jQuery AJAX request events - done,fail,success

Question

I have code like that

var ajaxrequest = $.ajax({
            type: "POST",
            dataType: "json",
            url: "xy.php", 
            data: {
                action : "read"
            }
            }).fail(function(){
                //something to do when ajaxreq fails
            }).done(function(data){

               //something to do when ajaxreq is done
            });

It is working no problem. My question is why this doesnt work:

var ajaxrequest = $.ajax({
            type: "POST",
            dataType: "json",
            url: "n3_vaje_api.php", //Relative or absolute path to response.php file
            data: {
                action : "read",
            },
            fail:function(){
                //something to do when ajaxreq fails
            },
            done:function(data){
              //something to do when ajaxreq is done
            }
        });

Fail and done are just examples, complete also doesnt work if used inside. But using it outside like:

ajaxrequest.complete(f(){});

is working just fine... I know instead of done I should use success, but thats not my point here. Whats the deal here?

Solution

you need to use success and error is the method you need to use if you want to use your second option

this is example of ajax request without promise, where you are getting success and error function as parameter

 $.ajax({url:"demo_test.txt"
      ,error : function (xhr,status,error)
        { //alert error}
      ,success:function(result){
      $("#div1").html(result);
    }});

---

In the first opetion you are using promise object return by ajax requst that is the reason you are getting done and fail method.

this is example of promise object , in below example request is promise object

var request = $.ajax({
  url: "script.php",
  type: "POST",
  data: { id : menuId },
  dataType: "html"
});

request.done(function( msg ) {
  $( "#log" ).html( msg );
});

request.fail(function( jqXHR, textStatus ) {
  alert( "Request failed: " + textStatus );
});

Comments

[Arun P Johny]

you need to use success and error

[zmajeric]

Its a school assignment and I used first thing I got working. Also AJAX request was REQUIRED so that was my option.

[zmajeric]

Thank you.I kinda understand now

[Pranay Rana]

@user3271259 - you can read about promise object on jquery site or google ...and dont forget to upvote and accept answer