How To Access Jquery In Html 5 Web Worker

April 22, 2024 Post a Comment

I am unable to to access jQuery inside an HTML5 web worker. Is there a way I can do that?

Solution 1:

tl;dr: include this script before jQuery

JQuery initally accesses lots of document properties to check for browser features. document is not defined in Worker and you actually cannot create Document instance in web workers at this moment. JQuery isn't prepared for that - as you could see in comments on your question, nobody seems to understand what would you do with JQuery without DOM.

Since, as I said, JQuery needs document to initialise, I created a dummy fake document object. This object acts as real document during JQuery tests:

vardocument = self.document = {parentNode: null, nodeType: 9, toString: function() {return"FakeDocument"}};
varwindow = self.window = self;
var fakeElement = Object.create(document);
fakeElement.nodeType = 1;
fakeElement.toString=function() {return"FakeElement"};
fakeElement.parentNode = fakeElement.firstChild = fakeElement.lastChild = fakeElement;
fakeElement.ownerDocument = document;

document.head = document.body = fakeElement;
document.ownerDocument = document.documentElement = document;
document.getElementById = document.createElement = function() {return fakeElement;};
document.createDocumentFragment = function() {returnthis;};
document.getElementsByTagName = document.getElementsByClassName = function() {return [fakeElement];};
document.getAttribute = document.setAttribute = document.removeChild = 
  document.addEventListener = document.removeEventListener = 
  function() {returnnull;};
document.cloneNode = document.appendChild = function() {returnthis;};
document.appendChild = function(child) {return child;};

Beware that this fake document is only meant to allow jQuery to load, it won't allow any real DOM operations.

Example usage:

importScripts("workerFakeDOM.js");
importScripts('jquery-2.1.4.min.js');
console.log("JQuery version:", $.fn.jquery);

Test script

Allows you to try various versions of JQuery with my script.

JSfiddle

Check that you're using http://, my domain doesn't work with https://.

Download as script

Solution 2:

The answer of Tomáš Zato was correct, but no longer works with newer jQuery version. I added some more for jQuery 3.1.1:

vardocument = self.document = { parentNode: null, nodeType: 9, toString: function () { return"FakeDocument" } };
varwindow = self.window = self;
var fakeElement = Object.create(document);
fakeElement.nodeType = 1;
fakeElement.toString = function () { return"FakeElement" };
fakeElement.parentNode = fakeElement.firstChild = fakeElement.lastChild = fakeElement;
fakeElement.ownerDocument = document;

document.head = document.body = fakeElement;
document.ownerDocument = document.documentElement = document;
document.getElementById = document.createElement = function () { return fakeElement; };
document.createDocumentFragment = function () { returnthis; };
document.getElementsByTagName = document.getElementsByClassName = function () { return [fakeElement]; };
document.getAttribute = document.setAttribute = document.removeChild =
    document.addEventListener = document.removeEventListener =
    function () { returnnull; };
document.cloneNode = document.appendChild = function () { returnthis; };
document.appendChild = function (child) { return child; };
document.childNodes = [];
document.implementation = {
    createHTMLDocument: function () { returndocument; }
}

Solution 3:

Has anyone tried the jQuery - No DOM Edition? https://github.com/kpozin/jquery-nodom.

This is a small subset of the jQuery library intended for use in Web Worker contexts, where most of the browser API does not exist.

This is achieved primarily by modifying jQuery build instructions (Makefile) to only include the non-DOM modules.

This might help resolve the issue as this build has no DOM dependency, which is a hurdle when importing jQuery in webworker. Will try to provide some sample code soon for this

Solution 4:

There is a nice plugin to use Web Worker with jQuery by one of jQuery's own leaders. Check out his plugin on GitHub.

Solution 5:

Does using:

importScripts("jQueryWhatever.js");
$.blahblahblah();

Not work as expected? I suspect it will load jQuery without trouble, but most of the calls associated with good-ole $ will not work as expected as there is no DOM access inside a WebWorker.

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