$.ajax context option

Question

Episode 11 of the yayQuery podcast mentions the $.ajax context option. How would I use this option in the success callback? What I'm currently doing is passing my input parameters back to the success callback so that I can animate the id that was called after success/error. If I use the context option, then perhaps I don't have to pass the parameters back from the called routine.

In this example, I pass STATEID back to the success field so that the state is removed from the DOM once it's been deleted from the database:

$('td.delete').click(function() {
  var confirm = window.confirm('Are you sure?');
  if (confirm) {
    var StateID = $(this).parents('tr').attr('id');
    $.ajax({
      url: 'Remote/State.cfc',
      data: {
        method: 'Delete',
        'StateID': StateID
      },
      success: function(result) {
        if (result.MSG == '') {
          $('#' + result.STATEID).remove();
        } else {
          $('#msg').text(result.MSG).addClass('err');;
        };
      }
    });
  }
});

user113716 user113716 · Accepted Answer · 2011-02-23T21:15:03

All the context does is it sets the value of this in the callbacks.

So if you're in an event handler, and you want this in the callbacks to be the element that received the event, you'd do:

context:this,
success:function() {
    // "this" is whatever the value was where this ajax call was made
}

If you wanted it to be some other type, just set that, and this will refer to that:

context:{some:'value'},
success:function() {
    // "this" the object you passed
    alert( this.some ); // "value"
}

In the code you added to the question, you could use StateID, but you wouldn't really need to since you already have access to that variable.

var StateID = $(this).parents('tr').attr('id');
$.ajax({
    url: 'Remote/State.cfc'
    ,data: {
        method:'Delete'
        ,'StateID':StateID
    }
    ,context: StateID
    ,success: function(result){

        alert(this);     // the value of StateID
        alert(StateID);  // same as above

        if (result.MSG == '') {
            $('#' + result.STATEID).remove();
        } else {
            $('#msg').text(result.MSG).addClass('err');;
        };
    }
});

$.ajax context option

2 Answers