Gaurav » open source http://allyourcodearebelongto.me/blog All About Everything Sun, 23 Nov 2008 19:44:48 +0000 http://wordpress.org/?v=2.9.1 en hourly 1 Using RubyAmf for creating a CRUD application in Rails http://allyourcodearebelongto.me/blog/2008/11/12/using-rubyamf-for-creating-a-crud-application-in-rails/ http://allyourcodearebelongto.me/blog/2008/11/12/using-rubyamf-for-creating-a-crud-application-in-rails/#comments Wed, 12 Nov 2008 11:35:45 +0000 Gaurav http://allyourcodearebelongto.me/blog/2008/11/12/using-rubyamf-for-creating-a-crud-application-in-rails/ CRUD applications can be easily created using Ruby on Rails as the backend and Flex as the frontend app using the XML format as demonstrated here.

Another way to create such applications is using the AMF protocol which is optimized for network communications and stores objects in binary format so consumes less bandwidth. Another compelling reason for using this library is that it doesn’t feel like a hack as it integrates very nicely with Rails :)

The Ruby port of this protocol known as RubyAmf can be downloaded from from here. More information about this protocol can be found here.

Lets start making the application.

 

Create a Rails Application:

   1: > rails amf_demo

This will create a rails application. Please note that I am using Rails 2.1.2 for this example and it is not tested on any other Rails version.

Generate a scaffold:

   1: > ruby script/generate scaffold blog_post title:string body:text

Create Tables and run Migrations:

   1: > rake db:migrate

   1: > rake db:create

Install the RubyAmf Plugin:

 

 

Step 1: Lets try if everything is working fine by creating a new Flex Project

Open Flex Builder and create a new Flex Project

image

 

Select all the default options and click Finish.

Now right click on the project you just created in Flex Navigator and select Properties. The Flex Build Path should have the following settings:

image

The Output folder will point to the public folder of the amf_demo Rails application and the Output folder URL will point to the Rails server which in  my case is localhost on port 80.

 

Start the Rails server:

   1: > ruby script/server -p 80

And start the project in Debugging mode. The Web Browser will show up a blank page.

image

 

Some helper files can be downloaded from the RubyAmf project site here

These are located in the “flash9_helloworld\flash9_helloworld\app\flash\org” of the archive.

Or just download the extracted archive from here. Put these files in the “src” directory of your Flex project. So the “src” folder should now have a folder with name “org” inside it.

Fetching Data off the server:

Firstly we will need to update the “BlogPostsController” so that it can generate amf content. It can be done by modifying the the index action to following:

   1: def index
   2:   @blog_posts = BlogPost.find(:all)
   3:  
   4:   respond_to do |format|
   5:     format.html # index.html.erb
   6:     format.amf  { render :amf => @blog_posts }
   7:     format.xml  { render :xml => @blog_posts }
   8:   end
   9: end

 

Now change the main mxml file of the Flex project to include code that fetches data off the server. In the current project the name of the file should be “amf_demo.mxml”

   1: <?xml version="1.0" encoding="utf-8"?>
   2: <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical"
   3:     creationComplete="creationCompleteEvent(event)" xmlns:ssr="org.rubyamf.remoting.ssr.*">
   4:     <mx:Script>
   5:         <![CDATA[
   6:             import org.rubyamf.remoting.ssr.FaultEvent;
   7:             import org.rubyamf.remoting.ssr.ResultEvent;
   8:             import org.rubyamf.remoting.ssr.RemotingService;
   9:             private function creationCompleteEvent(evemt:Event):void{
  10:                 var service:RemotingService = new RemotingService("/rubyamf/gateway", "BlogPostsController");
  11:                 service.index([], onIndexResult, onFault);
  12:             }
  13:             private function onIndexResult(event:ResultEvent):void{
  14:                 trace(event.result);
  15:             }
  16:             private function onFault(event:FaultEvent):void{
  17:                 trace(event.fault);
  18:             }
  19:         ]]>
  20:     </mx:Script>
  21: </mx:Application>

 

The main component of this code is the “RemoteService” class and in the above given example it is invoking the index action on the server. On running this example the onIndexResult should be triggered and the debug window should show all the BlogPosts in the db. You can also put  a break-pointer to analyze the results.

image

One thing you will notice here is that the output result are plain ActionScript Objects. In the next step I will show how to map these objects to an ActionScript class.

Download code for upto this point:

  1. Rails Code
  2. Flex Code

 

Step 2: Mapping results to Action Script classes

Generate Mappings:

In the project root directory run the following command.

   1: > ruby script/generate rubyamf_mappings

Copy the output of this command to config/rubyamf_config.rb in the Rails project and now this file should look like this after some modifications:

   1: require 'app/configuration'
   2: module RubyAMF
   3:   module Configuration
   4:     #set the service path used in all requests
   5:     # RubyAMF::App::RequestStore.service_path = File.expand_path(RAILS_ROOT) + '/app/controllers'
   6:  
   7:     # => CLASS MAPPING CONFIGURATION
   8:     
   9:     # => Global Property Ignoring
  10:     # By putting attribute names into this array, you opt in to globally ignore these properties on incoming objects.
  11:     # If you want to ignore specific properties on certain objects, use the :ignore_fields property in a 
  12:     # Class Mapping definition (see CLASS MAPPING DEFINITIONS)
  13:     # ClassMappings.ignore_fields = ['created_at','created_on','updated_at','updated_on']
  14:   
  15:     # => Case Translations
  16:     # Most actionscript uses camelCase instead of snake_case. Set ClassMappings.translate_case to true if want translations to occur.
  17:     # The translations only occur on object properties
  18:     # An incoming property like: myProperty gets turned into my_property
  19:     # An outgoing property like my_property gets turned into myProperty
  20:     ClassMappings.translate_case = true
  21:   
  22:     # => Force Active Record Ids
  23:     # includes the id field for activerecord objects even if you don't specify it when using custom attributes. This is important for deserialization
  24:     # where ids are needed to keep active record association integrity.
  25:     # ClassMappings.force_active_record_ids = true
  26:     
  27:     # => Hash key access
  28:     # You can choose how keys in hashes are created. As :string, :symbol, or :indifferent. 
  29:     # :string creates keys as hash['key']
  30:     # :symbol creates keys as hash[:key]
  31:     # :indifferent uses rails HashWithIndifferentAccess so you can use hash[:key] of hash['key']
  32:     # There are performance issues with HashWithIndifferentAccess. Use :symbol or :string for best performance.
  33:     # The default is :symbol
  34:     ClassMappings.hash_key_access = :string
  35:     
  36:     # => Assume Class Types
  37:     # This tells RubyAMF to assume class type transfers. So when you register a class Alias from Flash or Flex like this:
  38:     # Flash::   fl.net.registerClassAlias('User',User)
  39:     # Flex::    [RemoteClass(alias='User')]
  40:     # RubyAMF will automagically convert it to a User active record without you having to create a class mapping.
  41:     # This also works with non active record class mappings. See the wiki on the google code page for a downloadable example.
  42:     # ClassMappings.assume_types = false
  43:     
  44:     # => Class Mapping Definitions
  45:     # A Class Mapping definition conists of at least these two properties:
  46:     # :actionscript   # The incoming action script class to watch for
  47:     # :ruby           # The ruby class to turn it into
  48:     #
  49:     # => Optional value object properties:
  50:     # :type           # Used to spectify the type of VO, valid options are 'active_record', 'custom',  (or don't specify at all)
  51:     # :associations   # Specify which associations to read on the active record (only applies to active records)
  52:     # :attributes     # Specifically which attributes to include in the serialization
  53:     # :methods        # An array of methods to call and place values in a similarly named attribute on the Actionscript Object (outgoing, or Rails => Actionscript only)
  54:     # :ignore_fields  # An array of field names you want to ignore on incoming classes
  55:     #
  56:     # If you are using ActiveRecord VO's you do not need to specify a fully qualified class path to the model, you can just define the class name, 
  57:     # EX: ClassMappings.register(:actionscript => 'vo.Person', :ruby => 'Person', :type => 'active_record')
  58:     #
  59:     # If you are using custom VO's you would need to specify the fully qualified class path to the file
  60:     # EX: ClassMappings.register(:actionscript => 'vo.Person', :ruby => 'org.mypackage.Person')
  61:     #
  62:     # ClassMappings.register(:actionscript => 'Person', :ruby => 'Person', :type => 'active_record', :attributes => ["id", "address_id"])
  63:     # ClassMappings.register(:actionscript => 'User', :ruby => 'User', :type => 'active_record', :associations=> ["addresses", "credit_cards"])
  64:     # ClassMappings.register(:actionscript => 'Address', :ruby => 'Address', :type => 'active_record')
  65:     # ClassMappings.register(:actionscript => 'User', :ruby => 'User', :type => 'active_record', :associations=> ["addresses", "credit_cards"], :methods => ["friends"])
  66:     #
  67:     # => Class Mapping Scope (Advanced Usage)
  68:     # You can also specify a class mapping scope if you want. For example, lets say you need certain attributes for a book when you are viewing a book
  69:     # in flex as opposed to editing a book (where you would need more parameters). You can define a scope mapping parameter for ":attributes"
  70:     # or for ":associations." You're mapping would look something like this.
  71:     # ClassMappings.register(
  72:     #   :actionscript  => 'com.mixbook.vo.books.BookVO',      
  73:     #   :ruby          => 'Book',      
  74:     #   :type          => 'active_record',
  75:     #   :associations  => ["access_info", "pages", "page_ratio"],  
  76:     #   :attributes    => {:viewing => ["description", "title"], :editing => ["id","published_at","theme_id"] }    <=== notice the hash instead of an array
  77:     #
  78:     # Now, to call the class mapping scope of editing (you are sending objects to the editing application), your controller call would look like this:
  79:     # EX: render :amf => book, :class_mapping_scope => :editing
  80:     #
  81:     # You can also specify a default scope to use. If you don't set this and you don't specify a class mapping scope on an attribute or association, then 
  82:     # it will not have a scope to use and will not add any attributes or associations (whichever it cant match) to that association.
  83:     # ClassMappings.default_mapping_scope = :viewing
  84:   
  85:     # => Date Conversion
  86:     # Incoming dates from Flash by default are Time objects, this can conver to DateTime if needed
  87:     # ClassMappings.use_ruby_date_time = false
  88:   
  89:     # => Use Array Collection
  90:     # By setting this to true, you opt in to using array collections for all the arrays generated by the body of your request.
  91:     # Note: This only works for amf3 with Remote Object, NOT with Net Connection.
  92:     # ClassMappings.use_array_collection = false
  93:   
  94:     # => Check for Associations
  95:     # Enabling this will automagically pick up eager loaded association data on objects returned through RubyAMF.
  96:     # If this is disabled, you will need to specify any associations you DO want picked up in the ClassMapping
  97:     # ClassMappings.check_for_associations = true
  98:     
  99:     # => NAMED PARAMETER MAPPING CONFIGURATION
 100:     
 101:     #=> Always Put Remoting Parameters into the "params" hash
 102:     # If set to true, arguments from Flash/Flex will come in to the controllers as params[0], params[1], etc.. This is especally useful if you are sending huge objects
 103:     # from Flex into Ruby so it doesnt eat up all your output window with outputting the params in the controller/action header information while in dev mode.
 104:     # Even if its set to false, if you specify specific ParameterMappings, those will still get entered as the param keys you specify. Likewise, you
 105:     # always have access to the parameters from rubyamf in your controller by calling rubyamf_params[0], rubyamf_params[1], etc regardless of
 106:     # if it this is set or not.
 107:     # ParameterMappings.always_add_to_params = true
 108:      
 109:     # => Return Top Level Hash
 110:     # For those scaffolding users out there, who want the top-level object to come as a hash so scaffolding works out of the box.
 111:     ParameterMappings.scaffolding = true
 112:   
 113:     # => Incoming Remoting Parameter Mappings
 114:     # Incoming Remoting Parameter mappings allow you to map an incoming requests parameters into rails' params hash
 115:     #
 116:     # Here's an example:
 117:     # ParameterMappings.register(:controller => :UserController, :action => :find_friend, :params => { :friend => "[0]['friend']" })
 118:     ClassMappings.register(
 119:       :actionscript  => 'BlogPost',
 120:       :ruby          => 'BlogPost',
 121:       :type          => 'active_record',
 122:       :attributes    => ["id", "title", "body", "created_at", "updated_at"])
 123:   end
 124: end

 

Create a new ActionScript Class with name “BlogPost” and it should have the following code:

   1: package
   2: {
   3:     [RemoteClass(alias='BlogPost')]
   4:     public class BlogPost
   5:     {
   6:         public var id:int;
   7:         public var title:String; 
   8:         public var body:String;
   9:     }
  10: }

 

And modify the “amf_demo.mxml” file to include this file. Also change the “service.index” method to to use this file:

   1: service.index([], onIndexResult, onFault, BlogPost);

 

Now when you debug and check the output in the “onIndexResult” it should look like:

image

 

Download code for upto this point:

  1. Rails Code
  2. Flex Code

 

Step 3: Creating a UI

Change the amf_demo.mxml to the following code.

   1: <?xml version="1.0" encoding="utf-8"?>
   2: <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical"
   3:     creationComplete="creationCompleteEvent(event)" xmlns:ssr="org.rubyamf.remoting.ssr.*">
   4:     <mx:Script>
   5:         <![CDATA[
   6:             import mx.collections.ArrayCollection;
   7:             import org.rubyamf.remoting.ssr.FaultEvent;
   8:             import org.rubyamf.remoting.ssr.ResultEvent;
   9:             import org.rubyamf.remoting.ssr.RemotingService;
  10:             [Bindable]
  11:             private var blogPosts:ArrayCollection;
  12:             
  13:             private function creationCompleteEvent(evemt:Event):void{
  14:                 var service:RemotingService = new RemotingService("/rubyamf/gateway", "BlogPostsController");
  15:                 service.index([], onIndexResult, onFault, BlogPost);
  16:             }
  17:             private function onIndexResult(event:ResultEvent):void{
  18:                 blogPosts = new ArrayCollection(event.result as Array);
  19:             }
  20:             private function onFault(event:FaultEvent):void{
  21:                 trace(event.fault);
  22:             }
  23:         ]]>
  24:     </mx:Script>
  25:     
  26:     <mx:List width="300" dataProvider="{blogPosts}" labelField="title" />
  27: </mx:Application>

Here the result of the onIndexResult event is bound to a list to Display all the blog posts in the database. This is probably the simplest way to do this. The output will look like:

image

Download code for upto this point:

  1. Rails Code (no changes)
  2. Flex Code

 

Step 4: Refactoring Completing CRUD

As a single page can display more than one list, it would make more sense if we move the code into separate files for each list. So I will be moving all the BlogPost related code in the “BlogPost” class.

So the “BlogPost.as” will look like:

   1: package
   2: {
   3:     import mx.collections.ArrayCollection;
   4:     import org.rubyamf.remoting.ssr.FaultEvent;
   5:     import org.rubyamf.remoting.ssr.ResultEvent;
   6:     import org.rubyamf.remoting.ssr.RemotingService;
   7:             
   8:     [RemoteClass(alias='BlogPost')]
   9:     public class BlogPost
  10:     {
  11:         public var id:int;
  12:         public var title:String; 
  13:         public var body:String;
  14:         
  15:         [Bindable]
  16:         public static var blogPosts:ArrayCollection;
  17:         private var service:RemotingService = new RemotingService("/rubyamf/gateway", "BlogPostsController");
  18:         
  19:         public static function getBlogPosts():void{
  20:             (new BlogPost()).getBlogPosts();
  21:         }
  22:         private function getBlogPosts():void{
  23:             service.index([], onIndexResult, onFault, BlogPost);
  24:         }
  25:         private function onIndexResult(event:ResultEvent):void{
  26:             BlogPost.blogPosts = new ArrayCollection(event.result as Array);
  27:         }
  28:         private function onFault(event:FaultEvent):void{
  29:             trace(event.fault);
  30:         }
  31:     }
  32: }

 

And “amf_demo.mxml”:

   1: <?xml version="1.0" encoding="utf-8"?>
   2: <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical"
   3:     creationComplete="creationCompleteEvent(event)" xmlns:ssr="org.rubyamf.remoting.ssr.*">
   4:     <mx:Script>
   5:         <![CDATA[
   6:             private function creationCompleteEvent(evemt:Event):void{
   7:                 BlogPost.getBlogPosts();
   8:             }
   9:         ]]>
  10:     </mx:Script>
  11:     <mx:List width="300" dataProvider="{BlogPost.blogPosts}" labelField="title" />
  12: </mx:Application>

 

Download code for upto this point:

  1. Rails Code (no changes)
  2. Flex Code

 

Step 5: Completing CRUD

After further refactoring the code and adding methods for creating/editing/destroying the code looks like:

  • amf_demo.mxml 
   1: <?xml version="1.0" encoding="utf-8"?>
   2: <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical"
   3:     creationComplete="creationCompleteEvent(event)" xmlns:ssr="org.rubyamf.remoting.ssr.*">
   4:     <mx:Script>
   5:         <![CDATA[
   6:             private function creationCompleteEvent(event:Event):void{
   7:                 BlogPost.parentContainer = this;
   8:                 BlogPost.getBlogPosts();
   9:             }
  10:             private function blogPostCreateEvent(event:Event):void{
  11:                 (new BlogPost(title.text, body.text)).create();
  12:             }
  13:             private function blogPostUpdateEvent(event:Event):void{
  14:                 var blogPost:BlogPost     = currentPost();
  15:                 blogPost.title             = title.text;
  16:                 blogPost.body              = body.text; 
  17:                 blogPost.update();
  18:             }
  19:             private function blogPostdestroyEvent(event:Event):void{
  20:                 currentPost().destroy();
  21:             }
  22:             private function currentPost():BlogPost{
  23:                 return blogPosts.selectedItem as BlogPost;
  24:             }
  25:         ]]>
  26:     </mx:Script>
  27:     <mx:List width="300" dataProvider="{BlogPost.blogPosts}" labelField="title" id="blogPosts"/>
  28:     <mx:Panel layout="vertical" paddingBottom="5" paddingLeft="5" paddingRight="5" paddingTop="5">
  29:         <mx:HBox width="100%">
  30:             <mx:Label text="Post Title" width="60"/>
  31:             <mx:TextInput id="title" text="{blogPosts.selectedItem.title}"/>
  32:         </mx:HBox>
  33:         <mx:HBox width="100%">
  34:             <mx:Label text="Post Body" width="60" />
  35:             <mx:TextArea id="body" text="{blogPosts.selectedItem.body}"/>
  36:         </mx:HBox>
  37:         <mx:ControlBar>
  38:             <mx:Button label="Create" click="blogPostCreateEvent(event)" />
  39:             <mx:Button label="Update" click="blogPostUpdateEvent(event)" />
  40:             <mx:Button label="Destroy" click="blogPostdestroyEvent(event)" />
  41:         </mx:ControlBar>
  42:     </mx:Panel>
  43: </mx:Application>

  • BlogPost.as 
   1: package
   2: {
   3:     import mx.collections.ArrayCollection;
   4:     import mx.core.UIComponent;
   5:     
   6:     import org.rubyamf.remoting.ssr.FaultEvent;
   7:     import org.rubyamf.remoting.ssr.RemotingService;
   8:     import org.rubyamf.remoting.ssr.ResultEvent;
   9:             
  10:     [RemoteClass(alias='BlogPost')]
  11:     public class BlogPost
  12:     {
  13:         public var id:int;
  14:         public var title:String; 
  15:         public var body:String;
  16:         public var simpleErrors:Object;
  17:         
  18:         [Bindable]
  19:         public static var blogPosts:ArrayCollection;
  20:         public static var parentContainer:UIComponent;
  21:         private var service:RemotingService = new RemotingService("/rubyamf/gateway", "BlogPostsController");
  22:         
  23:         public function BlogPost(title:String = "", body:String = ""){
  24:             this.title = title;
  25:             this.body  = body;
  26:         }
  27:         // index methods
  28:         public static function getBlogPosts():void{
  29:             (new BlogPost()).getBlogPosts();
  30:         }
  31:         private function getBlogPosts():void{
  32:             service.index([], onIndexResult, onFault, BlogPost);
  33:         }
  34:         private function onIndexResult(event:ResultEvent):void{
  35:             BlogPost.blogPosts = new ArrayCollection(event.result as Array);
  36:         }
  37:         // create methods
  38:         public function create():void{
  39:             service.create([this], onCreateResult, onFault, BlogPost);
  40:         }
  41:         private function onCreateResult(event:ResultEvent):void{
  42:             var blogPost:BlogPost = event.result as BlogPost;
  43:             if(BlogPost.count(blogPost.simpleErrors) == 0)
  44:                 BlogPost.blogPosts.addItem(blogPost);
  45:             else
  46:                 showErrors(blogPost.simpleErrors);
  47:         }
  48:         // update methods
  49:         public function update():void{
  50:             service.update([this], onUpdateResult, onFault, BlogPost);
  51:         }
  52:         private function onUpdateResult(event:ResultEvent):void{
  53:             var blogPost:BlogPost = event.result as BlogPost;
  54:             if(BlogPost.count(blogPost.simpleErrors) == 0)
  55:                 BlogPost.blogPosts[BlogPost.blogPosts.getItemIndex(this)] = blogPost;
  56:             else
  57:                 showErrors(blogPost.simpleErrors);
  58:         }
  59:         // update methods
  60:         public function destroy():void{
  61:             service.destroy([this], onDestroyResult, onFault, BlogPost);
  62:         }
  63:         private function onDestroyResult(event:ResultEvent):void{
  64:             var blogPost:BlogPost = event.result as BlogPost;
  65:             BlogPost.blogPosts.removeItemAt(BlogPost.blogPosts.getItemIndex(this));
  66:         }
  67:         
  68:         // common methods
  69:         private function showErrors(errors:Object):void{
  70:             for(var error:String in errors){
  71:                 var field:UIComponent =  parentContainer[error] as UIComponent;
  72:                 field.errorString = (errors[error] as Array).join('\r');
  73:             }
  74:         }
  75:         private static function count(object:Object):int{
  76:             var i:int = i;
  77:             for(var obj:* in object) i++;
  78:             return i;
  79:         }
  80:         private function onFault(event:FaultEvent):void{
  81:             trace(event.fault);
  82:         }
  83:     }
  84: }

 

  • BlogPostsController 
   1: class BlogPostsController < ApplicationController
   2:   before_filter :filter_attributes, :only=> [:create, :update]
   3:  
   4:   def filter_attributes
   5:     params[:blog_post] && params[:blog_post][:attributes] && params[:blog_post] = params[:blog_post][:attributes]
   6:   end
   7:   
   8:   # GET /blog_posts
   9:   # GET /blog_posts.xml
  10:   def index
  11:     @blog_posts = BlogPost.find(:all)
  12:  
  13:     respond_to do |format|
  14:       format.html # index.html.erb
  15:       format.amf  { render :amf => @blog_posts }
  16:       format.xml  { render :xml => @blog_posts }
  17:     end
  18:   end
  19:   
  20:   # GET /blog_posts/1
  21:   # GET /blog_posts/1.xml
  22:   def show
  23:     @blog_post = BlogPost.find(params[:id])
  24:  
  25:     respond_to do |format|
  26:       format.html # show.html.erb
  27:       format.xml  { render :xml => @blog_post }
  28:     end
  29:   end
  30:  
  31:   # GET /blog_posts/new
  32:   # GET /blog_posts/new.xml
  33:   def new
  34:     @blog_post = BlogPost.new
  35:  
  36:     respond_to do |format|
  37:       format.html # new.html.erb
  38:       format.xml  { render :xml => @blog_post }
  39:     end
  40:   end
  41:  
  42:   # GET /blog_posts/1/edit
  43:   def edit
  44:     @blog_post = BlogPost.find(params[:id])
  45:   end
  46:  
  47:   # POST /blog_posts
  48:   # POST /blog_posts.xml
  49:   def create
  50:     @blog_post = BlogPost.new(params[:blog_post])
  51:  
  52:     respond_to do |format|
  53:       if @blog_post.save
  54:         flash[:notice] = 'BlogPost was successfully created.'
  55:         format.html { redirect_to(@blog_post) }
  56:         format.amf  { render :amf => @blog_post }
  57:         format.xml  { render :xml => @blog_post, :status => :created, :location => @blog_post }
  58:       else
  59:         format.html { render :action => "new" }
  60:         format.amf  { render :amf => @blog_post }
  61:         format.xml  { render :xml => @blog_post.errors, :status => :unprocessable_entity }
  62:       end
  63:     end
  64:   end
  65:  
  66:   # PUT /blog_posts/1
  67:   # PUT /blog_posts/1.xml
  68:   def update
  69:     @blog_post = BlogPost.find(params[:id])
  70:  
  71:     respond_to do |format|
  72:       if @blog_post.update_attributes(params[:blog_post])
  73:         flash[:notice] = 'BlogPost was successfully updated.'
  74:         format.html { redirect_to(@blog_post) }
  75:         format.amf  { render :amf => @blog_post }
  76:         format.xml  { head :ok }
  77:       else
  78:         format.html { render :action => "edit" }
  79:         format.amf  { render :amf => @blog_post }
  80:         format.xml  { render :xml => @blog_post.errors, :status => :unprocessable_entity }
  81:       end
  82:     end
  83:   end
  84:  
  85:   # DELETE /blog_posts/1
  86:   # DELETE /blog_posts/1.xml
  87:   def destroy
  88:     @blog_post = BlogPost.find(params[:id])
  89:     @blog_post.destroy
  90:  
  91:     respond_to do |format|
  92:       format.html { redirect_to(blog_posts_url) }
  93:       format.amf  { render :amf => @blog_post }
  94:       format.xml  { head :ok }
  95:     end
  96:   end
  97: end

Please note the before filter in the rails controller which is converting the params in appropriate format so that rest of the code continues to work seamlessly.

 

Here is what the output looks like when you run the application

image

 

Download code for upto this point:

  1. Rails Code
  2. Flex Code

 

So the steps taken in completing this application were:

  1. Creating a Rails app
  2. Install RubyAmf plugin
  3. Configure the RubyAmf plugin
  4. Create a Flex app
  5. Install the appropriate libraries in it
  6. Create and refactor code

 

Questions and comments are welcome :)

]]> http://allyourcodearebelongto.me/blog/2008/11/12/using-rubyamf-for-creating-a-crud-application-in-rails/feed/ 8 Compiling and Installing GIT on windows under cygwin http://allyourcodearebelongto.me/blog/2008/04/11/compiling-and-installing-git-on-windows-under-cygwin/ http://allyourcodearebelongto.me/blog/2008/04/11/compiling-and-installing-git-on-windows-under-cygwin/#comments Fri, 11 Apr 2008 19:56:10 +0000 Gaurav http://techblogging.wordpress.com/2008/04/11/installing-git-on-windows/ Using GIT was one of the requirements of one of the project that I am doing. Here is how I installed GIT on Windows.

So What is GIT?

The supplied documentation of GIT says that:

Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.

Here is the link for the wikipedia entry.

Where can I download GIT?

Here is the link.

Before following the given steps you will need to install cygwin on your system, and add its bin directory to the system path (so that all the cygwin commands are available from inside the command prompt).

So after installing cygwin run setup.exe inside the cygwin installation folder and make sure the following modules are installed.

  1. make
  2. gcc c anc c++ compilers
  3. openssl-devel
  4. curl-devel
  5. Any other dependencies that are missing..

image

All these packages are located inside the Devel branch of the package tree. Required dependencies will be selected automatically.

Click next to install selected packages.

Compiling GIT form source

Untar the GIT source you downloaded using the command “tar xvzf git-1.5.5.tar.gz” .

Navigate to the untarred directory using a command prompt. Now run the “make” command inside the GIT source directory.

If it runs successfully then run “make install”.

Before running the command make sure you have Perl (language) installed. You can check it by running the command:

perl -MCPAN -e 'shell'

and then running the following inside the cpan shell:

install blib

it should show no error. I am not sure if this is the best way to do this as I am not much of a Perl guy.

So as I mentioned before you need to run the following two command to make and install Perl:

   1: make
   2: make install

If these two steps complete successfully then your GIT is ready to go :). You can test this by running the “git” command. This command is located inside the “C:/cygwin/home/gaurav/bin”. You might to add this folder to the system path too.

Pre-configured version

Here is a cygwin version pre-configured to compile GIT. It is installed on my system and works fine. Cygwin 1.5.25 and GIT 1.5.5 are preinstalled in this archive. Just decompress this archive under folder “C:\cygwin” and add “C:\cygwin\bin” and “C:/cygwin/home/gaurav/bin” to your system path and GIT should work form any command window.

]]> http://allyourcodearebelongto.me/blog/2008/04/11/compiling-and-installing-git-on-windows-under-cygwin/feed/ 3 Setting up BlazeDS with Flex http://allyourcodearebelongto.me/blog/2008/03/02/setting-up-blazeds-with-flex/ http://allyourcodearebelongto.me/blog/2008/03/02/setting-up-blazeds-with-flex/#comments Sun, 02 Mar 2008 11:49:42 +0000 Gaurav http://techblogging.wordpress.com/2008/03/02/setting-up-blazeds-with-flex/  

Let me give some introduction first.

BlazeDS is a server-based Java remoting and web messaging technology that allows to connect to back-end distributed data and push data in real-time to Adobe Flex and Adobe AIR rich Internet applications (RIA). Because of its open licensing, BlazeDS is not precluded from being used with other client platforms, such as JavaScript/AJAX. (wikipedia)

Adobe Flex is a collection of technologies released by Adobe Systems for the development and deployment of cross platform, rich Internet applications based on the proprietary Adobe Flash platform. The initial release in March 2004 by Macromedia included a software development kit, an IDE, and a J2EE integration application known as Flex Data Services. Since Adobe acquired Macromedia in 2005, subsequent releases of Flex no longer require a license for Flex Data Services, which has become a separate product rebranded as LiveCycle Data Services. (wikipedia)

Setting up JAVA:

Install the java sdk (jdk) and setup the environment by setting up the following two variables.

image

 

Setting up BlazeDS:

BlazeDS can be downloaded from: here. We will be using the turnkey download as it is preconfigured.

Now unzip blazeds in any folder. In my case I unzipped it to: “D:\Blaze_ds”

Now I will be setting up a new project in this directory: “D:\Blaze_ds\tomcat\webapps\blazeds”

 

Setting up Flex Builder:

A 60 ay trial can be downloaded form: here

Download flex builder 3 and install it. I installed flex builder in: “D:\Flex”

 

Creating a new project:

Now fire up flex builder and create a new flex project inside it.

 image

 image

Now fill in the appropriate entries and click on the “Validate Configuration” button. Now before you click on the button Tomcat needs to be started or the configuration won’t be validated. To start the server start a console and navigate to bin directory of Tomcat which is “D:\Blaze_ds\tomcat\bin” in my case. Now the configuration should validate. I have selected the current project directory as the output directory. Click on finish and a new project should be created.

The configuration is complete now. Just write some code to test the configuration.

   1: <?xml version="1.0" encoding="utf-8"?>

   2: <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"

   3:     creationComplete="consumer.subscribe()">

   4:     

   5:     <mx:Script>

   6:         <![CDATA[

   7:         

   8:             import mx.messaging.messages.AsyncMessage;

   9:             import mx.messaging.messages.IMessage;

  10:             

  11:             private function send():void

  12:             {

  13:                 var message:IMessage = new AsyncMessage();

  14:                 message.body.chatMessage = msg.text;

  15:                 producer.send(message);

  16:                 msg.text = "";

  17:             }

  18:                             

  19:             private function messageHandler(message:IMessage):void

  20:             {

  21:                 log.text += message.body.chatMessage + "n";    

  22:             }

  23:             

  24:         ]]>

  25:     </mx:Script>

  26:     

  27:     <mx:Producer id="producer" destination="data_sample"/>

  28:     <mx:Consumer id="consumer" destination="data_sample" message="messageHandler(event.message)"/>

  29:     

  30:     <mx:Panel title="Chat" width="100%" height="100%">

  31:         <mx:TextArea id="log" width="100%" height="100%"/>

  32:         <mx:ControlBar>

  33:              <mx:TextInput id="msg" width="100%" enter="send()"/>

  34:              <mx:Button label="Send" click="send()"/> 

  35:         </mx:ControlBar>

  36:     </mx:Panel>

  37:     

  38: </mx:Application>

This is some code taken from on of the samples provided. I guess, it is as simple as it can get.

The destination given in the Producer and Consumer needs to be defined in the “messaging-config.xml” file which is located “D:\Blaze_ds\tomcat\webapps\blazeds\WEB-INF\flex\messaging-config.xml”.

Just add <destination id=”data_sample”/> inside the service tag.

Thats it. To test run application in two browser windows and the messages between the two windows showd be synchronized.

image

]]> http://allyourcodearebelongto.me/blog/2008/03/02/setting-up-blazeds-with-flex/feed/ 6 Amarok 2: now with 100% more audio playing on Windows – Amarok Blog http://allyourcodearebelongto.me/blog/2007/12/08/amarok-2-now-with-100-more-audio-playing-on-windows-amarok-blog/ http://allyourcodearebelongto.me/blog/2007/12/08/amarok-2-now-with-100-more-audio-playing-on-windows-amarok-blog/#comments Sat, 08 Dec 2007 16:18:48 +0000 Gaurav http://techblogging.wordpress.com/2007/12/08/amarok-2-now-with-100-more-audio-playing-on-windows-amarok-blog/ Amarok 2: now with 100% more audio playing on Windows – Amarok Blog

Here is come great news for windows users. The great linux music player is being ported to the windows platform. Here is a screenshot of amarok playing on windows.

image

But as the site says that it is still an alpha software so somewhat unstable. I am eagerly waiting the first version to come. I hope it comes out soon.

]]> http://allyourcodearebelongto.me/blog/2007/12/08/amarok-2-now-with-100-more-audio-playing-on-windows-amarok-blog/feed/ 0 10 of my favorite softwares http://allyourcodearebelongto.me/blog/2007/10/09/10-of-my-favorite-softwares/ http://allyourcodearebelongto.me/blog/2007/10/09/10-of-my-favorite-softwares/#comments Tue, 09 Oct 2007 17:05:50 +0000 Gaurav http://techblogging.wordpress.com/2007/10/09/10-of-my-favorite-softwares/ I like to explore softwares. I usually install a lot of softwares on my system. I thought that I should make a list of my favorite softwares and share it with everybody. All of there softwares are either open-source or free.

1. Autohotkey(FOSS): It manages your hotkeys globally and allows you to create complex actions based on the keys pressed. Its actually got its own scripting language which is rather easy to learn. Just write a script in a file with extension .ahk and double click the file to execute it.

image

With AutoHotKey you can:

  • manage processes, windows and control both keyboard and mouse.
  • create macros saving you precious keystrokes.
  • re-map keys and buttons on your keyboard and mouse.

I have been using AutoHotKey for quite a while now and I use it to manage my code snippets, have consistent hotkeys across applications and creating macros like googling the selected text in any application. The following is the AutoHotKey script for it:

   1: #g::
   2: Send ^c
   3: Run http://www.google.co.in/search?hl=en&q=%clipboard%
   4: return

So by using this script whenever I press Ctrl+G the script will open a browser and search the selected text in google. Nice isn’t it?

2. CCleaner(FREE): CCleaner is a simple system cleanup tool that removes temporary files, empty folders, redundant registries and application log files. It recognizes a lot of softwares on the system and removes their temporary and log files too. Its really simple to use, just right click on the recycle bin and select Run CCleaner. Some advanced options are revealed when the application is run from the start menu. Usually it just takes few seconds to clean up the system and makes the system speedier by removing useless stuff.

image

3. Console2(FOSS): Console is a Windows console window enhancement. Currently in beta but still packs a punch.

Features include:

  • Tabbed interface
  • Customizable background
  • Custom tabs

Each tab open a different process. I normally have tabs for powershell, ruby and irb. Each of there tabs are bound to a different hotkey.

I think Microsoft should include Console2 with default once it comes out of beta because normal console just sucks.

image

4. Foxit PDF Reader(FREE): Foxit is one PDF reader that is actually fast. Opens up just as fast as notepad and I am yet to come across a pdf that it doesn’t render correctly. Its got a real small install size (~1.5 MB) and the whole application is contained inside a single exe, so no messing around with the system. Its got the same feature set as Adobe reader although searching seems a bit better in Adobe reader, but speed matters to me the most.

image

5. FlashGet(FREE): Flashget is a download manager that has only recently become free. It makes multiple connections to the server download the same file thus speeding up the download. Its interface is simple to use and the download options are really easy to configure. It also supports other protocols like Bit-Torrent and e-Mule.

Capture

6. ImgBurn(Free): Image Burn software is used for burning CDs and DVDs. It can also be used to creating ISOs from CDs and DVDs. The best part about is software it is really easy to use, lightweight ~1.5 MB and of course FREE.

Unlike the most famous software (~ 1 GB size) in this category ImgBurn doesn’t bring your system to a drag when using it and also doesn’t mess around with your settings.

image

7. Media Player Classic(FOSS): MPC is a compact media player that mimics the look and feel of Window Media Player 6.4. I don’t install it as a standalone software but as a part of K-lite codec pack which allows me to play encoded video files. Its got a really simple look and feel but has a fast interface and nice default hotkeys. One of its features that I like is ability to change the aspect ratio of the video to anything.

image

8. Microsoft Virtual PC(FREE): It is a virtualization suite from Microsoft which is optimized for windows based systems. Although other virtualization softwares are available that run Linux much better as a guest OS but Microsoft Virtual PC is better if you want to run a windows OS as the guest. Virtualized OS runs almost as fast as natively and its great for testing softwares that only run in older versions of windows like IE6. I usually need to run IE6 to test web-pages and a virtual machine is the only way possible to run IE6 alongside IE7.

Capture

9. Microsoft Visual studio express editions(Free): Primarily I am a Ruby on Rails developer but I also love to program in C#. Microsoft has a free edition of Visual Studio for hobbyists like me. Its a bit limited in features as compared to Visual Studio. You can only program only in one language at a time, but that is good enough for me. Its fast, feature rich and Free, what more can I want :)

image

10. Paint.NET(FOSS): An easy to use image editing software. This is one of the most famous open source software for windows. It is meant to be a free alternate to MS-Paint that comes bundled with windows but it has a feature set that rivals to other expensive image editing softwares.

Paint.NET has a really small installation size, runs fast, supports for layers and supports a wide variety of image formats.

image

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