Question

I am trying to organize my code in Dojo but I, do not understanding how things work. I want to catch the json data after a REST call but it isn’t working. The testJson property, which I’m assigning REST return to, is always NULL.

How can I do this? I’ve copied my current code below. (I want to use my code in a ClassDAO and Controller.

define([
    'dojo/_base/declare',
    'dojo/request/xhr'
], function (declare, xhr) {

    return declare(null, {


        testJson: null,

        constructor: function(){

        },

        get: function(){

            xhr('/rest/reports', {
                method: 'get',
                handleAs: 'json',
                headers: {
                    Accept: 'application/json'
                }

            }).then(function(jsonData){

                    testJson = jsonData;

                }, function(err){
                    alert(err);
                }, function(evt){
                    // Handle a progress event from the request if the
                    // browser supports XHR2
                });

        }

    });
});

Answer 1

It looks like you are trying to set a class property as a variable; hence,

testJson = jsonData;

ought to be:

this.testJson = jsonData

Otherwise you are actually setting the global variable testJson, instead of a property. You also need to scope your then() function to your class:

.then(lang.hitch(this, function(jsonData){
    this.testJson = jsonData;
}))

The lang object is dojo/_base/lang and needs adding to the define()

define([
    "dojo/_base/declare",
    "dojo/request/xhr",
    "dojo/_base/lang"
], function (declare, xhr, lang) {

Scoping is an important concept of Javascript that has tripped us all up in the past. See the documentation for the hitch() command for more details.