these "child"-views are handled by the parent view which in turn pass the event to the presenter, and visa versa for supplying events back down to child elements. Each view, be it the main parent or smaller child views are each wired into there own presenter and model. You can literately just drop a view control into an existing form and it will have the functionality ready, just needs wiring into a presenter behind the scenes. Section E Should everything have an interface, now based on how the MVP is done in the above examples will affect this answer as they might not be cross-compatible. Everything has an interface, the View, Presenter and Model. Each of these then obviously has a concrete implementation. Even if you only have one concrete view, model and presenter. The View and Model have an interface. This allows the views and models to differ. The presenter creates/is given view and model objects and it just serves to pass messages between them. Only the View has an interface. The Model has static methods and is not created, thus no need for an interface. If you want a different model, the presenter calls a different set of static class methods. Being static the Model has no link to the presenter. Personal thoughts From all the different variations I have presented (most I have probably used in some form) of which I am sure there are more. I prefer A3 as keeping business logic reusable outside just MVP, B2 for less data duplication and less events being fired. C1 for not adding in another class, sure it puts a small amount of non unit testable logic into a view (how a domain object is visualised) but this could be code reviewed, or simply viewed in the application. If the logic was complex I would agree to an adapter class but not in all cases. For section D, i feel D1 creates a view that is too big atleast for a menu example. I have used D2 and D3 before. Problem with D2 is you end up having to write lots of code to route events to and from the presenter to the correct child view, and its not drag/drop compatible, each new control needs more wiring in to support the single presenter. D3 is my prefered choice but adds in yet more classes as presenters and models to deal with the view, even if the view happens to be very simple or has no need to be reused. i think a mixture of D2 and D3 is best based on circumstances. As to section E, I think everything having an interface could be overkill I already do it for domain/business objects and often see no advantage in the "design" by doing so, but it does help in mocking objects in tests. Personally I would see E2 as a classic solution, although have seen E3 used in 2 projects I have worked on previously. Question Am I implementing MVP correctly? Is there a right way of going about it? I've read Martin Fowler's work that has variations, and I remember when I first started doing MVC, I understood the concept, but could not originally work out where is the entry point, everything has its own function but what controls and creates the original set of MVC objects.

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  • Entity Framework v1 &ndash; tips and Tricks Part 3

    - by Rohit Gupta
    General Tips on Entity Framework v1 & Linq to Entities: ToTraceString() If you need to know the underlying SQL that the EF generates for a Linq To Entities query, then use the ToTraceString() method of the ObjectQuery class. (or use LINQPAD) Note that you need to cast the LINQToEntities query to ObjectQuery before calling TotraceString() as follows: 1: string efSQL = ((ObjectQuery)from c in ctx.Contact 2: where c.Address.Any(a => a.CountryRegion == "US") 3: select c.ContactID).ToTraceString(); ================================================================================ MARS or MultipleActiveResultSet When you create a EDM Model (EDMX file) from the database using Visual Studio, it generates a connection string with the same name as the name of the EntityContainer in CSDL. In the ConnectionString so generated it sets the MultipleActiveResultSet attribute to true by default. So if you are running the following query then it streams multiple readers over the same connection: 1: using (BAEntities context = new BAEntities()) 2: { 3: var cons = 4: from con in context.Contacts 5: where con.FirstName == "Jose" 6: select con; 7: foreach (var c in cons) 8: { 9: if (c.AddDate < new System.DateTime(2007, 1, 1)) 10: { 11: c.Addresses.Load(); 12: } 13: } 14: } ================================================================================= Explicitly opening and closing EntityConnection When you call ToList() or foreach on a LINQToEntities query the EF automatically closes the connection after all the records from the query have been consumed. Thus if you need to run many LINQToEntities queries over the same connection then explicitly open and close the connection as follows: 1: using (BAEntities context = new BAEntities()) 2: { 3: context.Connection.Open(); 4: var cons = from con in context.Contacts where con.FirstName == "Jose" 5: select con; 6: var conList = cons.ToList(); 7: var allCustomers = from con in context.Contacts.OfType<Customer>() 8: select con; 9: var allcustList = allCustomers.ToList(); 10: context.Connection.Close(); 11: } ====================================================================== Dispose ObjectContext only if required After you retrieve entities using the ObjectContext and you are not explicitly disposing the ObjectContext then insure that your code does consume all the records from the LinqToEntities query by calling .ToList() or foreach statement, otherwise the the database connection will remain open and will be closed by the garbage collector when it gets to dispose the ObjectContext. Secondly if you are making updates to the entities retrieved using LinqToEntities then insure that you dont inadverdently dispose of the ObjectContext after the entities are retrieved and before calling .SaveChanges() since you need the SAME ObjectContext to keep track of changes made to the Entities (by using ObjectStateEntry objects). So if you do need to explicitly dispose of the ObjectContext do so only after calling SaveChanges() and only if you dont need to change track the entities retrieved any further. ======================================================================= SQL InjectionAttacks under control with EFv1 LinqToEntities and LinqToSQL queries are parameterized before they are sent to the DB hence they are not vulnerable to SQL Injection attacks. EntitySQL may be slightly vulnerable to attacks since it does not use parameterized queries. However since the EntitySQL demands that the query be valid Entity SQL syntax and valid native SQL syntax at the same time. So the only way one can do a SQLInjection Attack is by knowing the SSDL of the EDM Model and be able to write the correct EntitySQL (note one cannot append regular SQL since then the query wont be a valid EntitySQL syntax) and append it to a parameter. ====================================================================== Improving Performance You can convert the EntitySets and AssociationSets in a EDM Model into precompiled Views using the edmgen utility. for e.g. the Customer Entity can be converted into a precompiled view using edmgen and all LinqToEntities query against the contaxt.Customer EntitySet will use the precompiled View instead of the EntitySet itself (the same being true for relationships (EntityReference & EntityCollections of a Entity)). The advantage being that when using precompiled views the performance will be much better. The syntax for generating precompiled views for a existing EF project is : edmgen /mode:ViewGeneration /inssdl:BAModel.ssdl /incsdl:BAModel.csdl /inmsl:BAModel.msl /p:Chap14.csproj Note that this will only generate precompiled views for EntitySets and Associations and not for existing LinqToEntities queries in the project.(for that use CompiledQuery.Compile<>) Secondly if you have a LinqToEntities query that you need to run multiple times, then one should precompile the query using CompiledQuery.Compile method. The CompiledQuery.Compile<> method accepts a lamda expression as a parameter, which denotes the LinqToEntities query  that you need to precompile. The following is a example of a lamda that we can pass into the CompiledQuery.Compile() method 1: Expression<Func<BAEntities, string, IQueryable<Customer>>> expr = (BAEntities ctx1, string loc) => 2: from c in ctx1.Contacts.OfType<Customer>() 3: where c.Reservations.Any(r => r.Trip.Destination.DestinationName == loc) 4: select c; Then we call the Compile Query as follows: 1: var query = CompiledQuery.Compile<BAEntities, string, IQueryable<Customer>>(expr); 2:  3: using (BAEntities ctx = new BAEntities()) 4: { 5: var loc = "Malta"; 6: IQueryable<Customer> custs = query.Invoke(ctx, loc); 7: var custlist = custs.ToList(); 8: foreach (var item in custlist) 9: { 10: Console.WriteLine(item.FullName); 11: } 12: } Note that if you created a ObjectQuery or a Enitity SQL query instead of the LINQToEntities query, you dont need precompilation for e.g. 1: An Example of EntitySQL query : 2: string esql = "SELECT VALUE c from Contacts AS c where c is of(BAGA.Customer) and c.LastName = 'Gupta'"; 3: ObjectQuery<Customer> custs = CreateQuery<Customer>(esql); 1: An Example of ObjectQuery built using ObjectBuilder methods: 2: from c in Contacts.OfType<Customer>().Where("it.LastName == 'Gupta'") 3: select c This is since the Query plan is cached and thus the performance improves a bit, however since the ObjectQuery or EntitySQL query still needs to materialize the results into Entities hence it will take the same amount of performance hit as with LinqToEntities. However note that not ALL EntitySQL based or QueryBuilder based ObjectQuery plans are cached. So if you are in doubt always create a LinqToEntities compiled query and use that instead ============================================================ GetObjectStateEntry Versus GetObjectByKey We can get to the Entity being referenced by the ObjectStateEntry via its Entity property and there are helper methods in the ObjectStateManager (osm.TryGetObjectStateEntry) to get the ObjectStateEntry for a entity (for which we know the EntityKey). Similarly The ObjectContext has helper methods to get an Entity i.e. TryGetObjectByKey(). TryGetObjectByKey() uses GetObjectStateEntry method under the covers to find the object, however One important difference between these 2 methods is that TryGetObjectByKey queries the database if it is unable to find the object in the context, whereas TryGetObjectStateEntry only looks in the context for existing entries. It will not make a trip to the database ============================================================= POCO objects with EFv1: To create POCO objects that can be used with EFv1. We need to implement 3 key interfaces: IEntityWithKey IEntityWithRelationships IEntityWithChangeTracker Implementing IEntityWithKey is not mandatory, but if you dont then we need to explicitly provide values for the EntityKey for various functions (for e.g. the functions needed to implement IEntityWithChangeTracker and IEntityWithRelationships). Implementation of IEntityWithKey involves exposing a property named EntityKey which returns a EntityKey object. Implementation of IEntityWithChangeTracker involves implementing a method named SetChangeTracker since there can be multiple changetrackers (Object Contexts) existing in memory at the same time. 1: public void SetChangeTracker(IEntityChangeTracker changeTracker) 2: { 3: _changeTracker = changeTracker; 4: } Additionally each property in the POCO object needs to notify the changetracker (objContext) that it is updating itself by calling the EntityMemberChanged and EntityMemberChanging methods on the changeTracker. for e.g.: 1: public EntityKey EntityKey 2: { 3: get { return _entityKey; } 4: set 5: { 6: if (_changeTracker != null) 7: { 8: _changeTracker.EntityMemberChanging("EntityKey"); 9: _entityKey = value; 10: _changeTracker.EntityMemberChanged("EntityKey"); 11: } 12: else 13: _entityKey = value; 14: } 15: } 16: ===================== Custom Property ==================================== 17:  18: [EdmScalarPropertyAttribute(IsNullable = false)] 19: public System.DateTime OrderDate 20: { 21: get { return _orderDate; } 22: set 23: { 24: if (_changeTracker != null) 25: { 26: _changeTracker.EntityMemberChanging("OrderDate"); 27: _orderDate = value; 28: _changeTracker.EntityMemberChanged("OrderDate"); 29: } 30: else 31: _orderDate = value; 32: } 33: } Finally you also need to create the EntityState property as follows: 1: public EntityState EntityState 2: { 3: get { return _changeTracker.EntityState; } 4: } The IEntityWithRelationships involves creating a property that returns RelationshipManager object: 1: public RelationshipManager RelationshipManager 2: { 3: get 4: { 5: if (_relManager == null) 6: _relManager = RelationshipManager.Create(this); 7: return _relManager; 8: } 9: } ============================================================ Tip : ProviderManifestToken – change EDMX File to use SQL 2008 instead of SQL 2005 To use with SQL Server 2008, edit the EDMX file (the raw XML) changing the ProviderManifestToken in the SSDL attributes from "2005" to "2008" ============================================================= With EFv1 we cannot use Structs to replace a anonymous Type while doing projections in a LINQ to Entities query. While the same is supported with LINQToSQL, it is not with LinqToEntities. For e.g. the following is not supported with LinqToEntities since only parameterless constructors and initializers are supported in LINQ to Entities. (the same works with LINQToSQL) 1: public struct CompanyInfo 2: { 3: public int ID { get; set; } 4: public string Name { get; set; } 5: } 6: var companies = (from c in dc.Companies 7: where c.CompanyIcon == null 8: select new CompanyInfo { Name = c.CompanyName, ID = c.CompanyId }).ToList(); ;

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  • Updating entities in response to collisions - should this be in the collision-detection class or in the entity-updater class?

    - by Prog
    In a game I'm working on, there's a class responsible for collision detection. It's method detectCollisions(List<Entity> entities) is called from the main gameloop. The code to update the entities (i.e. where the entities 'act': update their positions, invoke AI, etc) is in a different class, in the method updateEntities(List<Entity> entities). Also called from the gameloop, after the collision detection. When there's a collision between two entities, usually something needs to be done. For example, zero the velocity of both entities in the collision, or kill one of the entities. It would be easy to have this code in the CollisionDetector class. E.g. in psuedocode: for(Entity entityA in entities){ for(Entity entityB in entities){ if(collision(entityA, entityB)){ if(entityA instanceof Robot && entityB instanceof Robot){ entityA.setVelocity(0,0); entityB.setVelocity(0,0); } if(entityA instanceof Missile || entityB instanceof Missile){ entityA.die(); entityB.die(); } } } } However, I'm not sure if updating the state of entities in response to collision should be the job of CollisionDetector. Maybe it should be the job of EntityUpdater, which runs after the collision detection in the gameloop. Is it okay to have the code responding to collisions in the collision detection system? Or should the collision detection class only detect collisions, report them to some other class and have that class affect the state of the entities?

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  • Combobox with collection view itemssource does not update selection box item on changes to the Model

    - by Vinit Sankhe
    Hello, Sorry for the earlier lengthy post. Here is my concise (!) description. I bind a collection view to a combobox as a itemsSource and also bind its selectedvalue with a property from my view model. I must keep IsSynchronizedWithCurrentItem="False". I change the source list ofr the view and then refresh the view. The changed (added, removed, edited) items appear correctly in the item list of the combo. But problem is with the selected item. When I change its property which is also the displaymember path of the combo, the changed property value does not reflect back on the selecton box of the combo. If you open the combo dropdown it appears correctly on the item list but not on the selection box. Now if I change the combobox tag to Listbox in my XAML (keeping all attributes as it is) then when selected item's displaymember property value is updated, the changes reflect back on the selected item of the list box . Why this issue? Just FYI: My View Model has properties EmployeeCollectionView and SelectedEmployeeId which are bound to combo as ItemsSource and SelectedValue resp. This VM implements the INotifyPropertyChanged interface. My core employee class (list of which is the source for the EmployeeCollectionView) is simply a Model class without INotifyPropertyChanged. DisplayMemberPath is "Name" property of employee Model class. I change this by some means and expect the combo selection box to update the value. I tried refreshing ther SelectedEmployeeId by setting it 0 (where it correctly selects the dummy "-- Select All --" employee entry from itemsSource) and old selected value back. But no use. The old value takes me back to the old label. Items collection has latest entry though. When I make combobox's IsEditable=True before the view's refresh and after refresh I make IsEditable=False then the things work out correctly! But this is a patch and is unnecessary. Thx Vinit Sankhe

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