Search Results

Search found 16565 results on 663 pages for 'private meta'.

Page 298/663 | < Previous Page | 294 295 296 297 298 299 300 301 302 303 304 305  | Next Page >

  • C# XNA Handle mouse events?

    - by user406470
    I'm making a 2D game engine called Clixel over on GitHub. The problem I have relates to two classes, ClxMouse and ClxButton. In it I have a mouse class - the code for that can be viewed here. ClxMouse using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; namespace org.clixel { public class ClxMouse : ClxSprite { private MouseState _curmouse, _lastmouse; public int Sensitivity = 3; public bool Lock = true; public Vector2 Change { get { return new Vector2(_curmouse.X - _lastmouse.X, _curmouse.Y - _lastmouse.Y); } } private int _scrollwheel; public int ScrollWheel { get { return _scrollwheel; } } public bool LeftDown { get { if (_curmouse.LeftButton == ButtonState.Pressed) return true; else return false; } } public bool RightDown { get { if (_curmouse.RightButton == ButtonState.Pressed) return true; else return false; } } public bool MiddleDown { get { if (_curmouse.MiddleButton == ButtonState.Pressed) return true; else return false; } } public bool LeftPressed { get { if (_curmouse.LeftButton == ButtonState.Pressed && _lastmouse.LeftButton == ButtonState.Released) return true; else return false; } } public bool RightPressed { get { if (_curmouse.RightButton == ButtonState.Pressed && _lastmouse.RightButton == ButtonState.Released) return true; else return false; } } public bool MiddlePressed { get { if (_curmouse.MiddleButton == ButtonState.Pressed && _lastmouse.MiddleButton == ButtonState.Released) return true; else return false; } } public bool LeftReleased { get { if (_curmouse.LeftButton == ButtonState.Released && _lastmouse.LeftButton == ButtonState.Pressed) return true; else return false; } } public bool RightReleased { get { if (_curmouse.RightButton == ButtonState.Released && _lastmouse.RightButton == ButtonState.Pressed) return true; else return false; } } public bool MiddleReleased { get { if (_curmouse.MiddleButton == ButtonState.Released && _lastmouse.MiddleButton == ButtonState.Pressed) return true; else return false; } } public MouseState CurMouse { get { return _curmouse; } } public MouseState LastMouse { get { return _lastmouse; } } public ClxMouse() : base(ClxG.Textures.Default.Cursor) { _curmouse = Mouse.GetState(); _lastmouse = _curmouse; CollisionBox = new Rectangle(ClxG.Screen.Center.X, ClxG.Screen.Center.Y, Texture.Width, Texture.Height); this.Solid = false; DefaultPosition = new Vector2(CollisionBox.X, CollisionBox.Y); Mouse.SetPosition(CollisionBox.X, CollisionBox.Y); } public ClxMouse(Texture2D _texture) : base(_texture) { _curmouse = Mouse.GetState(); _lastmouse = _curmouse; CollisionBox = new Rectangle(ClxG.Screen.Center.X, ClxG.Screen.Center.Y, Texture.Width, Texture.Height); DefaultPosition = new Vector2(CollisionBox.X, CollisionBox.Y); } public override void Update() { _lastmouse = _curmouse; _curmouse = Mouse.GetState(); if (_curmouse != _lastmouse) { if (ClxG.Game.IsActive) { _scrollwheel = _curmouse.ScrollWheelValue; Velocity = new Vector2(Change.X / Sensitivity, Change.Y / Sensitivity); if (Lock) Mouse.SetPosition(ClxG.Screen.Center.X, ClxG.Screen.Center.Y); _curmouse = Mouse.GetState(); } base.Update(); } } public override void Draw(SpriteBatch _sb) { base.Draw(_sb); } } } ClxButton using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Graphics; namespace org.clixel { public class ClxButton : ClxSprite { /// <summary> /// The color when the mouse is over the button /// </summary> public Color HoverColor; /// <summary> /// The color when the color is being clicked /// </summary> public Color ClickColor; /// <summary> /// The color when the button is inactive /// </summary> public Color InactiveColor; /// <summary> /// The color when the button is active /// </summary> public Color ActiveColor; /// <summary> /// The color after the button has been clicked. /// </summary> public Color ClickedColor; /// <summary> /// The text to be displayed on the button, set to "" if no text is needed. /// </summary> public string Text; /// <summary> /// The ClxText object to be displayed. /// </summary> public ClxText TextRender; /// <summary> /// The ClxState that should be ResetAndShow() when the button is clicked. /// </summary> public ClxState ClickState; /// <summary> /// Collision check to make sure onCollide() only runs once per frame, /// since only the mouse needs to be collision checked. /// </summary> private bool _runonce = false; /// <summary> /// Gets a value indicating whether this instance is colliding. /// </summary> /// <value> /// <c>true</c> if this instance is colliding; otherwise, <c>false</c>. /// </value> public bool IsColliding { get { return _runonce; } } /// <summary> /// Initializes a new instance of the <see cref="ClxButton"/> class. /// </summary> public ClxButton() : base(ClxG.Textures.Default.Button) { HoverColor = Color.Red; ClickColor = Color.Blue; InactiveColor = Color.Gray; ActiveColor = Color.White; ClickedColor = Color.Yellow; Text = Name + ID + " Unset!"; TextRender = new ClxText(); TextRender.Text = Text; TextRender.TextPadding = new Vector2(5, 5); ClickState = null; CollideObjects(ClxG.Mouse); } /// <summary> /// Initializes a new instance of the <see cref="ClxButton"/> class. /// </summary> /// <param name="_texture">The button texture.</param> public ClxButton(Texture2D _texture) : base(_texture) { HoverColor = Color.Red; ClickColor = Color.Blue; InactiveColor = Color.Gray; ActiveColor = Color.White; ClickedColor = Color.Yellow; Texture = _texture; Text = Name + ID; TextRender = new ClxText(); TextRender.Name = this.Name + ".TextRender"; TextRender.Text = Text; TextRender.TextPadding = new Vector2(5, 5); TextRender.Reset(); ClickState = null; CollideObjects(ClxG.Mouse); } /// <summary> /// Draws the debug information, run from ClxG.DrawDebug unless manual control is assumed. /// </summary> /// <param name="_sb">SpriteBatch used for drawing.</param> public override void DrawDebug(SpriteBatch _sb) { _runonce = false; TextRender.DrawDebug(_sb); _sb.Draw(Texture, ActualRectangle, new Rectangle(0, 0, Texture.Width, Texture.Height), DebugColor, Rotation, Origin, Flip, Layer); _sb.Draw(ClxG.Textures.Default.DebugBG, new Rectangle(ActualRectangle.X - DebugLineWidth, ActualRectangle.Y - DebugLineWidth, ActualRectangle.Width + DebugLineWidth * 2, ActualRectangle.Height + DebugLineWidth * 2), new Rectangle(0, 0, ClxG.Textures.Default.DebugBG.Width, ClxG.Textures.Default.DebugBG.Height), DebugOutline, Rotation, Origin, Flip, Layer - 0.1f); _sb.Draw(ClxG.Textures.Default.DebugBG, ActualRectangle, new Rectangle(0, 0, ClxG.Textures.Default.DebugBG.Width, ClxG.Textures.Default.DebugBG.Height), DebugBGColor, Rotation, Origin, Flip, Layer - 0.01f); } /// <summary> /// Draws using the SpriteBatch, run from ClxG.Draw unless manual control is assumed. /// </summary> /// <param name="_sb">SpriteBatch used for drawing.</param> public override void Draw(SpriteBatch _sb) { _runonce = false; TextRender.Draw(_sb); if (Visible) if (Debug) { DrawDebug(_sb); } else _sb.Draw(Texture, ActualRectangle, new Rectangle(0, 0, Texture.Width, Texture.Height), Color, Rotation, Origin, Flip, Layer); } /// <summary> /// Updates this instance. /// </summary> public override void Update() { if (this.Color != ActiveColor) this.Color = ActiveColor; TextRender.Layer = this.Layer + 0.03f; TextRender.Text = Text; TextRender.Scale = .5f; TextRender.Name = this.Name + ".TextRender"; TextRender.Origin = new Vector2(TextRender.CollisionBox.Center.X, TextRender.CollisionBox.Center.Y); TextRender.Center(this); TextRender.Update(); this.CollisionBox.Width = (int)(TextRender.CollisionBox.Width * TextRender.Scale) + (int)(TextRender.TextPadding.X * 2); this.CollisionBox.Height = (int)(TextRender.CollisionBox.Height * TextRender.Scale) + (int)(TextRender.TextPadding.Y * 2); base.Update(); } /// <summary> /// Collide event, takes the colliding object to call it's proper collision code. /// You'd want to use something like if(typeof(collider) == typeof(ClxObject) /// </summary> /// <param name="collider">The colliding object.</param> public override void onCollide(ClxObject collider) { if (!_runonce) { _runonce = true; UpdateEvents(); base.onCollide(collider); } } /// <summary> /// Updates the mouse based events. /// </summary> public void UpdateEvents() { onHover(); if (ClxG.Mouse.LeftReleased) { onLeftReleased(); return; } if (ClxG.Mouse.RightReleased) { onRightReleased(); return; } if (ClxG.Mouse.MiddleReleased) { onMiddleReleased(); return; } if (ClxG.Mouse.LeftPressed) { onLeftClicked(); return; } if (ClxG.Mouse.RightPressed) { onRightClicked(); return; } if (ClxG.Mouse.MiddlePressed) { onMiddleClicked(); return; } if (ClxG.Mouse.LeftDown) { onLeftClick(); return; } if (ClxG.Mouse.RightDown) { onRightClick(); return; } if (ClxG.Mouse.MiddleDown) { onMiddleClick(); return; } } /// <summary> /// Shows the state of the click. /// </summary> public void ShowClickState() { if (ClickState != null) { ClickState.ResetAndShow(); } } /// <summary> /// Hover event /// </summary> virtual public void onHover() { this.Color = HoverColor; } /// <summary> /// Left click event /// </summary> virtual public void onLeftClick() { this.Color = ClickColor; } /// <summary> /// Right click event /// </summary> virtual public void onRightClick() { } /// <summary> /// Middle click event /// </summary> virtual public void onMiddleClick() { } /// <summary> /// Left click event, called once per click /// </summary> virtual public void onLeftClicked() { ShowClickState(); } /// <summary> /// Right click event, called once per click /// </summary> virtual public void onRightClicked() { this.Reset(); } /// <summary> /// Middle click event, called once per click /// </summary> virtual public void onMiddleClicked() { } /// <summary> /// Ons the left released. /// </summary> virtual public void onLeftReleased() { this.Color = ClickedColor; } virtual public void onRightReleased() { } virtual public void onMiddleReleased() { } } } The issue I have is that I have all these have event styled methods, especially in ClxButton with all the onLeftClick, onRightClick, etc, etc. Is there a better way for me to handle these events to be a lot more easier for a programmer to use? I was looking at normal events on some other sites, (I'd post them but I need more rep.) and didn't really see a good way to implement delegate events into my framework. I'm not really sure how these events work, could someone possibly lay out how these events are processed for me? TL:DR * Is there a better way to handle events like this? * Are events a viable solution to this problem? Thanks in advance for any help.

    Read the article

  • Bound Command not firing on another viewModel? What Am I doing wrong?

    - by devnet247
    Hi I cannot seem to bind a command to a button.I have a treeview on the left showing Country City etc.. And I tabcontrol on the right. do I This uses 4 viewModels rootviewModel-ContinentViewModel-CountryViewModel-CityViewModel What I am building is based on http://www.codeproject.com/KB/WPF/TreeViewWithViewModel.aspx Now on one of the tabs I have a Toolbar with a button "TestButton" that I have mapped in zaml. This does not fire! The reason is not firing is because I m binding the RootViewModel but the command that is bound in zaml is in the cityViewModel. How Do I pass the datacontext from one view to the other? or how do I make the button fire. I need the command to be in the cityViewModel. Any Suggestions on how I bind it? View "WorldExplorerView" where I bind the main DataContext public partial class WorldExplorerView { public WorldExplorerView() { InitializeComponent(); var continents = Database.GetContinents(); var rootViewModel = new RootViewModel(continents); DataContext = rootViewModel; } } CityViewModel public class CityViewModel : TreeViewItemViewModel { private City _city; private RelayCommand _testCommand; public CityViewModel(City city, CountryViewModel countryViewModel):base(countryViewModel,false) { _city = city; } Properties etc...... public ICommand TestCommand { get { if(_testCommand==null) { _testCommand = new RelayCommand(param => GetTestCommand(), param => CanCallTestCommand); ; } return _testCommand; } } protected bool CanCallTestCommand { get { return true; } } private static void GetTestCommand() { MessageBox.Show("It works"); } } ZAML <DockPanel> <DockPanel LastChildFill="True"> <Label DockPanel.Dock="top" Content="Title " HorizontalAlignment="Center"></Label> <StatusBar DockPanel.Dock="Bottom"> <StatusBarItem Content="Status Bar" ></StatusBarItem> </StatusBar> <Grid DockPanel.Dock="Top"> <Grid.ColumnDefinitions> <ColumnDefinition/> <ColumnDefinition Width="Auto"/> <ColumnDefinition Width="2*"/> </Grid.ColumnDefinitions> <TreeView Name="tree" ItemsSource="{Binding Continents}"> <TreeView.ItemContainerStyle> <Style TargetType="{x:Type TreeViewItem}"> <Setter Property="IsExpanded" Value="{Binding IsExpanded,Mode=TwoWay}"/> <Setter Property="IsSelected" Value="{Binding IsSelected,Mode=TwoWay}"/> <Setter Property="FontWeight" Value="Normal"/> <Style.Triggers> <Trigger Property="IsSelected" Value="True"> <Setter Property="FontWeight" Value="Bold"></Setter> </Trigger> </Style.Triggers> </Style> </TreeView.ItemContainerStyle> <TreeView.Resources> <HierarchicalDataTemplate DataType="{x:Type ViewModels:ContinentViewModel}" ItemsSource="{Binding Children}"> <StackPanel Orientation="Horizontal"> <Image Width="16" Height="16" Margin="3,0" Source="Images\Continent.png"/> <TextBlock Text="{Binding ContinentName}"/> </StackPanel> </HierarchicalDataTemplate> <HierarchicalDataTemplate DataType="{x:Type ViewModels:CountryViewModel}" ItemsSource="{Binding Children}"> <StackPanel Orientation="Horizontal"> <Image Width="16" Height="16" Margin="3,0" Source="Images\Country.png"/> <TextBlock Text="{Binding CountryName}"/> </StackPanel> </HierarchicalDataTemplate> <DataTemplate DataType="{x:Type ViewModels:CityViewModel}" > <StackPanel Orientation="Horizontal"> <Image Width="16" Height="16" Margin="3,0" Source="Images\City.png"/> <TextBlock Text="{Binding CityName}"/> </StackPanel> </DataTemplate> </TreeView.Resources> </TreeView> <GridSplitter Grid.Row="0" Grid.Column="1" Background="LightGray" Width="5" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/> <Grid Grid.Column="2" Margin="5" > <TabControl> <TabItem Header="Demo"> <DockPanel LastChildFill="True"> <ToolBar DockPanel.Dock="Top"> <!-- DOES NOT WORK--> <Button Name="btnTest" Command="{Binding TestCommand}" Content="Press me see if works"></Button> </ToolBar> <TextBox></TextBox> </DockPanel> </TabItem> <TabItem Header="Details" DataContext="{Binding Path=SelectedItem.City, ElementName=tree, Mode=OneWay}"> <StackPanel > <TextBlock VerticalAlignment="Center" FontSize="12" Text="{Binding CityName}"/> <TextBlock VerticalAlignment="Center" FontSize="12" Text="{Binding Area}"/> <TextBlock VerticalAlignment="Center" FontSize="12" Text="{Binding Population}"/> <TextBlock VerticalAlignment="Center" FontSize="12" Text="{Binding CityDetailsInfo.ClubsCount}"/> <TextBlock VerticalAlignment="Center" FontSize="12" Text="{Binding CityDetailsInfo.PubsCount}"/> </StackPanel> </TabItem> </TabControl> </Grid> </Grid> </DockPanel> </DockPanel>

    Read the article

  • Get XML from Server for Use on Windows Phone

    - by psheriff
    When working with mobile devices you always need to take into account bandwidth usage and power consumption. If you are constantly connecting to a server to retrieve data for an input screen, then you might think about moving some of that data down to the phone and cache the data on the phone. An example would be a static list of US State Codes that you are asking the user to select from. Since this is data that does not change very often, this is one set of data that would be great to cache on the phone. Since the Windows Phone does not have an embedded database, you can just use an XML string stored in Isolated Storage. Of course, then you need to figure out how to get data down to the phone. You can either ship it with the application, or connect and retrieve the data from your server one time and thereafter cache it and retrieve it from the cache. In this blog post you will see how to create a WCF service to retrieve data from a Product table in a database and send that data as XML to the phone and store it in Isolated Storage. You will then read that data from Isolated Storage using LINQ to XML and display it in a ListBox. Step 1: Create a Windows Phone Application The first step is to create a Windows Phone application called WP_GetXmlFromDataSet (or whatever you want to call it). On the MainPage.xaml add the following XAML within the “ContentPanel” grid: <StackPanel>  <Button Name="btnGetXml"          Content="Get XML"          Click="btnGetXml_Click" />  <Button Name="btnRead"          Content="Read XML"          IsEnabled="False"          Click="btnRead_Click" />  <ListBox Name="lstData"            Height="430"            ItemsSource="{Binding}"            DisplayMemberPath="ProductName" /></StackPanel> Now it is time to create the WCF Service Application that you will call to get the XML from a table in a SQL Server database. Step 2: Create a WCF Service Application Add a new project to your solution called WP_GetXmlFromDataSet.Services. Delete the IService1.* and Service1.* files and the App_Data folder, as you don’t generally need these items. Add a new WCF Service class called ProductService. In the IProductService class modify the void DoWork() method with the following code: [OperationContract]string GetProductXml(); Open the code behind in the ProductService.svc and create the GetProductXml() method. This method (shown below) will connect up to a database and retrieve data from a Product table. public string GetProductXml(){  string ret = string.Empty;  string sql = string.Empty;  SqlDataAdapter da;  DataSet ds = new DataSet();   sql = "SELECT ProductId, ProductName,";  sql += " IntroductionDate, Price";  sql += " FROM Product";   da = new SqlDataAdapter(sql,    ConfigurationManager.ConnectionStrings["Sandbox"].ConnectionString);   da.Fill(ds);   // Create Attribute based XML  foreach (DataColumn col in ds.Tables[0].Columns)  {    col.ColumnMapping = MappingType.Attribute;  }   ds.DataSetName = "Products";  ds.Tables[0].TableName = "Product";  ret = ds.GetXml();   return ret;} After retrieving the data from the Product table using a DataSet, you will want to set each column’s ColumnMapping property to Attribute. Using attribute based XML will make the data transferred across the wire a little smaller. You then set the DataSetName property to the top-level element name you want to assign to the XML. You then set the TableName property on the DataTable to the name you want each element to be in your XML. The last thing you need to do is to call the GetXml() method on the DataSet object which will return an XML string of the data in your DataSet object. This is the value that you will return from the service call. The XML that is returned from the above call looks like the following: <Products>  <Product ProductId="1"           ProductName="PDSA .NET Productivity Framework"           IntroductionDate="9/3/2010"           Price="5000" />  <Product ProductId="3"           ProductName="Haystack Code Generator for .NET"           IntroductionDate="7/1/2010"           Price="599.00" />  ...  ...  ... </Products> The GetProductXml() method uses a connection string from the Web.Config file, so add a <connectionStrings> element to the Web.Config file in your WCF Service application. Modify the settings shown below as needed for your server and database name. <connectionStrings>  <add name="Sandbox"        connectionString="Server=Localhost;Database=Sandbox;                         Integrated Security=Yes"/></connectionStrings> The Product Table You will need a Product table that you can read data from. I used the following structure for my product table. Add any data you want to this table after you create it in your database. CREATE TABLE Product(  ProductId int PRIMARY KEY IDENTITY(1,1) NOT NULL,  ProductName varchar(50) NOT NULL,  IntroductionDate datetime NULL,  Price money NULL) Step 3: Connect to WCF Service from Windows Phone Application Back in your Windows Phone application you will now need to add a Service Reference to the WCF Service application you just created. Right-mouse click on the Windows Phone Project and choose Add Service Reference… from the context menu. Click on the Discover button. In the Namespace text box enter “ProductServiceRefrence”, then click the OK button. If you entered everything correctly, Visual Studio will generate some code that allows you to connect to your Product service. On the MainPage.xaml designer window double click on the Get XML button to generate the Click event procedure for this button. In the Click event procedure make a call to a GetXmlFromServer() method. This method will also need a “Completed” event procedure to be written since all communication with a WCF Service from Windows Phone must be asynchronous.  Write these two methods as follows: private const string KEY_NAME = "ProductData"; private void GetXmlFromServer(){  ProductServiceClient client = new ProductServiceClient();   client.GetProductXmlCompleted += new     EventHandler<GetProductXmlCompletedEventArgs>      (client_GetProductXmlCompleted);   client.GetProductXmlAsync();  client.CloseAsync();} void client_GetProductXmlCompleted(object sender,                                   GetProductXmlCompletedEventArgs e){  // Store XML data in Isolated Storage  IsolatedStorageSettings.ApplicationSettings[KEY_NAME] = e.Result;   btnRead.IsEnabled = true;} As you can see, this is a fairly standard call to a WCF Service. In the Completed event you get the Result from the event argument, which is the XML, and store it into Isolated Storage using the IsolatedStorageSettings.ApplicationSettings class. Notice the constant that I added to specify the name of the key. You will use this constant later to read the data from Isolated Storage. Step 4: Create a Product Class Even though you stored XML data into Isolated Storage when you read that data out you will want to convert each element in the XML file into an actual Product object. This means that you need to create a Product class in your Windows Phone application. Add a Product class to your project that looks like the code below: public class Product{  public string ProductName{ get; set; }  public int ProductId{ get; set; }  public DateTime IntroductionDate{ get; set; }  public decimal Price{ get; set; }} Step 5: Read Settings from Isolated Storage Now that you have the XML data stored in Isolated Storage, it is time to use it. Go back to the MainPage.xaml design view and double click on the Read XML button to generate the Click event procedure. From the Click event procedure call a method named ReadProductXml().Create this method as shown below: private void ReadProductXml(){  XElement xElem = null;   if (IsolatedStorageSettings.ApplicationSettings.Contains(KEY_NAME))  {    xElem = XElement.Parse(     IsolatedStorageSettings.ApplicationSettings[KEY_NAME].ToString());     // Create a list of Product objects    var products =         from prod in xElem.Descendants("Product")        orderby prod.Attribute("ProductName").Value        select new Product        {          ProductId = Convert.ToInt32(prod.Attribute("ProductId").Value),          ProductName = prod.Attribute("ProductName").Value,          IntroductionDate =             Convert.ToDateTime(prod.Attribute("IntroductionDate").Value),          Price = Convert.ToDecimal(prod.Attribute("Price").Value)        };     lstData.DataContext = products;  }} The ReadProductXml() method checks to make sure that the key name that you saved your XML as exists in Isolated Storage prior to trying to open it. If the key name exists, then you retrieve the value as a string. Use the XElement’s Parse method to convert the XML string to a XElement object. LINQ to XML is used to iterate over each element in the XElement object and create a new Product object from each attribute in your XML file. The LINQ to XML code also orders the XML data by the ProductName. After the LINQ to XML code runs you end up with an IEnumerable collection of Product objects in the variable named “products”. You assign this collection of product data to the DataContext of the ListBox you created in XAML. The DisplayMemberPath property of the ListBox is set to “ProductName” so it will now display the product name for each row in your products collection. Summary In this article you learned how to retrieve an XML string from a table in a database, return that string across a WCF Service and store it into Isolated Storage on your Windows Phone. You then used LINQ to XML to create a collection of Product objects from the data stored and display that data in a Windows Phone list box. This same technique can be used in Silverlight or WPF applications too. NOTE: You can download the complete sample code at my website. http://www.pdsa.com/downloads. Choose Tips & Tricks, then "Get XML From Server for Use on Windows Phone" from the drop-down. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **Visit http://www.pdsa.com/Event/Blog for a free video on Silverlight entitled Silverlight XAML for the Complete Novice - Part 1.  

    Read the article

  • C++ Mutexes and STL Lists Across Subclasses

    - by Genesis
    I am currently writing a multi-threaded C++ server using Poco and am now at the point where I need to be keeping information on which users are connected, how many connections each of them have, and given it is a proxy server, where each of those connections are proxying through to. For this purpose I have created a ServerStats class which holds an STL list of ServerUser objects. The ServerStats class includes functions which can add and remove objects from the list as well as find a user in the list an return a pointer to them so I can access member functions within any given ServerUser object in the list. The ServerUser class contains an STL list of ServerConnection objects and much like the ServerStats class it contains functions to add, remove and find elements within this list. Now all of the above is working but I am now trying to make it threadsafe. I have defined a Poco::FastMutex within the ServerStats class and can lock/unlock this in the appropriate places so that STL containers are not modified at the same time as being searched for example. I am however having an issue setting up mutexes within the ServerUser class and am getting the following compiler error: /root/poco/Foundation/include/Poco/Mutex.h: In copy constructor âServerUser::ServerUser(const ServerUser&)â: src/SocksServer.cpp:185: instantiated from âvoid __gnu_cxx::new_allocator<_Tp::construct(_Tp*, const _Tp&) [with _Tp = ServerUser]â /usr/include/c++/4.4/bits/stl_list.h:464: instantiated from âstd::_List_node<_Tp* std::list<_Tp, _Alloc::_M_create_node(const _Tp&) [with _Tp = ServerUser, _Alloc = std::allocator]â /usr/include/c++/4.4/bits/stl_list.h:1407: instantiated from âvoid std::list<_Tp, _Alloc::_M_insert(std::_List_iterator<_Tp, const _Tp&) [with _Tp = ServerUser, _Alloc = std::allocator]â /usr/include/c++/4.4/bits/stl_list.h:920: instantiated from âvoid std::list<_Tp, _Alloc::push_back(const _Tp&) [with _Tp = ServerUser, _Alloc = std::allocator]â src/SocksServer.cpp:301: instantiated from here /root/poco/Foundation/include/Poco/Mutex.h:164: error: âPoco::FastMutex::FastMutex(const Poco::FastMutex&)â is private src/SocksServer.cpp:185: error: within this context In file included from /usr/include/c++/4.4/x86_64-linux-gnu/bits/c++allocator.h:34, from /usr/include/c++/4.4/bits/allocator.h:48, from /usr/include/c++/4.4/string:43, from /root/poco/Foundation/include/Poco/Bugcheck.h:44, from /root/poco/Foundation/include/Poco/Foundation.h:147, from /root/poco/Net/include/Poco/Net/Net.h:45, from /root/poco/Net/include/Poco/Net/TCPServerParams.h:43, from src/SocksServer.cpp:1: /usr/include/c++/4.4/ext/new_allocator.h: In member function âvoid __gnu_cxx::new_allocator<_Tp::construct(_Tp*, const _Tp&) [with _Tp = ServerUser]â: /usr/include/c++/4.4/ext/new_allocator.h:105: note: synthesized method âServerUser::ServerUser(const ServerUser&)â first required here src/SocksServer.cpp: At global scope: src/SocksServer.cpp:118: warning: âstd::string getWord(std::string)â defined but not used make: * [/root/poco/SocksServer/obj/Linux/x86_64/debug_shared/SocksServer.o] Error 1 The code for the ServerStats, ServerUser and ServerConnection classes is below: class ServerConnection { public: bool continue_connection; int bytes_in; int bytes_out; string source_address; string destination_address; ServerConnection() { continue_connection = true; } ~ServerConnection() { } }; class ServerUser { public: string username; int connection_count; string client_ip; ServerUser() { } ~ServerUser() { } ServerConnection* addConnection(string source_address, string destination_address) { //FastMutex::ScopedLock lock(_connection_mutex); ServerConnection connection; connection.source_address = source_address; connection.destination_address = destination_address; client_ip = getWord(source_address, ":"); _connections.push_back(connection); connection_count++; return &_connections.back(); } void removeConnection(string source_address) { //FastMutex::ScopedLock lock(_connection_mutex); for(list<ServerConnection>::iterator it = _connections.begin(); it != _connections.end(); it++) { if(it->source_address == source_address) { it = _connections.erase(it); connection_count--; } } } void disconnect() { //FastMutex::ScopedLock lock(_connection_mutex); for(list<ServerConnection>::iterator it = _connections.begin(); it != _connections.end(); it++) { it->continue_connection = false; } } list<ServerConnection>* getConnections() { return &_connections; } private: list<ServerConnection> _connections; //UNCOMMENTING THIS LINE BREAKS IT: //mutable FastMutex _connection_mutex; }; class ServerStats { public: int current_users; ServerStats() { current_users = 0; } ~ServerStats() { } ServerUser* addUser(string username) { FastMutex::ScopedLock lock(_user_mutex); for(list<ServerUser>::iterator it = _users.begin(); it != _users.end(); it++) { if(it->username == username) { return &(*it); } } ServerUser newUser; newUser.username = username; _users.push_back(newUser); current_users++; return &_users.back(); } void removeUser(string username) { FastMutex::ScopedLock lock(_user_mutex); for(list<ServerUser>::iterator it = _users.begin(); it != _users.end(); it++) { if(it->username == username) { _users.erase(it); current_users--; break; } } } ServerUser* getUser(string username) { FastMutex::ScopedLock lock(_user_mutex); for(list<ServerUser>::iterator it = _users.begin(); it != _users.end(); it++) { if(it->username == username) { return &(*it); } } return NULL; } private: list<ServerUser> _users; mutable FastMutex _user_mutex; }; Now I have never used C++ for a project of this size or mutexes for that matter so go easy please :) Firstly, can anyone tell me why the above is causing a compiler error? Secondly, can anyone suggest a better way of storing the information I require? Bear in mind that I need to update this info whenever connections come or go and it needs to be global to the whole server.

    Read the article

  • implement N-Tier Entity Framework 4.0 with DTOs

    - by kathy
    Hi, I'm currently building a web based system and trying to implement N-Tier Entity Framework 4.0 with DTOs in a SOA Architecture. I am having a problem understanding how I should implement the Data Access Layer (DAL) , the Business Logic Layer (BLL) and the Presentation Layer. Let’s suppose that I have a “useraccount” entity has the following : Id FirstName LastName AuditFields_InsertDate AuditFields_UpdateDate In the DAL I created a class “UserAccountsData.cs” as the following : using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace OrderSystemDAL { public static class UserAccountsData { public static int Insert(string firstName, string lastName, DateTime insertDate) { using (OrderSystemEntities db = new OrderSystemEntities()) { return Insert(db, firstName, lastName, insertDate); } } public static int Insert(OrderSystemEntities db, string firstName, string lastName, DateTime insertDate) { return db.UserAccounts_Insert(firstName, lastName, insertDate, insertDate).ElementAt(0).Value; } public static void Update(int id, string firstName, string lastName, DateTime updateDate) { using (OrderSystemEntities db = new OrderSystemEntities()) { Update(db, id, firstName, lastName, updateDate); } } public static void Update(OrderSystemEntities db, int id, string firstName, string lastName, DateTime updateDate) { db.UserAccounts_Update(id, firstName, lastName, updateDate); } public static void Delete(int id) { using (OrderSystemEntities db = new OrderSystemEntities()) { Delete(db, id); } } public static void Delete(OrderSystemEntities db, int id) { db.UserAccounts_Delete(id); } public static UserAccount SelectById(int id) { using (OrderSystemEntities db = new OrderSystemEntities()) { return SelectById(db, id); } } public static UserAccount SelectById(OrderSystemEntities db, int id) { return db.UserAccounts_SelectById(id).ElementAtOrDefault(0); } public static List<UserAccount> SelectAll() { using (OrderSystemEntities db = new OrderSystemEntities()) { return SelectAll(db); } } public static List<UserAccount> SelectAll(OrderSystemEntities db) { return db.UserAccounts_SelectAll().ToList(); } } } And in the BLL I created a class “UserAccountEO.cs” as the following : using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Collections; using OrderSystemDAL; namespace OrderSystemBLL { public class UserAccountEO { public int Id { get; set; } public string FirstName { get; set; } public string LastName { get; set; } public DateTime InsertDate { get; set; } public DateTime UpdateDate { get; set; } public string FullName { get { return LastName + ", " + FirstName; } } public bool Save(ref ArrayList validationErrors) { ValidateSave(ref validationErrors); if (validationErrors.Count == 0) { if (Id == 0) { Id = UserAccountsData.Insert(FirstName, LastName, DateTime.Now); } else { UserAccountsData.Update(Id, FirstName, LastName, DateTime.Now); } return true; } else { return false; } } private void ValidateSave(ref ArrayList validationErrors) { if (FirstName.Trim() == "") { validationErrors.Add("The First Name is required."); } if (LastName.Trim() == "") { validationErrors.Add("The Last Name is required."); } } public void Delete(ref ArrayList validationErrors) { ValidateDelete(ref validationErrors); if (validationErrors.Count == 0) { UserAccountsData.Delete(Id); } } private void ValidateDelete(ref ArrayList validationErrors) { //Check for referential integrity. } public bool Select(int id) { UserAccount userAccount = UserAccountsData.SelectById(id); if (userAccount != null) { MapData(userAccount); return true; } else { return false; } } internal void MapData(UserAccount userAccount) { Id = userAccount.Id; FirstName = userAccount.FristName; LastName = userAccount.LastName; InsertDate = userAccount.AuditFields_InsertDate; UpdateDate = userAccount.AuditFields_UpdateDate; } public static List<UserAccountEO> SelectAll() { List<UserAccountEO> userAccounts = new List<UserAccountEO>(); List<UserAccount> userAccountDTOs = UserAccountsData.SelectAll(); foreach (UserAccount userAccountDTO in userAccountDTOs) { UserAccountEO userAccountEO = new UserAccountEO(); userAccountEO.MapData(userAccountDTO); userAccounts.Add(userAccountEO); } return userAccounts; } } } And in the PL I created a webpage as the following : using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using OrderSystemBLL; using System.Collections; namespace OrderSystemUI { public partial class Users : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { LoadUserDropDownList(); } } private void LoadUserDropDownList() { ddlUsers.DataSource = UserAccountEO.SelectAll(); ddlUsers.DataTextField = "FullName"; ddlUsers.DataValueField = "Id"; ddlUsers.DataBind(); } } } Is the above way the right way to Implement the DTOs pattern in n-tier Architecture using EF4 ??? I would appreciate your help Thanks.

    Read the article

  • Error Creating RSS Feed XML file - Java

    - by GigaPr
    Hi, i am trying to create an RssFeed using java this is the class i use import com.rssFeed.domain.RSS; import com.rssFeed.domain.RSSItem; import java.io.FileOutputStream; import java.util.Iterator; import javax.xml.stream.XMLEventFactory; import javax.xml.stream.XMLEventWriter; import javax.xml.stream.XMLOutputFactory; import javax.xml.stream.XMLStreamException; import javax.xml.stream.events.Characters; import javax.xml.stream.events.EndElement; import javax.xml.stream.events.StartDocument; import javax.xml.stream.events.StartElement; import javax.xml.stream.events.XMLEvent; public class RssBuilder { private static String XML_BLOCK = "\n"; private static String XML_INDENT = "\t"; public static void BuildRss(RSS rss, String xmlfile) throws Exception { XMLOutputFactory output = XMLOutputFactory.newInstance(); XMLEventWriter writer = output.createXMLEventWriter(new FileOutputStream(xmlfile)); try { XMLEventFactory eventFactory = XMLEventFactory.newInstance(); XMLEvent endSection = eventFactory.createDTD(XML_BLOCK); StartDocument startDocument = eventFactory.createStartDocument(); writer.add(startDocument); writer.add(endSection); StartElement rssStart = eventFactory.createStartElement("", "", "rss"); writer.add(rssStart); writer.add(eventFactory.createAttribute("version", "2.0")); writer.add(endSection); writer.add(eventFactory.createStartElement("", "", "channel")); writer.add(endSection); createNode(writer, "title", rss.getTitle()); createNode(writer, "description", rss.getDescription()); createNode(writer, "link", rss.getLink()); createNode(writer, "dateCreated", rss.getDateCreated().toString()); createNode(writer, "language", rss.getLanguage()); createNode(writer, "pubDate", rss.getPubDate().toString()); createNode(writer, "dateModified", rss.getDateModified().toString()); createNode(writer, "dateModified", rss.getDateModified().toString()); createNode(writer, "pubDate", rss.getPubDate().toString()); createNode(writer, "lastBuildDate", rss.getLastBuildDate().toString()); createNode(writer, "language", rss.getLanguage().toString()); createNode(writer, "rating", rss.getRating().toString()); Iterator<RSSItem> iterator = rss.getRssItems().iterator(); while (iterator.hasNext()) { RSSItem entry = iterator.next(); writer.add(eventFactory.createStartElement("", "", "item")); writer.add(endSection); createNode(writer, "title", entry.getTitle()); createNode(writer, "description", entry.getDescription()); createNode(writer, "link", entry.getLink()); createNode(writer, "dateCreated", entry.getDateCreated().toString()); createNode(writer, "pubDate", entry.getDateModified().toString()); writer.add(eventFactory.createEndElement("", "", "item")); writer.add(endSection); } writer.add(endSection); writer.add(eventFactory.createEndElement("", "", "channel")); writer.add(endSection); writer.add(eventFactory.createEndElement("", "", "rss")); writer.add(endSection); writer.add(eventFactory.createEndDocument()); writer.close(); } catch(Exception e) { writer.close(); } } private static void createNode(XMLEventWriter eventWriter, String name, String value)throws XMLStreamException { XMLEventFactory eventFactory = XMLEventFactory.newInstance(); XMLEvent endSection = eventFactory.createDTD(XML_BLOCK); XMLEvent tabSection = eventFactory.createDTD(XML_INDENT); StartElement sElement = eventFactory.createStartElement("", "", name); eventWriter.add(tabSection); eventWriter.add(sElement); Characters characters = eventFactory.createCharacters(value); eventWriter.add(characters); EndElement eElement = eventFactory.createEndElement("", "", name); eventWriter.add(eElement); eventWriter.add(endSection); } } But i get the following error type Exception report message descriptionThe server encountered an internal error () that prevented it from fulfilling this request. exception org.springframework.web.util.NestedServletException: Request processing failed; nested exception is javax.xml.stream.XMLStreamException: Can not write DOCTYPE declaration (DTD) when not in prolog any more (state 2; start element(s) written) root cause javax.xml.stream.XMLStreamException: Can not write DOCTYPE declaration (DTD) when not in prolog any more (state 2; start element(s) written) what does it mean?

    Read the article

  • Understanding C# async / await (1) Compilation

    - by Dixin
    Now the async / await keywords are in C#. Just like the async and ! in F#, this new C# feature provides great convenience. There are many nice documents talking about how to use async / await in specific scenarios, like using async methods in ASP.NET 4.5 and in ASP.NET MVC 4, etc. In this article we will look at the real code working behind the syntax sugar. According to MSDN: The async modifier indicates that the method, lambda expression, or anonymous method that it modifies is asynchronous. Since lambda expression / anonymous method will be compiled to normal method, we will focus on normal async method. Preparation First of all, Some helper methods need to make up. internal class HelperMethods { internal static int Method(int arg0, int arg1) { // Do some IO. WebClient client = new WebClient(); Enumerable.Repeat("http://weblogs.asp.net/dixin", 10) .Select(client.DownloadString).ToArray(); int result = arg0 + arg1; return result; } internal static Task<int> MethodTask(int arg0, int arg1) { Task<int> task = new Task<int>(() => Method(arg0, arg1)); task.Start(); // Hot task (started task) should always be returned. return task; } internal static void Before() { } internal static void Continuation1(int arg) { } internal static void Continuation2(int arg) { } } Here Method() is a long running method doing some IO. Then MethodTask() wraps it into a Task and return that Task. Nothing special here. Await something in async method Since MethodTask() returns Task, let’s try to await it: internal class AsyncMethods { internal static async Task<int> MethodAsync(int arg0, int arg1) { int result = await HelperMethods.MethodTask(arg0, arg1); return result; } } Because we used await in the method, async must be put on the method. Now we get the first async method. According to the naming convenience, it is called MethodAsync. Of course a async method can be awaited. So we have a CallMethodAsync() to call MethodAsync(): internal class AsyncMethods { internal static async Task<int> CallMethodAsync(int arg0, int arg1) { int result = await MethodAsync(arg0, arg1); return result; } } After compilation, MethodAsync() and CallMethodAsync() becomes the same logic. This is the code of MethodAsyc(): internal class CompiledAsyncMethods { [DebuggerStepThrough] [AsyncStateMachine(typeof(MethodAsyncStateMachine))] // async internal static /*async*/ Task<int> MethodAsync(int arg0, int arg1) { MethodAsyncStateMachine methodAsyncStateMachine = new MethodAsyncStateMachine() { Arg0 = arg0, Arg1 = arg1, Builder = AsyncTaskMethodBuilder<int>.Create(), State = -1 }; methodAsyncStateMachine.Builder.Start(ref methodAsyncStateMachine); return methodAsyncStateMachine.Builder.Task; } } It just creates and starts a state machine MethodAsyncStateMachine: [CompilerGenerated] [StructLayout(LayoutKind.Auto)] internal struct MethodAsyncStateMachine : IAsyncStateMachine { public int State; public AsyncTaskMethodBuilder<int> Builder; public int Arg0; public int Arg1; public int Result; private TaskAwaiter<int> awaitor; void IAsyncStateMachine.MoveNext() { try { if (this.State != 0) { this.awaitor = HelperMethods.MethodTask(this.Arg0, this.Arg1).GetAwaiter(); if (!this.awaitor.IsCompleted) { this.State = 0; this.Builder.AwaitUnsafeOnCompleted(ref this.awaitor, ref this); return; } } else { this.State = -1; } this.Result = this.awaitor.GetResult(); } catch (Exception exception) { this.State = -2; this.Builder.SetException(exception); return; } this.State = -2; this.Builder.SetResult(this.Result); } [DebuggerHidden] void IAsyncStateMachine.SetStateMachine(IAsyncStateMachine param0) { this.Builder.SetStateMachine(param0); } } The generated code has been cleaned up so it is readable and can be compiled. Several things can be observed here: The async modifier is gone, which shows, unlike other modifiers (e.g. static), there is no such IL/CLR level “async” stuff. It becomes a AsyncStateMachineAttribute. This is similar to the compilation of extension method. The generated state machine is very similar to the state machine of C# yield syntax sugar. The local variables (arg0, arg1, result) are compiled to fields of the state machine. The real code (await HelperMethods.MethodTask(arg0, arg1)) is compiled into MoveNext(): HelperMethods.MethodTask(this.Arg0, this.Arg1).GetAwaiter(). CallMethodAsync() will create and start its own state machine CallMethodAsyncStateMachine: internal class CompiledAsyncMethods { [DebuggerStepThrough] [AsyncStateMachine(typeof(CallMethodAsyncStateMachine))] // async internal static /*async*/ Task<int> CallMethodAsync(int arg0, int arg1) { CallMethodAsyncStateMachine callMethodAsyncStateMachine = new CallMethodAsyncStateMachine() { Arg0 = arg0, Arg1 = arg1, Builder = AsyncTaskMethodBuilder<int>.Create(), State = -1 }; callMethodAsyncStateMachine.Builder.Start(ref callMethodAsyncStateMachine); return callMethodAsyncStateMachine.Builder.Task; } } CallMethodAsyncStateMachine has the same logic as MethodAsyncStateMachine above. The detail of the state machine will be discussed soon. Now it is clear that: async /await is a C# level syntax sugar. There is no difference to await a async method or a normal method. A method returning Task will be awaitable. State machine and continuation To demonstrate more details in the state machine, a more complex method is created: internal class AsyncMethods { internal static async Task<int> MultiCallMethodAsync(int arg0, int arg1, int arg2, int arg3) { HelperMethods.Before(); int resultOfAwait1 = await MethodAsync(arg0, arg1); HelperMethods.Continuation1(resultOfAwait1); int resultOfAwait2 = await MethodAsync(arg2, arg3); HelperMethods.Continuation2(resultOfAwait2); int resultToReturn = resultOfAwait1 + resultOfAwait2; return resultToReturn; } } In this method: There are multiple awaits. There are code before the awaits, and continuation code after each await After compilation, this multi-await method becomes the same as above single-await methods: internal class CompiledAsyncMethods { [DebuggerStepThrough] [AsyncStateMachine(typeof(MultiCallMethodAsyncStateMachine))] // async internal static /*async*/ Task<int> MultiCallMethodAsync(int arg0, int arg1, int arg2, int arg3) { MultiCallMethodAsyncStateMachine multiCallMethodAsyncStateMachine = new MultiCallMethodAsyncStateMachine() { Arg0 = arg0, Arg1 = arg1, Arg2 = arg2, Arg3 = arg3, Builder = AsyncTaskMethodBuilder<int>.Create(), State = -1 }; multiCallMethodAsyncStateMachine.Builder.Start(ref multiCallMethodAsyncStateMachine); return multiCallMethodAsyncStateMachine.Builder.Task; } } It creates and starts one single state machine, MultiCallMethodAsyncStateMachine: [CompilerGenerated] [StructLayout(LayoutKind.Auto)] internal struct MultiCallMethodAsyncStateMachine : IAsyncStateMachine { public int State; public AsyncTaskMethodBuilder<int> Builder; public int Arg0; public int Arg1; public int Arg2; public int Arg3; public int ResultOfAwait1; public int ResultOfAwait2; public int ResultToReturn; private TaskAwaiter<int> awaiter; void IAsyncStateMachine.MoveNext() { try { switch (this.State) { case -1: HelperMethods.Before(); this.awaiter = AsyncMethods.MethodAsync(this.Arg0, this.Arg1).GetAwaiter(); if (!this.awaiter.IsCompleted) { this.State = 0; this.Builder.AwaitUnsafeOnCompleted(ref this.awaiter, ref this); } break; case 0: this.ResultOfAwait1 = this.awaiter.GetResult(); HelperMethods.Continuation1(this.ResultOfAwait1); this.awaiter = AsyncMethods.MethodAsync(this.Arg2, this.Arg3).GetAwaiter(); if (!this.awaiter.IsCompleted) { this.State = 1; this.Builder.AwaitUnsafeOnCompleted(ref this.awaiter, ref this); } break; case 1: this.ResultOfAwait2 = this.awaiter.GetResult(); HelperMethods.Continuation2(this.ResultOfAwait2); this.ResultToReturn = this.ResultOfAwait1 + this.ResultOfAwait2; this.State = -2; this.Builder.SetResult(this.ResultToReturn); break; } } catch (Exception exception) { this.State = -2; this.Builder.SetException(exception); } } [DebuggerHidden] void IAsyncStateMachine.SetStateMachine(IAsyncStateMachine stateMachine) { this.Builder.SetStateMachine(stateMachine); } } The above code is already cleaned up, but there are still a lot of things. More clean up can be done, and the state machine can be very simple: [CompilerGenerated] [StructLayout(LayoutKind.Auto)] internal struct MultiCallMethodAsyncStateMachine : IAsyncStateMachine { // State: // -1: Begin // 0: 1st await is done // 1: 2nd await is done // ... // -2: End public int State; public TaskCompletionSource<int> ResultToReturn; // int resultToReturn ... public int Arg0; // int Arg0 public int Arg1; // int arg1 public int Arg2; // int arg2 public int Arg3; // int arg3 public int ResultOfAwait1; // int resultOfAwait1 ... public int ResultOfAwait2; // int resultOfAwait2 ... private Task<int> currentTaskToAwait; /// <summary> /// Moves the state machine to its next state. /// </summary> void IAsyncStateMachine.MoveNext() { try { switch (this.State) { // Orginal code is splitted by "case"s: // case -1: // HelperMethods.Before(); // MethodAsync(Arg0, arg1); // case 0: // int resultOfAwait1 = await ... // HelperMethods.Continuation1(resultOfAwait1); // MethodAsync(arg2, arg3); // case 1: // int resultOfAwait2 = await ... // HelperMethods.Continuation2(resultOfAwait2); // int resultToReturn = resultOfAwait1 + resultOfAwait2; // return resultToReturn; case -1: // -1 is begin. HelperMethods.Before(); // Code before 1st await. this.currentTaskToAwait = AsyncMethods.MethodAsync(this.Arg0, this.Arg1); // 1st task to await // When this.currentTaskToAwait is done, run this.MoveNext() and go to case 0. this.State = 0; IAsyncStateMachine this1 = this; // Cannot use "this" in lambda so create a local variable. this.currentTaskToAwait.ContinueWith(_ => this1.MoveNext()); // Callback break; case 0: // Now 1st await is done. this.ResultOfAwait1 = this.currentTaskToAwait.Result; // Get 1st await's result. HelperMethods.Continuation1(this.ResultOfAwait1); // Code after 1st await and before 2nd await. this.currentTaskToAwait = AsyncMethods.MethodAsync(this.Arg2, this.Arg3); // 2nd task to await // When this.currentTaskToAwait is done, run this.MoveNext() and go to case 1. this.State = 1; IAsyncStateMachine this2 = this; // Cannot use "this" in lambda so create a local variable. this.currentTaskToAwait.ContinueWith(_ => this2.MoveNext()); // Callback break; case 1: // Now 2nd await is done. this.ResultOfAwait2 = this.currentTaskToAwait.Result; // Get 2nd await's result. HelperMethods.Continuation2(this.ResultOfAwait2); // Code after 2nd await. int resultToReturn = this.ResultOfAwait1 + this.ResultOfAwait2; // Code after 2nd await. // End with resultToReturn. this.State = -2; // -2 is end. this.ResultToReturn.SetResult(resultToReturn); break; } } catch (Exception exception) { // End with exception. this.State = -2; // -2 is end. this.ResultToReturn.SetException(exception); } } /// <summary> /// Configures the state machine with a heap-allocated replica. /// </summary> /// <param name="stateMachine">The heap-allocated replica.</param> [DebuggerHidden] void IAsyncStateMachine.SetStateMachine(IAsyncStateMachine stateMachine) { // No core logic. } } Only Task and TaskCompletionSource are involved in this version. And MultiCallMethodAsync() can be simplified to: [DebuggerStepThrough] [AsyncStateMachine(typeof(MultiCallMethodAsyncStateMachine))] // async internal static /*async*/ Task<int> MultiCallMethodAsync_(int arg0, int arg1, int arg2, int arg3) { MultiCallMethodAsyncStateMachine multiCallMethodAsyncStateMachine = new MultiCallMethodAsyncStateMachine() { Arg0 = arg0, Arg1 = arg1, Arg2 = arg2, Arg3 = arg3, ResultToReturn = new TaskCompletionSource<int>(), // -1: Begin // 0: 1st await is done // 1: 2nd await is done // ... // -2: End State = -1 }; (multiCallMethodAsyncStateMachine as IAsyncStateMachine).MoveNext(); // Original code are in this method. return multiCallMethodAsyncStateMachine.ResultToReturn.Task; } Now the whole state machine becomes very clear - it is about callback: Original code are split into pieces by “await”s, and each piece is put into each “case” in the state machine. Here the 2 awaits split the code into 3 pieces, so there are 3 “case”s. The “piece”s are chained by callback, that is done by Builder.AwaitUnsafeOnCompleted(callback), or currentTaskToAwait.ContinueWith(callback) in the simplified code. A previous “piece” will end with a Task (which is to be awaited), when the task is done, it will callback the next “piece”. The state machine’s state works with the “case”s to ensure the code “piece”s executes one after another. Callback Since it is about callback, the simplification  can go even further – the entire state machine can be completely purged. Now MultiCallMethodAsync() becomes: internal static Task<int> MultiCallMethodAsync(int arg0, int arg1, int arg2, int arg3) { TaskCompletionSource<int> taskCompletionSource = new TaskCompletionSource<int>(); try { // Oringinal code begins. HelperMethods.Before(); MethodAsync(arg0, arg1).ContinueWith(await1 => { int resultOfAwait1 = await1.Result; HelperMethods.Continuation1(resultOfAwait1); MethodAsync(arg2, arg3).ContinueWith(await2 => { int resultOfAwait2 = await2.Result; HelperMethods.Continuation2(resultOfAwait2); int resultToReturn = resultOfAwait1 + resultOfAwait2; // Oringinal code ends. taskCompletionSource.SetResult(resultToReturn); }); }); } catch (Exception exception) { taskCompletionSource.SetException(exception); } return taskCompletionSource.Task; } Please compare with the original async / await code: HelperMethods.Before(); int resultOfAwait1 = await MethodAsync(arg0, arg1); HelperMethods.Continuation1(resultOfAwait1); int resultOfAwait2 = await MethodAsync(arg2, arg3); HelperMethods.Continuation2(resultOfAwait2); int resultToReturn = resultOfAwait1 + resultOfAwait2; return resultToReturn; Yeah that is the magic of C# async / await: Await is literally pretending to wait. In a await expression, a Task object will be return immediately so that caller is not blocked. The continuation code is compiled as that Task’s callback code. When that task is done, continuation code will execute. Please notice that many details inside the state machine are omitted for simplicity, like context caring, etc. If you want to have a detailed picture, please do check out the source code of AsyncTaskMethodBuilder and TaskAwaiter.

    Read the article

  • How to implement drag and drop in Flex Grid control?

    - by Bogdan
    I have a simple Grid control with some buttons that I want to be able to move around. The code below does work, but it takes a lot of effort to actually do the drag&drop and it is not clear where the drop will happen. I have to move the mouse around a lot to get to a state where the drop is not rejected. I would appreciate any suggestions on how to make this more "user friendly". <?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical" verticalAlign="middle" horizontalAlign="center" height="200" width="200"> <mx:Script> <![CDATA[ import mx.containers.GridItem; import mx.controls.Button; import mx.core.DragSource; import mx.events.*; import mx.managers.DragManager; private function dragInit(event:MouseEvent):void { if(event.buttonDown) { var button:Button = event.currentTarget as Button; var dragSource:DragSource = new DragSource(); dragSource.addData(button, 'button'); DragManager.doDrag(button, dragSource, event); } } private function dragEnter(event:DragEvent): void { var target:GridItem = event.currentTarget as GridItem; if (event.dragSource.hasFormat('button') && target.getChildren().length == 0) { DragManager.acceptDragDrop(target); DragManager.showFeedback(DragManager.MOVE); } } private function dragDrop(event:DragEvent): void { var target:GridItem = event.currentTarget as GridItem; var button:Button = event.dragSource.dataForFormat('button') as Button; target.addChild(button); } ]]> </mx:Script> <mx:Grid> <mx:GridRow width="100%" height="100%"> <mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)"> </mx:GridItem> <mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)"> </mx:GridItem> <mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)"> <mx:Button label="A" width="40" height="40" mouseMove="dragInit(event)"/> </mx:GridItem> </mx:GridRow> <mx:GridRow width="100%" height="100%"> <mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)"> </mx:GridItem> <mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)"> <mx:Button label="B" width="40" height="40" mouseMove="dragInit(event)"/> </mx:GridItem> <mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)"> </mx:GridItem> </mx:GridRow> <mx:GridRow width="100%" height="100%"> <mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)"> <mx:Button label="C" width="40" height="40" mouseMove="dragInit(event)"/> </mx:GridItem> <mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)"> </mx:GridItem> <mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)"> </mx:GridItem> </mx:GridRow> </mx:Grid> <mx:Style> GridItem { borderColor: #A09999; borderStyle: solid; borderThickness: 2; horizontal-align: center; vertical-align: center; } Grid { borderColor: #A09999; borderStyle: solid; borderThickness: 2; horizontalGap: 0; verticalGap: 0; horizontal-align: center; vertical-align: center; } </mx:Style> </mx:Application>

    Read the article

  • Android app in eclipse

    - by Colin
    Hello everybody, i've searched for days but cant find an answer, perhaps you guys can help. I'm creating an android app in eclipse, it all works just one thing is bugging me. this is my main.java: package com.test; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Toast; public class Main extends Activity implements OnClickListener { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // Add Click listeners for all buttons View firstButton = findViewById(R.id.btn_rassen); firstButton.setOnClickListener(this); View secondButton = findViewById(R.id.button2); secondButton.setOnClickListener(this); } // Process the button click events @Override public void onClick(View v) { switch(v.getId()){ case R.id.btn_rassen: Intent j = new Intent(this, Webscreen.class); j.putExtra(com.test.Webscreen.URL, "http://www.google.com/"); startActivity(j); break; case R.id.button2: Intent k = new Intent(this, Webscreen.class); k.putExtra(com.test.Webscreen.URL, "http://notworkingurltotest.com"); startActivity(k); break; } } } now when it calls the webview.java the page called shows up but not the buttons i created in the layout xml page. does anybody have any idea why this is? your help is much appreciated! ohw this is my webscreen.java package com.test; import android.app.Activity; import android.app.AlertDialog; import android.app.ProgressDialog; import android.content.DialogInterface; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.util.Log; import android.view.Window; import android.webkit.WebSettings; import android.webkit.WebView; import android.webkit.WebViewClient; import android.widget.Toast; public class Webscreen extends Activity { public static final String URL = ""; private static final String TAG = "WebscreenClass"; private WebView webview; private ProgressDialog progressDialog; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.webscreen); this.getIntent().getExtras(); this.webview = (WebView) findViewById(R.string.webview); String turl = getIntent().getStringExtra(URL); Log.i(TAG, " URL = "+turl); WebView webview = new WebView(this); setContentView(webview); final Activity activity = this; webview.setWebViewClient(new WebViewClient() { public boolean shouldOverrideUrlLoading(WebView view, String url) { view.loadUrl(url); return true; } public void onLoadResource (WebView view, String url) { if (progressDialog == null) { progressDialog = new ProgressDialog(activity); progressDialog.setMessage("Bezig met laden..."); progressDialog.show(); } } public void onPageFinished(WebView view, String url) { if (progressDialog.isShowing()) { progressDialog.dismiss(); progressDialog = null; } } public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) { Intent myIntent = new Intent(); myIntent.setClassName("com.test", "com.test.Main"); startActivity(myIntent); Toast.makeText(activity, "Laden van onderdeel mislukt, probeer het later nog eens! ", Toast.LENGTH_LONG).show(); progressDialog.show(); } }); webview.loadUrl(turl); } } webscreen.xml layout: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <!-- <1> --> <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content"> <EditText android:id="@+id/url" android:layout_height="wrap_content" android:layout_width="wrap_content" android:lines="1" android:layout_weight="1.0" android:hint="http://" android:visibility="visible" /> <Button android:id="@+id/go_button" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="go_button" /> </LinearLayout> <!-- <2> --> <WebView android:id="@string/webview" android:layout_width="fill_parent" android:layout_height="0dip" /> </LinearLayout>

    Read the article

  • Extending the ADF Controller exception handler

    - by frank.nimphius
    The Oracle ADF controller provides a declarative option for developers to define a view activity, method activity or router activity to handle exceptions in bounded or unbounded task flows. Exception handling however is for exceptions only and not handling all types of Throwable. Furthermore, exceptions that occur during the JSF RENDER RESPONSE phase are not looked at either as it is considered too late in the cycle. For developers to try themselves to handle unhandled exceptions in ADF Controller, it is possible to extend the default exception handling, while still leveraging the declarative configuration. To add your own exception handler: · Create a Java class that extends ExceptionHandler · Create a textfile with the name “oracle.adf.view.rich.context.Exceptionhandler” (without the quotes) and store it in .adf\META-INF\services (you need to create the “services” folder) · In the file, add the absolute name of your custom exception handler class (package name and class name without the “.class” extension) For any exception you don't handle in your custom exception handler, just re-throw it for the default handler to give it a try … import oracle.adf.view.rich.context.ExceptionHandler; public class MyCustomExceptionHandler extends ExceptionHandler { public MyCustomExceptionHandler() {      super(); } public void handleException(FacesContext facesContext,                              Throwable throwable, PhaseId phaseId)                              throws Throwable {    String error_message;    error_message = throwable.getMessage();    //check error message and handle it if you can    if( … ){          //handle exception        …    }    else{       //delegate to the default ADFc exception handler        throw throwable;}    } } Note however, that it is recommended to first try and handle exceptions with the ADF Controller default exception handling mechanism. In the past, I've seen attempts on OTN to handle regular application use cases with custom exception handlers for where there was no need to override the exception handler. So don't go for this solution to quickly and always think of alternative solutions. Sometimes a try-catch-final block does it better than sophisticated web exception handling.

    Read the article

  • java.sql.SQLException: Operation not allowed after ResultSet closed

    - by javatraniee
    Why am I getting an Resultset already closed error? public class Server implements Runnable { private static int port = 1600, maxConnections = 0; public static Connection connnew = null; public static Connection connnew1 = null; public static Statement stnew, stnew1, stnew2, stnew3, stnew4; public void getConnection() { try { Class.forName("org.gjt.mm.mysql.Driver"); connnew = DriverManager.getConnection("jdbc:mysql://localhost/db_alldata", "root", "flashkit"); connnew1 = DriverManager.getConnection("jdbc:mysql://localhost/db_main", "root", "flashkit"); stnew = connnew.createStatement(); stnew1 = connnew.createStatement(); stnew2 = connnew1.createStatement(); stnew3 = connnew1.createStatement(); stnew4 = connnew1.createStatement(); } catch (Exception e) { System.out.print("Get Connection Exception---" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "----- > " + e); } } public void closeConnection() { try { if (!(connnew.isClosed())) { stnew.close(); stnew1.close(); connnew.close(); } if (!(connnew1.isClosed())) { stnew2.close(); stnew3.close(); stnew4.close(); connnew1.close(); } } catch (Exception e) { System.out.print("Close Connection Closing Exception-----" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "------->" + e); } } Server() { try { } catch (Exception ee) { System.out.print("Server Exceptions in main connection--" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "------>" + ee); } } public static void main(String[] args) throws SQLException { int i = 0; Server STUD = new Server(); STUD.getConnection(); try { ServerSocket listener = new ServerSocket(port); Socket server; while ((i++ < maxConnections) || (maxConnections == 0)) { @SuppressWarnings("unused") doComms connection; server = listener.accept(); try { ResultSet checkconnection = stnew4 .executeQuery("select count(*) from t_studentdetails"); if (checkconnection.next()) { // DO NOTHING IF EXCEPTION THEN CLOSE ALL CONNECTIONS AND OPEN NEW // CONNECTIONS } } catch (Exception e) { System.out.print("Db Connection Lost Closing And Re-Opning It--------" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "--------" + e); STUD.closeConnection(); STUD.getConnection(); } doComms conn_c = new doComms(server, stnew, stnew1, stnew2, stnew3); Thread t = new Thread(conn_c); t.start(); } } catch (IOException ioe) { System.out.println("Main IOException on socket listen: " + ioe); } } public void run() { } } class doComms implements Runnable { private Socket server; private String input; static Connection conn = null; static Connection conn1 = null; static Statement st, st1, st2, st3; doComms(Socket server, Statement st, Statement st1, Statement st2, Statement st3) { this.server = server; doComms.st = st; doComms.st1 = st1; doComms.st2 = st2; doComms.st3 = st3; } @SuppressWarnings("deprecation") public void run() { input = ""; // char ch; try { DataInputStream in = new DataInputStream(server.getInputStream()); OutputStreamWriter outgoing = new OutputStreamWriter(server.getOutputStream()); while (!(null == (input = in.readLine()))) { savetodatabase(input, server.getPort(), outgoing); } } catch (IOException ioe) { System.out.println("RUN IOException on socket listen:-------" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "----- " + ioe); ioe.printStackTrace(); } } public void savetodatabase(String line, int port1, OutputStreamWriter outgoing) { try { String Rollno = "-", name = "-", div = "-", storeddate = "-", storedtime = "-", mailfrom = ""; String newline = line; String unitid = "-"; storeddate = new SimpleDateFormat("yyyy-MM-dd").format(new java.util.Date()); storedtime = new SimpleDateFormat("HH:mm:ss").format(new java.util.Date()); String sql2 = "delete from t_currentport where PortNumber='" + port1 + "''"; st2.executeUpdate(sql2); sql2 = "insert into t_currentport (unitid, portnumber,thedate,thetime) values >('" + unitid + "','" + port1 + "','" + storeddate + "','" + storedtime + "')"; st2.executeUpdate(sql2); String tablename = GetTable(); String sql = "select * from t_studentdetails where Unitid='" + unitid + "'"; ResultSet rst = st2.executeQuery(sql); if (rst.next()) { Rollno = rst.getString("Rollno"); name = rst.getString("name"); div = rst.getString("div"); } String sql1 = "insert into studentInfo StoredDate,StoredTime,Subject,UnitId,Body,Status,Rollno,div,VehId,MailDate,MailTime,MailFrom,MailTo,Header,UnProcessedStamps) values('" + storeddate + "','" + storedtime + "','" + unitid + "','" + unitid + "','" + newline + "','Pending','" + Rollno + "','" + div + "','" + name + "','" + storeddate + "','" + storedtime + "','" + mailfrom + "','" + mailfrom + "','-','-')"; st1.executeUpdate(sql1); } catch (Exception e) { System.out.print("Save to db Connection Exception--" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "-->" + e); } } }

    Read the article

  • Understanding C# async / await (1) Compilation

    - by Dixin
    Now the async / await keywords are in C#. Just like the async and ! in F#, this new C# feature provides great convenience. There are many nice documents talking about how to use async / await in specific scenarios, like using async methods in ASP.NET 4.5 and in ASP.NET MVC 4, etc. In this article we will look at the real code working behind the syntax sugar. According to MSDN: The async modifier indicates that the method, lambda expression, or anonymous method that it modifies is asynchronous. Since lambda expression / anonymous method will be compiled to normal method, we will focus on normal async method. Preparation First of all, Some helper methods need to make up. internal class HelperMethods { internal static int Method(int arg0, int arg1) { // Do some IO. WebClient client = new WebClient(); Enumerable.Repeat("http://weblogs.asp.net/dixin", 10) .Select(client.DownloadString).ToArray(); int result = arg0 + arg1; return result; } internal static Task<int> MethodTask(int arg0, int arg1) { Task<int> task = new Task<int>(() => Method(arg0, arg1)); task.Start(); // Hot task (started task) should always be returned. return task; } internal static void Before() { } internal static void Continuation1(int arg) { } internal static void Continuation2(int arg) { } } Here Method() is a long running method doing some IO. Then MethodTask() wraps it into a Task and return that Task. Nothing special here. Await something in async method Since MethodTask() returns Task, let’s try to await it: internal class AsyncMethods { internal static async Task<int> MethodAsync(int arg0, int arg1) { int result = await HelperMethods.MethodTask(arg0, arg1); return result; } } Because we used await in the method, async must be put on the method. Now we get the first async method. According to the naming convenience, it is named MethodAsync. Of course a async method can be awaited. So we have a CallMethodAsync() to call MethodAsync(): internal class AsyncMethods { internal static async Task<int> CallMethodAsync(int arg0, int arg1) { int result = await MethodAsync(arg0, arg1); return result; } } After compilation, MethodAsync() and CallMethodAsync() becomes the same logic. This is the code of MethodAsyc(): internal class CompiledAsyncMethods { [DebuggerStepThrough] [AsyncStateMachine(typeof(MethodAsyncStateMachine))] // async internal static /*async*/ Task<int> MethodAsync(int arg0, int arg1) { MethodAsyncStateMachine methodAsyncStateMachine = new MethodAsyncStateMachine() { Arg0 = arg0, Arg1 = arg1, Builder = AsyncTaskMethodBuilder<int>.Create(), State = -1 }; methodAsyncStateMachine.Builder.Start(ref methodAsyncStateMachine); return methodAsyncStateMachine.Builder.Task; } } It just creates and starts a state machine, MethodAsyncStateMachine: [CompilerGenerated] [StructLayout(LayoutKind.Auto)] internal struct MethodAsyncStateMachine : IAsyncStateMachine { public int State; public AsyncTaskMethodBuilder<int> Builder; public int Arg0; public int Arg1; public int Result; private TaskAwaiter<int> awaitor; void IAsyncStateMachine.MoveNext() { try { if (this.State != 0) { this.awaitor = HelperMethods.MethodTask(this.Arg0, this.Arg1).GetAwaiter(); if (!this.awaitor.IsCompleted) { this.State = 0; this.Builder.AwaitUnsafeOnCompleted(ref this.awaitor, ref this); return; } } else { this.State = -1; } this.Result = this.awaitor.GetResult(); } catch (Exception exception) { this.State = -2; this.Builder.SetException(exception); return; } this.State = -2; this.Builder.SetResult(this.Result); } [DebuggerHidden] void IAsyncStateMachine.SetStateMachine(IAsyncStateMachine param0) { this.Builder.SetStateMachine(param0); } } The generated code has been refactored, so it is readable and can be compiled. Several things can be observed here: The async modifier is gone, which shows, unlike other modifiers (e.g. static), there is no such IL/CLR level “async” stuff. It becomes a AsyncStateMachineAttribute. This is similar to the compilation of extension method. The generated state machine is very similar to the state machine of C# yield syntax sugar. The local variables (arg0, arg1, result) are compiled to fields of the state machine. The real code (await HelperMethods.MethodTask(arg0, arg1)) is compiled into MoveNext(): HelperMethods.MethodTask(this.Arg0, this.Arg1).GetAwaiter(). CallMethodAsync() will create and start its own state machine CallMethodAsyncStateMachine: internal class CompiledAsyncMethods { [DebuggerStepThrough] [AsyncStateMachine(typeof(CallMethodAsyncStateMachine))] // async internal static /*async*/ Task<int> CallMethodAsync(int arg0, int arg1) { CallMethodAsyncStateMachine callMethodAsyncStateMachine = new CallMethodAsyncStateMachine() { Arg0 = arg0, Arg1 = arg1, Builder = AsyncTaskMethodBuilder<int>.Create(), State = -1 }; callMethodAsyncStateMachine.Builder.Start(ref callMethodAsyncStateMachine); return callMethodAsyncStateMachine.Builder.Task; } } CallMethodAsyncStateMachine has the same logic as MethodAsyncStateMachine above. The detail of the state machine will be discussed soon. Now it is clear that: async /await is a C# language level syntax sugar. There is no difference to await a async method or a normal method. As long as a method returns Task, it is awaitable. State machine and continuation To demonstrate more details in the state machine, a more complex method is created: internal class AsyncMethods { internal static async Task<int> MultiCallMethodAsync(int arg0, int arg1, int arg2, int arg3) { HelperMethods.Before(); int resultOfAwait1 = await MethodAsync(arg0, arg1); HelperMethods.Continuation1(resultOfAwait1); int resultOfAwait2 = await MethodAsync(arg2, arg3); HelperMethods.Continuation2(resultOfAwait2); int resultToReturn = resultOfAwait1 + resultOfAwait2; return resultToReturn; } } In this method: There are multiple awaits. There are code before the awaits, and continuation code after each await After compilation, this multi-await method becomes the same as above single-await methods: internal class CompiledAsyncMethods { [DebuggerStepThrough] [AsyncStateMachine(typeof(MultiCallMethodAsyncStateMachine))] // async internal static /*async*/ Task<int> MultiCallMethodAsync(int arg0, int arg1, int arg2, int arg3) { MultiCallMethodAsyncStateMachine multiCallMethodAsyncStateMachine = new MultiCallMethodAsyncStateMachine() { Arg0 = arg0, Arg1 = arg1, Arg2 = arg2, Arg3 = arg3, Builder = AsyncTaskMethodBuilder<int>.Create(), State = -1 }; multiCallMethodAsyncStateMachine.Builder.Start(ref multiCallMethodAsyncStateMachine); return multiCallMethodAsyncStateMachine.Builder.Task; } } It creates and starts one single state machine, MultiCallMethodAsyncStateMachine: [CompilerGenerated] [StructLayout(LayoutKind.Auto)] internal struct MultiCallMethodAsyncStateMachine : IAsyncStateMachine { public int State; public AsyncTaskMethodBuilder<int> Builder; public int Arg0; public int Arg1; public int Arg2; public int Arg3; public int ResultOfAwait1; public int ResultOfAwait2; public int ResultToReturn; private TaskAwaiter<int> awaiter; void IAsyncStateMachine.MoveNext() { try { switch (this.State) { case -1: HelperMethods.Before(); this.awaiter = AsyncMethods.MethodAsync(this.Arg0, this.Arg1).GetAwaiter(); if (!this.awaiter.IsCompleted) { this.State = 0; this.Builder.AwaitUnsafeOnCompleted(ref this.awaiter, ref this); } break; case 0: this.ResultOfAwait1 = this.awaiter.GetResult(); HelperMethods.Continuation1(this.ResultOfAwait1); this.awaiter = AsyncMethods.MethodAsync(this.Arg2, this.Arg3).GetAwaiter(); if (!this.awaiter.IsCompleted) { this.State = 1; this.Builder.AwaitUnsafeOnCompleted(ref this.awaiter, ref this); } break; case 1: this.ResultOfAwait2 = this.awaiter.GetResult(); HelperMethods.Continuation2(this.ResultOfAwait2); this.ResultToReturn = this.ResultOfAwait1 + this.ResultOfAwait2; this.State = -2; this.Builder.SetResult(this.ResultToReturn); break; } } catch (Exception exception) { this.State = -2; this.Builder.SetException(exception); } } [DebuggerHidden] void IAsyncStateMachine.SetStateMachine(IAsyncStateMachine stateMachine) { this.Builder.SetStateMachine(stateMachine); } } Once again, the above state machine code is already refactored, but it still has a lot of things. More clean up can be done if we only keep the core logic, and the state machine can become very simple: [CompilerGenerated] [StructLayout(LayoutKind.Auto)] internal struct MultiCallMethodAsyncStateMachine : IAsyncStateMachine { // State: // -1: Begin // 0: 1st await is done // 1: 2nd await is done // ... // -2: End public int State; public TaskCompletionSource<int> ResultToReturn; // int resultToReturn ... public int Arg0; // int Arg0 public int Arg1; // int arg1 public int Arg2; // int arg2 public int Arg3; // int arg3 public int ResultOfAwait1; // int resultOfAwait1 ... public int ResultOfAwait2; // int resultOfAwait2 ... private Task<int> currentTaskToAwait; /// <summary> /// Moves the state machine to its next state. /// </summary> public void MoveNext() // IAsyncStateMachine member. { try { switch (this.State) { // Original code is split by "await"s into "case"s: // case -1: // HelperMethods.Before(); // MethodAsync(Arg0, arg1); // case 0: // int resultOfAwait1 = await ... // HelperMethods.Continuation1(resultOfAwait1); // MethodAsync(arg2, arg3); // case 1: // int resultOfAwait2 = await ... // HelperMethods.Continuation2(resultOfAwait2); // int resultToReturn = resultOfAwait1 + resultOfAwait2; // return resultToReturn; case -1: // -1 is begin. HelperMethods.Before(); // Code before 1st await. this.currentTaskToAwait = AsyncMethods.MethodAsync(this.Arg0, this.Arg1); // 1st task to await // When this.currentTaskToAwait is done, run this.MoveNext() and go to case 0. this.State = 0; MultiCallMethodAsyncStateMachine that1 = this; // Cannot use "this" in lambda so create a local variable. this.currentTaskToAwait.ContinueWith(_ => that1.MoveNext()); break; case 0: // Now 1st await is done. this.ResultOfAwait1 = this.currentTaskToAwait.Result; // Get 1st await's result. HelperMethods.Continuation1(this.ResultOfAwait1); // Code after 1st await and before 2nd await. this.currentTaskToAwait = AsyncMethods.MethodAsync(this.Arg2, this.Arg3); // 2nd task to await // When this.currentTaskToAwait is done, run this.MoveNext() and go to case 1. this.State = 1; MultiCallMethodAsyncStateMachine that2 = this; this.currentTaskToAwait.ContinueWith(_ => that2.MoveNext()); break; case 1: // Now 2nd await is done. this.ResultOfAwait2 = this.currentTaskToAwait.Result; // Get 2nd await's result. HelperMethods.Continuation2(this.ResultOfAwait2); // Code after 2nd await. int resultToReturn = this.ResultOfAwait1 + this.ResultOfAwait2; // Code after 2nd await. // End with resultToReturn. this.State = -2; // -2 is end. this.ResultToReturn.SetResult(resultToReturn); break; } } catch (Exception exception) { // End with exception. this.State = -2; // -2 is end. this.ResultToReturn.SetException(exception); } } /// <summary> /// Configures the state machine with a heap-allocated replica. /// </summary> /// <param name="stateMachine">The heap-allocated replica.</param> [DebuggerHidden] public void SetStateMachine(IAsyncStateMachine stateMachine) // IAsyncStateMachine member. { // No core logic. } } Only Task and TaskCompletionSource are involved in this version. And MultiCallMethodAsync() can be simplified to: [DebuggerStepThrough] [AsyncStateMachine(typeof(MultiCallMethodAsyncStateMachine))] // async internal static /*async*/ Task<int> MultiCallMethodAsync(int arg0, int arg1, int arg2, int arg3) { MultiCallMethodAsyncStateMachine multiCallMethodAsyncStateMachine = new MultiCallMethodAsyncStateMachine() { Arg0 = arg0, Arg1 = arg1, Arg2 = arg2, Arg3 = arg3, ResultToReturn = new TaskCompletionSource<int>(), // -1: Begin // 0: 1st await is done // 1: 2nd await is done // ... // -2: End State = -1 }; multiCallMethodAsyncStateMachine.MoveNext(); // Original code are moved into this method. return multiCallMethodAsyncStateMachine.ResultToReturn.Task; } Now the whole state machine becomes very clean - it is about callback: Original code are split into pieces by “await”s, and each piece is put into each “case” in the state machine. Here the 2 awaits split the code into 3 pieces, so there are 3 “case”s. The “piece”s are chained by callback, that is done by Builder.AwaitUnsafeOnCompleted(callback), or currentTaskToAwait.ContinueWith(callback) in the simplified code. A previous “piece” will end with a Task (which is to be awaited), when the task is done, it will callback the next “piece”. The state machine’s state works with the “case”s to ensure the code “piece”s executes one after another. Callback If we focus on the point of callback, the simplification  can go even further – the entire state machine can be completely purged, and we can just keep the code inside MoveNext(). Now MultiCallMethodAsync() becomes: internal static Task<int> MultiCallMethodAsync(int arg0, int arg1, int arg2, int arg3) { TaskCompletionSource<int> taskCompletionSource = new TaskCompletionSource<int>(); try { // Oringinal code begins. HelperMethods.Before(); MethodAsync(arg0, arg1).ContinueWith(await1 => { int resultOfAwait1 = await1.Result; HelperMethods.Continuation1(resultOfAwait1); MethodAsync(arg2, arg3).ContinueWith(await2 => { int resultOfAwait2 = await2.Result; HelperMethods.Continuation2(resultOfAwait2); int resultToReturn = resultOfAwait1 + resultOfAwait2; // Oringinal code ends. taskCompletionSource.SetResult(resultToReturn); }); }); } catch (Exception exception) { taskCompletionSource.SetException(exception); } return taskCompletionSource.Task; } Please compare with the original async / await code: HelperMethods.Before(); int resultOfAwait1 = await MethodAsync(arg0, arg1); HelperMethods.Continuation1(resultOfAwait1); int resultOfAwait2 = await MethodAsync(arg2, arg3); HelperMethods.Continuation2(resultOfAwait2); int resultToReturn = resultOfAwait1 + resultOfAwait2; return resultToReturn; Yeah that is the magic of C# async / await: Await is not to wait. In a await expression, a Task object will be return immediately so that execution is not blocked. The continuation code is compiled as that Task’s callback code. When that task is done, continuation code will execute. Please notice that many details inside the state machine are omitted for simplicity, like context caring, etc. If you want to have a detailed picture, please do check out the source code of AsyncTaskMethodBuilder and TaskAwaiter.

    Read the article

  • What constitutes a "substantial, good-faith effort to remove the links"

    - by Luke McCallum
    We engaged the services of a 3rd party SEO consultant to assist us in managing our Meta data and to write regular blogs on our site http://cyberdesignworks.com.au Without our authorisation, the SEO also ran a link building campaign which has seen us Penguin slapped and we no longer appear in Google for a number of our core keywords. Since notification by Google that we have "unnatural links" back in March we have undertaken a significant campaign to rid ourselves of these dodgy backlinks by a number of methods. I have just received feedback on my 4th or 5th resubmission which is still advising that we need to make a "substantial, good-faith effort to remove the links" before Google will reconsider us for inclusion. After the effort that I have gone through to get links removed, I am now at a loss as to what else I can do to demonstrate "substantial, good-faith effort to remove the links". Below is a summary of the actions that we have taken to date. According to http://removem.com we had about 5584 back-linking domains. Of those we have successfully contacted and had removed links from 344 domains We ignored links from 625 domains as they were either legitimate press releases, natural backlinks or client websites containing an attribution link in the footer that points back to us. Due to our efforts, or the sites simply becoming defunct, removem.com reports that links from 3262 domains have been removed. We have contacted but are yet to receive feedback from 1666 domains so we can assume that the backlinks remain. We have configured an automatic 301 redirect for each of the links from these 1666 domains to point to http://redirects.sanscode.com/ which we are calling our Bad Link Catcher (a stroke of genius I thought). i.e http://www.mysimplewebdesign.com/create-a-perfect-webpage-with-four-important-tips-from-sydney-web-development-service-companies.php As we are a web design agency, we have a large number of client websites which contain an attribution link in their footer which points back to us. We have gone through the vast majority of these and updated these links to replace anchor text with an image and rel="nofollow" link. i.e <a rel="nofollow" target="_blank" href="http://www.cyberdesignworks.com.au/"><img src="https://sessions.sanscode.com/site/assets/media/badges/Badge_CDW_SANSCODE.png"></a> See http://www.milkatwork.com.au/ An export from http://removem.com detailing the number of times we have contacted each link and whether it is still found or not was also supplied with each resubmission. The total back links reported in Google Web Master Tools has dropped from over 100K to 87K and I expect it to drop significantly lower once Google re-crawls each back-linking page. Based on all of the above, I am not sure what else I can do to to demonstrate a "substantial, good-faith effort to remove the links". I would sincerely appreciate any feedback or suggestions that you may have as I am out of ideas.

    Read the article

  • How can I get popup window using commandButton in Trinidad?

    - by vikram
    How can I get popup window using commandButton in Trinidad? My problem is that by clicking on Add button from dialogdemo.jspx, not any popup window or dialog box is opened. This is dialogdemo.jspx file: <jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:f="http://java.sun.com/jsf/core" xmlns:tr="http://myfaces.apache.org/trinidad" version="1.2"> <jsp:directive.page contentType="text/html;charset=utf-8" /> <f:view> <tr:document title="Dialog Demo"> <tr:form> <!-- The field for the value; we point partialTriggers at the button to ensure it gets redrawn when we return --> <tr:inputText label="Pick a number:" partialTriggers="buttonId" value="#{launchDialog.input}" /> <!-- The button for launching the dialog: we've also configured the width and height of that window --> <tr:commandButton text="Add" action="dialog:chooseInteger" id="buttonId" windowWidth="300" windowHeight="200" partialSubmit="true" useWindow="true" returnListener="#{launchDialog.returned}" /> </tr:form> </tr:document> </f:view> </jsp:root> Here is the associated managed bean LaunchDialogBean.java: package jsfpkg; import org.apache.myfaces.trinidad.component.UIXInput; import org.apache.myfaces.trinidad.event.ReturnEvent; public class LaunchDialogBean { private UIXInput _input; public UIXInput getInput() { return _input; } public void setInput(UIXInput input) { _input = input; } public void returned(ReturnEvent event) { if (event.getReturnValue() != null) { getInput().setSubmittedValue(null); getInput().setValue(event.getReturnValue()); } } } Here is the popup file Popup.jspx: <jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:f="http://java.sun.com/jsf/core" xmlns:h="http://java.sun.com/jsf/html" xmlns:trh="http://myfaces.apache.org/trinidad/html" xmlns:tr="http://myfaces.apache.org/trinidad" version="2.0"> <jsp:directive.page contentType="text/html;charset=utf-8" /> <f:view> <tr:document title="Add dialog"> <tr:form> <!-- Two input fields --> <tr:panelForm> <tr:inputText label="Number 1:" value="#{chooseInteger.value1}" required="true" /> <tr:inputText label="Number 2:" value="#{chooseInteger.value2}" required="true" /> </tr:panelForm> <!-- Two buttons --> <tr:panelGroup layout="horizontal"> <tr:commandButton text="Submit" action="#{chooseInteger.select}" /> <tr:commandButton text="Cancel" immediate="true" action="#{chooseInteger.cancel}" /> </tr:panelGroup> </tr:form> </tr:document> </f:view> </jsp:root> For that I have written the bean ChooseIntegerBean.java package jsfpkg; import org.apache.myfaces.trinidad.context.RequestContext; public class ChooseIntegerBean { private Integer _value1; private Integer _value2; public Integer getValue1() { return _value1; } public void setValue1(Integer value1) { _value1 = value1; } public Integer getValue2() { return _value2; } public void setValue2(Integer value2) { _value2 = value2; } public String cancel() { RequestContext.getCurrentInstance().returnFromDialog(null, null); return null; } public String select() { Integer value = new Integer(getValue1().intValue() + getValue2().intValue()); RequestContext.getCurrentInstance().returnFromDialog(value, null); return null; } } Here is my faces-config.xml: <managed-bean> <managed-bean-name>chooseInteger</managed-bean-name> <managed-bean-class>jsfpkg.ChooseIntegerBean</managed-bean-class> <managed-bean-scope>request</managed-bean-scope> </managed-bean> <managed-bean> <managed-bean-name>launchDialog</managed-bean-name> <managed-bean-class>jsfpkg.LaunchDialogBean</managed-bean-class> <managed-bean-scope> request </managed-bean-scope> </managed-bean> <navigation-rule> <from-view-id>/dialogdemo.jspx</from-view-id> <navigation-case> <from-outcome>dialog:chooseInteger</from-outcome> <to-view-id>/dialogbox.jspx</to-view-id> </navigation-case> </navigation-rule>

    Read the article

  • Signals and threads - good or bad design decision?

    - by Jens
    I have to write a program that performs highly computationally intensive calculations. The program might run for several days. The calculation can be separated easily in different threads without the need of shared data. I want a GUI or a web service that informs me of the current status. My current design uses BOOST::signals2 and BOOST::thread. It compiles and so far works as expected. If a thread finished one iteration and new data is available it calls a signal which is connected to a slot in the GUI class. My question(s): Is this combination of signals and threads a wise idea? I another forum somebody advised someone else not to "go down this road". Are there potential deadly pitfalls nearby that I failed to see? Is my expectation realistic that it will be "easy" to use my GUI class to provide a web interface or a QT, a VTK or a whatever window? Is there a more clever alternative (like other boost libs) that I overlooked? following code compiles with g++ -Wall -o main -lboost_thread-mt <filename>.cpp code follows: #include <boost/signals2.hpp> #include <boost/thread.hpp> #include <boost/bind.hpp> #include <iostream> #include <iterator> #include <string> using std::cout; using std::cerr; using std::string; /** * Called when a CalcThread finished a new bunch of data. */ boost::signals2::signal<void(string)> signal_new_data; /** * The whole data will be stored here. */ class DataCollector { typedef boost::mutex::scoped_lock scoped_lock; boost::mutex mutex; public: /** * Called by CalcThreads call the to store their data. */ void push(const string &s, const string &caller_name) { scoped_lock lock(mutex); _data.push_back(s); signal_new_data(caller_name); } /** * Output everything collected so far to std::out. */ void out() { typedef std::vector<string>::const_iterator iter; for (iter i = _data.begin(); i != _data.end(); ++i) cout << " " << *i << "\n"; } private: std::vector<string> _data; }; /** * Several of those can calculate stuff. * No data sharing needed. */ struct CalcThread { CalcThread(string name, DataCollector &datcol) : _name(name), _datcol(datcol) { } /** * Expensive algorithms will be implemented here. * @param num_results how many data sets are to be calculated by this thread. */ void operator()(int num_results) { for (int i = 1; i <= num_results; ++i) { std::stringstream s; s << "["; if (i == num_results) s << "LAST "; s << "DATA " << i << " from thread " << _name << "]"; _datcol.push(s.str(), _name); } } private: string _name; DataCollector &_datcol; }; /** * Maybe some VTK or QT or both will be used someday. */ class GuiClass { public: GuiClass(DataCollector &datcol) : _datcol(datcol) { } /** * If the GUI wants to present or at least count the data collected so far. * @param caller_name is the name of the thread whose data is new. */ void slot_data_changed(string caller_name) const { cout << "GuiClass knows: new data from " << caller_name << std::endl; } private: DataCollector & _datcol; }; int main() { DataCollector datcol; GuiClass mc(datcol); signal_new_data.connect(boost::bind(&GuiClass::slot_data_changed, &mc, _1)); CalcThread r1("A", datcol), r2("B", datcol), r3("C", datcol), r4("D", datcol), r5("E", datcol); boost::thread t1(r1, 3); boost::thread t2(r2, 1); boost::thread t3(r3, 2); boost::thread t4(r4, 2); boost::thread t5(r5, 3); t1.join(); t2.join(); t3.join(); t4.join(); t5.join(); datcol.out(); cout << "\nDone" << std::endl; return 0; }

    Read the article

  • Java MVC - How to divide a done text game into MVC?

    - by Zopyrus
    Been sitting here for hours now trying to figure this out, so a bit sympathy for this large question. :) The Goal: I simply want to divide my done code into MVC (Model View Controller) parts. I have the game logics done and text based - the code works fine. The Problem: Well, I want to implement this code into MVC, but where do explain for the MODEL that it should use text-based? Because the VIEW is only for the layout (graphically) correct? I am having a REALLY hard time figuring out where to begin at all. Any pointers would be so nice! Here is my game logics code: import mind.*; import javax.swing.*; import java.util.*; import java.lang.*; import java.awt.*; public class Drive { String[] mellan; boolean gameEnd, checkempty, checkempty2, enemy, enemy2; String gr,rd,tom; int digits; public Drive() { // Gamepieces in textform gr="G"; rd="R"; tom=" "; mellan = new String[7]; String[] begin = {gr,gr,gr,tom,rd,rd,rd}; String[] end = {rd,rd,rd,tom,gr,gr,gr}; //input Scanner in = new Scanner(System.in); mellan=begin; gameEnd=false; while (gameEnd == false) { for(int i=0; i<mellan.length; i++) { System.out.print(mellan[i]); } System.out.print(" Choose 0-6: "); digits = in.nextInt(); move(); checkWin(); } } void move() { //BOOLEAN for gameruls!!! checkempty = digits<6 && mellan[digits+1]==tom; checkempty2 = digits>0 && mellan[digits-1]==tom; enemy = (mellan[digits]==gr && mellan[digits+1]==rd && mellan[digits+2]==tom); enemy2 = (mellan[digits]==rd && mellan[digits-1]==gr && mellan[digits-2]==tom); if(checkempty) { mellan[digits+1]=mellan[digits]; mellan[digits]=tom; } else if (checkempty2) { mellan[digits-1]=mellan[digits]; mellan[digits]=tom; } else if (enemy) { mellan[digits+2]=mellan[digits]; mellan[digits]=tom; } else if (enemy2) { mellan[digits-2]=mellan[digits]; mellan[digits]=tom; } } void checkWin() { String[] end = {rd,rd,rd,tom,gr,gr,gr}; for (int i=0; i<mellan.length; i++){ } if (Arrays.equals(mellan,end)) { for (int j=0; j<mellan.length; j++) { System.out.print(mellan[j]); } displayWin(); } } void displayWin() { gameEnd = true; System.out.println("\nNicely Done!"); return; } // Kör Drive! public static void main(String args[]) { new Drive(); } } Here is how I defined my DriveView thus far: (just trying to make one button to work) import mind.*; import javax.swing.*; import java.util.*; import java.lang.*; import java.awt.*; import java.awt.event.*; public class DriveView extends JFrame { JButton ruta1 = new JButton("Green"); JButton ruta2 = new JButton("Green"); JButton rutatom = new JButton(""); JButton ruta6 = new JButton("Red"); private DriveModel m_model; public DriveView(DriveModel model) { m_model = model; //Layout for View JPanel myPanel = new JPanel(); myPanel.setLayout(new FlowLayout()); myPanel.add(ruta1); myPanel.add(ruta2); myPanel.add(rutatom); myPanel.add(ruta6); this.setContentPane(myPanel); this.pack(); this.setTitle("Drive"); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } void addMouseListener(ActionListener mol) { ruta2.addActionListener(mol); } } And DriveController which gives me error at compile import mind.*; import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.lang.*; public class DriveController { private DriveModel m_model; private DriveView m_view; public DriveController(DriveModel model, DriveView view) { m_model = model; m_view = view; view.addMouseListener(new MouseListener()); } class MouseListener implements ActionListener { public void actionPerformed(ActionEvent e) { String mening; mening = e.getActionCommand(); if (mening.equals("Green")) { setForeground(Color.red); } } } }

    Read the article

  • Hibernate Query Language Problem

    - by Sarang
    Well, I have implemented a distinct query in hibernate. It returns me result. But, while casting the fields are getting interchanged. So, it generates casting error. What should be the solution? As an example, I do have database, "ProjectAssignment" that has three fields, aid, pid & userName. I want all distinct userName data from this table. I have applied query : select distinct userName, aid, pid from ProjectAssignment Whereas the ProjectAssignment.java file has the fields in sequence aid, pid & userName. Now, here the userName is first field in output. So, Casting is not getting possible. Also, query : select aid, pid, distinct userName from ProjectAssignment is not working. What is the proper query for the same ? Or what else the solution ? The code is as below : System Utilization Service Bean Method where I have to retrieve data : public List<ProjectAssignment> getProjectAssignments() { projectAssignments = ProjectAssignmentHelper.getAllResources(); //Here comes the error return projectAssignments; } ProjectAssignmentHelper from where I fetch Data : package com.hibernate; import java.util.List; import org.hibernate.Query; import org.hibernate.Session; public class ProjectAssignmentHelper { public static List<ProjectAssignment> getAllResources() { List<ProjectAssignment> projectMasters; Session session = HibernateUtil.getSessionFactory().openSession(); Query query = session.createQuery("select distinct aid, pid, userName from ProjectAssignment"); projectMasters = (List<ProjectAssignment>) query.list(); session.close(); return projectMasters; } } Hibernate Data Bean : package com.hibernate; public class ProjectAssignment implements java.io.Serializable { private short aid; private String pid; private String userName; public ProjectAssignment() { } public ProjectAssignment(short aid) { this.aid = aid; } public ProjectAssignment(short aid, String pid, String userName) { this.aid = aid; this.pid = pid; this.userName = userName; } public short getAid() { return this.aid; } public void setAid(short aid) { this.aid = aid; } public String getPid() { return this.pid; } public void setPid(String pid) { this.pid = pid; } public String getUserName() { return this.userName; } public void setUserName(String userName) { this.userName = userName; } } Error : For input string: "userName" java.lang.NumberFormatException: For input string: "userName" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48) at java.lang.Integer.parseInt(Integer.java:447) at java.lang.Integer.parseInt(Integer.java:497) at javax.el.ArrayELResolver.toInteger(ArrayELResolver.java:375) at javax.el.ArrayELResolver.getValue(ArrayELResolver.java:195) at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:175) at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72) at com.sun.el.parser.AstValue.getValue(AstValue.java:116) at com.sun.el.parser.AstValue.getValue(AstValue.java:163) at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:219) at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:102) at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:190) at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:178) at javax.faces.component.UICommand.getValue(UICommand.java:218) at org.primefaces.component.commandlink.CommandLinkRenderer.encodeMarkup(CommandLinkRenderer.java:113) at org.primefaces.component.commandlink.CommandLinkRenderer.encodeEnd(CommandLinkRenderer.java:54) at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:878) at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:70) at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:54) at org.primefaces.component.datatable.DataTableRenderer.encodeTable(DataTableRenderer.java:525) at org.primefaces.component.datatable.DataTableRenderer.encodeMarkup(DataTableRenderer.java:407) at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:193) at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:878) at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:70) at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:54) at org.primefaces.component.tabview.TabViewRenderer.encodeContents(TabViewRenderer.java:198) at org.primefaces.component.tabview.TabViewRenderer.encodeMarkup(TabViewRenderer.java:130) at org.primefaces.component.tabview.TabViewRenderer.encodeEnd(TabViewRenderer.java:48) at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:878) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1620) at javax.faces.render.Renderer.encodeChildren(Renderer.java:168) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:848) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1613) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1616) at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:380) at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:126) at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:127) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:313) at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523) at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:802) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:664) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:497) at org.apache.catalina.core.ApplicationDispatcher.doDispatch(ApplicationDispatcher.java:468) at org.apache.catalina.core.ApplicationDispatcher.dispatch(ApplicationDispatcher.java:364) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:314) at org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:783) at org.apache.jsp.welcome_jsp._jspService(welcome_jsp.java from :59) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:109) at javax.servlet.http.HttpServlet.service(HttpServlet.java:847) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:406) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:483) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:373) at javax.servlet.http.HttpServlet.service(HttpServlet.java:847) at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641) at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97) at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185) at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:332) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:233) at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165) at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791) at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693) at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954) at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170) at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135) at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102) at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88) at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76) at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53) at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57) at com.sun.grizzly.ContextTask.run(ContextTask.java:69) at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330) at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309) at java.lang.Thread.run(Thread.java:619)

    Read the article

  • TechEd 2010 Day Three: The Database Designer (Isn't)

    - by BuckWoody
    Yesterday at TechEd 2010 here in New Orleans I worked the front-booth, answering general SQL Server questions for the masses. I was actually a little surprised to find most of the questions I got were from folks that wanted to know more about Stream Insight and Master Data Services. In past conferences I've been asked a lot of "free consulting" questions, about problems folks have had from older products. I don't mind that a bit - in fact, I'm always happy to help in any way I can. But this time people are really interested in the new features in the product, and I like that they are thinking ahead, not just having to solve problems in production. My presentation was on "Database Design in an Hour". We had the usual fun, and SideShow Bob made an appearance - I kid you not. The guy in the back of the room looked just like Sideshow Bob, so I quickly held a "bes thair" contest, and he won. Duing the presentation, I explain the tools you can use to design databases. I also explain that the "Database Designer" tool in SQL Server Management Studio (SSMS) isn't truly a desinger - it uses non-standard notation, doesn't have a meta-data dictionary, and worst of all, it works at the physical level. In other words, whatever you do in SSMS will automatically change the field/table/relationship structures in the database. We fixed this in SSMS 2008 and higher by adding an option to block that, but the tool is not a good design function nonetheless. To be fair, no one I know of at Microsoft recommends that it is - but I was shocked to hear so many developers in the room defending it as a good tool. I think the main issue for someone who doesn't have to work with Relational Systems a great deal is that it can be difficult to figure out Foreign Keys. The syntax makes them look "backwards", so it's just easier to grab a field and place it on the table you want to point to. There are options. You can download a couple of free tools (CA has a community edition of ER-WIN, Quest has one, and Embarcadero also has one) and if you design more than one or two databases a year, it may be worth buying a true design tool. For years I used Visio, but we changed it so that it doesn't forward-engineer (create the DDL) any more, so it isn't a true design tool either. So investigate those free and not-so-free tools. You'll find they help you in your job - but stay away from the Database Designer in SSMS. Or I'll send Sideshow Bob over there to straighten you out. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

    Read the article

  • How do I create an instance of this class in Android?

    - by Lloyd Banks
    I was wondering if it is possible to create an instance of this class (from the link, which creates a listview) from another class so that I can call on either lazyadapter.java or customizedlistview.java (not sure which one) to inflate that same listview. Is this possible? This is what I tried (obviously incorrect): CustomizedListView clv = new CustomizedListView(); clv.onCreate(...); source: http://www.androidhive.info/2012/02/android-custom-listview-with-image-and-text/ LazyAdapter.java import java.util.ArrayList; import java.util.HashMap; import android.app.Activity; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.TextView; public class LazyAdapter extends BaseAdapter { private Activity activity; private ArrayList&lt;HashMap&lt;String, String&gt;&gt; data; private static LayoutInflater inflater=null; public ImageLoader imageLoader; public LazyAdapter(Activity a, ArrayList&lt;HashMap&lt;String, String&gt;&gt; d) { activity = a; data=d; inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE); imageLoader=new ImageLoader(activity.getApplicationContext()); } public int getCount() { return data.size(); } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { View vi=convertView; if(convertView==null) vi = inflater.inflate(R.layout.list_row, null); TextView title = (TextView)vi.findViewById(R.id.title); // title TextView artist = (TextView)vi.findViewById(R.id.artist); // artist name TextView duration = (TextView)vi.findViewById(R.id.duration); // duration ImageView thumb_image=(ImageView)vi.findViewById(R.id.list_image); // thumb image HashMap&lt;String, String&gt; song = new HashMap&lt;String, String&gt;(); song = data.get(position); // Setting all values in listview title.setText(song.get(CustomizedListView.KEY_TITLE)); artist.setText(song.get(CustomizedListView.KEY_ARTIST)); duration.setText(song.get(CustomizedListView.KEY_DURATION)); imageLoader.DisplayImage(song.get(CustomizedListView.KEY_THUMB_URL), thumb_image); return vi; } } CustomizedListView.java import java.util.ArrayList; import java.util.HashMap; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.NodeList; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ListView; public class CustomizedListView extends Activity { // All static variables static final String URL = "http://api.androidhive.info/music/music.xml"; // XML node keys static final String KEY_SONG = "song"; // parent node static final String KEY_ID = "id"; static final String KEY_TITLE = "title"; static final String KEY_ARTIST = "artist"; static final String KEY_DURATION = "duration"; static final String KEY_THUMB_URL = "thumb_url"; ListView list; LazyAdapter adapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); ArrayList&lt;HashMap&lt;String, String&gt;&gt; songsList = new ArrayList&lt;HashMap&lt;String, String&gt;&gt;(); XMLParser parser = new XMLParser(); String xml = parser.getXmlFromUrl(URL); // getting XML from URL Document doc = parser.getDomElement(xml); // getting DOM element NodeList nl = doc.getElementsByTagName(KEY_SONG); // looping through all song nodes &lt;song&gt; for (int i = 0; i &lt; nl.getLength(); i++) { // creating new HashMap HashMap&lt;String, String&gt; map = new HashMap&lt;String, String&gt;(); Element e = (Element) nl.item(i); // adding each child node to HashMap key =&gt; value map.put(KEY_ID, parser.getValue(e, KEY_ID)); map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE)); map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST)); map.put(KEY_DURATION, parser.getValue(e, KEY_DURATION)); map.put(KEY_THUMB_URL, parser.getValue(e, KEY_THUMB_URL)); // adding HashList to ArrayList songsList.add(map); } list=(ListView)findViewById(R.id.list); // Getting adapter by passing xml data ArrayList adapter=new LazyAdapter(this, songsList); list.setAdapter(adapter); // Click event for single list row list.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView&lt;?&gt; parent, View view, int position, long id) { } }); } }

    Read the article

  • A ToDynamic() Extension Method For Fluent Reflection

    - by Dixin
    Recently I needed to demonstrate some code with reflection, but I felt it inconvenient and tedious. To simplify the reflection coding, I created a ToDynamic() extension method. The source code can be downloaded from here. Problem One example for complex reflection is in LINQ to SQL. The DataContext class has a property Privider, and this Provider has an Execute() method, which executes the query expression and returns the result. Assume this Execute() needs to be invoked to query SQL Server database, then the following code will be expected: using (NorthwindDataContext database = new NorthwindDataContext()) { // Constructs the query. IQueryable<Product> query = database.Products.Where(product => product.ProductID > 0) .OrderBy(product => product.ProductName) .Take(2); // Executes the query. Here reflection is required, // because Provider, Execute(), and ReturnValue are not public members. IEnumerable<Product> results = database.Provider.Execute(query.Expression).ReturnValue; // Processes the results. foreach (Product product in results) { Console.WriteLine("{0}, {1}", product.ProductID, product.ProductName); } } Of course, this code cannot compile. And, no one wants to write code like this. Again, this is just an example of complex reflection. using (NorthwindDataContext database = new NorthwindDataContext()) { // Constructs the query. IQueryable<Product> query = database.Products.Where(product => product.ProductID > 0) .OrderBy(product => product.ProductName) .Take(2); // database.Provider PropertyInfo providerProperty = database.GetType().GetProperty( "Provider", BindingFlags.NonPublic | BindingFlags.GetProperty | BindingFlags.Instance); object provider = providerProperty.GetValue(database, null); // database.Provider.Execute(query.Expression) // Here GetMethod() cannot be directly used, // because Execute() is a explicitly implemented interface method. Assembly assembly = Assembly.Load("System.Data.Linq"); Type providerType = assembly.GetTypes().SingleOrDefault( type => type.FullName == "System.Data.Linq.Provider.IProvider"); InterfaceMapping mapping = provider.GetType().GetInterfaceMap(providerType); MethodInfo executeMethod = mapping.InterfaceMethods.Single(method => method.Name == "Execute"); IExecuteResult executeResult = executeMethod.Invoke(provider, new object[] { query.Expression }) as IExecuteResult; // database.Provider.Execute(query.Expression).ReturnValue IEnumerable<Product> results = executeResult.ReturnValue as IEnumerable<Product>; // Processes the results. foreach (Product product in results) { Console.WriteLine("{0}, {1}", product.ProductID, product.ProductName); } } This may be not straight forward enough. So here a solution will implement fluent reflection with a ToDynamic() extension method: IEnumerable<Product> results = database.ToDynamic() // Starts fluent reflection. .Provider.Execute(query.Expression).ReturnValue; C# 4.0 dynamic In this kind of scenarios, it is easy to have dynamic in mind, which enables developer to write whatever code after a dot: using (NorthwindDataContext database = new NorthwindDataContext()) { // Constructs the query. IQueryable<Product> query = database.Products.Where(product => product.ProductID > 0) .OrderBy(product => product.ProductName) .Take(2); // database.Provider dynamic dynamicDatabase = database; dynamic results = dynamicDatabase.Provider.Execute(query).ReturnValue; } This throws a RuntimeBinderException at runtime: 'System.Data.Linq.DataContext.Provider' is inaccessible due to its protection level. Here dynamic is able find the specified member. So the next thing is just writing some custom code to access the found member. .NET 4.0 DynamicObject, and DynamicWrapper<T> Where to put the custom code for dynamic? The answer is DynamicObject’s derived class. I first heard of DynamicObject from Anders Hejlsberg's video in PDC2008. It is very powerful, providing useful virtual methods to be overridden, like: TryGetMember() TrySetMember() TryInvokeMember() etc.  (In 2008 they are called GetMember, SetMember, etc., with different signature.) For example, if dynamicDatabase is a DynamicObject, then the following code: dynamicDatabase.Provider will invoke dynamicDatabase.TryGetMember() to do the actual work, where custom code can be put into. Now create a type to inherit DynamicObject: public class DynamicWrapper<T> : DynamicObject { private readonly bool _isValueType; private readonly Type _type; private T _value; // Not readonly, for value type scenarios. public DynamicWrapper(ref T value) // Uses ref in case of value type. { if (value == null) { throw new ArgumentNullException("value"); } this._value = value; this._type = value.GetType(); this._isValueType = this._type.IsValueType; } public override bool TryGetMember(GetMemberBinder binder, out object result) { // Searches in current type's public and non-public properties. PropertyInfo property = this._type.GetTypeProperty(binder.Name); if (property != null) { result = property.GetValue(this._value, null).ToDynamic(); return true; } // Searches in explicitly implemented properties for interface. MethodInfo method = this._type.GetInterfaceMethod(string.Concat("get_", binder.Name), null); if (method != null) { result = method.Invoke(this._value, null).ToDynamic(); return true; } // Searches in current type's public and non-public fields. FieldInfo field = this._type.GetTypeField(binder.Name); if (field != null) { result = field.GetValue(this._value).ToDynamic(); return true; } // Searches in base type's public and non-public properties. property = this._type.GetBaseProperty(binder.Name); if (property != null) { result = property.GetValue(this._value, null).ToDynamic(); return true; } // Searches in base type's public and non-public fields. field = this._type.GetBaseField(binder.Name); if (field != null) { result = field.GetValue(this._value).ToDynamic(); return true; } // The specified member is not found. result = null; return false; } // Other overridden methods are not listed. } In the above code, GetTypeProperty(), GetInterfaceMethod(), GetTypeField(), GetBaseProperty(), and GetBaseField() are extension methods for Type class. For example: internal static class TypeExtensions { internal static FieldInfo GetBaseField(this Type type, string name) { Type @base = type.BaseType; if (@base == null) { return null; } return @base.GetTypeField(name) ?? @base.GetBaseField(name); } internal static PropertyInfo GetBaseProperty(this Type type, string name) { Type @base = type.BaseType; if (@base == null) { return null; } return @base.GetTypeProperty(name) ?? @base.GetBaseProperty(name); } internal static MethodInfo GetInterfaceMethod(this Type type, string name, params object[] args) { return type.GetInterfaces().Select(type.GetInterfaceMap).SelectMany(mapping => mapping.TargetMethods) .FirstOrDefault( method => method.Name.Split('.').Last().Equals(name, StringComparison.Ordinal) && method.GetParameters().Count() == args.Length && method.GetParameters().Select( (parameter, index) => parameter.ParameterType.IsAssignableFrom(args[index].GetType())).Aggregate( true, (a, b) => a && b)); } internal static FieldInfo GetTypeField(this Type type, string name) { return type.GetFields( BindingFlags.GetField | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic).FirstOrDefault( field => field.Name.Equals(name, StringComparison.Ordinal)); } internal static PropertyInfo GetTypeProperty(this Type type, string name) { return type.GetProperties( BindingFlags.GetProperty | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic).FirstOrDefault( property => property.Name.Equals(name, StringComparison.Ordinal)); } // Other extension methods are not listed. } So now, when invoked, TryGetMember() searches the specified member and invoke it. The code can be written like this: dynamic dynamicDatabase = new DynamicWrapper<NorthwindDataContext>(ref database); dynamic dynamicReturnValue = dynamicDatabase.Provider.Execute(query.Expression).ReturnValue; This greatly simplified reflection. ToDynamic() and fluent reflection To make it even more straight forward, A ToDynamic() method is provided: public static class DynamicWrapperExtensions { public static dynamic ToDynamic<T>(this T value) { return new DynamicWrapper<T>(ref value); } } and a ToStatic() method is provided to unwrap the value: public class DynamicWrapper<T> : DynamicObject { public T ToStatic() { return this._value; } } In the above TryGetMember() method, please notice it does not output the member’s value, but output a wrapped member value (that is, memberValue.ToDynamic()). This is very important to make the reflection fluent. Now the code becomes: IEnumerable<Product> results = database.ToDynamic() // Here starts fluent reflection. .Provider.Execute(query.Expression).ReturnValue .ToStatic(); // Unwraps to get the static value. With the help of TryConvert(): public class DynamicWrapper<T> : DynamicObject { public override bool TryConvert(ConvertBinder binder, out object result) { result = this._value; return true; } } ToStatic() can be omitted: IEnumerable<Product> results = database.ToDynamic() .Provider.Execute(query.Expression).ReturnValue; // Automatically converts to expected static value. Take a look at the reflection code at the beginning of this post again. Now it is much much simplified! Special scenarios In 90% of the scenarios ToDynamic() is enough. But there are some special scenarios. Access static members Using extension method ToDynamic() for accessing static members does not make sense. Instead, DynamicWrapper<T> has a parameterless constructor to handle these scenarios: public class DynamicWrapper<T> : DynamicObject { public DynamicWrapper() // For static. { this._type = typeof(T); this._isValueType = this._type.IsValueType; } } The reflection code should be like this: dynamic wrapper = new DynamicWrapper<StaticClass>(); int value = wrapper._value; int result = wrapper.PrivateMethod(); So accessing static member is also simple, and fluent of course. Change instances of value types Value type is much more complex. The main problem is, value type is copied when passing to a method as a parameter. This is why ref keyword is used for the constructor. That is, if a value type instance is passed to DynamicWrapper<T>, the instance itself will be stored in this._value of DynamicWrapper<T>. Without the ref keyword, when this._value is changed, the value type instance itself does not change. Consider FieldInfo.SetValue(). In the value type scenarios, invoking FieldInfo.SetValue(this._value, value) does not change this._value, because it changes the copy of this._value. I searched the Web and found a solution for setting the value of field: internal static class FieldInfoExtensions { internal static void SetValue<T>(this FieldInfo field, ref T obj, object value) { if (typeof(T).IsValueType) { field.SetValueDirect(__makeref(obj), value); // For value type. } else { field.SetValue(obj, value); // For reference type. } } } Here __makeref is a undocumented keyword of C#. But method invocation has problem. This is the source code of TryInvokeMember(): public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result) { if (binder == null) { throw new ArgumentNullException("binder"); } MethodInfo method = this._type.GetTypeMethod(binder.Name, args) ?? this._type.GetInterfaceMethod(binder.Name, args) ?? this._type.GetBaseMethod(binder.Name, args); if (method != null) { // Oops! // If the returnValue is a struct, it is copied to heap. object resultValue = method.Invoke(this._value, args); // And result is a wrapper of that copied struct. result = new DynamicWrapper<object>(ref resultValue); return true; } result = null; return false; } If the returned value is of value type, it will definitely copied, because MethodInfo.Invoke() does return object. If changing the value of the result, the copied struct is changed instead of the original struct. And so is the property and index accessing. They are both actually method invocation. For less confusion, setting property and index are not allowed on struct. Conclusions The DynamicWrapper<T> provides a simplified solution for reflection programming. It works for normal classes (reference types), accessing both instance and static members. In most of the scenarios, just remember to invoke ToDynamic() method, and access whatever you want: StaticType result = someValue.ToDynamic()._field.Method().Property[index]; In some special scenarios which requires changing the value of a struct (value type), this DynamicWrapper<T> does not work perfectly. Only changing struct’s field value is supported. The source code can be downloaded from here, including a few unit test code.

    Read the article

  • Configurable Objects - Introduction

    - by Anthony Shorten
    One of the interesting facilities in the framework is Configurable Object functionality (it is also known as Task Optimization and also known as Cool Tools). The idea is that any implementation can create their own views of the base product objects and services and implement functionality against those new views. For example, in Oracle Utilities Customer Care and Billing, there is a Person object. That object is used to store and manage information about individuals as well as companies. In the base product you would use the Person Maintenance screen and fill in some of the screen when you wanted to register or maintain and individual as well and fill out other parts of the screen when you wanted to register or maintain a company. This can be somewhat confusing to some customers. Using Configurable Objects this can be simplified. A business object can be created that is a view of the any object. For example, you could create a Human business object which would cover the aspects of the Person object pertaining to an individual and a Company business object to cover the aspects unique to a company. Even the tag names (i.e. Field Names) in the object can be changed to be more what the implementation is familiar with. The object can also restructure the object. For example, a common identifier for an individual in the USA is the Social Security number, this value is a Person Identifier (as this varies in each country). In the new Human object you can remap the Person Identifier as a Social Security number. To define a Business Object you use a schema editor built into the browser user interface and use a mapping language to setup the business objects. An example of the language is shown below in an extract of the schema for the Human business object. As you can see there are mapping as well as formatting and other tags. This information can be built manually or using a wizard which generates the base structure for you to alter. This is all stored as meta data when saved. Once a Business object is built it can be used as basis for code, other business objects (we support inheritance), called by a screen (called a UI Map) or even as a Web Service. This is just a start with Configurable Objects as you can also create views of base services called Business Services, Service Scripts used for non-object or complex object processing (as well as other things), UI Maps used for screens and Data Areas to reuse definitions across multiple objects. Configurable Objects are powerful and I only really touched on them here. Over the next few months I hope to add lots more entries about them.

    Read the article

  • MySQL Enterprise Backup 3.8.2 - Overview

    - by Priya Jayakumar
      MySQL Enterprise Backup (MEB) is the ideal solution for backing up MySQL databases. MEB 3.8.2 is released in June 2013. MySQL Enterprise Backup 3.8.2 release’s main goal is to improve usability. With this release, users can know the progress of backup completed both in terms of size and as a percentage of the total. This release also offers options to be able to manage the behavior of MEB in case the space on the secondary storage is completely exhausted during backup. The progress indicator is a (short) string that indicates how far the execution of a time-consuming MEB command has progressed. It consists of one or more "meters" that measures the progress of the command. There are two options introduced to control the progress reporting function of mysqlbackup command (1) –show-progress (2) –progress-interval. The user can control the progress indicator by using “--show-progress” option in any of the MEB operations. This option instructs MEB to output periodically short reports on the progress of time-consuming commands. The argument of this option instructs where the output could be sent. For example it could be stderr, stdout, file, fifo and table. With the “--show-progress” option both the total size of the backup to be copied and the size that’s already copied will be shown. Along with this, the state of the operation for example data or meta-data being copied or tables being locked and other such operations will also be reported. This gives more clear information to the DBA on the progress of the backup that’s happening. Interval between progress report in seconds is controlled by “--progress-interval” option. For more information on this please refer progress-report-options. MEB can also be accessed through GUI from MySQL WorkBench’s next version. This can be used as the front end interface for MEB users to perform backup operations at the click of a button. This feature was highly requested by DBAs and will be very useful. Refer http://insidemysql.com/mysql-workbench-6-0-a-sneak-preview/ for WorkBench upcoming release info. Along with the progress report feature some of the important issues like below are also addressed in MEB 3.8.2. In MEB 3.8.2 a new command line option “--on-disk-full” is introduced to abort or warn the user when a backup process encounters a full disk condition. When no option is given, by default it would abort. A few issues related to “incremental-backup” are also addressed in this release. Please refer 3.8.2 documentation for more details. It would be good for MEB users to move to 3.8.2 to take incremental backups. Overall the added usability and the important defects fixed in this release makes MySQL Enterprise Backup 3.8.2 a promising release.  

    Read the article

  • MVVM - implementing 'IsDirty' functionality to a ModelView in order to save data

    - by Brendan
    Hi, Being new to WPF & MVVM I struggling with some basic functionality. Let me first explain what I am after, and then attach some example code... I have a screen showing a list of users, and I display the details of the selected user on the right-hand side with editable textboxes. I then have a Save button which is DataBound, but I would only like this button to display when data has actually changed. ie - I need to check for "dirty data". I have a fully MVVM example in which I have a Model called User: namespace Test.Model { class User { public string UserName { get; set; } public string Surname { get; set; } public string Firstname { get; set; } } } Then, the ViewModel looks like this: using System.Collections.ObjectModel; using System.Collections.Specialized; using System.Windows.Input; using Test.Model; namespace Test.ViewModel { class UserViewModel : ViewModelBase { //Private variables private ObservableCollection<User> _users; RelayCommand _userSave; //Properties public ObservableCollection<User> User { get { if (_users == null) { _users = new ObservableCollection<User>(); //I assume I need this Handler, but I am stuggling to implement it successfully //_users.CollectionChanged += HandleChange; //Populate with users _users.Add(new User {UserName = "Bob", Firstname="Bob", Surname="Smith"}); _users.Add(new User {UserName = "Smob", Firstname="John", Surname="Davy"}); } return _users; } } //Not sure what to do with this?!?! //private void HandleChange(object sender, NotifyCollectionChangedEventArgs e) //{ // if (e.Action == NotifyCollectionChangedAction.Remove) // { // foreach (TestViewModel item in e.NewItems) // { // //Removed items // } // } // else if (e.Action == NotifyCollectionChangedAction.Add) // { // foreach (TestViewModel item in e.NewItems) // { // //Added items // } // } //} //Commands public ICommand UserSave { get { if (_userSave == null) { _userSave = new RelayCommand(param => this.UserSaveExecute(), param => this.UserSaveCanExecute); } return _userSave; } } void UserSaveExecute() { //Here I will call my DataAccess to actually save the data } bool UserSaveCanExecute { get { //This is where I would like to know whether the currently selected item has been edited and is thus "dirty" return false; } } //constructor public UserViewModel() { } } } The "RelayCommand" is just a simple wrapper class, as is the "ViewModelBase". (I'll attach the latter though just for clarity) using System; using System.ComponentModel; namespace Test.ViewModel { public abstract class ViewModelBase : INotifyPropertyChanged, IDisposable { protected ViewModelBase() { } public event PropertyChangedEventHandler PropertyChanged; protected virtual void OnPropertyChanged(string propertyName) { PropertyChangedEventHandler handler = this.PropertyChanged; if (handler != null) { var e = new PropertyChangedEventArgs(propertyName); handler(this, e); } } public void Dispose() { this.OnDispose(); } protected virtual void OnDispose() { } } } Finally - the XAML <Window x:Class="Test.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:vm="clr-namespace:Test.ViewModel" Title="MainWindow" Height="350" Width="525"> <Window.DataContext> <vm:UserViewModel/> </Window.DataContext> <Grid> <ListBox Height="238" HorizontalAlignment="Left" Margin="12,12,0,0" Name="listBox1" VerticalAlignment="Top" Width="197" ItemsSource="{Binding Path=User}" IsSynchronizedWithCurrentItem="True"> <ListBox.ItemTemplate> <DataTemplate> <StackPanel> <TextBlock Text="{Binding Path=Firstname}"/> <TextBlock Text="{Binding Path=Surname}"/> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox> <Label Content="Username" Height="28" HorizontalAlignment="Left" Margin="232,16,0,0" Name="label1" VerticalAlignment="Top" /> <TextBox Height="23" HorizontalAlignment="Left" Margin="323,21,0,0" Name="textBox1" VerticalAlignment="Top" Width="120" Text="{Binding Path=User/UserName}" /> <Label Content="Surname" Height="28" HorizontalAlignment="Left" Margin="232,50,0,0" Name="label2" VerticalAlignment="Top" /> <TextBox Height="23" HorizontalAlignment="Left" Margin="323,52,0,0" Name="textBox2" VerticalAlignment="Top" Width="120" Text="{Binding Path=User/Surname}" /> <Label Content="Firstname" Height="28" HorizontalAlignment="Left" Margin="232,84,0,0" Name="label3" VerticalAlignment="Top" /> <TextBox Height="23" HorizontalAlignment="Left" Margin="323,86,0,0" Name="textBox3" VerticalAlignment="Top" Width="120" Text="{Binding Path=User/Firstname}" /> <Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="368,159,0,0" Name="button1" VerticalAlignment="Top" Width="75" Command="{Binding Path=UserSave}" /> </Grid> </Window> So basically, when I edit a surname, the Save button should be enabled; and if I undo my edit - well then it should be Disabled again as nothing has changed. I have seen this in many examples, but have not yet found out how to do it. Any help would be much appreciated! Brendan

    Read the article

  • Possible to manipulate UI elements via dispatchEvent()?

    - by rinogo
    Hi all! I'm trying to manually dispatch events on a textfield so I can manipulate it indirectly via code (e.g. place cursor at a given set of x/y coordinates). However, my events seem to have no effect. I've written a test to experiment with this phenomenon: package sandbox { import flash.display.Sprite; import flash.events.MouseEvent; import flash.text.TextField; import flash.text.TextFieldType; import flash.text.TextFieldAutoSize; import flash.utils.setTimeout; public class Test extends Sprite { private var tf:TextField; private var tf2:TextField; public function Test() { super(); tf = new TextField(); tf.text = 'Interact here'; tf.type = TextFieldType.INPUT; addChild(tf); tf2 = new TextField(); tf2.text = 'Same events replayed with five second delay here'; tf2.autoSize = TextFieldAutoSize.LEFT; tf2.type = TextFieldType.INPUT; tf2.y = 30; addChild(tf2); tf.addEventListener(MouseEvent.CLICK, mouseListener); tf.addEventListener(MouseEvent.DOUBLE_CLICK, mouseListener); tf.addEventListener(MouseEvent.MOUSE_DOWN, mouseListener); tf.addEventListener(MouseEvent.MOUSE_MOVE, mouseListener); tf.addEventListener(MouseEvent.MOUSE_OUT, mouseListener); tf.addEventListener(MouseEvent.MOUSE_OVER, mouseListener); tf.addEventListener(MouseEvent.MOUSE_UP, mouseListener); tf.addEventListener(MouseEvent.MOUSE_WHEEL, mouseListener); tf.addEventListener(MouseEvent.ROLL_OUT, mouseListener); tf.addEventListener(MouseEvent.ROLL_OVER, mouseListener); } private function mouseListener(event:MouseEvent):void { //trace(event); setTimeout(function():void {trace(event); tf2.dispatchEvent(event);}, 5000); } } } Essentially, all this test does is to use setTimeout to effectively 'record' events on TextField tf and replay them five seconds later on TextField tf2. When an event is dispatched on tf2, it is traced to the console output. The console output upon running this program and clicking on tf is: [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=0 localY=1 stageX=0 stageY=1 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="rollOver" bubbles=false cancelable=false eventPhase=2 localX=0 localY=1 stageX=0 stageY=1 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseOver" bubbles=true cancelable=false eventPhase=3 localX=0 localY=1 stageX=0 stageY=1 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=2 localY=1 stageX=2 stageY=1 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=2 localY=2 stageX=2 stageY=2 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=2 localY=3 stageX=2 stageY=3 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=3 localY=3 stageX=3 stageY=3 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=5 localY=3 stageX=5 stageY=3 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=6 localY=5 stageX=6 stageY=5 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=7 localY=5 stageX=7 stageY=5 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=9 localY=5 stageX=9 stageY=5 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=10 localY=5 stageX=10 stageY=5 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=11 localY=5 stageX=11 stageY=5 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=12 localY=5 stageX=12 stageY=5 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseDown" bubbles=true cancelable=false eventPhase=3 localX=12 localY=5 stageX=12 stageY=5 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseUp" bubbles=true cancelable=false eventPhase=3 localX=12 localY=5 stageX=12 stageY=5 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="click" bubbles=true cancelable=false eventPhase=3 localX=12 localY=5 stageX=12 stageY=5 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=10 localY=4 stageX=10 stageY=4 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=9 localY=2 stageX=9 stageY=2 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseMove" bubbles=true cancelable=false eventPhase=3 localX=9 localY=1 stageX=9 stageY=1 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="mouseOut" bubbles=true cancelable=false eventPhase=3 localX=-1 localY=-1 stageX=-1 stageY=-1 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] [MouseEvent type="rollOut" bubbles=false cancelable=false eventPhase=2 localX=-1 localY=-1 stageX=-1 stageY=-1 relatedObject=null ctrlKey=false altKey=false shiftKey=false delta=0] As we can see, the events are being captured and replayed successfully. However, no change occurs in tf2 - the mouse cursor does not appear in tf2 as we would expect. In fact, the cursor remains in tf even after the tf2 events are dispatched. Please help! Thanks, -Rich

    Read the article

  • HttpTransportSE requestDump gives NullPointerException

    - by Chamila
    Hi, I'm trying to access a webservice in Android via Ksoap2 for android. The SoapObject is created ok, the S.o.p of the bodyOut outputs the desired strings. But when I do a requestDump of the HttpTransportSE object I create to make the call, a NullPointerException happens. In other words, the transport object is null. How can this happen? Web Service is at http://srilanka.lk:9080/services/CropServiceProxy?wsdl This service works very well with SoapUI. SoapUI Request <soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:v1="http://schemas.icta.lk/xsd/crop/handler/v1/"> <soap:Header/> <soap:Body> <v1:getCropDataList> <v1:code>ABK</v1:code> </v1:getCropDataList> </soap:Body> </soap:Envelope> SoapUI Response <soapenv:Envelope xmlns:soapenv="http://www.w3.org/2003/05/soap-envelope"> <soapenv:Body> <ns1:getCropDataListResponse xmlns:ns1="http://schemas.icta.lk/xsd/crop/handler/v1/"> <ns1:cropInfo> <ns1:name>Ambul Kesel</ns1:name> <ns1:price>35.0</ns1:price> <ns1:location>Dambulla</ns1:location> </ns1:cropInfo> <ns1:cropInfo> <ns1:name>Ambul Kesel</ns1:name> <ns1:price>40.0</ns1:price> <ns1:location>Dambulla</ns1:location> </ns1:cropInfo> </ns1:getCropDataListResponse> </soapenv:Body> </soapenv:Envelope> Client Side Complex Type KvmSerializable implementation public class CropInfo implements KvmSerializable { private String name; private float price; private String location; @Override public Object getProperty(int arg0) { switch (arg0){ case 0: return name; case 1: return price; case 2: return location; default: return null; } } @Override public int getPropertyCount() { return 3; } @Override public void getPropertyInfo(int arg0, Hashtable arg1, PropertyInfo arg2) { switch (arg0){ case 0: arg2.type = PropertyInfo.STRING_CLASS; arg2.name = "Name"; break; case 1: arg2.type = Float.class; arg2.name = "Price"; break; case 2: arg2.type = PropertyInfo.STRING_CLASS; arg2.name = "Location"; break; default: break; } } @Override public void setProperty(int arg0, Object arg1) { switch(arg0){ case 0: name = arg1.toString(); break; case 1: price = Float.parseFloat(arg1.toString()); case 2: location = arg1.toString(); default: break; } } } Web Service Call public void btnOnClick(View v){ String NAMESPACE = "http://schemas.icta.lk/xsd/crop/handler/v1/"; String URL = "http://220.247.225.202:9080/services/CropServiceProxy.CropServiceProxyHttpSoap12Endpoint"; String method_name = "getCropDataList"; String SOAP_ACTION = "http://schemas.icta.lk/xsd/crop/handler/v1/getCropDataList"; SoapObject soap_request = new SoapObject(NAMESPACE, method_name); soap_request.addProperty("code", "ABK" ); SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER12); envelope.setOutputSoapObject(soap_request); envelope.addMapping(NAMESPACE, "cropInfo", CropInfo.class); //envelope.dotNet=true; Marshal floatMarshal = new MarshalFloat(); floatMarshal.register(envelope); System.out.println("body out : " + envelope.bodyOut.toString()); //AndroidHttpTransport http_transport = new AndroidHttpTransport(URL); HttpTransportSE http_transport = new HttpTransportSE(URL); try { //NullPointerException HERE System.out.println(http_transport.requestDump); http_transport.call(SOAP_ACTION, envelope); //because we should expect a vector, two kinds of prices are given Vector<CropInfo> result_array = (Vector<CropInfo>)envelope.getResponse(); if(result_array != null){ for (CropInfo current_crop: result_array){ System.out.println(current_crop.getName()); System.out.println(Float.toString(current_crop.getPrice())); } } } catch (Exception e) { e.printStackTrace(); answer.setText("error caught"); //System.out.println(http_transport.responseDump); } // String result_string[] = (String[])result; //answer.setText("returned"); } Can anyone explain this?

    Read the article

< Previous Page | 294 295 296 297 298 299 300 301 302 303 304 305  | Next Page >