Using requirejs with backbonejs (Rails)

So, after fighting with it for hours, finally I got it working so I thought it might help someone. I will got through step by step

1 - Create a new Rails application and set it up so that it loads an empty index page
     (Create a controller with an index action + add an index view + edit the routes file accordingly)

2 - Add the following line to the Gemfile - gem 'requirejs-rails'


3 - In application.html.erb file, replace
     <%= javascript_include_tag "application" %> with <%= requirejs_include_tag "application" %>


4 - Add a requirejs.yml file under config directory and delete all the content of application.js

5 - In the vendor/assets/javascripts directory, add backbone.js, underscore.js and JQuery libraries

6 - Add the code as shown below to the corresponding files
   
    

	-----------------------------------------------
	application.js
	-----------------------------------------------
	require [
	'backbone',
	'path/to/router/with/index/handler'],
	(Backbone, IndexRouter) ->
	$ ->
	Main = new IndexRouter()
	Backbone.history.start()
	-----------------------------------------------
	requirejs.yml
	-----------------------------------------------
	modules:
	- name: 'application'
	shim: {
	'backbone': {
	# These script dependencies should be loaded before loading
	# backbone.js
	deps: ['underscore', 'jquery'],
	# Once loaded, use the global 'Backbone' as the
	# module value.
	exports: 'Backbone'
	}
	}
	------------------------------------------------
	MainRouter.js
	------------------------------------------------
	define [
	'backbone'],
	(Backbone, $) ->
	class IndexRouter extends Backbone.Router
	routes:
	'': 'index'
	index: () ->
	alert("wooo..It works")

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7 - Credit goes to - https://github.com/jwhitley/requirejs-rails

8 - Thanks

Rails like flash messages using JQuery for JS or AJAX calls

	# This gist shows how to display Rails like flash messages while handling AJAX or JS requests
	# Note - This might not be the best way to do this but it works for me
	Step 1. Create a partial which will contain the message to be displayed
	Example - _success.html.erb
	<div id="flash_message">
	<p>Success</p>
	</div>
	Step 2. In the Controller, add code to call this partial on a JS request
	Example - ExampleController.rb
	class ExampleController < ApplicationController
	.
	.
	.
	def example_action
	.
	.
	respond_to |format|
	# This call will search for action success, if not present, it will call the template named success.js
	# Note - success.js is created in step 3
	format.js { render :action => 'success' if some_condition }
	end
	end
	end
	Step 3. Create a file called success.js which will render the flash message
	Example - success.js.erb
	$("#element_where_flash_to_appear").prepend(
	$("<%= escape_javascript(render :partial => 'success') %>").
	hide().fadeIn(1000, function(){
	$(this).remove();
	})
	);
	Step 4. CSS for flash message
	#flash_message {
	text-align: center;
	background: #ffe;
	width:100%;
	margin-left:auto;
	margin-right:auto;
	border:1px solid gray;
	margin:0px;
	}

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Fibonacci in log(n) Java code

	/*
	* | 1 1 |n |Fn+1 Fn |
	* | 1 0 | = |Fn Fn-1 |
	*
	* Figure 1
	*/
	public int FibonacciLogN(int n)
	{
	if(n <= 0)
	return 0;
	if(n == 1 || n == 2)
	return 1;
	// calculate n - 1 term (see above figure 1)
	return FibonacciMatrix(FIBONACCI_MATRIX, n - 1)[0][0];
	}
	private int[][] FibonacciMatrix(int[][] m, int n)
	{
	if(n == 1)
	return FIBONACCI_MATRIX;
	if(n == 2)
	return multiply(FIBONACCI_MATRIX, FIBONACCI_MATRIX);
	int solution[][] = FibonacciMatrix(m, n/2);
	solution = multiply(solution, solution);
	if(n%2 != 0)
	solution = multiply(solution, FIBONACCI_MATRIX);
	return solution;
	}
	// for quick multiplication
	private int[][] multiply(int[][] m, int[][] n)
	{
	int[][] result = new int[2][2];
	result[0][0] = m[0][0] * n[0][0] + m[0][1] * n[1][0];
	result[0][1] = m[0][0] * n[0][1] + m[0][1] * n[1][1];
	result[1][0] = m[1][0] * n[0][0] + m[1][1] * n[1][0];
	result[1][1] = m[1][0] * n[0][1] + m[1][1] * n[1][1];
	return result;
	}
	private int[][] FIBONACCI_MATRIX = new int[][] { {1,1}, {1,0} };

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Posting code to Blogger using - GitHub Gists :)

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    Embed All Files: show embed
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5. And wallah !!

Ruby on Rails - Downloading data as xls or excel without using a Gem

    

      

        

  

    
    


        


  


  

        

          

          
# This gist demonstrates - How to download data from database in excel or xls format in Ruby on Rails
        
        

          

          
# Tested with - Ruby 1.9.3, rails 3.2.1, db - postgres
        
        

          

          


        
        

          

          
class DownloadsController < ApplicationController
        
        

          

          
  before_filter :define_header, :except => :index
        
        

          

          


        
        

          

          
  def index
        
        

          

          
    ...
        
        

          

          
  end
        
        

          

          


        
        

          

          
  def download_choclates
        
        

          

          
    @choclates = Choclate.all
        
        

          

          
    
        
        

          

          
    respond_to do |format|
        
        

          

          
      format.html { render :partial => 'download_choclates' }
        
        

          

          
    end
        
        

          

          
  end
        
        

          

          


        
        

          

          
  private
        
        

          

          
  # sets the header. You can specify the file name
        
        

          

          
  # For my project I am sending the name of the file in params
        
        

          

          
  # so I use 
        
        

          

          
  # headers['Content-Disposition'] = "attachment; filename=#{params[:name]}.xls"
        
        

          

          


        
        

          

          
  def define_header
        
        

          

          
    headers['Content-Type'] = "application/vnd.ms-excel"
        
        

          

          
    headers['Content-Disposition'] = "attachment; filename=filename.xls"
        
        

          

          
    headers['Cache-Control'] = ''
        
        

          

          
  end
        
        

          

          
end
        
        

          

          


        
        

          

          
# Partial to be rendered
        
        

          

          
# _download_choclates.html.erb
        
        

          

          
<table border="1">
        
        

          

          
  <tr>
        
        

          

          
    <th>Id</th>
        
        

          

          
    <th>Description</th>
        
        

          

          
    <th>Price</th>
        
        

          

          
    <th>Feedback</th>    
        
        

          

          
    <th>Created At</th>
        
        

          

          
    <th>Updated At</th>
        
        

          

          
  </tr>
        
        

          

          


        
        

          

          
<% @choclates.each do |choclate| %>
        
        

          

          
  <tr>
        
        

          

          
    <td><%= choclate.id %></td>
        
        

          

          
    <td><%= choclate.description %></td>
        
        

          

          
    <td><%= choclate.price %></td>
        
        

          

          
    <td><%= choclate.feedback %></td>
        
        

          

          
    <td><%= choclate.created_at %></td>
        
        

          

          
    <td><%= choclate.updated_at %></td>
        
        

          

          
  </tr>
        
        

          

          
<% end %>
        
        

          

          
</table>
        
  



    

  


      
      

        view raw
        
          download_xls.rb
        
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