[jquery] deferred and promise

 jquery   deferred    promise  

▌Introduction

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This article will shows the basic usage of deferred and promise in jquery.

▌Sample code

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Codepen

▌Implement

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▋deferred and promise

function getData(filter) {     var deferred = $.Deferred();     try {         //Do ajax calls         deferred.resolve(data);     }     catch (e) {         deferred.reject(e);     }     return deferred.promise(); }

getData().then((data) => {     //callback… }).fail(e => { console.log(e); });

▋Use $.when to deal with promises

$.when(getData(filter1), getData(filter)).done((data1, data2) => {     //callback… }).fail((e) => {     console.log(e); });

▌Reference

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▋jQuery.Deferred()

▋deferred.promise()

▋deferred.resolve()

▋deferred.reject()

▋jQuery.when()