Ruby on Rails中的Ajax成功回调

Question

Hi want to implement ajax in my ruby on rails tutorials and the controller will return an object on handling the ajax request. I dont know to handle the response in my javascript file. I want to update some div based on object returned in javascript file.

Here is what I have written in my showcomments.js.erb

$('.show_comment').bind('ajax:success', function() {
    $(this).closest('tr')="Something here from the object returned");
});

My link where ajax call is called is via this line of code

 <td><%= link_to 'Show Comment', :action => 'showcomment' , :id =>article, :remote => true ,:class=>'show_comment' %></td>

My controller action where this request is handled is like this

def showcomment
   @article = Article.find(params[:article_id])
   @comment = @article.comments.find(params[:id])
    respond_to do |format|
      format.js{ render :nothing => true }
    end
end

How can this be done?

Answer 1

I just wanted to try and expand on the other answers a little bit.

In rails when you add :remote => true to a link it essentially takes care of the first part of a jquery ajax call. That's why you don't need bind.(ajax:success, function(){ # do stuff here });

This is a typical jquery ajax call

$.ajax({
  url: "test.html",
  type: "POST"
}).done(function() {
  $( this ).addClass( "done" );
});

Rails takes care of the first part, up to the .done callback. So anything in your javascript erb template is put in the callback like this

.done(function() {
  #your showcomments.js.erb file is inserted here
});

To render the showcomments.js.erb template from the controller just do this

def showcomment
  @article = Article.find(params[:article_id])
  @comment = @article.comments.find(params[:id])
  respond_to do |format|
    format.js
  end
end

You don't need anything after format.js because the default rails action at that point is to render a js template with the same name as the action, in this case it's showcomment.js.erb .

Now you know when that link is clicked it will go straight to rendering that showcomment template , and any javascript in there will be run instantly. Rails makes using ajax very simple. I hope that helps.

Answer 2

change showcomment to this:

def showcomment
   @article = Article.find(params[:article_id])
   @comment = @article.comments.find(params[:id])
    respond_to { |format| format.js }
end 

In showcomments.js.erb you can access both objects @article and @comment . A sample use is as below:

$('#yourdiv').html('<%= @article.name %>');

Answer 3

You render nothing when responding to js format. So code in showcomments.js.erb isn't evaluated. Remove { render :nothing => true } in controller and do whatever you want in showcomments.js.erb . BTW you don't need ajax:success event. It is the end of request already.

showcomments.js.erb

$('.show_comment').closest('tr').html("<%= # you may render partial here or whatever %>");