Prevent ajax call from firing twice

Question

I have an ajax call

$('#button1').on('click', function(e){
    $.ajax({
      url:  url,
      type: 'POST',
      async: true,
      dataType: 'json',
      enctype: 'multipart/form-data',
      cache: false,
      success: function(data){

      },
      error: function(){}
    });
    e.stopImmediatePropagation();
    return false;
});

Now here the response is received after 10 minutes . So the ajax call is called multiple times. Why does this happen / how can we ensure that ajax call is called only once?

Answer 1

An alternative to disabling the button would be to use the .one() method and re-bind the event handler after callback:

var clickHandler = function(e){
    $.ajax({
      url:  url,
      type: 'POST',
      async: true,
      dataType: 'json',
      enctype: 'multipart/form-data',
      cache: false,
      success: function(data){
        $('#button1').one('click', clickHandler);
      },
      error: function(){}
    });
    e.stopImmediatePropagation();
    return false;
}

$('#button1').one('click', clickHandler);

Answer 2

I was facing the same issue and it works when I set async: false. Sample code will be like this

$('#button1').on('click', function(e){
    $.ajax({
      url:  url,
      type: 'POST',
      async: false,
      dataType: 'json',
      enctype: 'multipart/form-data',
      cache: false,
      success: function(data){

      },
      error: function(){}
    });
});

Answer 3

Simply call .off() right before you call .on().

This will remove all event handlers:

$(element).off().on('click', function() {
    // function body
});

To only remove registered 'click' event handlers:

$(element).off('click').on('click', function() {
    // function body
});

Answer 4

As per the answer by Brennan,

$('#button1').on('click', function(e){
    $('#button1').attr('disabled', 'disabled');
    $.ajax({
      url:  url,
      type: 'POST',
      async: true,
      dataType: 'json',
      enctype: 'multipart/form-data',
      cache: false,
      success: function(data){
         $('#button1').removeAttr('disabled');
      },
      error: function(){}
    });
    e.stopImmediatePropagation();
    return false;
});

Here the button will be disabled and will be enabled on success