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  • How do I ensure that a JPanel Shrinks when the parent frame is resized?

    - by dah
    I have a basic notes panel that I'm looking to shrink the width of when the parent jframe is resized but it isn't happening. I'm using nested gridbaglayouts. package com.protocase.notes.views; import com.protocase.notes.controller.NotesController; import com.protocase.notes.model.Subject; import com.protocase.notes.model.Note; import com.protocase.notes.model.database.PMSNotesAdapter; import java.awt.Color; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import javax.swing.BorderFactory; import javax.swing.JButton; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JScrollPane; /** * @author DavidH */ public class NotesViewer extends JPanel { // <editor-fold defaultstate="collapsed" desc="Attributes"> private Subject subject; private NotesController controller; //</editor-fold> // <editor-fold defaultstate="collapsed" desc="Getters N' Setters"> /** * Gets back the current subject. * @return */ public Subject getSubject() { return subject; } public NotesController getController() { return controller; } public void setController(NotesController controller) { this.controller = controller; } /** * Should clear the panel of the current subject and load the details for * the other object. * @param subject */ public void setSubject(Subject subject) { this.subject = subject; } //</editor-fold> // <editor-fold defaultstate="collapsed" desc="Constructor"> /** * -- Sets up a note viewer with a subject and a controller. Likely this * would be the constructor used if you were passing off from another * NoteViewer or something else that used a notes adapter or controller. * @param subject * @param controller */ public NotesViewer(Subject subject, NotesController controller) { this.subject = subject; this.controller = controller; initComponents(); } /** * -- Sets up a note view with a subject and creates a new controller. This * would be the constructor typically chosen if choosing notes was * infrequent and only one or two notes needs to be displayed. * @param subject */ public NotesViewer(Subject subject) { this(subject, new NotesController(new PMSNotesAdapter())); } /** * -- Sets up a note view without a subject and creates a new controller. * This would be for a note viewer without any notes, perhaps populating * as you choose values in another form. * @param subject */ public NotesViewer() { this(null); } //</editor-fold> // <editor-fold defaultstate="collapsed" desc="initComponents()"> /** * Sets up the view for the NotesViewer */ private void initComponents() { // -- Make a new panel for the header JPanel panel = new JPanel(); panel.setLayout(new GridBagLayout()); GridBagConstraints c = new GridBagConstraints(); c.gridx = 0; c.fill = GridBagConstraints.HORIZONTAL; c.gridy = 0; c.weightx = .5; //c.anchor = GridBagConstraints.NORTHWEST; JLabel label = new JLabel("Viewing Notes for [Subject]"); label.setAlignmentX(JLabel.LEFT_ALIGNMENT); label.setBorder(BorderFactory.createLineBorder(Color.YELLOW)); panel.add(label); JButton newNoteButton = new JButton("New"); c = new GridBagConstraints(); // c.fill = GridBagConstraints.HORIZONTAL; c.gridx = 1; c.gridy = 0; c.weightx = .5; c.anchor = GridBagConstraints.EAST; panel.add(newNoteButton, c); // -- NotePanels c = new GridBagConstraints(); c.fill = GridBagConstraints.HORIZONTAL; c.weightx = 1; c.weighty = 1; c.gridx = 0; c.gridwidth = 2; int y = 1; for (Note n : subject.getNotes()) { c.gridy = y++; panel.add(new NotesPanel(n, controller), c); } this.setLayout(new GridBagLayout()); GridBagConstraints pc = new GridBagConstraints(); pc.gridx = 0; pc.gridy = 0; pc.weightx = 1; pc.weighty = 1; pc.fill = GridBagConstraints.BOTH; panel.setBackground(Color.blue); JScrollPane scroll = new JScrollPane(); scroll.setViewportView(panel); //scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); this.add(scroll, pc); //this.add(panel, pc); // -- Add it all to the layout } //</editor-fold> // <editor-fold defaultstate="collapsed" desc="private methods"> //</editor-fold> } package com.protocase.notes.views; import com.protocase.notes.controller.NotesController; import com.protocase.notes.model.Note; import java.awt.CardLayout; import java.awt.Color; import java.awt.Component; import java.awt.Dimension; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.text.DateFormat; import java.text.SimpleDateFormat; import javax.swing.BorderFactory; import javax.swing.JButton; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.JTextField; import javax.swing.border.BevelBorder; import javax.swing.border.Border; import javax.swing.border.MatteBorder; /** * @author dah01 */ public class NotesPanel extends JPanel { // <editor-fold defaultstate="collapsed" desc="Attributes"> private Note note; private NotesController controller; private CardLayout cardLayout; private JTextArea viewTextArea; private JTextArea editTextArea; //</editor-fold> // <editor-fold defaultstate="collapsed" desc="Getters N' Setters"> public NotesController getController() { return controller; } public void setController(NotesController controller) { this.controller = controller; } public Note getNote() { return note; } public void setNote(Note note) { this.note = note; } //</editor-fold> // <editor-fold defaultstate="collapsed" desc="Constructor"> /** * Sets up a note panel that shows everything about the note. * @param note */ public NotesPanel(Note note, NotesController controller) { this.note = note; cardLayout = new CardLayout(); this.setLayout(cardLayout); // -- Setup the layout manager. this.setBackground(new Color(199, 187, 192)); this.setBorder(new BevelBorder(BevelBorder.RAISED)); // -- ViewPanel this.add("ViewPanel", initViewPanel()); this.add("EditPanel", initEditPanel()); } //</editor-fold> // <editor-fold defaultstate="collapsed" desc="EditPanel"> private JPanel initEditPanel() { JPanel editPanel = new JPanel(); editPanel.setLayout(new GridBagLayout()); GridBagConstraints c = new GridBagConstraints(); c.fill = GridBagConstraints.HORIZONTAL; c.gridy = 0; c.weightx = 1; c.weighty = 0.3; editPanel.add(initCreatorLabel(), c); c.gridy++; editPanel.add(initEditTextScroll(), c); c.gridy++; c.anchor = GridBagConstraints.WEST; c.fill = GridBagConstraints.NONE; editPanel.add(initEditorLabel(), c); c.gridx++; c.anchor = GridBagConstraints.EAST; editPanel.add(initSaveButton(), c); return editPanel; } private JScrollPane initEditTextScroll() { this.editTextArea = new JTextArea(note.getContents()); editTextArea.setLineWrap(true); editTextArea.setWrapStyleWord(true); JScrollPane scrollPane = new JScrollPane(editTextArea); scrollPane.setAlignmentX(JScrollPane.LEFT_ALIGNMENT); Border b = scrollPane.getViewportBorder(); MatteBorder mb = BorderFactory.createMatteBorder(2, 2, 2, 2, Color.BLUE); scrollPane.setBorder(mb); return scrollPane; } private JButton initSaveButton() { final CardLayout l = this.cardLayout; final JPanel p = this; final NotesController c = this.controller; final Note n = this.note; final JTextArea noteText = this.viewTextArea; final JTextArea textToSubmit = this.editTextArea; ActionListener al = new ActionListener() { @Override public void actionPerformed(ActionEvent e) { //controller.saveNote(n); noteText.setText(textToSubmit.getText()); l.next(p); } }; JButton saveButton = new JButton("Save"); saveButton.addActionListener(al); saveButton.setPreferredSize(new Dimension(62, 26)); return saveButton; } //</editor-fold> // <editor-fold defaultstate="collapsed" desc="ViewPanel"> private JPanel initViewPanel() { JPanel viewPanel = new JPanel(); viewPanel.setLayout(new GridBagLayout()); GridBagConstraints c = new GridBagConstraints(); c.fill = GridBagConstraints.HORIZONTAL ; c.gridy = 0; c.weightx = 1; c.weighty = 0.3; viewPanel.add(initCreatorLabel(), c); c.gridy++; viewPanel.add(this.initNoteTextArea(), c); c.fill = GridBagConstraints.NONE; c.anchor = GridBagConstraints.WEST; c.gridy++; viewPanel.add(initEditorLabel(), c); c.gridx++; c.anchor = GridBagConstraints.EAST; viewPanel.add(initEditButton(), c); return viewPanel; } private JLabel initCreatorLabel() { DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); if (note != null) { String noteBy = "Note by " + note.getCreator(); String noteCreated = formatter.format(note.getDateCreated()); JLabel creatorLabel = new JLabel(noteBy + " @ " + noteCreated); creatorLabel.setAlignmentX(JLabel.LEFT_ALIGNMENT); return creatorLabel; } else { System.out.println("NOTE IS NULL"); return null; } } private JScrollPane initNoteTextArea() { // -- Setup the notes area. this.viewTextArea = new JTextArea(note.getContents()); viewTextArea.setEditable(false); viewTextArea.setLineWrap(true); viewTextArea.setWrapStyleWord(true); JScrollPane scrollPane = new JScrollPane(viewTextArea); scrollPane.setAlignmentX(JScrollPane.LEFT_ALIGNMENT); return scrollPane; } private JLabel initEditorLabel() { // -- Setup the edited by label. JLabel editorLabel = new JLabel(" -- Last edited by " + note.getLastEdited() + " at " + note.getDateModified()); editorLabel.setAlignmentX(Component.LEFT_ALIGNMENT); return editorLabel; } private JButton initEditButton() { final CardLayout l = this.cardLayout; final JPanel p = this; ActionListener ar = new ActionListener() { @Override public void actionPerformed(ActionEvent e) { l.next(p); } }; JButton editButton = new JButton("Edit"); editButton.setPreferredSize(new Dimension(62,26)); editButton.addActionListener(ar); return editButton; } //</editor-fold> // <editor-fold defaultstate="collapsed" desc="Grow Width When Resized"> @Override public Dimension getPreferredSize() { int fw = this.getParent().getSize().width; int fh = super.getPreferredSize().height; return new Dimension(fw,fh); } //</editor-fold> }

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  • DDD and validation of aggregate root

    - by Mik378
    Suppose an aggregate root : MailConfiguration (wrapping an AddressPart object). The AddressPart object is a simple immutable value object with some fields like senderAdress, recipentAddress (to make example simple). As being an invariant object, AddressPart should logically wrap its own Validator (by the way of external a kind of AddressValidator for respecting Single Responsibility Principle) I read some articles that claimed an aggregateRoot must validate its 'children'. However, if we follow this principle, one could create an AddressPart with an uncohesive/invalid state. What are your opinion? Should I move the collaborator AddressValidator(used in constructor so in order to validate immediately the cohesion of an AddressPart) from AddressPart and assign it to aggregateRoot (MailConfiguration) ?

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  • Of which bad practice is require calling functions in order a sign?

    - by stijn
    Sometimes I find myself writing comments on class methods like this: class A : public Base { public: /** * Sets variable; * should be called before ImplementsInterfaceMtehod(), * else has no effect. */ void SetSomeVariable( var_type value ); virtual void ImplementsInterfaceMethod(); } The callers of Base::ImplementsInterfaceMethod obviously do not know about the variable, and should not. But the users of A should set the variable if they want it to take effect. It is not required to set the variable (else it could be a parameter for the constructor), so I cannot throw exceptions in ImplementsInterfaceMethod if it is not set. Is this a sign of some typical bad practice? Is there a better way than writing a comment as shown to deal with this?

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  • Is it bad practice to use the same name for arguments and members?

    - by stijn
    Sometimes I write constructor code like class X { public: X( const int numberOfThingsToDo ) : numberOfThingsToDo( numberOfThingsToDo ) { } private: int numberOfThingsToDo; }; or in C# class X { public X( int numberOfThingsToDo ) { this.numberOfThingsToDo = numberOfThingsToDo; } private int numberOfThingsToDo; } I think the main reason is that when I come up with a suitable member name, I see no reason to use a different one for the argument initializing it, and since I'm also no fan of using underscores the easiest is just to pick the same name. After all it's suitable. Is this considered bad practice however? Any drawbacks (apart from shooting yourself in the foot when forgetting the this in C#)?

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  • How can I access bitmaps created in another activity?

    - by user22241
    I am currently loading my game bitmaps when the user presses 'start' in my animated splash screen activity (the first / launch activity) and the app progresses from my this activity to the main game activity, This is causing choppy animation in the splashscreen while it loads/creates the bitmaps for the new activity. I've been told that I should load all my bitmaps in one go at the very beginning. However, I can't work out how to do this - could anyone please point me in the right direction? I have 2 activities, a splash screen and the main game. Each consist of a class that extends activity and a class that extends SurfaceView (with an inner class for the rendering / logic updating). So, for example at the moment I am creating my bitmaps in the constructor of my SurfaceView class like so: public class OptionsScreen extends SurfaceView implements SurfaceHolder.Callback { //Create variables here public OptionsScreen(Context context) { Create bitmaps here } public void intialise(){ //This method is called from onCreate() of corresponding application context // Create scaled bitmaps here (from bitmaps previously created) }

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  • How should I write new code when the old codebase and the environment uses lots of globals in PHP

    - by Nicola Peluchetti
    I'm working in the Wordpress environment which itself heavily relies on globals and the codebase I'm maintaining introduces some more. I want this to change and so I'm trying to think how should I handle this. For the globals our code has introduced I think I will set them as dependencies in the constructor or in getter / setter so that I don't rely on them being globals and then refactor the old codebase little by little so that we have no globals. With Wordpress globals I was thinking to wrap all WP globals inside a Wrapper class and hide them in there. Like this class WpGlobals { public static function getDb() { global $wpdb; return $wpdb; } } Would this be of any help? The idea is that I centralize all globals in one class and do not scatter them through the code, so that if Wordpress kills one of them I need to modify code only in one place. What would you do?

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  • In C++, is it a reflection of poor software design if objects are deleted manually?

    - by grokus
    With the advent of smart pointers, is it a sign of poor design if I see objects are deleted? I'm seeing some software components in our product that people are still doing this. This practice strikes me as un-idiomatic, but I need to be sure this is the industry consensus. I'm not starting a crusade but it'd be nice to be prepared theory wise. Edit: legit uses of delete, Klaim mentioned the object pool use case. I agree. Bad examples of using delete, I am seeing many new's in constructor or start() and corresponding delete's in the destructor or stop(), why not use scoped_ptr? It makes the code cleaner.

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  • Handling array passed to object at creation

    - by cecilli0n
    When creating my object I pass it an array of a row from my database. (everything in the array we will need, disregarding unnecessary elements at sql query level) When I need to access certain array elements from within my class, I do so like $this->row['element'] However, As I continue development, I sometimes forget what exactly is in this passed array.(this itself doesn't seem good) I am wondering if their is a professional approach to dealing with this, Or am I the only one who has these "I wonder whats in the array" thoughts. One approach to tackling this could be that when we originally pass the array, in the constructor, we assign each element of the array to its own variable, but is this considered professional practice? Additionally by doing this, we could make those variables constants, in a attempt at immutability. Overall I am trying to adhere to good software craftsmanship. Regards.

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  • Navigation in a #WP7 application with MVVM Light

    - by Laurent Bugnion
    In MVVM applications, it can be a bit of a challenge to send instructions to the view (for example a page) from a viewmodel. Thankfully, we have good tools at our disposal to help with that. In his excellent series “MVVM Light Toolkit soup to nuts”, Jesse Liberty proposes one approach using the MVVM Light messaging infrastructure. While this works fine, I would like to show here another approach using what I call a “view service”, i.e. an abstracted service that is invoked from the viewmodel, and implemented on the view. Multiple kinds of view services In fact, I use view services quite often, and even started standardizing them for the Windows Phone 7 applications I work on. If there is interest, I will be happy to show other such view services, for example Animation services, responsible to start/stop animations on the view. Dialog service, in charge of displaying messages to the user and gathering feedback. Navigation service, in charge of navigating to a given page directly from the viewmodel. In this article, I will concentrate on the navigation service. The INavigationService interface In most WP7 apps, the navigation service is used in quite a straightforward way. We want to: Navigate to a given URI. Go back. Be notified when a navigation is taking place, and be able to cancel. The INavigationService interface is quite simple indeed: public interface INavigationService { event NavigatingCancelEventHandler Navigating; void NavigateTo(Uri pageUri); void GoBack(); } Obviously, this interface can be extended if necessary, but in most of the apps I worked on, I found that this covers my needs. The NavigationService class It is possible to nicely pack the navigation service into its own class. To do this, we need to remember that all the PhoneApplicationPage instances use the same instance of the navigation service, exposed through their NavigationService property. In fact, in a WP7 application, it is the main frame (RootFrame, of type PhoneApplicationFrame) that is responsible for this task. So, our implementation of the NavigationService class can leverage this. First the class will grab the PhoneApplicationFrame and store a reference to it. Also, it registers a handler for the Navigating event, and forwards the event to the listening viewmodels (if any). Then, the NavigateTo and the GoBack methods are implemented. They are quite simple, because they are in fact just a gateway to the PhoneApplicationFrame. The whole class is as follows: public class NavigationService : INavigationService { private PhoneApplicationFrame _mainFrame; public event NavigatingCancelEventHandler Navigating; public void NavigateTo(Uri pageUri) { if (EnsureMainFrame()) { _mainFrame.Navigate(pageUri); } } public void GoBack() { if (EnsureMainFrame() && _mainFrame.CanGoBack) { _mainFrame.GoBack(); } } private bool EnsureMainFrame() { if (_mainFrame != null) { return true; } _mainFrame = Application.Current.RootVisual as PhoneApplicationFrame; if (_mainFrame != null) { // Could be null if the app runs inside a design tool _mainFrame.Navigating += (s, e) => { if (Navigating != null) { Navigating(s, e); } }; return true; } return false; } } Exposing URIs I find that it is a good practice to expose each page’s URI as a constant. In MVVM Light applications, a good place to do that is the ViewModelLocator, which already acts like a central point of setup for the views and their viewmodels. Note that in some cases, it is necessary to expose the URL as a string, for instance when a query string needs to be passed to the view. So for example we could have: public static readonly Uri MainPageUri = new Uri("/MainPage.xaml", UriKind.Relative); public const string AnotherPageUrl = "/AnotherPage.xaml?param1={0}&param2={1}"; Creating and using the NavigationService Normally, we only need one instance of the NavigationService class. In cases where you use an IOC container, it is easy to simply register a singleton instance. For example, I am using a modified version of a super simple IOC container, and so I can register the navigation service as follows: SimpleIoc.Register<INavigationService, NavigationService>(); Then, it can be resolved where needed with: SimpleIoc.Resolve<INavigationService>(); Or (more frequently), I simply declare a parameter on the viewmodel constructor of type INavigationService and let the IOC container do its magic and inject the instance of the NavigationService when the viewmodel is created. On supported platforms (for example Silverlight 4), it is also possible to use MEF. Or, of course, we can simply instantiate the NavigationService in the ViewModelLocator, and pass this instance as a parameter of the viewmodels’ constructor, injected as a property, etc… Once the instance has been passed to the viewmodel, it can be used, for example with: NavigationService.NavigateTo(ViewModelLocator.ComparisonPageUri); Testing Thanks to the INavigationService interface, navigation can be mocked and tested when the viewmodel is put under unit test. Simply implement and inject a mock class, and assert that the methods are called as they should by the viewmodel. Conclusion As usual, there are multiple ways to code a solution answering your needs. I find that view services are a really neat way to delegate view-specific responsibilities such as animation, dialogs and of course navigation to other classes through an abstracted interface. In some cases, such as the NavigationService class exposed here, it is even possible to standardize the implementation and pack it in a class library for reuse. I hope that this sample is useful! Happy coding. Laurent   Laurent Bugnion (GalaSoft) Subscribe | Twitter | Facebook | Flickr | LinkedIn

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  • Texture not drawing on cubes

    - by Christian Frantz
    I can draw the cubes fine but they are just solid black besides the occasional lighting that goes on. The basic effect is being set for each cube also. public void Draw(BasicEffect effect) { foreach (EffectPass pass in effect.CurrentTechnique.Passes) { pass.Apply(); device.SetVertexBuffer(vertexBuffer); device.Indices = indexBuffer; device.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, 8, 0, 12); } } The cubes draw method. TextureEnabled is set to true in my main draw method. My texture is also loading fine. public Cube(GraphicsDevice graphicsDevice, Vector3 Position, Texture2D Texture) { device = graphicsDevice; texture = Texture; cubePosition = Position; effect = new BasicEffect(device); } The constructor seems fine too. Could this be caused by the Vector2's of my VertexPositionNormalTexture? Even if they were out of order something should still be drawn other than a black cube

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  • Should I use the factory design pattern for every class?

    - by Frog
    I've been writing a website in PHP. As the code becomes more complex, I keep finding problems that can be solved using the factory design pattern. For example: I've a got a class Page which has subclasses HTMLPage, XMLPage, etc. Depending on some input I need to return an object of either one of these classes. I use the factory design pattern to do this. But as I encounter this problem in more classes, I keep having to change code which still initiates an object using its constructor. So now I'm wondering: is it a good idea to change all code so that it uses the factory design pattern? Or are there big drawbacks? I'm currently in a position to change this, so your answers would be really helpful.

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  • Loading assets in Monogame

    - by Matebu
    I'm creating a MonoGame application on Visual Studio 2012, yet when trying to load a texture I get the following problem: Could not load Menu/btnPlay asset! I have set content directory: Content.RootDirectory = "Assets"; Also the file btnPlay.png has properties set: Build Action: Content and Copy to Output directory: Copy if newer. My constructor and LoadContent functions are totally empty, but have a look yourself: public WizardGame() { Window.Title = "Just another Wizard game"; _graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Assets"; } protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. _spriteBatch = new SpriteBatch(GraphicsDevice); Texture2D texture = Content.Load<Texture2D>("Menu/btnPlay"); _graphics.IsFullScreen = true; _graphics.ApplyChanges(); } How do I properly load a texture?

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  • XNA content.load Dependancy

    - by Richard
    Quick question, My project i'm building for test purposes is working fine but i have dependencies flying around everywhere due to the XNA framework. In Update i have gametime passed everywhere... this is okay. In Draw i have gametime & spritebatch passed everywhere... this is okay. My issue is in the content.load textures/sounds/fonts. I have them as public variables ie Texture1 = Content.load(of texture2d)("Texture1") I'm passing a 'Game1' pointer into the constructor of every new class being instantiated to gain access to these variables. Am i missing an OOP trick to prevent me having to pass a pointer to 'game1' to every New class?

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  • Local LINQtoSQL Database For Your Windows Phone 7 Application

    - by Tim Murphy
    There aren’t many applications that are of value without having some for of data store.  In Windows Phone development we have a few options.  You can store text directly to isolated storage.  You can also use a number of third party libraries to create or mimic databases in isolated storage.  With Mango we gained the ability to have a native .NET database approach which uses LINQ to SQL.  In this article I will try to bring together the components needed to implement this last type of data store and fill in some of the blanks that I think other articles have left out. Defining A Database The first things you are going to need to do is define classes that represent your tables and a data context class that is used as the overall database definition.  The table class consists of column definitions as you would expect.  They can have relationships and constraints as with any relational DBMS.  Below is an example of a table definition. First you will need to add some assembly references to the code file. using System.ComponentModel;using System.Data.Linq;using System.Data.Linq.Mapping; You can then add the table class and its associated columns.  It needs to implement INotifyPropertyChanged and INotifyPropertyChanging.  Each level of the class needs to be decorated with the attribute appropriate for that part of the definition.  Where the class represents the table the properties represent the columns.  In this example you will see that the column is marked as a primary key and not nullable with a an auto generated value. You will also notice that the in the column property’s set method It uses the NotifyPropertyChanging and NotifyPropertyChanged methods in order to make sure that the proper events are fired. [Table]public class MyTable: INotifyPropertyChanged, INotifyPropertyChanging{ public event PropertyChangedEventHandler PropertyChanged; private void NotifyPropertyChanged(string propertyName) { if(PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } public event PropertyChangingEventHandler PropertyChanging; private void NotifyPropertyChanging(string propertyName) { if(PropertyChanging != null) { PropertyChanging(this, new PropertyChangingEventArgs(propertyName)); } } private int _TableKey; [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)] public int TableKey { get { return _TableKey; } set { NotifyPropertyChanging("TableKey"); _TableKey = value; NotifyPropertyChanged("TableKey"); } } The last part of the database definition that needs to be created is the data context.  This is a simple class that takes an isolated storage location connection string its constructor and then instantiates tables as public properties. public class MyDataContext: DataContext{ public MyDataContext(string connectionString): base(connectionString) { MyRecords = this.GetTable<MyTable>(); } public Table<MyTable> MyRecords;} Creating A New Database Instance Now that we have a database definition it is time to create an instance of the data context within our Windows Phone app.  When your app fires up it should check if the database already exists and create an instance if it does not.  I would suggest that this be part of the constructor of your ViewModel. db = new MyDataContext(connectionString);if(!db.DatabaseExists()){ db.CreateDatabase();} The next thing you have to know is how the connection string for isolated storage should be constructed.  The main sticking point I have found is that the database cannot be created unless the file mode is read/write.  You may have different connection strings but the initial one needs to be similar to the following. string connString = "Data Source = 'isostore:/MyApp.sdf'; File Mode = read write"; Using you database Now that you have done all the up front work it is time to put the database to use.  To make your life a little easier and keep proper separation between your view and your viewmodel you should add a couple of methods to the viewmodel.  These will do the CRUD work of your application.  What you will notice is that the SubmitChanges method is the secret sauce in all of the methods that change data. private myDataContext myDb;private ObservableCollection<MyTable> _viewRecords;public ObservableCollection<MyTable> ViewRecords{ get { return _viewRecords; } set { _viewRecords = value; NotifyPropertyChanged("ViewRecords"); }}public void LoadMedstarDbData(){ var tempItems = from MyTable myRecord in myDb.LocalScans select myRecord; ViewRecords = new ObservableCollection<MyTable>(tempItems);}public void SaveChangesToDb(){ myDb.SubmitChanges();}public void AddMyTableItem(MyTable newScan){ myDb.LocalScans.InsertOnSubmit(newScan); myDb.SubmitChanges();}public void DeleteMyTableItem(MyTable newScan){ myDb.LocalScans.DeleteOnSubmit(newScan); myDb.SubmitChanges();} Updating existing database What happens when you need to change the structure of your database?  Unfortunately you have to add code to your application that checks the version of the database which over time will create some pollution in your codes base.  On the other hand it does give you control of the update.  In this example you will see the DatabaseSchemaUpdater in action.  Assuming we added a “Notes” field to the MyTable structure, the following code will check if the database is the latest version and add the field if it isn’t. if(!myDb.DatabaseExists()){ myDb.CreateDatabase();}else{ DatabaseSchemaUpdater dbUdater = myDb.CreateDatabaseSchemaUpdater(); if(dbUdater.DatabaseSchemaVersion < 2) { dbUdater.AddColumn<MyTable>("Notes"); dbUdater.DatabaseSchemaVersion = 2; dbUdater.Execute(); }} Summary This approach does take a fairly large amount of work, but I think the end product is robust and very native for .NET developers.  It turns out to be worth the investment. del.icio.us Tags: Windows Phone,Windows Phone 7,LINQ to SQL,LINQ,Database,Isolated Storage

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  • best practice for initializing class members in php

    - by rgvcorley
    I have lots of code like this in my constructors:- function __construct($params) { $this->property = isset($params['property']) ? $params['property'] : default_val; } Is it better to do this rather than specify the default value in the property definition? i.e. public $property = default_val? Sometimes there is logic for the default value, and some default values are taken from other properties, which was why I was doing this in the constructor. Should I be using setters so all the logic for default values is separated?

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  • Using mocks to set up object even if you will not be mocking any behavior or verifying any interaction with it?

    - by smp7d
    When building a unit test, is it appropriate to use a mocking tool to assist you in setting up an object even if you will not be mocking any behavior or verifying any interaction with that object? Here is a simple example in pseudo-code: //an object we actually want to mock Object someMockedObject = Mock(Object.class); EqualityChecker checker = new EqualityChecker(someMockedObject); //an object we are mocking only to avoid figuring out how to instantiate or //tying ourselves to some constructor that may be removed in the future ComplicatedObject someObjectThatIsHardToInstantiate = Mock(ComplicatedObject.class); //set the expectation on the mock When(someMockedObject).equals(someObjectThatIsHardToInstantiate).return(false); Assert(equalityChecker.check(someObjectThatIsHardToInstantiate)).isFalse(); //verify that the mock was interacted with properly Verify(someMockedObject).equals(someObjectThatIsHardToInstantiate).oneTime(); Is it appropriate to mock ComplicatedObject in this scenario?

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  • should I create a new class for a specific piece of business logic?

    - by Riz
    I have a Request class based on the same Entity in my Domain. It currently only has property definitions. I'd like to add a method for checking a duplicate Request which I'll call from my controller. Should I add a method called CheckDuplicate in the Request class? Would I be violating the SRP? The method will need to access a database context to check already existing requests. I'm thinking creating another class altogether for this logic that accepts a datacontext as part of its constructor. But creating a whole new class for just one method seems like a waste too. Any advice?

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  • Domain Model and Querying

    - by Tyrsius
    I am new to DDD, having worked only in Transaction-Script apps with an anemic model, or just Big Balls of Mud, so please forgive any terminology I abuse. I am trying to understand the proper separation between the domain model and the repository. What is the proper way to construct a domain object that is coming from a database, assuming the (incredibly simplified) need to query for objects by status (returns enumerable), or by ID. Should a factory be building the objects, exposing methods for GetByStatus() and GetByID(), using a DIed repository? Should a repository be called directly, knowing how to build a domain model from the DTO? Should the domain model have a constructor for get by ID, using a DIed repoistory to load the initial state, using some other (?) method for the list? I am not really sure what the best way would be, and this question has an answer advocating each one (these are certainly mutuallu exclusive).

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  • using static methods and classes

    - by vedant1811
    I know that static methods/variables are associated with the class and not the objects of the class and are useful in situations when we need to keep count of, say the number of objects of the class that were created. Non-static members on the other hand may need to work on the specific object (i.e. to use the variables initialized by the constructor) My question what should we do when we need neither of the functionalities? Say I just need a utility function that accepts value(s) and returns a value besed solely on the values passed. I want to know whether such methods should be static or not. How is programming efficiency affected and which is a better coding practice/convention and why. PS: I don't want to spark off a debate, I just want a subjective answer and/or references.

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  • Should single purpose utility app use a class

    - by jmoreno
    When writing a small utility app, that does just one thing, should that one thing be encapsulated in a seperate class, or just let it be part of whatever class/module is used to start the application? I.e. Main would consist of 2 or three lines calling the constructor and then the DoIt methods, nothing else. Or should Main be the DoIt method, with whatever functions it needs added to the main class? Asking because I want to get some alternative perspective, but couldn't find a similar question. If my google-fu is bad and there's a dup, please close.

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  • Separating Db from business with Inherited classes using multiple views

    - by catalinux
    I have a software that has a car model that will be used in different views (listing, ads, detail page, carousel, up sell widget,etc). class CarModel extends DbModel{ } I look for a "nice way" (a combination of flexible, easy to maintain,etc) to have this used in views. I'm thinking at two different ways Having object views for each context CarViewBase{ var car;// of type CarModel function constructor(args){ //will instantienta internal variable car based on args } function getThumb(){ } function getTitle(){ } } CarListingView extends CarViewBase{ function getListing(){ } } CarAdsView extends CarViewBase{ //the busines rule changes for ads widget function getThumb(){ } } Extending directly the CarModel The challenges comes when My Car Model might need an abstract factory. Let's say I have a field on my car object that states the type of the car : a truck, or a bike, or van. How would affect that my object view? Let's say that getTitle() rule would be different for each type of it. How would you do it?

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  • How should dependencies be managed across a modular application?

    - by bear
    Let's say that we have a structure like this: Application -- Modules --Module1 -- Controller -- PublicHelper --Module2 -- Controller -- PublicHelper Whereby a module's Public Helper can provide helper functions. In nearly every module helper, the helper needs to access another module's public helper methods. Let's say for instance, in a PHP application: Module1 provides functionality to create a sale, and as part of the class Module1PublicHelper extends AbstractModuleHelper { public function createSale($customerId, $param, $param) { $userPublicHelper = // grab an instance of the user public helper $currentUser = $userPublicHelper->getCurrentUser(); } } class Module2PublicHelper extends AbstractModuleHelper { public function getCurrentUser() { //do something return $user; } } In this situation, the method needs to obtain an instance, either new or whatever of the user public helper. Given that all of Module Public Helper classes are instantiated with a minimum set of constructor params, e.g. EntityManager, what would be the best way to get a copy of it? Obviously, we can't really inject the user public helper class into the class containing createSale One solution would be to use a service locator or registry, however, testing the application isn't exactly easy.

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  • Knockout.js - Filtering, Sorting, and Paging

    - by jtimperley
    Originally posted on: http://geekswithblogs.net/jtimperley/archive/2013/07/28/knockout.js---filtering-sorting-and-paging.aspxKnockout.js is fantastic! Maybe I missed it but it appears to be missing flexible filtering, sorting, and pagination of its grids. This is a summary of my attempt at creating this functionality which has been working out amazingly well for my purposes. Before you continue, this post is not intended to teach you the basics of Knockout. They have already created a fantastic tutorial for this purpose. You'd be wise to review this before you continue. http://learn.knockoutjs.com/ Please view the full source code and functional example on jsFiddle. Below you will find a brief explanation of some of the components. http://jsfiddle.net/JTimperley/pyCTN/13/ First we need to create a model to represent our records. This model is a simple container with defined and guaranteed members. function CustomerModel(data) { if (!data) { data = {}; } var self = this; self.id = data.id; self.name = data.name; self.status = data.status; } Next we need a model to represent the page as a whole with an array of the previously defined records. I have intentionally overlooked the filtering and sorting options for now. Note how the filtering, sorting, and pagination are chained together to accomplish all three goals. This strategy allows each of these pieces to be used selectively based on the page's needs. If you only need sorting, just sort, etc. function CustomerPageModel(data) { if (!data) { data = {}; } var self = this; self.customers = ExtractModels(self, data.customers, CustomerModel); var filters = […]; var sortOptions = […]; self.filter = new FilterModel(filters, self.customers); self.sorter = new SorterModel(sortOptions, self.filter.filteredRecords); self.pager = new PagerModel(self.sorter.orderedRecords); } The code currently supports text box and drop down filters. Text box filters require defining the current 'Value' and the 'RecordValue' function to retrieve the filterable value from the provided record. Drop downs allow defining all possible values, the current option, and the 'RecordValue' as before. Once defining these filters, they are automatically added to the screen and any changes to their values will automatically update the results, causing their sort and pagination to be re-evaluated. var filters = [ { Type: "text", Name: "Name", Value: ko.observable(""), RecordValue: function(record) { return record.name; } }, { Type: "select", Name: "Status", Options: [ GetOption("All", "All", null), GetOption("New", "New", true), GetOption("Recently Modified", "Recently Modified", false) ], CurrentOption: ko.observable(), RecordValue: function(record) { return record.status; } } ]; Sort options are more simplistic and are also automatically added to the screen. Simply provide each option's name and value for the sort drop down as well as function to allow defining how the records are compared. This mechanism can easily be adapted for using table headers as the sort triggers. That strategy hasn't crossed my functionality needs at this point. var sortOptions = [ { Name: "Name", Value: "Name", Sort: function(left, right) { return CompareCaseInsensitive(left.name, right.name); } } ]; Paging options are completely contained by the pager model. Because we will be chaining arrays between our filtering, sorting, and pagination models, the following utility method is used to prevent errors when handing an observable array to another observable array. function GetObservableArray(array) { if (typeof(array) == 'function') { return array; }   return ko.observableArray(array); }

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  • JMSContext, @JMSDestinationDefintion, DefaultJMSConnectionFactory with simplified JMS API: TOTD #213

    - by arungupta
    "What's New in JMS 2.0" Part 1 and Part 2 provide comprehensive introduction to new messaging features introduced in JMS 2.0. The biggest improvement in JMS 2.0 is introduction of the "new simplified API". This was explained in the Java EE 7 Launch Technical Keynote. You can watch a complete replay here. Sending and Receiving a JMS message using JMS 1.1 requires lot of boilerplate code, primarily because the API was designed 10+ years ago. Here is a code that shows how to send a message using JMS 1.1 API: @Statelesspublic class ClassicMessageSender { @Resource(lookup = "java:comp/DefaultJMSConnectionFactory") ConnectionFactory connectionFactory; @Resource(mappedName = "java:global/jms/myQueue") Queue demoQueue; public void sendMessage(String payload) { Connection connection = null; try { connection = connectionFactory.createConnection(); connection.start(); Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); MessageProducer messageProducer = session.createProducer(demoQueue); TextMessage textMessage = session.createTextMessage(payload); messageProducer.send(textMessage); } catch (JMSException ex) { ex.printStackTrace(); } finally { if (connection != null) { try { connection.close(); } catch (JMSException ex) { ex.printStackTrace(); } } } }} There are several issues with this code: A JMS ConnectionFactory needs to be created in a application server-specific way before this application can run. Application-specific destination needs to be created in an application server-specific way before this application can run. Several intermediate objects need to be created to honor the JMS 1.1 API, e.g. ConnectionFactory -> Connection -> Session -> MessageProducer -> TextMessage. Everything is a checked exception and so try/catch block must be specified. Connection need to be explicitly started and closed, and that bloats even the finally block. The new JMS 2.0 simplified API code looks like: @Statelesspublic class SimplifiedMessageSender { @Inject JMSContext context; @Resource(mappedName="java:global/jms/myQueue") Queue myQueue; public void sendMessage(String message) { context.createProducer().send(myQueue, message); }} The code is significantly improved from the previous version in the following ways: The JMSContext interface combines in a single object the functionality of both the Connection and the Session in the earlier JMS APIs.  You can obtain a JMSContext object by simply injecting it with the @Inject annotation.  No need to explicitly specify a ConnectionFactory. A default ConnectionFactory under the JNDI name of java:comp/DefaultJMSConnectionFactory is used if no explicit ConnectionFactory is specified. The destination can be easily created using newly introduced @JMSDestinationDefinition as: @JMSDestinationDefinition(name = "java:global/jms/myQueue",        interfaceName = "javax.jms.Queue") It can be specified on any Java EE component and the destination is created during deployment. JMSContext, Session, Connection, JMSProducer and JMSConsumer objects are now AutoCloseable. This means that these resources are automatically closed when they go out of scope. This also obviates the need to explicitly start the connection JMSException is now a runtime exception. Method chaining on JMSProducers allows to use builder patterns. No need to create separate Message object, you can specify the message body as an argument to the send() method instead. Want to try this code ? Download source code! Download Java EE 7 SDK and install. Start GlassFish: bin/asadmin start-domain Build the WAR (in the unzipped source code directory): mvn package Deploy the WAR: bin/asadmin deploy <source-code>/jms/target/jms-1.0-SNAPSHOT.war And access the application at http://localhost:8080/jms-1.0-SNAPSHOT/index.jsp to send and receive a message using classic and simplified API. A replay of JMS 2.0 session from Java EE 7 Launch Webinar provides complete details on what's new in this specification: Enjoy!

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  • Preloading multiple comboboxes/listbox itemssource with enumerated values using WCF RIA Services

    - by Dale Halliwell
    I would like to be able to load several RIA entitysets in a single call without chaining/nesting several small LoadOperations together so that they load sequentially. I have several pages that have a number of comboboxes on them. These comboboxes are populated with static values from a database (for example status values). Right now I preload these values in my VM by one method that strings together a series of LoadOperations for each type that I want to load. For example: public void LoadEnums() { context.Load(context.GetMyStatusValues1Query()).Completed += (s, e) => { this.StatusValues1 = context.StatusValues1; context.Load(context.GetMyStatusValues2()).Completed += (s1, e1) => { this.StatusValues2 = context.StatusValues2; context.Load(context.GetMyStatusValues3Query()).Completed += (s2, e2) => { this.StatusValues3 = context.StatusValues3; (....and so on) }; }; }; }; While this works fine, it seems a bit nasty. Also, I would like to know when the last loadoperation completes so that I can load whatever entity I want to work on after this, so that these enumerated values resolve properly in form elements like comboboxes and listboxes. (I think) I can't do this easily above without creating a delegate and calling that on the completion of the last loadoperation. So my question is: does anyone out there know a better pattern to use, ideally where I can load all my static entitysets in a single LoadOperation?

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