Facebook Like Tagging: Integration with Rails

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I got an opportunity to learn Jquery in my last project, The user interface quite resembles with the Facebook.
	
I have to impelement Facebook like autosuggest with tagging support, There are number of Jquery plugins available which does this, 
i found most of them incomplete or not to easy to modify

I choose http://code.drewwilson.com/entry/autosuggest-jquery-plugin, because of beautifully written ruby and easy customizable.
The full description of this plugin can read at above  addr.	

However understanding some of the options is little confusing like 'format list' callback
In this post you will see how to use this callback with server side rails ruby working out of the box :)

In this post i will focus on integration with Rails
I have forked the original respository, added and modified some of the options
My github id : psahni


How it works

Step 1: Configration

	copy the js files in public/javascripts

	copy the css files in public/stylesheets

	include them 
							<ruby>
	  						<%=stylesheet_link_tag 'name_of_css.css'%>
		            <%=javascript_inclu_tag 'name_of_js.js'%>
							</ruby>		


Step 2: 
	My use case
	I want user to able add his/her favorite movies, i used acts_as_taggable_on plugin for that
	
	In User model, i wrote 

	<ruby>	
		acts_as_taggable_on :favorite_movies
	</ruby>

	In view i wrote
	
	...................
	..................
	<ruby>
	<div class='field'>
		<%=form.text_field :favorite_movie_list, :id => 'movies'%> 
	</div>
	</ruby>
	...................
	...................



Step 3: Calling the autosuggest

 'View'
 
 I wanted to retrieve autosuggest options(movies) from the rails server
	
 As per plugin requirement, I will process the data with Ajax request, so I will send js request to the rails server
	write the javascript in same or in application.js 
	.........
	<ruby>
	<script type = 'text/javascript'>
		$("#movies").autoSuggest("/users/favorite_movies.js",
			{minChars: 1, matchCase: false, selectedItemProp: "name", searchObjProps: "name", startText: "Your favorite movies", 
			asHtmlID:"favorite_foods",  neverSubmit: true});
	</script>
	</ruby>



	Note: The explanation about these options can be read at link - [email protected]:psahni/jquery-autosuggest.git
				I have also created a 'demo' folder there in which it works out of the box.
	 
	Here $("#movies").autoSuggest("/users/favorite_movies.js",.....................

	The call to $("#movies").autoSuggest........... will turn the normal input field into an 'autocomplete box'  on the fly 
	(The input field gets hidden then)

	users is a controller and favorite movies is an action

	we are sending 	'js' request to the server and expecting a 'json' response in return
	JSON is an extremely easy format to work with (You can first read about it if you have not used it till now.)

	When an AJAX request is made the search string is sent over in a param named "q" by default. This search string is customizabel
 you can change that name with the queryParam option. Here is an example http://users/favorite_movies/?q=incepti
"mick" would be the search query that was typed into the input box. 

	
	SERVER SIDE ruby



   'Controller'

		<ruby>
		def favorite_movies
			data = User.favorite_movie_tags(params[:q])
			respond_to do |format|			
				format.html{}
				format.js{
						render :json => data
					}			
			end
		end
		</ruby>
		
	'Model'
    
	<ruby>
		def favorite_movie_tags(str)
			taggings = User.tag_counts_on(:favorite_movies).collect{|t| [t.id, t.name]}
			user_tags = taggings.select{|tag| tag[1].downcase.match("#{ str }".downcase)}.uniq
          data = Array.new
          user_tags.each do |tag|
           json = Hash.new
           json['name']  = tag[1] #name
           json['value'] = tag[0] #id
           data << json
        end
       return data
      end
		end	
	</ruby>