Angular promise did not assign a value to a variable

Question

Angular promise did not assign a value to a variable

Can someone assist me with a problem I'm facing? After the first callback, the variable doesn't seem to change as expected. Below is my code snippet:

    this.handlerLocalDef = function(defer) {
        var hash = {};

        defer.then(
               function(response) {
                   hash = response;
               },
               function(err) {
                   showPopup(err);
               }
        );

        return hash;
    };

    var initialized = function()  {
        var localRegDef = Localization.getLocalizedDefer('regularform'),
            localPaymDef = Localization.getLocalizedDefer('payment');

            localizeRegForm = self.handlerLocalDef(localRegDef);

            $timeout(function() {
                console.log("localizeRegForm", localizeRegForm);
            }, 5000);
   }();

Upon checking the console log, it shows `localizeRegForm: {}`

javascript angularjs

Answer 1

Answer №1

Simply assigning hash = response only changes the reference of the local variable, not the original object itself. To properly update the original object with the values from response, you can use angular.extend(hash,response);. This will effectively copy all members of response into the hash object, ensuring that the receiver sees these changes.

Note: Be aware that this method may not work for primitive values (strings, numbers, booleans, etc.) or arrays.

Here is a fiddle showcasing the suggested approach: http://jsfiddle.net/sVRCg/3/

If you have concerns about how to verify that hash has been extended with response, using polling like setTimeout is not ideal. Consider returning a promise instead to accurately track when the response is ready.

Alternatively, explore implementations similar to how ngResource handles this process, although it may involve more complexity in the code structure.

Answer 2

Simply assigning hash = response only changes the reference of the local variable, not the original object itself. To properly update the original object with the values from response, you can use angular.extend(hash,response);. This will effectively copy all members of response into the hash object, ensuring that the receiver sees these changes.

Note: Be aware that this method may not work for primitive values (strings, numbers, booleans, etc.) or arrays.

Here is a fiddle showcasing the suggested approach: http://jsfiddle.net/sVRCg/3/

If you have concerns about how to verify that hash has been extended with response, using polling like setTimeout is not ideal. Consider returning a promise instead to accurately track when the response is ready.

Alternatively, explore implementations similar to how ngResource handles this process, although it may involve more complexity in the code structure.

Answer 3

Answer №2

Async programming should not involve setting arbitrary timeouts and hoping for data at a specific point in time. It's important to use deferred objects as intended and utilize callbacks for more reliable functionality. Here is a suggestion on how you can restructure your code to ensure it works properly, although effectiveness may vary based on your unique circumstances:


    this.handlerLocalDef = function(defer,callback) {

        defer.then(
               function(response) {
                   callback.apply(this,[response])
               },

               function(err) {
                   showPopup(err);
               }
        );

    };



    var initialized = function()  {
        var localRegDef = Localization.getLocalizedDefer('regularform'),
            localPaymDef = Localization.getLocalizedDefer('payment');


            self.handlerLocalDef(localRegDef,function(response) {
                console.log(response);
            });
   }();

Answer 4

Async programming should not involve setting arbitrary timeouts and hoping for data at a specific point in time. It's important to use deferred objects as intended and utilize callbacks for more reliable functionality. Here is a suggestion on how you can restructure your code to ensure it works properly, although effectiveness may vary based on your unique circumstances:


    this.handlerLocalDef = function(defer,callback) {

        defer.then(
               function(response) {
                   callback.apply(this,[response])
               },

               function(err) {
                   showPopup(err);
               }
        );

    };



    var initialized = function()  {
        var localRegDef = Localization.getLocalizedDefer('regularform'),
            localPaymDef = Localization.getLocalizedDefer('payment');


            self.handlerLocalDef(localRegDef,function(response) {
                console.log(response);
            });
   }();

Angular promise did not assign a value to a variable

Answer №1

Answer №2

Similar questions

Transforming the NavBar in React: A guide to dynamically updating values

Django Vue3 encounters access-control-allow-origin restriction

How can I ensure that the size of the Dropdown Menu Item matches its parent in both Bootstrap and CSS styles?

Using Bootstrap multiselect, you can easily control the display of a second menu based on the selection in the first menu

What is the best way to prevent images from being loaded with broken links?

Can the autocomplete feature be utilized in an input field without incorporating a map?

Ways to monitor the status of a server request using jQuery (ajax)?

Tips for implementing an automated date picker in Selenium using Node.js

SweetAlert html is not recognizing ng-app, but it functions correctly within the html body

When using Material UI, I ran into an issue where my Card Component was being added to my Appbar. To improve user interaction, I desire for the cards to only appear once

Divide a given number of elements within an array of arrays

Is it possible to submit a form through a JavaScript hotkey?

tips for setting the value of a checkbox to true in React Material-UI with the help of React Hooks

The issue of underscorejs being undefined arises when trying to load it using both XMLHttpRequest and

Please be patient until setInterval() completes its task

Refreshing html in nodejs after a fetch promise remains in a pending state

How to create a vertically scrollable div within another div by utilizing scrollTop in jQuery

Is it possible to expand the Angular Material Data Table Header Row to align with the width of the row content?

Looking for an uncomplicated SSO system similar to Google Identity Toolkit but with a customizable UI interface?

Limitation on calling $http.get() multiple times is in place