Adding a class to a button in jquery

I am trying to add a css class to my button a开发者_JAVA技巧fter some ajax:

$('a.vote-up-0').click(function() {

    var id = $(this).siblings('.reply-id').val();
    var ajax_auth_token = $('#auth_token').val();


    $.post('user/?action=ajax', {
        vote_type: 'up',
        reply_id: id,
        auth_token: ajax_auth_token
    }, function(data, return_status) {   

        var json_data = jQuery.parseJSON(data);

        switch(json_data.r_message)
        {
           case "success": 
              output = "Yay it works!"; // change 
               alert(output);
               $(this).addClass('vote-up-1'); // ** the culprit **
           break;

The alert works, however it does not add the class vote-up-1 to it. There are several instances of the same class (i.e. vote-up-0) on the page, so If I change (this) to 'vote-up-0', it changes all of them. Anyone have any ideas?

Up at the top of your "click" handler, stash the this value:

var theButton = this;

Then, in your ".post()" handler:

$(theButton).addClass('vote-up-1');

The problem is that this will not refer to the button when jQuery calls your ".post()" handler. Thus, you save a copy into a local variable, and it'll be there waiting for the handler when the time comes.

Brother: $(this).addClass('vote-up-1'); // ** the culprit ** is truly the culprit. $(this) is not available in this scope so it's better that you get the handle of the button before doing any ajax. such as:

var btnHnd = $(this); Now you can do the post stuff: $.post('user/?action=ajax', { ...

change this

 $(putyourbuttonidhere).addClass('vote-up-1');