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  • Ingame menu is not working correctly

    - by Johnny
    The ingame menu opens when the player presses Escape during the main game. If the player presses Y in the ingame menu, the game switches to the main menu. Up to here, everything works. But: On the other hand, if the player presses N in the ingame menu, the game should switch back to the main game(should resume the main game). But that doesn't work. The game just rests in the ingame menu if the player presses N. I set a breakpoint in this line of the Ingamemenu class: KeyboardState kbState = Keyboard.GetState(); CurrentSate/currentGameState and LastState/lastGameState have the same state: IngamemenuState. But LastState/lastGameState should not have the same state than CurrentSate/currentGameState. What is wrong? Why is the ingame menu not working correctly? public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; IState lastState, currentState; public enum GameStates { IntroState = 0, MenuState = 1, MaingameState = 2, IngamemenuState = 3 } public void ChangeGameState(GameStates newState) { lastGameState = currentGameState; lastState = currentState; switch (newState) { case GameStates.IntroState: currentState = new Intro(this); currentGameState = GameStates.IntroState; break; case GameStates.MenuState: currentState = new Menu(this); currentGameState = GameStates.MenuState; break; case GameStates.MaingameState: currentState = new Maingame(this); currentGameState = GameStates.MaingameState; break; case GameStates.IngamemenuState: currentState = new Ingamemenu(this); currentGameState = GameStates.IngamemenuState; break; } currentState.Load(Content); } public void ChangeCurrentToLastGameState() { currentGameState = lastGameState; currentState = lastState; } public GameStates CurrentState { get { return currentGameState; } set { currentGameState = value; } } public GameStates LastState { get { return lastGameState; } set { lastGameState = value; } } private GameStates currentGameState = GameStates.IntroState; private GameStates lastGameState; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; } protected override void Initialize() { ChangeGameState(GameStates.IntroState); base.Initialize(); } protected override void LoadContent() { spriteBatch = new SpriteBatch(GraphicsDevice); currentState.Load(Content); } protected override void Update(GameTime gameTime) { currentState.Update(gameTime); if ((lastGameState == GameStates.MaingameState) && (currentGameState == GameStates.IngamemenuState)) { lastState.Update(gameTime); } base.Update(gameTime); } protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); spriteBatch.Begin(); if ((lastGameState == GameStates.MaingameState) && (currentGameState == GameStates.IngamemenuState)) { lastState.Render(spriteBatch); } currentState.Render(spriteBatch); spriteBatch.End(); base.Draw(gameTime); } } public interface IState { void Load(ContentManager content); void Update(GameTime gametime); void Render(SpriteBatch batch); } public class Intro : IState { Texture2D Titelbildschirm; private Game1 game1; public Intro(Game1 game) { game1 = game; } public void Load(ContentManager content) { Titelbildschirm = content.Load<Texture2D>("gruft"); } public void Update(GameTime gametime) { KeyboardState kbState = Keyboard.GetState(); if (kbState.IsKeyDown(Keys.Space)) game1.ChangeGameState(Game1.GameStates.MenuState); } public void Render(SpriteBatch batch) { batch.Draw(Titelbildschirm, new Rectangle(0, 0, 1280, 720), Color.White); } } public class Menu:IState { Texture2D Choosescreen; private Game1 game1; public Menu(Game1 game) { game1 = game; } public void Load(ContentManager content) { Choosescreen = content.Load<Texture2D>("menubild"); } public void Update(GameTime gametime) { KeyboardState kbState = Keyboard.GetState(); if (kbState.IsKeyDown(Keys.Enter)) game1.ChangeGameState(Game1.GameStates.MaingameState); if (kbState.IsKeyDown(Keys.Escape)) game1.Exit(); } public void Render(SpriteBatch batch) { batch.Draw(Choosescreen, new Rectangle(0, 0, 1280, 720), Color.White); } } public class Maingame : IState { Texture2D Spielbildschirm, axe; Vector2 position = new Vector2(100,100); private Game1 game1; public Maingame(Game1 game) { game1 = game; } public void Load(ContentManager content) { Spielbildschirm = content.Load<Texture2D>("hauszombie"); axe = content.Load<Texture2D>("axxx"); } public void Update(GameTime gametime) { KeyboardState keyboardState = Keyboard.GetState(); float delta = (float)gametime.ElapsedGameTime.TotalSeconds; position.X += 5 * delta; position.Y += 3 * delta; if (keyboardState.IsKeyDown(Keys.Escape)) game1.ChangeGameState(Game1.GameStates.IngamemenuState); } public void Render(SpriteBatch batch) { batch.Draw(Spielbildschirm, new Rectangle(0, 0, 1280, 720), Color.White); batch.Draw(axe, position, Color.White); } } public class Ingamemenu : IState { Texture2D Quitscreen; private Game1 game1; public Ingamemenu(Game1 game) { game1 = game; } public void Load(ContentManager content) { Quitscreen = content.Load<Texture2D>("quit"); } public void Update(GameTime gametime) { KeyboardState kbState = Keyboard.GetState(); if (kbState.IsKeyDown(Keys.Y)) game1.ChangeGameState(Game1.GameStates.MenuState); if (kbState.IsKeyDown(Keys.N)) game1.ChangeCurrentToLastGameState(); } public void Render(SpriteBatch batch) { batch.Draw(Quitscreen, new Rectangle(200, 200, 200, 200), Color.White); } }

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  • url template tag in django template

    - by user192048
    guys: I was trying to use the url template tag in django, but no lucky, I defined my urls.py like this urlpatterns = patterns('', url(r'^analyse/$', views.home, name="home"), url(r'^analyse/index.html', views.index, name="index"), url(r'^analyse/setup.html', views.setup, name="setup"), url(r'^analyse/show.html', views.show, name="show"), url(r'^analyse/generate.html', views.generate, name="generate"), I defined the url pattern in my view like this {% url 'show'%} then I got this error message Caught an exception while rendering: Reverse for ''show'' with arguments '()' and keyword arguments '{}' not found. Original Traceback (most recent call last): File "/Library/Python/2.5/site-packages/django/template/debug.py", line 71, in render_node result = node.render(context) File "/Library/Python/2.5/site-packages/django/template/defaulttags.py", line 155, in render nodelist.append(node.render(context)) File "/Library/Python/2.5/site-packages/django/template/defaulttags.py", line 382, in render raise e NoReverseMatch: Reverse for ''show'' with arguments '()' and keyword arguments '{}' not found. I am wondering why django failed to render? what is the right way to define it in the tempalte?

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  • How to merge two FBOs?

    - by DevDevDev
    OK so I have 4 buffers, 3 FBOs and a render buffer. Let me explain. I have a view FBO, which will store the scene before I render it to the render buffer. I have a background buffer, which contains the background of the scene. I have a user buffer, which the user manipulates. When the user makes some action I draw to the user buffer, using some blending. Then to redraw the whole scene what I want to do is clear the view buffer, draw the background buffer to the view buffer, change the blending, then draw the user buffer to the view buffer. Finally render the view buffer to the render buffer. However I can't figure out how to draw a FBO to another FBO. What I want to do is essentially merge and blend two FBOs, but I can't figure out how! I'm very new to OpenGL ES, so thanks for all the help.

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  • Decorator for determining HTTP response from a view

    - by polera
    I want to create a decorator that will allow me to return a raw or "string" representation of a view if a GET parameter "raw" equals "1". The concept works, but I'm stuck on how to pass context to my renderer. Here's what I have so far: from django.shortcuts import render_to_response from django.http import HttpResponse from django.template.loader import render_to_string def raw_response(template): def wrap(view): def response(request,*args,**kwargs): if request.method == "GET": try: if request.GET['raw'] == "1": render = HttpResponse(render_to_string(template,{}),content_type="text/plain") return render except Exception: render = render_to_response(template,{}) return render return response return wrap Currently, the {} is there just as a place holder. Ultimately, I'd like to be able to pass a dict like this: @raw_response('my_template_name.html') def view_name(request): render({"x":42}) Any assistance is appreciated.

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  • Instead of the specified Texture, black circles on a green background are getting rendered. Why?

    - by vinzBad
    I'm trying to render a Texture via OpenGL. But instead of the texture black circles on a green background are rendered. (They scale, depending what the rotation of the texture is) Example: The texture I'm trying to render is the following: This is the code I use to render the texture, it's located in my Sprite-class. public void Render() { Matrix4 matrix = Matrix4.CreateTranslation(-OriginX, -OriginY, 0) * Matrix4.CreateRotationZ(Rotation) * Matrix4.CreateTranslation(X, Y, 0); Vector2[] corners = { new Vector2(0,0), //top left new Vector2(Width ,0),//top right new Vector2(Width,Height),//bottom rigth new Vector2(0,Height)//bottom left }; //copy the corners to the uv coordinates Vector2[] uv = corners.ToArray<Vector2>(); //transform the coordinates for (int i = 0; i < 4; i++) corners[i] = new Vector2(Vector3.Transform(new Vector3(corners[i]), matrix)); //GL.Color3(TintColor); GL.BindTexture(TextureTarget.Texture2D, _ID); GL.Begin(BeginMode.Quads); { for (int i = 0; i < 4; i++) { GL.TexCoord2(uv[i]); GL.Vertex3(corners[i].X, corners[i].Y, _layerDepth); } } GL.End(); if (EnableDebugDraw) { GL.Color3(Color.Violet); GL.PointSize(3); GL.Begin(BeginMode.Points); { for (int i = 0; i < 4; i++) GL.Vertex2(corners[i]); } GL.End(); GL.Color3(Color.Green); GL.Begin(BeginMode.Points); GL.Vertex2(X, Y); GL.End(); } } This is how I setup OpenGL. public static void SetupGL() { GL.Enable(EnableCap.AlphaTest); GL.AlphaFunc(AlphaFunction.Greater, 0.1f); GL.Enable(EnableCap.Texture2D); GL.Hint(HintTarget.PerspectiveCorrectionHint, HintMode.Nicest); } With this function I load the texture: public static uint LoadTexture(string path) { uint id; GL.GenTextures(1, out id); GL.BindTexture(TextureTarget.Texture2D, id); Bitmap bitmap = new Bitmap(path); BitmapData data = bitmap.LockBits(new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb); GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, data.Width, data.Height, 0, OpenTK.Graphics.OpenGL.PixelFormat.Bgra, PixelType.UnsignedByte, data.Scan0); bitmap.UnlockBits(data); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear); return id; } And here I call Sprite.Render() protected override void OnRenderFrame(FrameEventArgs e) { GL.ClearColor(Color.MidnightBlue); GL.Clear(ClearBufferMask.ColorBufferBit); _sprite.Render(); SwapBuffers(); base.OnRenderFrame(e); } As I stole this code from the Textures-Example from OpenTK, I don't understand why this doesn't work.

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  • Custom rails route problem with 2.3.8 and Mongrel

    - by CHsurfer
    I have a controller called 'exposures' which I created automatically with the script/generate scaffold call. The scaffold pages work fine. I created a custom action called 'test' in the exposures controller. When I try to call the page (http://127.0.0.1:3000/exposures/test/1) I get a blank, white screen with no text at all in the source. I am using Rails 2.3.8 and mongrel in the development environment. There are no entries in development.log and the console that was used to open mongrel has the following error: You might have expected an instance of Array. The error occurred while evaluating nil.split D:/Rails/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/cgi_process.rb:52:in dispatch_cgi' D:/Rails/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/dispatcher.rb:101:in dispatch_cgi' D:/Rails/ruby/lib/ruby/gems/1.8/gems/actionpack-2.3.8/lib/action_controller/dispatcher.rb:27:in dispatch' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/rails.rb:76:in process' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/rails.rb:74:in synchronize' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/rails.rb:74:in process' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:159:in process_client' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:158:in each' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:158:in process_client' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:285:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:285:in initialize' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:285:in new' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:285:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:268:in initialize' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:268:in new' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel.rb:268:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/configurator.rb:282:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/configurator.rb:281:in each' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/configurator.rb:281:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/mongrel_rails:128:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/../lib/mongrel/command.rb:212:in run' D:/Rails/ruby/lib/ruby/gems/1.8/gems/mongrel-1.1.2-x86-mswin32/bin/mongrel_rails:281 D:/Rails/ruby/bin/mongrel_rails:19:in load' D:/Rails/ruby/bin/mongrel_rails:19 Here is the exposures_controller code: class ExposuresController < ApplicationController # GET /exposures # GET /exposures.xml def index @exposures = Exposure.all respond_to do |format| format.html # index.html.erb format.xml { render :xml => @exposures } end end #/exposure/graph/1 def graph @exposure = Exposure.find(params[:id]) project_name = @exposure.tender.project.name group_name = @exposure.tender.user.group.name tender_desc = @exposure.tender.description direction = "Cash Out" direction = "Cash In" if @exposure.supply currency_1_and_2 = "#{@exposure.currency_in} = #{@exposure.currency_out}" title = "#{project_name}:#{group_name}:#{tender_desc}/n" title += "#{direction}:#{currency_1_and_2}" factors = Array.new carrieds = Array.new days = Array.new @exposure.rates.each do |r| factors << r.factor carrieds << r.carried days << r.day.to_s end max = (factors+carrieds).max min = (factors+carrieds).min g = Graph.new g.title(title, '{font-size: 12px;}') g.set_data(factors) g.line_hollow(2, 4, '0x80a033', 'Bounces', 10) g.set_x_labels(days) g.set_x_label_style( 10, '#CC3399', 2 ); g.set_y_min(min*0.9) g.set_y_max(max*1.1) g.set_y_label_steps(5) render :text = g.render end def test render :text = "this works" end # GET /exposures/1 # GET /exposures/1.xml def show @exposure = Exposure.find(params[:id]) @graph = open_flash_chart_object(700,250, "/exposures/graph/#{@exposure.id}") #@graph = "/exposures/graph/#{@exposure.id}" respond_to do |format| format.html # show.html.erb format.xml { render :xml => @exposure } end end # GET /exposures/new # GET /exposures/new.xml def new @exposure = Exposure.new respond_to do |format| format.html # new.html.erb format.xml { render :xml => @exposure } end end # GET /exposures/1/edit def edit @exposure = Exposure.find(params[:id]) end # POST /exposures # POST /exposures.xml def create @exposure = Exposure.new(params[:exposure]) respond_to do |format| if @exposure.save flash[:notice] = 'Exposure was successfully created.' format.html { redirect_to(@exposure) } format.xml { render :xml => @exposure, :status => :created, :location => @exposure } else format.html { render :action => "new" } format.xml { render :xml => @exposure.errors, :status => :unprocessable_entity } end end end # PUT /exposures/1 # PUT /exposures/1.xml def update @exposure = Exposure.find(params[:id]) respond_to do |format| if @exposure.update_attributes(params[:exposure]) flash[:notice] = 'Exposure was successfully updated.' format.html { redirect_to(@exposure) } format.xml { head :ok } else format.html { render :action => "edit" } format.xml { render :xml => @exposure.errors, :status => :unprocessable_entity } end end end # DELETE /exposures/1 # DELETE /exposures/1.xml def destroy @exposure = Exposure.find(params[:id]) @exposure.destroy respond_to do |format| format.html { redirect_to(exposures_url) } format.xml { head :ok } end end end Clever readers will notice the 'graph' action. This is what I really want to work, but if I can't even get the test action working, then I'm sure I have no chance. Any ideas? I have restarted mongrel a few times with no change. Here is the output of Rake routes (but I don't believe this is the problem. The error would be in the form of and HTML error response). D:\Rails\rails_apps\fxrake routes (in D:/Rails/rails_apps/fx) DEPRECATION WARNING: Rake tasks in vendor/plugins/open_flash_chart/tasks are deprecated. Use lib/tasks instead. (called from D:/ by/gems/1.8/gems/rails-2.3.8/lib/tasks/rails.rb:10) rates GET /rates(.:format) {:controller="rates", :action="index"} POST /rates(.:format) {:controller="rates", :action="create"} new_rate GET /rates/new(.:format) {:controller="rates", :action="new"} edit_rate GET /rates/:id/edit(.:format) {:controller="rates", :action="edit"} rate GET /rates/:id(.:format) {:controller="rates", :action="show"} PUT /rates/:id(.:format) {:controller="rates", :action="update"} DELETE /rates/:id(.:format) {:controller="rates", :action="destroy"} tenders GET /tenders(.:format) {:controller="tenders", :action="index"} POST /tenders(.:format) {:controller="tenders", :action="create"} new_tender GET /tenders/new(.:format) {:controller="tenders", :action="new"} edit_tender GET /tenders/:id/edit(.:format) {:controller="tenders", :action="edit"} tender GET /tenders/:id(.:format) {:controller="tenders", :action="show"} PUT /tenders/:id(.:format) {:controller="tenders", :action="update"} DELETE /tenders/:id(.:format) {:controller="tenders", :action="destroy"} exposures GET /exposures(.:format) {:controller="exposures", :action="index"} POST /exposures(.:format) {:controller="exposures", :action="create"} new_exposure GET /exposures/new(.:format) {:controller="exposures", :action="new"} edit_exposure GET /exposures/:id/edit(.:format) {:controller="exposures", :action="edit"} exposure GET /exposures/:id(.:format) {:controller="exposures", :action="show"} PUT /exposures/:id(.:format) {:controller="exposures", :action="update"} DELETE /exposures/:id(.:format) {:controller="exposures", :action="destroy"} currencies GET /currencies(.:format) {:controller="currencies", :action="index"} POST /currencies(.:format) {:controller="currencies", :action="create"} new_currency GET /currencies/new(.:format) {:controller="currencies", :action="new"} edit_currency GET /currencies/:id/edit(.:format) {:controller="currencies", :action="edit"} currency GET /currencies/:id(.:format) {:controller="currencies", :action="show"} PUT /currencies/:id(.:format) {:controller="currencies", :action="update"} DELETE /currencies/:id(.:format) {:controller="currencies", :action="destroy"} projects GET /projects(.:format) {:controller="projects", :action="index"} POST /projects(.:format) {:controller="projects", :action="create"} new_project GET /projects/new(.:format) {:controller="projects", :action="new"} edit_project GET /projects/:id/edit(.:format) {:controller="projects", :action="edit"} project GET /projects/:id(.:format) {:controller="projects", :action="show"} PUT /projects/:id(.:format) {:controller="projects", :action="update"} DELETE /projects/:id(.:format) {:controller="projects", :action="destroy"} groups GET /groups(.:format) {:controller="groups", :action="index"} POST /groups(.:format) {:controller="groups", :action="create"} new_group GET /groups/new(.:format) {:controller="groups", :action="new"} edit_group GET /groups/:id/edit(.:format) {:controller="groups", :action="edit"} group GET /groups/:id(.:format) {:controller="groups", :action="show"} PUT /groups/:id(.:format) {:controller="groups", :action="update"} DELETE /groups/:id(.:format) {:controller="groups", :action="destroy"} users GET /users(.:format) {:controller="users", :action="index"} POST /users(.:format) {:controller="users", :action="create"} new_user GET /users/new(.:format) {:controller="users", :action="new"} edit_user GET /users/:id/edit(.:format) {:controller="users", :action="edit"} user GET /users/:id(.:format) {:controller="users", :action="show"} PUT /users/:id(.:format) {:controller="users", :action="update"} DELETE /users/:id(.:format) {:controller="users", :action="destroy"} /:controller/:action/:id /:controller/:action/:id(.:format) D:\Rails\rails_apps\fxrails -v Rails 2.3.8 Thanks in advance for the help -Jon

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  • Backbone events not firing (this.el undefined) & general feedback on use of the framework

    - by Leo
    I am very new to backbone.js and I am struggling a little. I figured out a way to get data from the server (in json) onto the screen successfully but am I doing it the right/best way? I know there is something wrong because the only view which contains a valid this.el is the parent view. I suspect that because of this, the events of the view are not firing ()... What is the best way forward? Here is the code: var surveyUrl = "/api/Survey?format=json&callback=?"; $(function () { AnswerOption = Backbone.Model.extend({}); AnswerOptionList = Backbone.Collection.extend({ initialize: function (models, options) { this.bind("add", options.view.render); } }); AnswerOptionView = Backbone.View.extend({ initialize: function () { this.answerOptionList = new AnswerOptionList(null, { view: this }); _.bindAll(this, 'render'); }, events: { "click .answerOptionControl": "updateCheckedState" //does not fire because there is no this.el }, render: function (model) { // Compile the template using underscore var template = _.template($("#questionAnswerOptionTemplate").html(), model.answerOption); $('#answerOptions' + model.answerOption.questionId + '>fieldset').append(template); return this; }, updateCheckedState: function (data) { //never hit... } }); Question = Backbone.Model.extend({}); QuestionList = Backbone.Collection.extend({ initialize: function (models, options) { this.bind("add", options.view.render); } }); QuestionView = Backbone.View.extend({ initialize: function () { this.questionlist = new QuestionList(null, { view: this }); _.bindAll(this, 'render'); }, render: function (model) { // Compile the template using underscore var template = _.template($("#questionTemplate").html(), model.question); $("#questions").append(template); //append answers using AnswerOptionView var view = new AnswerOptionView(); for (var i = 0; i < model.question.answerOptions.length; i++) { var qModel = new AnswerOption(); qModel.answerOption = model.question.answerOptions[i]; qModel.questionChoiceType = ChoiceType(); view.answerOptionList.add(qModel); } $('#questions').trigger('create'); return this; } }); Survey = Backbone.Model.extend({ url: function () { return this.get("id") ? surveyUrl + '/' + this.get("id") : surveyUrl; } }); SurveyList = Backbone.Collection.extend({ model: Survey, url: surveyUrl }); aSurvey = new Survey({ Id: 1 }); SurveyView = Backbone.View.extend({ model: aSurvey, initialize: function () { _.bindAll(this, 'render'); this.model.bind('refresh', this.render); this.model.bind('change', this.render); this.model.view = this; }, // Re-render the contents render: function () { var view = new QuestionView(); //{el:this.el}); for (var i = 0; i < this.model.attributes[0].questions.length; i++) { var qModel = new Question(); qModel.question = this.model.attributes[0].questions[i]; view.questionlist.add(qModel); } } }); window.App = new SurveyView(aSurvey); aSurvey.fetch(); }); -html <body> <div id="questions"></div> <!-- Templates --> <script type="text/template" id="questionAnswerOptionTemplate"> <input name="answerOptionGroup<%= questionId %>" id="answerOptionInput<%= id %>" type="checkbox" class="answerOptionControl"/> <label for="answerOptionInput<%= id %>"><%= text %></label> </script> <script type="text/template" id="questionTemplate"> <div id="question<%=id %>" class="questionWithCurve"> <h1><%= headerText %></h1> <h2><%= subText %></h2> <div data-role="fieldcontain" id="answerOptions<%= id %>" > <fieldset data-role="controlgroup" data-type="vertical"> <legend> </legend> </fieldset> </div> </div> </script> </body> And the JSON from the server: ? ({ "name": "Survey", "questions": [{ "surveyId": 1, "headerText": "Question 1", "subText": "subtext", "type": "Choice", "positionOrder": 1, "answerOptions": [{ "questionId": 1, "text": "Question 1 - Option 1", "positionOrder": 1, "id": 1, "createdOn": "\/Date(1333666034297+0100)\/" }, { "questionId": 1, "text": "Question 1 - Option 2", "positionOrder": 2, "id": 2, "createdOn": "\/Date(1333666034340+0100)\/" }, { "questionId": 1, "text": "Question 1 - Option 3", "positionOrder": 3, "id": 3, "createdOn": "\/Date(1333666034350+0100)\/" }], "questionValidators": [{ "questionId": 1, "value": "3", "type": "MaxAnswers", "id": 1, "createdOn": "\/Date(1333666034267+0100)\/" }, { "questionId": 1, "value": "1", "type": "MinAnswers", "id": 2, "createdOn": "\/Date(1333666034283+0100)\/" }], "id": 1, "createdOn": "\/Date(1333666034257+0100)\/" }, { "surveyId": 1, "headerText": "Question 2", "subText": "subtext", "type": "Choice", "positionOrder": 2, "answerOptions": [{ "questionId": 2, "text": "Question 2 - Option 1", "positionOrder": 1, "id": 4, "createdOn": "\/Date(1333666034427+0100)\/" }, { "questionId": 2, "text": "Question 2 - Option 2", "positionOrder": 2, "id": 5, "createdOn": "\/Date(1333666034440+0100)\/" }, { "questionId": 2, "text": "Question 2 - Option 3", "positionOrder": 3, "id": 6, "createdOn": "\/Date(1333666034447+0100)\/" }], "questionValidators": [{ "questionId": 2, "value": "3", "type": "MaxAnswers", "id": 3, "createdOn": "\/Date(1333666034407+0100)\/" }, { "questionId": 2, "value": "1", "type": "MinAnswers", "id": 4, "createdOn": "\/Date(1333666034417+0100)\/" }], "id": 2, "createdOn": "\/Date(1333666034377+0100)\/" }, { "surveyId": 1, "headerText": "Question 3", "subText": "subtext", "type": "Choice", "positionOrder": 3, "answerOptions": [{ "questionId": 3, "text": "Question 3 - Option 1", "positionOrder": 1, "id": 7, "createdOn": "\/Date(1333666034477+0100)\/" }, { "questionId": 3, "text": "Question 3 - Option 2", "positionOrder": 2, "id": 8, "createdOn": "\/Date(1333666034483+0100)\/" }, { "questionId": 3, "text": "Question 3 - Option 3", "positionOrder": 3, "id": 9, "createdOn": "\/Date(1333666034487+0100)\/" }], "questionValidators": [{ "questionId": 3, "value": "3", "type": "MaxAnswers", "id": 5, "createdOn": "\/Date(1333666034463+0100)\/" }, { "questionId": 3, "value": "1", "type": "MinAnswers", "id": 6, "createdOn": "\/Date(1333666034470+0100)\/" }], "id": 3, "createdOn": "\/Date(1333666034457+0100)\/" }, { "surveyId": 1, "headerText": "Question 4", "subText": "subtext", "type": "Choice", "positionOrder": 4, "answerOptions": [{ "questionId": 4, "text": "Question 4 - Option 1", "positionOrder": 1, "id": 10, "createdOn": "\/Date(1333666034500+0100)\/" }, { "questionId": 4, "text": "Question 4 - Option 2", "positionOrder": 2, "id": 11, "createdOn": "\/Date(1333666034507+0100)\/" }, { "questionId": 4, "text": "Question 4 - Option 3", "positionOrder": 3, "id": 12, "createdOn": "\/Date(1333666034507+0100)\/" }], "questionValidators": [{ "questionId": 4, "value": "3", "type": "MaxAnswers", "id": 7, "createdOn": "\/Date(1333666034493+0100)\/" }, { "questionId": 4, "value": "1", "type": "MinAnswers", "id": 8, "createdOn": "\/Date(1333666034497+0100)\/" }], "id": 4, "createdOn": "\/Date(1333666034490+0100)\/" }], "id": 1, "createdOn": "\/Date(1333666034243+0100)\/" })

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  • Rails: Should partials be aware of instance variables?

    - by Alexandre
    Ryan Bates' nifty_scaffolding, for example, does this edit.html.erb <%= render :partial => 'form' %> new.html.erb <%= render :partial => 'form' %> _form.html.erb <%= form_for @some_object_defined_in_action %> That hidden state makes me feel uncomfortable, so I usually like to do this edit.html.erb <%= render :partial => 'form', :locals => { :object => @my_object } %> _form.html.erb <%= form_for object %> So which is better: a) having partials access instance variables or b) passing a partial all the variables it needs? I've been opting for b) as of late, but I did run into a little pickle: some_action.html.erb <% @dad.sons.each do |a_son| %> <%= render :partial => 'partial', :locals => { :son => a_son } %> <% end %> _partial.html.erb The son's name is <%= son.name %> The dad's name is <%= son.dad.name %> son.dad makes a database call to fetch the dad! So I would either have to access @dad, which would be going back to a) having partials access instance variables or I would have to pass @dad in locals, changing render :partial to <%= render :partial = 'partial', :locals = { :dad = @dad, :son = a_son } %, and for some reason passing a bunch of vars to my partial makes me feel uncomfortable. Maybe others feel this way as well. Hopefully that made some sense. Looking for some insight into this whole thing... Thanks!

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  • How can I modify/merge Jinja2 dictionaries?

    - by Brian M. Hunt
    I have a Jinja2 dictionary and I want a single expression that modifies it - either by changing its content, or merging with another dictionary. >>> import jinja2 >>> e = jinja2.Environment() Modify a dict: Fails. >>> e.from_string("{{ x[4]=5 }}").render({'x':{1:2,2:3}}) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "jinja2/environment.py", line 743, in from_string return cls.from_code(self, self.compile(source), globals, None) File "jinja2/environment.py", line 469, in compile self.handle_exception(exc_info, source_hint=source) File "<unknown>", line 1, in template jinja2.exceptions.TemplateSyntaxError: expected token 'end of print statement', got '=' Two-stage update: Prints superfluous "None". >>> e.from_string("{{ x.update({4:5}) }} {{ x }}").render({'x':{1:2,2:3}}) u'None {1: 2, 2: 3, 4: 5}' >>> e.from_string("{{ dict(x.items()+ {3:4}.items()) }}").render({'x':{1:2,2:3}}) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "jinja2/environment.py", line 868, in render return self.environment.handle_exception(exc_info, True) File "<template>", line 1, in top-level template code TypeError: <lambda>() takes exactly 0 arguments (1 given) Use dict(x,**y): Fails. >>> e.from_string("{{ dict((3,4), **x) }}").render({'x':{1:2,2:3}}) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "jinja2/environment.py", line 868, in render return self.environment.handle_exception(exc_info, True) File "<template>", line 1, in top-level template code TypeError: call() keywords must be strings So how does one modify the dictionary x in Jinja2 by changing an attribute or merging with another dictionary? This question is similar to: How can I merge two Python dictionaries as a single expression? -- insofar as Jinja2 and Python are analogous.

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  • How does Backbone.js connect View to Model

    - by William Sham
    I am trying to learn backbone.js through the following example. Then I got stuck at the point ItemView = Backbone.View.extend why you can use this.model.get? I thought this is referring to the instance of ItemView that would be created. Then why would ItemView has a model property at all?!! (function($){ var Item = Backbone.Model.extend({ defaults: { part1: 'hello', part2: 'world' } }); var List = Backbone.Collection.extend({ model: Item }); var ItemView = Backbone.View.extend({ tagName: 'li', initialize: function(){ _.bindAll(this, 'render'); }, render: function(){ $(this.el).html('<span>'+this.model.get('part1')+' '+this.model.get('part2')+'</span>'); return this; } }); var ListView = Backbone.View.extend({ el: $('body'), events: { 'click button#add': 'addItem' }, initialize: function(){ _.bindAll(this, 'render', 'addItem', 'appendItem'); this.collection = new List(); this.collection.bind('add', this.appendItem); this.counter = 0; this.render(); }, render: function(){ $(this.el).append("<button id='add'>Add list item</button>"); $(this.el).append("<ul></ul>"); _(this.collection.models).each(function(item){ appendItem(item); }, this); }, addItem: function(){ this.counter++; var item = new Item(); item.set({ part2: item.get('part2') + this.counter }); this.collection.add(item); }, appendItem: function(item){ var itemView = new ItemView({ model: item }); $('ul', this.el).append(itemView.render().el); } }); var listView = new ListView(); })(jQuery);

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  • Javascript cloned object looses its prototype functions

    - by Jake M
    I am attempting to clone an object in Javascript. I have made my own 'class' that has prototype functions. My Problem: When I clone an object, the clone cant access/call any prototype functions. I get an error when I go to access a prototype function of the clone: clone.render is not a function Can you tell me how I can clone an object and keep its prototype functions This simple JSFiddle demonstrates the error I get: http://jsfiddle.net/VHEFb/1/ function cloneObject(obj) { // Handle the 3 simple types, and null or undefined if (null == obj || "object" != typeof obj) return obj; // Handle Date if (obj instanceof Date) { var copy = new Date(); copy.setTime(obj.getTime()); return copy; } // Handle Array if (obj instanceof Array) { var copy = []; for (var i = 0, len = obj.length; i < len; ++i) { copy[i] = cloneObject(obj[i]); } return copy; } // Handle Object if (obj instanceof Object) { var copy = {}; for (var attr in obj) { if (obj.hasOwnProperty(attr)) copy[attr] = cloneObject(obj[attr]); } return copy; } throw new Error("Unable to copy obj! Its type isn't supported."); } function MyObject(name) { this.name = name; // I have arrays stored in this object also so a simple cloneNode(true) call wont copy those // thus the need for the function cloneObject(); } MyObject.prototype.render = function() { alert("Render executing: "+this.name); } var base = new MyObject("base"); var clone = cloneObject(base); clone.name = "clone"; base.render(); clone.render(); // Error here: "clone.render is not a function"

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  • Reference an object, based on a variable with it's name in it

    - by James G
    I'm looking for a way to reference an object, based on a variable with it's name in it. I know I can do this for properties and sub properties: var req = {body: {jobID: 12}}; console.log(req.body.jobID); //12 var subProperty = "jobID"; console.log(req.body[subProperty ]); //12 var property = "body"; console.log(req[property][subProperty]); //12 is it possible for the object itself? var req = {body: {jobID: 12}}; var object = "req"; var property = "body"; var subProperty = "jobID"; console.log([object][property][subProperty]); //12 or console.log(this[object][property][subProperty]); //12 Note: I'm doing this in node.js not a browser. Here is an exert from the function: if(action.render){ res.render(action.render,renderData); }else if(action.redirect){ if(action.redirect.args){ var args = action.redirect.args; res.redirect(action.redirect.path+req[args[0]][args[1]]); }else{ res.redirect(action.redirect.path); } } I could work around it by changing it to this, but I was looking for something more dynamic. if(action.render){ res.render(action.render,renderData); }else if(action.redirect){ if(action.redirect.args){ var args = action.redirect.args; if(args[0]==="req"){ res.redirect(action.redirect.path+req[args[1]][args[2]]); }else if(args[0]==="rows"){ rows.redirect(action.redirect.path+rows[args[1]][args[2]]); } }else{ res.redirect(action.redirect.path); } }

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  • Interpolation using a sprite's previous frame and current frame

    - by user22241
    Overview I'm currently using a method which has been pointed out to me is extrapolation rather than interolation. As a result, I'm also now looking into the possibility of using another method which is based on a sprite's position at it's last (rendered) frame and it's current one. Assuming an interpolation value of 0.5 this is, (visually), how I understand it should affect my sprite's position.... This is how I'm obtaining an inerpolation value: public void onDrawFrame(GL10 gl) { // Set/re-set loop back to 0 to start counting again loops=0; while(System.currentTimeMillis() > nextGameTick && loops < maxFrameskip) { SceneManager.getInstance().getCurrentScene().updateLogic(); nextGameTick += skipTicks; timeCorrection += (1000d / ticksPerSecond) % 1; nextGameTick += timeCorrection; timeCorrection %= 1; loops++; tics++; } interpolation = (float)(System.currentTimeMillis() + skipTicks - nextGameTick) / (float)skipTicks; render(interpolation); } I am then applying it like so (in my rendering call): render(float interpolation) { spriteScreenX = (spriteScreenX - spritePreviousX) * interpolation + spritePreviousX; spritePreviousX = spriteScreenX; // update and store this for next time } Results This unfortunately does nothing to smooth the movement of my sprite. It's pretty much the same as without the interpolation code. I can't get my head around how this is supposed to work and I honestly can't find any decent resources which explain this in any detail. My understanding of extrapolation is that when we arrive at the rendering call, we calculate the time between the last update call and the render call, and then adjust the sprite's position to reflect this time (moving the sprite forward) - And yet, this (Interpolation) is moving the sprite back, so how can this produce smooth results? Any advise on this would be very much appreciated. Edit I've implemented the code from OriginalDaemon's answer like so: @Override public void onDrawFrame(GL10 gl) { newTime = System.currentTimeMillis()*0.001; frameTime = newTime - currentTime; if ( frameTime > (dt*25)) frameTime = (dt*25); currentTime = newTime; accumulator += frameTime; while ( accumulator >= dt ) { SceneManager.getInstance().getCurrentScene().updateLogic(); previousState = currentState; t += dt; accumulator -= dt; } interpolation = (float) (accumulator / dt); render(); } Interpolation values are now being produced between 0 and 1 as expected (similar to how they were in my original loop) - however, the results are the same as my original loop (my original loop allowed frames to skip if they took too long to draw which I think this loop is also doing). I appear to have made a mistake in my previous logging, it is logging as I would expect it to (interpolated position does appear to be inbetween the previous and current positions) - however, the sprites are most definitely choppy when the render() skipping happens.

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  • Why is a fully transparent pixel still rendered?

    - by Mr Bell
    I am trying to make a pixel shader that achieves an effect similar to this video http://www.youtube.com/watch?v=f1uZvurrhig&feature=related My basic idea is render the scene to a temp render target then Render the previously rendered image with a slight fade on to another temp render target Draw the current scene on top of that Draw the results on to a render target that persists between draws Draw the results on to the screen But I am having problems with the fading portion. If I have my pixel shader return a color with its A component set to 0, shouldn't that basically amount to drawing nothing? (Assuming that sprite batch blend mode is set to AlphaBlend) To test this I have my pixel shader return a transparent red color. Instead of nothing being drawn, it draws a partially transparent red box. I hope that my question makes sense, but if it doesnt please ask me to clarify Here is the drawing code public override void Draw(GameTime gameTime) { GraphicsDevice.SamplerStates[1] = SamplerState.PointWrap; drawImageOnClearedRenderTarget(presentationTarget, tempRenderTarget, fadeEffect); drawImageOnRenderTarget(sceneRenderTarget, tempRenderTarget); drawImageOnClearedRenderTarget(tempRenderTarget, presentationTarget); GraphicsDevice.SetRenderTarget(null); drawImage(backgroundTexture); drawImage(presentationTarget); base.Draw(gameTime); } private void drawImage(Texture2D image, Effect effect = null) { spriteBatch.Begin(0, BlendState.AlphaBlend, SamplerState.PointWrap, null, null, effect); spriteBatch.Draw(image, new Rectangle(0, 0, width, height), Color.White); spriteBatch.End(); } private void drawImageOnRenderTarget(Texture2D image, RenderTarget2D target, Effect effect = null) { GraphicsDevice.SetRenderTarget(target); drawImage(image, effect); } private void drawImageOnClearedRenderTarget(Texture2D image, RenderTarget2D target, Effect effect = null) { GraphicsDevice.SetRenderTarget(target); GraphicsDevice.Clear(Color.Transparent); drawImage(image, effect); } Here is the fade pixel shader sampler TextureSampler : register(s0); float4 PixelShaderFunction(float2 texCoord : TEXCOORD0) : COLOR0 { float4 c = 0; c = tex2D(TextureSampler, texCoord); //c.a = clamp(c.a - 0.05, 0, 1); c.r = 1; c.g = 0; c.b = 0; c.a = 0; return c; } technique Fade { pass Pass1 { PixelShader = compile ps_2_0 PixelShaderFunction(); } }

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  • LWJGL - Mixing 2D and 3D

    - by nathan
    I'm trying to mix 2D and 3D using LWJGL. I have wrote 2D little method that allow me to easily switch between 2D and 3D. protected static void make2D() { glEnable(GL_BLEND); GL11.glMatrixMode(GL11.GL_PROJECTION); GL11.glLoadIdentity(); glOrtho(0.0f, SCREEN_WIDTH, SCREEN_HEIGHT, 0.0f, 0.0f, 1.0f); GL11.glMatrixMode(GL11.GL_MODELVIEW); GL11.glLoadIdentity(); } protected static void make3D() { glDisable(GL_BLEND); GL11.glMatrixMode(GL11.GL_PROJECTION); GL11.glLoadIdentity(); // Reset The Projection Matrix GLU.gluPerspective(45.0f, ((float) SCREEN_WIDTH / (float) SCREEN_HEIGHT), 0.1f, 100.0f); // Calculate The Aspect Ratio Of The Window GL11.glMatrixMode(GL11.GL_MODELVIEW); glLoadIdentity(); } The in my rendering code i would do something like: make2D(); //draw 2D stuffs here make3D(); //draw 3D stuffs here What i'm trying to do is to draw a 3D shape (in my case a quad) and i 2D image. I found this example and i took the code from TextureLoader, Texture and Sprite to load and render a 2D image. Here is how i load the image. TextureLoader loader = new TextureLoader(); Sprite s = new Sprite(loader, "player.png") And how i render it: make2D(); s.draw(0, 0); It works great. Here is how i render my quad: glTranslatef(0.0f, 0.0f, 30.0f); glScalef(12.0f, 9.0f, 1.0f); DrawUtils.drawQuad(); Once again, no problem, the quad is properly rendered. DrawUtils is a simple class i wrote containing utility method to draw primitives shapes. Now my problem is when i want to mix both of the above, loading/rendering the 2D image, rendering the quad. When i try to load my 2D image with the following: s = new Sprite(loader, "player.png); My quad is not rendered anymore (i'm not even trying to render the 2D image at this point). Only the fact of creating the texture create the issue. After looking a bit at the code of Sprite and TextureLoader i found that the problem appears after the call of the glTexImage2d. In the TextureLoader class: glTexImage2D(target, 0, dstPixelFormat, get2Fold(bufferedImage.getWidth()), get2Fold(bufferedImage.getHeight()), 0, srcPixelFormat, GL_UNSIGNED_BYTE, textureBuffer); Commenting this like make the problem disappear. My question is then why? Is there anything special to do after calling this function to do 3D? Does this function alter the render part, the projection matrix?

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  • Are these non-standard applications of rendering practical in games?

    - by maul
    I've recently got into 3D and I came up with a few different "tricky" rendering techniques. Unfortunately I don't have the time to work on this myself, but I'd like to know if these are known methods and if they can be used in practice. Hybrid rendering Now I know that ray-tracing is still not fast enough for real-time rendering, at least on home computers. I also know that hybrid rendering (a combination of rasterization and ray-tracing) is a well known theory. However I had the following idea: one could separate a scene into "important" and "not important" objects. First you render the "not important" objects using traditional rasterization. In this pass you also render the "important" objects using a special shader that simply marks these parts on the image using a special color, or some stencil/depth buffer trickery. Then in the second pass you read back the results of the first pass and start ray tracing, but only from the pixels that were marked by the "important" object's shader. This would allow you to only ray-trace exactly what you need to. Could this be fast enough for real-time effects? Rendered physics I'm specifically talking about bullet physics - intersection of a very small object (point/bullet) that travels across a straight line with other, relatively slow-moving, fairly constant objects. More specifically: hit detection. My idea is that you could render the scene from the point of view of the gun (or the bullet). Every object in the scene would draw a different color. You only need to render a 1x1 pixel window - the center of the screen (again, from the gun's point of view). Then you simply check that central pixel and the color tells you what you hit. This is pixel-perfect hit detection based on the graphical representation of objects, which is not common in games. Afaik traditional OpenGL "picking" is a similar method. This could be extended in a few ways: For larger (non-bullet) objects you render a larger portion of the screen. If you put a special-colored plane in the middle of the scene (exactly where the bullet will be after the current frame) you get a method that works as the traditional slow-moving iterative physics test as well. You could simulate objects that the bullet can pass through (with decreased velocity) using alpha blending or some similar trick. So are these techniques in use anywhere, and/or are they practical at all?

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  • Variable number of GUI Buttons

    - by Wakaka
    I have a generic HTML5 Canvas GUI Button class and a Scene class. The Scene class has a method called createButton(), which will create a new Button with onclick parameter and store it in a list of buttons. I call createButton() for all UI buttons when initializing the Scene. Because buttons can appear and disappear very often during rendering, Scene would first deactivate all buttons (temporarily remove their onclick, onmouseover etc property) before each render frame. During rendering, the renderer would then activate the required buttons for that frame. The problem is that part of the UI requires a variable number of buttons, and their onclick, onmouseover etc properties change frequently. An example is a buffs system. The UI will list all buffs as square sprites for the current unit selected, and mousing over each square will bring up a tooltip with some information on the buff. But the number of buffs is variable thus I won't know how many buttons to create at the start. What's the best way to solve this problem? P.S. My game is in Javascript, and I know I can use HTML buttons, but would like to make my game purely Canvas-based. Create buttons on-the-fly during rendering. Thus I will only have buttons when I require them. After the render frame these buttons would be useless and removed. Create a fixed set of buttons that I'm going to assume the number of buffs per unit won't exceed. During each render frame activate the buttons accordingly and set their onmouseover property. Assign a button to each Buff instance. This sounds wrong as the buff button is a part of the GUI which can only have one unit selected. Assigning a button to every single Buff in the game seems to be overkill. Also, I would need to change the button's position every render frame since its order in the unit's list of buffs matter. Any other solutions? I'm actually quite for idea (1) but am worried about the memory/time issues of creating a new Button() object every render frame. But this is in Javascript where object creation is oh-so-common ({} mainly) due to automatic garbage collection. What is your take on this? Thanks!

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  • Django facebook integration error

    - by Gaurav
    I'm trying to integrate facebook into my application so that users can use their FB login to login to my site. I've got everything up and running and there are no issues when I run my site using the command line python manage.py runserver But this same code refuses to run when I try and run it through Apache. I get the following error: Environment: Request Method: GET Request URL: http://helvetica/foodfolio/login Django Version: 1.1.1 Python Version: 2.6.4 Installed Applications: ['django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.sites', 'foodfolio.app', 'foodfolio.facebookconnect'] Installed Middleware: ('django.contrib.sessions.middleware.SessionMiddleware', 'facebook.djangofb.FacebookMiddleware', 'django.middleware.common.CommonMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'facebookconnect.middleware.FacebookConnectMiddleware') Template error: In template /home/swat/website-apps/foodfolio/facebookconnect/templates/facebook/js.html, error at line 2 Caught an exception while rendering: No module named app.models 1 : <script type="text/javascript"> 2 : FB_RequireFeatures(["XFBML"], function() {FB.Facebook.init("{{ facebook_api_key }}", " {% url facebook_xd_receiver %} ")}); 3 : 4 : function facebookConnect(loginForm) { 5 : FB.Connect.requireSession(); 6 : FB.Facebook.get_sessionState().waitUntilReady(function(){loginForm.submit();}); 7 : } 8 : function pushToFacebookFeed(data){ 9 : if(data['success']){ 10 : var template_data = data['template_data']; 11 : var template_bundle_id = data['template_bundle_id']; 12 : feedTheFacebook(template_data,template_bundle_id,function(){}); Traceback: File "/usr/lib/pymodules/python2.6/django/core/handlers/base.py" in get_response 92. response = callback(request, *callback_args, **callback_kwargs) File "/home/swat/website-apps/foodfolio/app/controller.py" in __showLogin__ 238. context_instance = RequestContext(request)) File "/usr/lib/pymodules/python2.6/django/shortcuts/__init__.py" in render_to_response 20. return HttpResponse(loader.render_to_string(*args, **kwargs), **httpresponse_kwargs) File "/usr/lib/pymodules/python2.6/django/template/loader.py" in render_to_string 108. return t.render(context_instance) File "/usr/lib/pymodules/python2.6/django/template/__init__.py" in render 178. return self.nodelist.render(context) File "/usr/lib/pymodules/python2.6/django/template/__init__.py" in render 779. bits.append(self.render_node(node, context)) File "/usr/lib/pymodules/python2.6/django/template/debug.py" in render_node 71. result = node.render(context) File "/usr/lib/pymodules/python2.6/django/template/__init__.py" in render 946. autoescape=context.autoescape)) File "/usr/lib/pymodules/python2.6/django/template/__init__.py" in render 779. bits.append(self.render_node(node, context)) File "/usr/lib/pymodules/python2.6/django/template/debug.py" in render_node 81. raise wrapped Exception Type: TemplateSyntaxError at /foodfolio/login Exception Value: Caught an exception while rendering: No module named app.models

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  • C++ game designing & polymorphism question

    - by Kotti
    Hi! I'm trying to implement some sort of 'just-for-me' game engine and the problem's plot goes the following way: Suppose I have some abstract interface for a renderable entity, e.g. IRenderable. And it's declared the following way: interface IRenderable { // (...) // Suppose that Backend is some abstract backend used // for rendering, and it's implementation is not important virtual void Render(Backend& backend) = 0; }; What I'm doing right now is something like declaring different classes like class Ball : public IRenderable { virtual void Render(Backend& backend) { // Rendering implementation, that is specific for // the Ball object // (...) } }; And then everything looks fine. I can easily do something like std::vector<IRenderable*> items, push some items like new Ball() in this vector and then make a call similiar to foreach (IRenderable* in items) { item->Render(backend); } Ok, I guess it is the 'polymorphic' way, but what if I want to have different types of objects in my game and an ability to manipulate their state, where every object can be manipulated via it's own interface? I could do something like struct GameState { Ball ball; Bonus bonus; // (...) }; and then easily change objects state via their own methods, like ball.Move(...) or bonus.Activate(...), where Move(...) is specific for only Ball and Activate(...) - for only Bonus instances. But in this case I lose the opportunity to write foreach IRenderable* simply because I store these balls and bonuses as instances of their derived, not base classes. And in this case the rendering procedure turns into a mess like ball.Render(backend); bonus.Render(backend); // (...) and it is bad because we actually lose our polymorphism this way (no actual need for making Render function virtual, etc. The other approach means invoking downcasting via dynamic_cast or something with typeid to determine the type of object you want to manipulate and this looks even worse to me and this also breaks this 'polymorphic' idea. So, my question is - is there some kind of (probably) alternative approach to what I want to do or can my current pattern be somehow modified so that I would actually store IRenderable* for my game objects (so that I can invoke virtual Render method on each of them) while preserving the ability to easily change the state of these objects? Maybe I'm doing something absolutely wrong from the beginning, if so, please point it out :) Thanks in advance!

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  • Building an interleaved buffer for pyopengl and numpy

    - by Nick Sonneveld
    I'm trying to batch up a bunch of vertices and texture coords in an interleaved array before sending it to pyOpengl's glInterleavedArrays/glDrawArrays. The only problem is that I'm unable to find a suitably fast enough way to append data into a numpy array. Is there a better way to do this? I would have thought it would be quicker to preallocate the array and then fill it with data but instead, generating a python list and converting it to a numpy array is "faster". Although 15ms for 4096 quads seems slow. I have included some example code and their timings. #!/usr/bin/python import timeit import numpy import ctypes import random USE_RANDOM=True USE_STATIC_BUFFER=True STATIC_BUFFER = numpy.empty(4096*20, dtype=numpy.float32) def render(i): # pretend these are different each time if USE_RANDOM: tex_left, tex_right, tex_top, tex_bottom = random.random(), random.random(), random.random(), random.random() left, right, top, bottom = random.random(), random.random(), random.random(), random.random() else: tex_left, tex_right, tex_top, tex_bottom = 0.0, 1.0, 1.0, 0.0 left, right, top, bottom = -1.0, 1.0, 1.0, -1.0 ibuffer = ( tex_left, tex_bottom, left, bottom, 0.0, # Lower left corner tex_right, tex_bottom, right, bottom, 0.0, # Lower right corner tex_right, tex_top, right, top, 0.0, # Upper right corner tex_left, tex_top, left, top, 0.0, # upper left ) return ibuffer # create python list.. convert to numpy array at end def create_array_1(): ibuffer = [] for x in xrange(4096): data = render(x) ibuffer += data ibuffer = numpy.array(ibuffer, dtype=numpy.float32) return ibuffer # numpy.array, placing individually by index def create_array_2(): if USE_STATIC_BUFFER: ibuffer = STATIC_BUFFER else: ibuffer = numpy.empty(4096*20, dtype=numpy.float32) index = 0 for x in xrange(4096): data = render(x) for v in data: ibuffer[index] = v index += 1 return ibuffer # using slicing def create_array_3(): if USE_STATIC_BUFFER: ibuffer = STATIC_BUFFER else: ibuffer = numpy.empty(4096*20, dtype=numpy.float32) index = 0 for x in xrange(4096): data = render(x) ibuffer[index:index+20] = data index += 20 return ibuffer # using numpy.concat on a list of ibuffers def create_array_4(): ibuffer_concat = [] for x in xrange(4096): data = render(x) # converting makes a diff! data = numpy.array(data, dtype=numpy.float32) ibuffer_concat.append(data) return numpy.concatenate(ibuffer_concat) # using numpy array.put def create_array_5(): if USE_STATIC_BUFFER: ibuffer = STATIC_BUFFER else: ibuffer = numpy.empty(4096*20, dtype=numpy.float32) index = 0 for x in xrange(4096): data = render(x) ibuffer.put( xrange(index, index+20), data) index += 20 return ibuffer # using ctype array CTYPES_ARRAY = ctypes.c_float*(4096*20) def create_array_6(): ibuffer = [] for x in xrange(4096): data = render(x) ibuffer += data ibuffer = CTYPES_ARRAY(*ibuffer) return ibuffer def equals(a, b): for i,v in enumerate(a): if b[i] != v: return False return True if __name__ == "__main__": number = 100 # if random, don't try and compare arrays if not USE_RANDOM and not USE_STATIC_BUFFER: a = create_array_1() assert equals( a, create_array_2() ) assert equals( a, create_array_3() ) assert equals( a, create_array_4() ) assert equals( a, create_array_5() ) assert equals( a, create_array_6() ) t = timeit.Timer( "testing2.create_array_1()", "import testing2" ) print 'from list:', t.timeit(number)/number*1000.0, 'ms' t = timeit.Timer( "testing2.create_array_2()", "import testing2" ) print 'array: indexed:', t.timeit(number)/number*1000.0, 'ms' t = timeit.Timer( "testing2.create_array_3()", "import testing2" ) print 'array: slicing:', t.timeit(number)/number*1000.0, 'ms' t = timeit.Timer( "testing2.create_array_4()", "import testing2" ) print 'array: concat:', t.timeit(number)/number*1000.0, 'ms' t = timeit.Timer( "testing2.create_array_5()", "import testing2" ) print 'array: put:', t.timeit(number)/number*1000.0, 'ms' t = timeit.Timer( "testing2.create_array_6()", "import testing2" ) print 'ctypes float array:', t.timeit(number)/number*1000.0, 'ms' Timings using random numbers: $ python testing2.py from list: 15.0486779213 ms array: indexed: 24.8184704781 ms array: slicing: 50.2214789391 ms array: concat: 44.1691994667 ms array: put: 73.5879898071 ms ctypes float array: 20.6674289703 ms edit note: changed code to produce random numbers for each render to reduce object reuse and to simulate different vertices each time. edit note2: added static buffer and force all numpy.empty() to use dtype=float32 note 1/Apr/2010: still no progress and I don't really feel that any of the answers have solved the problem yet.

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  • How to view the filter graph used by Windows Media Player

    - by Ian Boyd
    i have a video that i cannot render in Graph Edit: GSpot cannot render: and AVISynth's DirectShowSource cannot open: And yet Windows Media Player (12) can play it fine. How can i figure out the filters that Windows Media Player is using, when DirectShow itself cannot render the file? i tried running GraphEdit as an adminstrator and connecting to a remote graph, but Windows Media Player does not register its graph in the running objects table: Related question: How can i access a file in AviSynth that Windows Media Player can play, but DirectShow cannot?

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  • blender rendering question

    - by Kombuwa
    hi, I need to render a 3d model that have been implement uv map in blender. When I press the render button it renders with normal blender material. But I need to render it with uv map textures. please help me.

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  • What video format works both on Windows and all Apple products out-of-the-box?

    - by Seppo Silaste
    What format and encoding should I use for video that would play out-of-the-box on both Windows and all Apple products (iPad, iPhone, etc.)? I know that the correct way to render an animation, is to first render it as images, but this is overkill when rendering short animations of a work in progress for the client to comment on. I have one client that views the vids on Windows and another that views them on iPad and iPhone. I'm hoping I could render just one video instead of rendering in two different formats.

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  • Hosting the Razor Engine for Templating in Non-Web Applications

    - by Rick Strahl
    Microsoft’s new Razor HTML Rendering Engine that is currently shipping with ASP.NET MVC previews can be used outside of ASP.NET. Razor is an alternative view engine that can be used instead of the ASP.NET Page engine that currently works with ASP.NET WebForms and MVC. It provides a simpler and more readable markup syntax and is much more light weight in terms of functionality than the full blown WebForms Page engine, focusing only on features that are more along the lines of a pure view engine (or classic ASP!) with focus on expression and code rendering rather than a complex control/object model. Like the Page engine though, the parser understands .NET code syntax which can be embedded into templates, and behind the scenes the engine compiles markup and script code into an executing piece of .NET code in an assembly. Although it ships as part of the ASP.NET MVC and WebMatrix the Razor Engine itself is not directly dependent on ASP.NET or IIS or HTTP in any way. And although there are some markup and rendering features that are optimized for HTML based output generation, Razor is essentially a free standing template engine. And what’s really nice is that unlike the ASP.NET Runtime, Razor is fairly easy to host inside of your own non-Web applications to provide templating functionality. Templating in non-Web Applications? Yes please! So why might you host a template engine in your non-Web application? Template rendering is useful in many places and I have a number of applications that make heavy use of it. One of my applications – West Wind Html Help Builder - exclusively uses template based rendering to merge user supplied help text content into customizable and executable HTML markup templates that provide HTML output for CHM style HTML Help. This is an older product and it’s not actually using .NET at the moment – and this is one reason I’m looking at Razor for script hosting at the moment. For a few .NET applications though I’ve actually used the ASP.NET Runtime hosting to provide templating and mail merge style functionality and while that works reasonably well it’s a very heavy handed approach. It’s very resource intensive and has potential issues with versioning in various different versions of .NET. The generic implementation I created in the article above requires a lot of fix up to mimic an HTTP request in a non-HTTP environment and there are a lot of little things that have to happen to ensure that the ASP.NET runtime works properly most of it having nothing to do with the templating aspect but just satisfying ASP.NET’s requirements. The Razor Engine on the other hand is fairly light weight and completely decoupled from the ASP.NET runtime and the HTTP processing. Rather it’s a pure template engine whose sole purpose is to render text templates. Hosting this engine in your own applications can be accomplished with a reasonable amount of code (actually just a few lines with the tools I’m about to describe) and without having to fake HTTP requests. It’s also much lighter on resource usage and you can easily attach custom properties to your base template implementation to easily pass context from the parent application into templates all of which was rather complicated with ASP.NET runtime hosting. Installing the Razor Template Engine You can get Razor as part of the MVC 3 (RC and later) or Web Matrix. Both are available as downloadable components from the Web Platform Installer Version 3.0 (!important – V2 doesn’t show these components). If you already have that version of the WPI installed just fire it up. You can get the latest version of the Web Platform Installer from here: http://www.microsoft.com/web/gallery/install.aspx Once the platform Installer 3.0 is installed install either MVC 3 or ASP.NET Web Pages. Once installed you’ll find a System.Web.Razor assembly in C:\Program Files\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\Assemblies\System.Web.Razor.dll which you can add as a reference to your project. Creating a Wrapper The basic Razor Hosting API is pretty simple and you can host Razor with a (large-ish) handful of lines of code. I’ll show the basics of it later in this article. However, if you want to customize the rendering and handle assembly and namespace includes for the markup as well as deal with text and file inputs as well as forcing Razor to run in a separate AppDomain so you can unload the code-generated assemblies and deal with assembly caching for re-used templates little more work is required to create something that is more easily reusable. For this reason I created a Razor Hosting wrapper project that combines a bunch of this functionality into an easy to use hosting class, a hosting factory that can load the engine in a separate AppDomain and a couple of hosting containers that provided folder based and string based caching for templates for an easily embeddable and reusable engine with easy to use syntax. If you just want the code and play with the samples and source go grab the latest code from the Subversion Repository at: http://www.west-wind.com:8080/svn/articles/trunk/RazorHosting/ or a snapshot from: http://www.west-wind.com/files/tools/RazorHosting.zip Getting Started Before I get into how hosting with Razor works, let’s take a look at how you can get up and running quickly with the wrapper classes provided. It only takes a few lines of code. The easiest way to use these Razor Hosting Wrappers is to use one of the two HostContainers provided. One is for hosting Razor scripts in a directory and rendering them as relative paths from these script files on disk. The other HostContainer serves razor scripts from string templates… Let’s start with a very simple template that displays some simple expressions, some code blocks and demonstrates rendering some data from contextual data that you pass to the template in the form of a ‘context’. Here’s a simple Razor template: @using System.Reflection Hello @Context.FirstName! Your entry was entered on: @Context.Entered @{ // Code block: Update the host Windows Form passed in through the context Context.WinForm.Text = "Hello World from Razor at " + DateTime.Now.ToString(); } AppDomain Id: @AppDomain.CurrentDomain.FriendlyName Assembly: @Assembly.GetExecutingAssembly().FullName Code based output: @{ // Write output with Response object from code string output = string.Empty; for (int i = 0; i < 10; i++) { output += i.ToString() + " "; } Response.Write(output); } Pretty easy to see what’s going on here. The only unusual thing in this code is the Context object which is an arbitrary object I’m passing from the host to the template by way of the template base class. I’m also displaying the current AppDomain and the executing Assembly name so you can see how compiling and running a template actually loads up new assemblies. Also note that as part of my context I’m passing a reference to the current Windows Form down to the template and changing the title from within the script. It’s a silly example, but it demonstrates two-way communication between host and template and back which can be very powerful. The easiest way to quickly render this template is to use the RazorEngine<TTemplateBase> class. The generic parameter specifies a template base class type that is used by Razor internally to generate the class it generates from a template. The default implementation provided in my RazorHosting wrapper is RazorTemplateBase. Here’s a simple one that renders from a string and outputs a string: var engine = new RazorEngine<RazorTemplateBase>(); // we can pass any object as context - here create a custom context var context = new CustomContext() { WinForm = this, FirstName = "Rick", Entered = DateTime.Now.AddDays(-10) }; string output = engine.RenderTemplate(this.txtSource.Text new string[] { "System.Windows.Forms.dll" }, context); if (output == null) this.txtResult.Text = "*** ERROR:\r\n" + engine.ErrorMessage; else this.txtResult.Text = output; Simple enough. This code renders a template from a string input and returns a result back as a string. It  creates a custom context and passes that to the template which can then access the Context’s properties. Note that anything passed as ‘context’ must be serializable (or MarshalByRefObject) – otherwise you get an exception when passing the reference over AppDomain boundaries (discussed later). Passing a context is optional, but is a key feature in being able to share data between the host application and the template. Note that we use the Context object to access FirstName, Entered and even the host Windows Form object which is used in the template to change the Window caption from within the script! In the code above all the work happens in the RenderTemplate method which provide a variety of overloads to read and write to and from strings, files and TextReaders/Writers. Here’s another example that renders from a file input using a TextReader: using (reader = new StreamReader("templates\\simple.csHtml", true)) { result = host.RenderTemplate(reader, new string[] { "System.Windows.Forms.dll" }, this.CustomContext); } RenderTemplate() is fairly high level and it handles loading of the runtime, compiling into an assembly and rendering of the template. If you want more control you can use the lower level methods to control each step of the way which is important for the HostContainers I’ll discuss later. Basically for those scenarios you want to separate out loading of the engine, compiling into an assembly and then rendering the template from the assembly. Why? So we can keep assemblies cached. In the code above a new assembly is created for each template rendered which is inefficient and uses up resources. Depending on the size of your templates and how often you fire them you can chew through memory very quickly. This slighter lower level approach is only a couple of extra steps: // we can pass any object as context - here create a custom context var context = new CustomContext() { WinForm = this, FirstName = "Rick", Entered = DateTime.Now.AddDays(-10) }; var engine = new RazorEngine<RazorTemplateBase>(); string assId = null; using (StringReader reader = new StringReader(this.txtSource.Text)) { assId = engine.ParseAndCompileTemplate(new string[] { "System.Windows.Forms.dll" }, reader); } string output = engine.RenderTemplateFromAssembly(assId, context); if (output == null) this.txtResult.Text = "*** ERROR:\r\n" + engine.ErrorMessage; else this.txtResult.Text = output; The difference here is that you can capture the assembly – or rather an Id to it – and potentially hold on to it to render again later assuming the template hasn’t changed. The HostContainers take advantage of this feature to cache the assemblies based on certain criteria like a filename and file time step or a string hash that if not change indicate that an assembly can be reused. Note that ParseAndCompileTemplate returns an assembly Id rather than the assembly itself. This is done so that that the assembly always stays in the host’s AppDomain and is not passed across AppDomain boundaries which would cause load failures. We’ll talk more about this in a minute but for now just realize that assemblies references are stored in a list and are accessible by this ID to allow locating and re-executing of the assembly based on that id. Reuse of the assembly avoids recompilation overhead and creation of yet another assembly that loads into the current AppDomain. You can play around with several different versions of the above code in the main sample form:   Using Hosting Containers for more Control and Caching The above examples simply render templates into assemblies each and every time they are executed. While this works and is even reasonably fast, it’s not terribly efficient. If you render templates more than once it would be nice if you could cache the generated assemblies for example to avoid re-compiling and creating of a new assembly each time. Additionally it would be nice to load template assemblies into a separate AppDomain optionally to be able to be able to unload assembli es and also to protect your host application from scripting attacks with malicious template code. Hosting containers provide also provide a wrapper around the RazorEngine<T> instance, a factory (which allows creation in separate AppDomains) and an easy way to start and stop the container ‘runtime’. The Razor Hosting samples provide two hosting containers: RazorFolderHostContainer and StringHostContainer. The folder host provides a simple runtime environment for a folder structure similar in the way that the ASP.NET runtime handles a virtual directory as it’s ‘application' root. Templates are loaded from disk in relative paths and the resulting assemblies are cached unless the template on disk is changed. The string host also caches templates based on string hashes – if the same string is passed a second time a cached version of the assembly is used. Here’s how HostContainers work. I’ll use the FolderHostContainer because it’s likely the most common way you’d use templates – from disk based templates that can be easily edited and maintained on disk. The first step is to create an instance of it and keep it around somewhere (in the example it’s attached as a property to the Form): RazorFolderHostContainer Host = new RazorFolderHostContainer(); public RazorFolderHostForm() { InitializeComponent(); // The base path for templates - templates are rendered with relative paths // based on this path. Host.TemplatePath = Path.Combine(Environment.CurrentDirectory, TemplateBaseFolder); // Add any assemblies you want reference in your templates Host.ReferencedAssemblies.Add("System.Windows.Forms.dll"); // Start up the host container Host.Start(); } Next anytime you want to render a template you can use simple code like this: private void RenderTemplate(string fileName) { // Pass the template path via the Context var relativePath = Utilities.GetRelativePath(fileName, Host.TemplatePath); if (!Host.RenderTemplate(relativePath, this.Context, Host.RenderingOutputFile)) { MessageBox.Show("Error: " + Host.ErrorMessage); return; } this.webBrowser1.Navigate("file://" + Host.RenderingOutputFile); } You can also render the output to a string instead of to a file: string result = Host.RenderTemplateToString(relativePath,context); Finally if you want to release the engine and shut down the hosting AppDomain you can simply do: Host.Stop(); Stopping the AppDomain and restarting it (ie. calling Stop(); followed by Start()) is also a nice way to release all resources in the AppDomain. The FolderBased domain also supports partial Rendering based on root path based relative paths with the same caching characteristics as the main templates. From within a template you can call out to a partial like this: @RenderPartial(@"partials\PartialRendering.cshtml", Context) where partials\PartialRendering.cshtml is a relative to the template root folder. The folder host example lets you load up templates from disk and display the result in a Web Browser control which demonstrates using Razor HTML output from templates that contain HTML syntax which happens to me my target scenario for Html Help Builder.   The Razor Engine Wrapper Project The project I created to wrap Razor hosting has a fair bit of code and a number of classes associated with it. Most of the components are internally used and as you can see using the final RazorEngine<T> and HostContainer classes is pretty easy. The classes are extensible and I suspect developers will want to build more customized host containers for their applications. Host containers are the key to wrapping up all functionality – Engine, BaseTemplate, AppDomain Hosting, Caching etc in a logical piece that is ready to be plugged into an application. When looking at the code there are a couple of core features provided: Core Razor Engine Hosting This is the core Razor hosting which provides the basics of loading a template, compiling it into an assembly and executing it. This is fairly straightforward, but without a host container that can cache assemblies based on some criteria templates are recompiled and re-created each time which is inefficient (although pretty fast). The base engine wrapper implementation also supports hosting the Razor runtime in a separate AppDomain for security and the ability to unload it on demand. Host Containers The engine hosting itself doesn’t provide any sort of ‘runtime’ service like picking up files from disk, caching assemblies and so forth. So my implementation provides two HostContainers: RazorFolderHostContainer and RazorStringHostContainer. The FolderHost works off a base directory and loads templates based on relative paths (sort of like the ASP.NET runtime does off a virtual). The HostContainers also deal with caching of template assemblies – for the folder host the file date is tracked and checked for updates and unless the template is changed a cached assembly is reused. The StringHostContainer similiarily checks string hashes to figure out whether a particular string template was previously compiled and executed. The HostContainers also act as a simple startup environment and a single reference to easily store and reuse in an application. TemplateBase Classes The template base classes are the base classes that from which the Razor engine generates .NET code. A template is parsed into a class with an Execute() method and the class is based on this template type you can specify. RazorEngine<TBaseTemplate> can receive this type and the HostContainers default to specific templates in their base implementations. Template classes are customizable to allow you to create templates that provide application specific features and interaction from the template to your host application. How does the RazorEngine wrapper work? You can browse the source code in the links above or in the repository or download the source, but I’ll highlight some key features here. Here’s part of the RazorEngine implementation that can be used to host the runtime and that demonstrates the key code required to host the Razor runtime. The RazorEngine class is implemented as a generic class to reflect the Template base class type: public class RazorEngine<TBaseTemplateType> : MarshalByRefObject where TBaseTemplateType : RazorTemplateBase The generic type is used to internally provide easier access to the template type and assignments on it as part of the template processing. The class also inherits MarshalByRefObject to allow execution over AppDomain boundaries – something that all the classes discussed here need to do since there is much interaction between the host and the template. The first two key methods deal with creating a template assembly: /// <summary> /// Creates an instance of the RazorHost with various options applied. /// Applies basic namespace imports and the name of the class to generate /// </summary> /// <param name="generatedNamespace"></param> /// <param name="generatedClass"></param> /// <returns></returns> protected RazorTemplateEngine CreateHost(string generatedNamespace, string generatedClass) { Type baseClassType = typeof(TBaseTemplateType); RazorEngineHost host = new RazorEngineHost(new CSharpRazorCodeLanguage()); host.DefaultBaseClass = baseClassType.FullName; host.DefaultClassName = generatedClass; host.DefaultNamespace = generatedNamespace; host.NamespaceImports.Add("System"); host.NamespaceImports.Add("System.Text"); host.NamespaceImports.Add("System.Collections.Generic"); host.NamespaceImports.Add("System.Linq"); host.NamespaceImports.Add("System.IO"); return new RazorTemplateEngine(host); } /// <summary> /// Parses and compiles a markup template into an assembly and returns /// an assembly name. The name is an ID that can be passed to /// ExecuteTemplateByAssembly which picks up a cached instance of the /// loaded assembly. /// /// </summary> /// <param name="namespaceOfGeneratedClass">The namespace of the class to generate from the template</param> /// <param name="generatedClassName">The name of the class to generate from the template</param> /// <param name="ReferencedAssemblies">Any referenced assemblies by dll name only. Assemblies must be in execution path of host or in GAC.</param> /// <param name="templateSourceReader">Textreader that loads the template</param> /// <remarks> /// The actual assembly isn't returned here to allow for cross-AppDomain /// operation. If the assembly was returned it would fail for cross-AppDomain /// calls. /// </remarks> /// <returns>An assembly Id. The Assembly is cached in memory and can be used with RenderFromAssembly.</returns> public string ParseAndCompileTemplate( string namespaceOfGeneratedClass, string generatedClassName, string[] ReferencedAssemblies, TextReader templateSourceReader) { RazorTemplateEngine engine = CreateHost(namespaceOfGeneratedClass, generatedClassName); // Generate the template class as CodeDom GeneratorResults razorResults = engine.GenerateCode(templateSourceReader); // Create code from the codeDom and compile CSharpCodeProvider codeProvider = new CSharpCodeProvider(); CodeGeneratorOptions options = new CodeGeneratorOptions(); // Capture Code Generated as a string for error info // and debugging LastGeneratedCode = null; using (StringWriter writer = new StringWriter()) { codeProvider.GenerateCodeFromCompileUnit(razorResults.GeneratedCode, writer, options); LastGeneratedCode = writer.ToString(); } CompilerParameters compilerParameters = new CompilerParameters(ReferencedAssemblies); // Standard Assembly References compilerParameters.ReferencedAssemblies.Add("System.dll"); compilerParameters.ReferencedAssemblies.Add("System.Core.dll"); compilerParameters.ReferencedAssemblies.Add("Microsoft.CSharp.dll"); // dynamic support! // Also add the current assembly so RazorTemplateBase is available compilerParameters.ReferencedAssemblies.Add(Assembly.GetExecutingAssembly().CodeBase.Substring(8)); compilerParameters.GenerateInMemory = Configuration.CompileToMemory; if (!Configuration.CompileToMemory) compilerParameters.OutputAssembly = Path.Combine(Configuration.TempAssemblyPath, "_" + Guid.NewGuid().ToString("n") + ".dll"); CompilerResults compilerResults = codeProvider.CompileAssemblyFromDom(compilerParameters, razorResults.GeneratedCode); if (compilerResults.Errors.Count > 0) { var compileErrors = new StringBuilder(); foreach (System.CodeDom.Compiler.CompilerError compileError in compilerResults.Errors) compileErrors.Append(String.Format(Resources.LineX0TColX1TErrorX2RN, compileError.Line, compileError.Column, compileError.ErrorText)); this.SetError(compileErrors.ToString() + "\r\n" + LastGeneratedCode); return null; } AssemblyCache.Add(compilerResults.CompiledAssembly.FullName, compilerResults.CompiledAssembly); return compilerResults.CompiledAssembly.FullName; } Think of the internal CreateHost() method as setting up the assembly generated from each template. Each template compiles into a separate assembly. It sets up namespaces, and assembly references, the base class used and the name and namespace for the generated class. ParseAndCompileTemplate() then calls the CreateHost() method to receive the template engine generator which effectively generates a CodeDom from the template – the template is turned into .NET code. The code generated from our earlier example looks something like this: //------------------------------------------------------------------------------ // <auto-generated> // This code was generated by a tool. // Runtime Version:4.0.30319.1 // // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ namespace RazorTest { using System; using System.Text; using System.Collections.Generic; using System.Linq; using System.IO; using System.Reflection; public class RazorTemplate : RazorHosting.RazorTemplateBase { #line hidden public RazorTemplate() { } public override void Execute() { WriteLiteral("Hello "); Write(Context.FirstName); WriteLiteral("! Your entry was entered on: "); Write(Context.Entered); WriteLiteral("\r\n\r\n"); // Code block: Update the host Windows Form passed in through the context Context.WinForm.Text = "Hello World from Razor at " + DateTime.Now.ToString(); WriteLiteral("\r\nAppDomain Id:\r\n "); Write(AppDomain.CurrentDomain.FriendlyName); WriteLiteral("\r\n \r\nAssembly:\r\n "); Write(Assembly.GetExecutingAssembly().FullName); WriteLiteral("\r\n\r\nCode based output: \r\n"); // Write output with Response object from code string output = string.Empty; for (int i = 0; i < 10; i++) { output += i.ToString() + " "; } } } } Basically the template’s body is turned into code in an Execute method that is called. Internally the template’s Write method is fired to actually generate the output. Note that the class inherits from RazorTemplateBase which is the generic parameter I used to specify the base class when creating an instance in my RazorEngine host: var engine = new RazorEngine<RazorTemplateBase>(); This template class must be provided and it must implement an Execute() and Write() method. Beyond that you can create any class you chose and attach your own properties. My RazorTemplateBase class implementation is very simple: public class RazorTemplateBase : MarshalByRefObject, IDisposable { /// <summary> /// You can pass in a generic context object /// to use in your template code /// </summary> public dynamic Context { get; set; } /// <summary> /// Class that generates output. Currently ultra simple /// with only Response.Write() implementation. /// </summary> public RazorResponse Response { get; set; } public object HostContainer {get; set; } public object Engine { get; set; } public RazorTemplateBase() { Response = new RazorResponse(); } public virtual void Write(object value) { Response.Write(value); } public virtual void WriteLiteral(object value) { Response.Write(value); } /// <summary> /// Razor Parser implements this method /// </summary> public virtual void Execute() {} public virtual void Dispose() { if (Response != null) { Response.Dispose(); Response = null; } } } Razor fills in the Execute method when it generates its subclass and uses the Write() method to output content. As you can see I use a RazorResponse() class here to generate output. This isn’t necessary really, as you could use a StringBuilder or StringWriter() directly, but I prefer using Response object so I can extend the Response behavior as needed. The RazorResponse class is also very simple and merely acts as a wrapper around a TextWriter: public class RazorResponse : IDisposable { /// <summary> /// Internal text writer - default to StringWriter() /// </summary> public TextWriter Writer = new StringWriter(); public virtual void Write(object value) { Writer.Write(value); } public virtual void WriteLine(object value) { Write(value); Write("\r\n"); } public virtual void WriteFormat(string format, params object[] args) { Write(string.Format(format, args)); } public override string ToString() { return Writer.ToString(); } public virtual void Dispose() { Writer.Close(); } public virtual void SetTextWriter(TextWriter writer) { // Close original writer if (Writer != null) Writer.Close(); Writer = writer; } } The Rendering Methods of RazorEngine At this point I’ve talked about the assembly generation logic and the template implementation itself. What’s left is that once you’ve generated the assembly is to execute it. The code to do this is handled in the various RenderXXX methods of the RazorEngine class. Let’s look at the lowest level one of these which is RenderTemplateFromAssembly() and a couple of internal support methods that handle instantiating and invoking of the generated template method: public string RenderTemplateFromAssembly( string assemblyId, string generatedNamespace, string generatedClass, object context, TextWriter outputWriter) { this.SetError(); Assembly generatedAssembly = AssemblyCache[assemblyId]; if (generatedAssembly == null) { this.SetError(Resources.PreviouslyCompiledAssemblyNotFound); return null; } string className = generatedNamespace + "." + generatedClass; Type type; try { type = generatedAssembly.GetType(className); } catch (Exception ex) { this.SetError(Resources.UnableToCreateType + className + ": " + ex.Message); return null; } // Start with empty non-error response (if we use a writer) string result = string.Empty; using(TBaseTemplateType instance = InstantiateTemplateClass(type)) { if (instance == null) return null; if (outputWriter != null) instance.Response.SetTextWriter(outputWriter); if (!InvokeTemplateInstance(instance, context)) return null; // Capture string output if implemented and return // otherwise null is returned if (outputWriter == null) result = instance.Response.ToString(); } return result; } protected virtual TBaseTemplateType InstantiateTemplateClass(Type type) { TBaseTemplateType instance = Activator.CreateInstance(type) as TBaseTemplateType; if (instance == null) { SetError(Resources.CouldnTActivateTypeInstance + type.FullName); return null; } instance.Engine = this; // If a HostContainer was set pass that to the template too instance.HostContainer = this.HostContainer; return instance; } /// <summary> /// Internally executes an instance of the template, /// captures errors on execution and returns true or false /// </summary> /// <param name="instance">An instance of the generated template</param> /// <returns>true or false - check ErrorMessage for errors</returns> protected virtual bool InvokeTemplateInstance(TBaseTemplateType instance, object context) { try { instance.Context = context; instance.Execute(); } catch (Exception ex) { this.SetError(Resources.TemplateExecutionError + ex.Message); return false; } finally { // Must make sure Response is closed instance.Response.Dispose(); } return true; } The RenderTemplateFromAssembly method basically requires the namespace and class to instantate and creates an instance of the class using InstantiateTemplateClass(). It then invokes the method with InvokeTemplateInstance(). These two methods are broken out because they are re-used by various other rendering methods and also to allow subclassing and providing additional configuration tasks to set properties and pass values to templates at execution time. In the default mode instantiation sets the Engine and HostContainer (discussed later) so the template can call back into the template engine, and the context is set when the template method is invoked. The various RenderXXX methods use similar code although they create the assemblies first. If you’re after potentially cashing assemblies the method is the one to call and that’s exactly what the two HostContainer classes do. More on that in a minute, but before we get into HostContainers let’s talk about AppDomain hosting and the like. Running Templates in their own AppDomain With the RazorEngine class above, when a template is parsed into an assembly and executed the assembly is created (in memory or on disk – you can configure that) and cached in the current AppDomain. In .NET once an assembly has been loaded it can never be unloaded so if you’re loading lots of templates and at some time you want to release them there’s no way to do so. If however you load the assemblies in a separate AppDomain that new AppDomain can be unloaded and the assemblies loaded in it with it. In order to host the templates in a separate AppDomain the easiest thing to do is to run the entire RazorEngine in a separate AppDomain. Then all interaction occurs in the other AppDomain and no further changes have to be made. To facilitate this there is a RazorEngineFactory which has methods that can instantiate the RazorHost in a separate AppDomain as well as in the local AppDomain. The host creates the remote instance and then hangs on to it to keep it alive as well as providing methods to shut down the AppDomain and reload the engine. Sounds complicated but cross-AppDomain invocation is actually fairly easy to implement. Here’s some of the relevant code from the RazorEngineFactory class. Like the RazorEngine this class is generic and requires a template base type in the generic class name: public class RazorEngineFactory<TBaseTemplateType> where TBaseTemplateType : RazorTemplateBase Here are the key methods of interest: /// <summary> /// Creates an instance of the RazorHost in a new AppDomain. This /// version creates a static singleton that that is cached and you /// can call UnloadRazorHostInAppDomain to unload it. /// </summary> /// <returns></returns> public static RazorEngine<TBaseTemplateType> CreateRazorHostInAppDomain() { if (Current == null) Current = new RazorEngineFactory<TBaseTemplateType>(); return Current.GetRazorHostInAppDomain(); } public static void UnloadRazorHostInAppDomain() { if (Current != null) Current.UnloadHost(); Current = null; } /// <summary> /// Instance method that creates a RazorHost in a new AppDomain. /// This method requires that you keep the Factory around in /// order to keep the AppDomain alive and be able to unload it. /// </summary> /// <returns></returns> public RazorEngine<TBaseTemplateType> GetRazorHostInAppDomain() { LocalAppDomain = CreateAppDomain(null); if (LocalAppDomain == null) return null; /// Create the instance inside of the new AppDomain /// Note: remote domain uses local EXE's AppBasePath!!! RazorEngine<TBaseTemplateType> host = null; try { Assembly ass = Assembly.GetExecutingAssembly(); string AssemblyPath = ass.Location; host = (RazorEngine<TBaseTemplateType>) LocalAppDomain.CreateInstanceFrom(AssemblyPath, typeof(RazorEngine<TBaseTemplateType>).FullName).Unwrap(); } catch (Exception ex) { ErrorMessage = ex.Message; return null; } return host; } /// <summary> /// Internally creates a new AppDomain in which Razor templates can /// be run. /// </summary> /// <param name="appDomainName"></param> /// <returns></returns> private AppDomain CreateAppDomain(string appDomainName) { if (appDomainName == null) appDomainName = "RazorHost_" + Guid.NewGuid().ToString("n"); AppDomainSetup setup = new AppDomainSetup(); // *** Point at current directory setup.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory; AppDomain localDomain = AppDomain.CreateDomain(appDomainName, null, setup); return localDomain; } /// <summary> /// Allow unloading of the created AppDomain to release resources /// All internal resources in the AppDomain are released including /// in memory compiled Razor assemblies. /// </summary> public void UnloadHost() { if (this.LocalAppDomain != null) { AppDomain.Unload(this.LocalAppDomain); this.LocalAppDomain = null; } } The static CreateRazorHostInAppDomain() is the key method that startup code usually calls. It uses a Current singleton instance to an instance of itself that is created cross AppDomain and is kept alive because it’s static. GetRazorHostInAppDomain actually creates a cross-AppDomain instance which first creates a new AppDomain and then loads the RazorEngine into it. The remote Proxy instance is returned as a result to the method and can be used the same as a local instance. The code to run with a remote AppDomain is simple: private RazorEngine<RazorTemplateBase> CreateHost() { if (this.Host != null) return this.Host; // Use Static Methods - no error message if host doesn't load this.Host = RazorEngineFactory<RazorTemplateBase>.CreateRazorHostInAppDomain(); if (this.Host == null) { MessageBox.Show("Unable to load Razor Template Host", "Razor Hosting", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); } return this.Host; } This code relies on a local reference of the Host which is kept around for the duration of the app (in this case a form reference). To use this you’d simply do: this.Host = CreateHost(); if (host == null) return; string result = host.RenderTemplate( this.txtSource.Text, new string[] { "System.Windows.Forms.dll", "Westwind.Utilities.dll" }, this.CustomContext); if (result == null) { MessageBox.Show(host.ErrorMessage, "Template Execution Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); return; } this.txtResult.Text = result; Now all templates run in a remote AppDomain and can be unloaded with simple code like this: RazorEngineFactory<RazorTemplateBase>.UnloadRazorHostInAppDomain(); this.Host = null; One Step further – Providing a caching ‘Runtime’ Once we can load templates in a remote AppDomain we can add some additional functionality like assembly caching based on application specific features. One of my typical scenarios is to render templates out of a scripts folder. So all templates live in a folder and they change infrequently. So a Folder based host that can compile these templates once and then only recompile them if something changes would be ideal. Enter host containers which are basically wrappers around the RazorEngine<t> and RazorEngineFactory<t>. They provide additional logic for things like file caching based on changes on disk or string hashes for string based template inputs. The folder host also provides for partial rendering logic through a custom template base implementation. There’s a base implementation in RazorBaseHostContainer, which provides the basics for hosting a RazorEngine, which includes the ability to start and stop the engine, cache assemblies and add references: public abstract class RazorBaseHostContainer<TBaseTemplateType> : MarshalByRefObject where TBaseTemplateType : RazorTemplateBase, new() { public RazorBaseHostContainer() { UseAppDomain = true; GeneratedNamespace = "__RazorHost"; } /// <summary> /// Determines whether the Container hosts Razor /// in a separate AppDomain. Seperate AppDomain /// hosting allows unloading and releasing of /// resources. /// </summary> public bool UseAppDomain { get; set; } /// <summary> /// Base folder location where the AppDomain /// is hosted. By default uses the same folder /// as the host application. /// /// Determines where binary dependencies are /// found for assembly references. /// </summary> public string BaseBinaryFolder { get; set; } /// <summary> /// List of referenced assemblies as string values. /// Must be in GAC or in the current folder of the host app/ /// base BinaryFolder /// </summary> public List<string> ReferencedAssemblies = new List<string>(); /// <summary> /// Name of the generated namespace for template classes /// </summary> public string GeneratedNamespace {get; set; } /// <summary> /// Any error messages /// </summary> public string ErrorMessage { get; set; } /// <summary> /// Cached instance of the Host. Required to keep the /// reference to the host alive for multiple uses. /// </summary> public RazorEngine<TBaseTemplateType> Engine; /// <summary> /// Cached instance of the Host Factory - so we can unload /// the host and its associated AppDomain. /// </summary> protected RazorEngineFactory<TBaseTemplateType> EngineFactory; /// <summary> /// Keep track of each compiled assembly /// and when it was compiled. /// /// Use a hash of the string to identify string /// changes. /// </summary> protected Dictionary<int, CompiledAssemblyItem> LoadedAssemblies = new Dictionary<int, CompiledAssemblyItem>(); /// <summary> /// Call to start the Host running. Follow by a calls to RenderTemplate to /// render individual templates. Call Stop when done. /// </summary> /// <returns>true or false - check ErrorMessage on false </returns> public virtual bool Start() { if (Engine == null) { if (UseAppDomain) Engine = RazorEngineFactory<TBaseTemplateType>.CreateRazorHostInAppDomain(); else Engine = RazorEngineFactory<TBaseTemplateType>.CreateRazorHost(); Engine.Configuration.CompileToMemory = true; Engine.HostContainer = this; if (Engine == null) { this.ErrorMessage = EngineFactory.ErrorMessage; return false; } } return true; } /// <summary> /// Stops the Host and releases the host AppDomain and cached /// assemblies. /// </summary> /// <returns>true or false</returns> public bool Stop() { this.LoadedAssemblies.Clear(); RazorEngineFactory<RazorTemplateBase>.UnloadRazorHostInAppDomain(); this.Engine = null; return true; } … } This base class provides most of the mechanics to host the runtime, but no application specific implementation for rendering. There are rendering functions but they just call the engine directly and provide no caching – there’s no context to decide how to cache and reuse templates. The key methods are Start and Stop and their main purpose is to start a new AppDomain (optionally) and shut it down when requested. The RazorFolderHostContainer – Folder Based Runtime Hosting Let’s look at the more application specific RazorFolderHostContainer implementation which is defined like this: public class RazorFolderHostContainer : RazorBaseHostContainer<RazorTemplateFolderHost> Note that a customized RazorTemplateFolderHost class template is used for this implementation that supports partial rendering in form of a RenderPartial() method that’s available to templates. The folder host’s features are: Render templates based on a Template Base Path (a ‘virtual’ if you will) Cache compiled assemblies based on the relative path and file time stamp File changes on templates cause templates to be recompiled into new assemblies Support for partial rendering using base folder relative pathing As shown in the startup examples earlier host containers require some startup code with a HostContainer tied to a persistent property (like a Form property): // The base path for templates - templates are rendered with relative paths // based on this path. HostContainer.TemplatePath = Path.Combine(Environment.CurrentDirectory, TemplateBaseFolder); // Default output rendering disk location HostContainer.RenderingOutputFile = Path.Combine(HostContainer.TemplatePath, "__Preview.htm"); // Add any assemblies you want reference in your templates HostContainer.ReferencedAssemblies.Add("System.Windows.Forms.dll"); // Start up the host container HostContainer.Start(); Once that’s done, you can render templates with the host container: // Pass the template path for full filename seleted with OpenFile Dialog // relativepath is: subdir\file.cshtml or file.cshtml or ..\file.cshtml var relativePath = Utilities.GetRelativePath(fileName, HostContainer.TemplatePath); if (!HostContainer.RenderTemplate(relativePath, Context, HostContainer.RenderingOutputFile)) { MessageBox.Show("Error: " + HostContainer.ErrorMessage); return; } webBrowser1.Navigate("file://" + HostContainer.RenderingOutputFile); The most critical task of the RazorFolderHostContainer implementation is to retrieve a template from disk, compile and cache it and then deal with deciding whether subsequent requests need to re-compile the template or simply use a cached version. Internally the GetAssemblyFromFileAndCache() handles this task: /// <summary> /// Internally checks if a cached assembly exists and if it does uses it /// else creates and compiles one. Returns an assembly Id to be /// used with the LoadedAssembly list. /// </summary> /// <param name="relativePath"></param> /// <param name="context"></param> /// <returns></returns> protected virtual CompiledAssemblyItem GetAssemblyFromFileAndCache(string relativePath) { string fileName = Path.Combine(TemplatePath, relativePath).ToLower(); int fileNameHash = fileName.GetHashCode(); if (!File.Exists(fileName)) { this.SetError(Resources.TemplateFileDoesnTExist + fileName); return null; } CompiledAssemblyItem item = null; this.LoadedAssemblies.TryGetValue(fileNameHash, out item); string assemblyId = null; // Check for cached instance if (item != null) { var fileTime = File.GetLastWriteTimeUtc(fileName); if (fileTime <= item.CompileTimeUtc) assemblyId = item.AssemblyId; } else item = new CompiledAssemblyItem(); // No cached instance - create assembly and cache if (assemblyId == null) { string safeClassName = GetSafeClassName(fileName); StreamReader reader = null; try { reader = new StreamReader(fileName, true); } catch (Exception ex) { this.SetError(Resources.ErrorReadingTemplateFile + fileName); return null; } assemblyId = Engine.ParseAndCompileTemplate(this.ReferencedAssemblies.ToArray(), reader); // need to ensure reader is closed if (reader != null) reader.Close(); if (assemblyId == null) { this.SetError(Engine.ErrorMessage); return null; } item.AssemblyId = assemblyId; item.CompileTimeUtc = DateTime.UtcNow; item.FileName = fileName; item.SafeClassName = safeClassName; this.LoadedAssemblies[fileNameHash] = item; } return item; } This code uses a LoadedAssembly dictionary which is comprised of a structure that holds a reference to a compiled assembly, a full filename and file timestamp and an assembly id. LoadedAssemblies (defined on the base class shown earlier) is essentially a cache for compiled assemblies and they are identified by a hash id. In the case of files the hash is a GetHashCode() from the full filename of the template. The template is checked for in the cache and if not found the file stamp is checked. If that’s newer than the cache’s compilation date the template is recompiled otherwise the version in the cache is used. All the core work defers to a RazorEngine<T> instance to ParseAndCompileTemplate(). The three rendering specific methods then are rather simple implementations with just a few lines of code dealing with parameter and return value parsing: /// <summary> /// Renders a template to a TextWriter. Useful to write output into a stream or /// the Response object. Used for partial rendering. /// </summary> /// <param name="relativePath">Relative path to the file in the folder structure</param> /// <param name="context">Optional context object or null</param> /// <param name="writer">The textwriter to write output into</param> /// <returns></returns> public bool RenderTemplate(string relativePath, object context, TextWriter writer) { // Set configuration data that is to be passed to the template (any object) Engine.TemplatePerRequestConfigurationData = new RazorFolderHostTemplateConfiguration() { TemplatePath = Path.Combine(this.TemplatePath, relativePath), TemplateRelativePath = relativePath, }; CompiledAssemblyItem item = GetAssemblyFromFileAndCache(relativePath); if (item == null) { writer.Close(); return false; } try { // String result will be empty as output will be rendered into the // Response object's stream output. However a null result denotes // an error string result = Engine.RenderTemplateFromAssembly(item.AssemblyId, context, writer); if (result == null) { this.SetError(Engine.ErrorMessage); return false; } } catch (Exception ex) { this.SetError(ex.Message); return false; } finally { writer.Close(); } return true; } /// <summary> /// Render a template from a source file on disk to a specified outputfile. /// </summary> /// <param name="relativePath">Relative path off the template root folder. Format: path/filename.cshtml</param> /// <param name="context">Any object that will be available in the template as a dynamic of this.Context</param> /// <param name="outputFile">Optional - output file where output is written to. If not specified the /// RenderingOutputFile property is used instead /// </param> /// <returns>true if rendering succeeds, false on failure - check ErrorMessage</returns> public bool RenderTemplate(string relativePath, object context, string outputFile) { if (outputFile == null) outputFile = RenderingOutputFile; try { using (StreamWriter writer = new StreamWriter(outputFile, false, Engine.Configuration.OutputEncoding, Engine.Configuration.StreamBufferSize)) { return RenderTemplate(relativePath, context, writer); } } catch (Exception ex) { this.SetError(ex.Message); return false; } return true; } /// <summary> /// Renders a template to string. Useful for RenderTemplate /// </summary> /// <param name="relativePath"></param> /// <param name="context"></param> /// <returns></returns> public string RenderTemplateToString(string relativePath, object context) { string result = string.Empty; try { using (StringWriter writer = new StringWriter()) { // String result will be empty as output will be rendered into the // Response object's stream output. However a null result denotes // an error if (!RenderTemplate(relativePath, context, writer)) { this.SetError(Engine.ErrorMessage); return null; } result = writer.ToString(); } } catch (Exception ex) { this.SetError(ex.Message); return null; } return result; } The idea is that you can create custom host container implementations that do exactly what you want fairly easily. Take a look at both the RazorFolderHostContainer and RazorStringHostContainer classes for the basic concepts you can use to create custom implementations. Notice also that you can set the engine’s PerRequestConfigurationData() from the host container: // Set configuration data that is to be passed to the template (any object) Engine.TemplatePerRequestConfigurationData = new RazorFolderHostTemplateConfiguration() { TemplatePath = Path.Combine(this.TemplatePath, relativePath), TemplateRelativePath = relativePath, }; which when set to a non-null value is passed to the Template’s InitializeTemplate() method. This method receives an object parameter which you can cast as needed: public override void InitializeTemplate(object configurationData) { // Pick up configuration data and stuff into Request object RazorFolderHostTemplateConfiguration config = configurationData as RazorFolderHostTemplateConfiguration; this.Request.TemplatePath = config.TemplatePath; this.Request.TemplateRelativePath = config.TemplateRelativePath; } With this data you can then configure any custom properties or objects on your main template class. It’s an easy way to pass data from the HostContainer all the way down into the template. The type you use is of type object so you have to cast it yourself, and it must be serializable since it will likely run in a separate AppDomain. This might seem like an ugly way to pass data around – normally I’d use an event delegate to call back from the engine to the host, but since this is running over AppDomain boundaries events get really tricky and passing a template instance back up into the host over AppDomain boundaries doesn’t work due to serialization issues. So it’s easier to pass the data from the host down into the template using this rather clumsy approach of set and forward. It’s ugly, but it’s something that can be hidden in the host container implementation as I’ve done here. It’s also not something you have to do in every implementation so this is kind of an edge case, but I know I’ll need to pass a bunch of data in some of my applications and this will be the easiest way to do so. Summing Up Hosting the Razor runtime is something I got jazzed up about quite a bit because I have an immediate need for this type of templating/merging/scripting capability in an application I’m working on. I’ve also been using templating in many apps and it’s always been a pain to deal with. The Razor engine makes this whole experience a lot cleaner and more light weight and with these wrappers I can now plug .NET based templating into my code literally with a few lines of code. That’s something to cheer about… I hope some of you will find this useful as well… Resources The examples and code require that you download the Razor runtimes. Projects are for Visual Studio 2010 running on .NET 4.0 Platform Installer 3.0 (install WebMatrix or MVC 3 for Razor Runtimes) Latest Code in Subversion Repository Download Snapshot of the Code Documentation (CHM Help File) © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  .NET  

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  • Cleaner HTML Markup with ASP.NET 4 Web Forms - Client IDs (VS 2010 and .NET 4.0 Series)

    - by ScottGu
    This is the sixteenth in a series of blog posts I’m doing on the upcoming VS 2010 and .NET 4 release. Today’s post is the first of a few blog posts I’ll be doing that talk about some of the important changes we’ve made to make Web Forms in ASP.NET 4 generate clean, standards-compliant, CSS-friendly markup.  Today I’ll cover the work we are doing to provide better control over the “ID” attributes rendered by server controls to the client. [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] Clean, Standards-Based, CSS-Friendly Markup One of the common complaints developers have often had with ASP.NET Web Forms is that when using server controls they don’t have the ability to easily generate clean, CSS-friendly output and markup.  Some of the specific complaints with previous ASP.NET releases include: Auto-generated ID attributes within HTML make it hard to write JavaScript and style with CSS Use of tables instead of semantic markup for certain controls (in particular the asp:menu control) make styling ugly Some controls render inline style properties even if no style property on the control has been set ViewState can often be bigger than ideal ASP.NET 4 provides better support for building standards-compliant pages out of the box.  The built-in <asp:> server controls with ASP.NET 4 now generate cleaner markup and support CSS styling – and help address all of the above issues.  Markup Compatibility When Upgrading Existing ASP.NET Web Forms Applications A common question people often ask when hearing about the cleaner markup coming with ASP.NET 4 is “Great - but what about my existing applications?  Will these changes/improvements break things when I upgrade?” To help ensure that we don’t break assumptions around markup and styling with existing ASP.NET Web Forms applications, we’ve enabled a configuration flag – controlRenderingCompatbilityVersion – within web.config that let’s you decide if you want to use the new cleaner markup approach that is the default with new ASP.NET 4 applications, or for compatibility reasons render the same markup that previous versions of ASP.NET used:   When the controlRenderingCompatbilityVersion flag is set to “3.5” your application and server controls will by default render output using the same markup generation used with VS 2008 and .NET 3.5.  When the controlRenderingCompatbilityVersion flag is set to “4.0” your application and server controls will strictly adhere to the XHTML 1.1 specification, have cleaner client IDs, render with semantic correctness in mind, and have extraneous inline styles removed. This flag defaults to 4.0 for all new ASP.NET Web Forms applications built using ASP.NET 4. Any previous application that is upgraded using VS 2010 will have the controlRenderingCompatbilityVersion flag automatically set to 3.5 by the upgrade wizard to ensure backwards compatibility.  You can then optionally change it (either at the application level, or scope it within the web.config file to be on a per page or directory level) if you move your pages to use CSS and take advantage of the new markup rendering. Today’s Cleaner Markup Topic: Client IDs The ability to have clean, predictable, ID attributes on rendered HTML elements is something developers have long asked for with Web Forms (ID values like “ctl00_ContentPlaceholder1_ListView1_ctrl0_Label1” are not very popular).  Having control over the ID values rendered helps make it much easier to write client-side JavaScript against the output, makes it easier to style elements using CSS, and on large pages can help reduce the overall size of the markup generated. New ClientIDMode Property on Controls ASP.NET 4 supports a new ClientIDMode property on the Control base class.  The ClientIDMode property indicates how controls should generate client ID values when they render.  The ClientIDMode property supports four possible values: AutoID—Renders the output as in .NET 3.5 (auto-generated IDs which will still render prefixes like ctrl00 for compatibility) Predictable (Default)— Trims any “ctl00” ID string and if a list/container control concatenates child ids (example: id=”ParentControl_ChildControl”) Static—Hands over full ID naming control to the developer – whatever they set as the ID of the control is what is rendered (example: id=”JustMyId”) Inherit—Tells the control to defer to the naming behavior mode of the parent container control The ClientIDMode property can be set directly on individual controls (or within container controls – in which case the controls within them will by default inherit the setting): Or it can be specified at a page or usercontrol level (using the <%@ Page %> or <%@ Control %> directives) – in which case controls within the pages/usercontrols inherit the setting (and can optionally override it): Or it can be set within the web.config file of an application – in which case pages within the application inherit the setting (and can optionally override it): This gives you the flexibility to customize/override the naming behavior however you want. Example: Using the ClientIDMode property to control the IDs of Non-List Controls Let’s take a look at how we can use the new ClientIDMode property to control the rendering of “ID” elements within a page.  To help illustrate this we can create a simple page called “SingleControlExample.aspx” that is based on a master-page called “Site.Master”, and which has a single <asp:label> control with an ID of “Message” that is contained with an <asp:content> container control called “MainContent”: Within our code-behind we’ll then add some simple code like below to dynamically populate the Label’s Text property at runtime:   If we were running this application using ASP.NET 3.5 (or had our ASP.NET 4 application configured to run using 3.5 rendering or ClientIDMode=AutoID), then the generated markup sent down to the client would look like below: This ID is unique (which is good) – but rather ugly because of the “ct100” prefix (which is bad). Markup Rendering when using ASP.NET 4 and the ClientIDMode is set to “Predictable” With ASP.NET 4, server controls by default now render their ID’s using ClientIDMode=”Predictable”.  This helps ensure that ID values are still unique and don’t conflict on a page, but at the same time it makes the IDs less verbose and more predictable.  This means that the generated markup of our <asp:label> control above will by default now look like below with ASP.NET 4: Notice that the “ct100” prefix is gone. Because the “Message” control is embedded within a “MainContent” container control, by default it’s ID will be prefixed “MainContent_Message” to avoid potential collisions with other controls elsewhere within the page. Markup Rendering when using ASP.NET 4 and the ClientIDMode is set to “Static” Sometimes you don’t want your ID values to be nested hierarchically, though, and instead just want the ID rendered to be whatever value you set it as.  To enable this you can now use ClientIDMode=static, in which case the ID rendered will be exactly the same as what you set it on the server-side on your control.  This will cause the below markup to be rendered with ASP.NET 4: This option now gives you the ability to completely control the client ID values sent down by controls. Example: Using the ClientIDMode property to control the IDs of Data-Bound List Controls Data-bound list/grid controls have historically been the hardest to use/style when it comes to working with Web Form’s automatically generated IDs.  Let’s now take a look at a scenario where we’ll customize the ID’s rendered using a ListView control with ASP.NET 4. The code snippet below is an example of a ListView control that displays the contents of a data-bound collection — in this case, airports: We can then write code like below within our code-behind to dynamically databind a list of airports to the ListView above: At runtime this will then by default generate a <ul> list of airports like below.  Note that because the <ul> and <li> elements in the ListView’s template are not server controls, no IDs are rendered in our markup: Adding Client ID’s to Each Row Item Now, let’s say that we wanted to add client-ID’s to the output so that we can programmatically access each <li> via JavaScript.  We want these ID’s to be unique, predictable, and identifiable. A first approach would be to mark each <li> element within the template as being a server control (by giving it a runat=server attribute) and by giving each one an id of “airport”: By default ASP.NET 4 will now render clean IDs like below (no ctl001-like ids are rendered):   Using the ClientIDRowSuffix Property Our template above now generates unique ID’s for each <li> element – but if we are going to access them programmatically on the client using JavaScript we might want to instead have the ID’s contain the airport code within them to make them easier to reference.  The good news is that we can easily do this by taking advantage of the new ClientIDRowSuffix property on databound controls in ASP.NET 4 to better control the ID’s of our individual row elements. To do this, we’ll set the ClientIDRowSuffix property to “Code” on our ListView control.  This tells the ListView to use the databound “Code” property from our Airport class when generating the ID: And now instead of having row suffixes like “1”, “2”, and “3”, we’ll instead have the Airport.Code value embedded within the IDs (e.g: _CLE, _CAK, _PDX, etc): You can use this ClientIDRowSuffix approach with other databound controls like the GridView as well. It is useful anytime you want to program row elements on the client – and use clean/identified IDs to easily reference them from JavaScript code. Summary ASP.NET 4 enables you to generate much cleaner HTML markup from server controls and from within your Web Forms applications.  In today’s post I covered how you can now easily control the client ID values that are rendered by server controls.  In upcoming posts I’ll cover some of the other markup improvements that are also coming with the ASP.NET 4 release. Hope this helps, Scott

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