Sending Javascript variable to Rails 3 controller using Jquery

Question

I am using Rails 3, Jquery-UJS and Jquery. I have a working setup of Jquery with Rails3 .I am trying to send a variable from Javascript to Rails controller by clicking a link.

My current approach is using js as follows to make an ajax call and pass msg string.

$("#select_link").click(function() {$.ajax({ type: 'POST', url: 'http://your_url/jmsg', data: {msg: "hello world"}, ;} }); }); 

Should I include this code in my application.js file?

In my .html.erb file I have

<%= link_to "Send variable", jmsg_path, :remote => true %> 

In my controller I have

def jmsg @message= params[:msg] respond_to do |format| format.js end end 

Till now, I've not been able to get the javascript variable in my @message instance variable

EDIT:

I made changes as suggested. However, the variable @message is not set when I do

 @message=params[:msg] 

When I check XHR using Fiebug, I see 302 Moved Temporarily for the POST action (the POST parameter msg is set correctly though). Response is - $("#show_message").html("")

My .js view is:

 $("#show_message").html("<%= @message %>") 

EDIT2 : When I check Firebug, it shows that there are two actions now: 1. POST /jmsg - with response @message = "hello world" 2. GET /jmsg - with response @message= " "

Answer 1

When i wanna get any value from controller, i always use json format by doing something like these.

// jmsg.js.erb

{ "message": "<%= @message %>" } 

// yourjs.js

$.ajaxSetup({ 'beforeSend': function(xhr) { xhr.setRequestHeader("Accept", "text/javascript") } }); $("#select_link").click(function(){ $.ajax({ type: 'POST', url: 'http://your_url/jmsg', dataType: 'json', data: {msg: "hello world"}, success: function(json, status, xhr){ // $("#show_message").html(json.message) } }); }); 

// in your.html.erb, remove :remote => true

<%= link_to "Send variable", jmsg_path %> 

Answer 2

Add the below code into your application js and try this

$(function(){ $("#select_link").click(function(){ $.ajax({ type: 'POST', url: 'http://your_url/jmsg', data: { msg: "hello world" }, }); }); }); 

Answer 3

Okay, I will share with you what I know about using AJAX and jQuery in Rails, in an unobtrusive manner:

First, include this at the beginning of your application.js file

jQuery.ajaxSetup({ 'beforeSend': function(xhr) { xhr.setRequestHeader("Accept", "text/javascript") } }); 

Then, in the same file, create a function as follows, with is the function that loads before the DOM loads. In this function, you write your own functions:

$(function() { $("#select_link").sendVar(); } jQuery.fn.sendVar = function(){ this.click( function() { var msg= 'hello world'; $.post('/your_url/jmsg/' + msg, function(data){ }) return false; }); } 

Make sure you have a route for this post request in your routes.config file, for e.g.

match 'your_url/jmsg/:msg', :controller => 'your_url', :action => 'jmsg', :via => :post 

Let me know if this works for you. A similar code worked for me, for a similar case. Thanks.