How to pick up the answer of an ajax call? [duplicate]

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How to pick up the answer of an ajax call? [duplicate]

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#1 by (2 votes)
#2 by (-1 votes)

2

I would like to pick up the answer from the following ajax call:

function prueba(callback){

       $.ajax({
            url: '/services/traps/view/',
            type: "POST",
            data: {
                csrfmiddlewaretoken: csrftoken
            },
            success: callback ,
            error: function(qXHR, textStatus, errorThrown) {
                console.log(errorThrown);
                console.log(qXHR);
                console.log(textStatus);

            },
        });
    };

function mycallback(data){
  //mi código
};

var mydata = prueba(mycallback);

In this case, mydata returns undefinded. I want to pick it up to manipulate it later with jquery.

jquery ajax

asked by Didina Deen 31.03.2016 в 10:58

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2 answers

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score 2 · Answer 1

There are several problems in the code for which you will get undefined in variable mydata :

The prueba function does not return anything

You are assigning mydata the value of the function prueba ... but test does not return anything, so mydata will always be undefined .

You want to perform a synchronous assignment of an asynchronous value

This is the real problem. The AJAX function is executed asynchronously (the call is made to the server and success / error is executed when the response returns) but the assignment is synchronous; therefore, even if prueba returned a value, it would not work because that value would not have been assigned before returning it.

Possible solutions: you can change the function so that it returns a value and make the AJAX call synchronously (doing async:false ). This way you make sure that the value will be there when you return it. This option is not the best and it is not recommended .

Another better alternative would be to package the code that makes use of the variable mydata in a function and call it in mycallback (where the value of mydata is assigned):

function prueba(callback){

       $.ajax({
            url: '/services/traps/view/',
            type: "POST",
            data: {
                csrfmiddlewaretoken: csrftoken
            },
            success: callback ,
            error: function(qXHR, textStatus, errorThrown) {
                console.log(errorThrown);
                console.log(qXHR);
                console.log(textStatus);

            },
        });
    };

function mycallback(data){
  //mi código
  mydata = data;
  operacionesConMyData();
};

function operacionesConMyData() {
    // mover aqui las operaciones que necesiten mydata
}

// llamada al AJAX
prueba(mycallback);

score -1 · Answer 2

Without using callback. You can take the value of the return in the success

function prueba(callback){

       $.ajax({
            url: '/services/traps/view/',
            type: "POST",
            data: {
                csrfmiddlewaretoken: csrftoken
            },
            success: function (retorno) {
          // El retorno contendra la información 

        },
            error: function(qXHR, textStatus, errorThrown) {
                console.log(errorThrown);
                console.log(qXHR);
                console.log(textStatus);

            },
        });
    };