{"id":1328,"date":"2019-04-03T13:00:00","date_gmt":"2019-04-03T13:00:00","guid":{"rendered":"https:\/\/demo.17thavenuedesigns.net\/audrey\/?p=1328"},"modified":"2024-05-22T15:22:36","modified_gmt":"2024-05-22T15:22:36","slug":"how-to-organically-boost-traffic-to-website","status":"publish","type":"post","link":"https:\/\/wspelt.com\/?p=1328","title":{"rendered":"Promises"},"content":{"rendered":"\n

Promise promise<\/em><\/p>\n\n\n\n

Introduction
<\/strong>In a lot of front-end SharePoint code that we write, we use asynchronous calls (ajax). For example, with JSOM (JavaScript Object Model), a Microsoft-generated collection of libraries that serve as a proxy to the server-side object model. But also when we call SharePoint’s REST API.<\/p>\n\n\n\n

During a job I encountered a complex set of nested JavaScript calls with callbacks in which calls with callbacks were called. Since JSOM calls are asynchronous, we sometimes encounter situations like this.<\/p>\n\n\n\n

What can help make it clearer is to work with JavaScript promises.
Below I will explain this and work out a solution for SharePoint.<\/p>\n\n\n\n

What is a promise?<\/h2>\n\n\n\n

By a “promise” we mean here “an object that may in the future return a single value: a resolved value or a reason that it has not been resolved (for example, a network error has occurred). A promise can be in one of the three possible states are: fulfilled, rejected, or pending.<\/p>\n\n\n\n

What do you need?<\/h2>\n\n\n\n

There are various options for using promises in your SharePoint solution:<\/p>\n\n\n\n