A web Employee (HTML Web Work)is a JavaScript that operates in the background without interfering with the page’s functionality.
What is a Web Worker?
When an HTML page has scripts running on it, the page stops responding until the script finishes.
A web Employee is a JavaScript script that executes in the background, apart from other scripts, and doesn’t impact the page’s performance. You can keep using the web Employee in the background, clicking and choosing objects as you choose.
Browser Support
The first browser version that fully supports Web Employees is shown by the numbers in the table.
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HTML Web Workers Example
A basic web Employee that counts integers in the background is created using the example below:
Example
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Check Web Worker Support
Make sure the user’s browser can handle the web Employee before creating it:
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Create a Web Worker File
Now, let’s create our web Employee in an external JavaScript.
Here, we create a script that counts. The script is stored in the “demo_Employees.js” file:
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The postMessage() method, which posts a message back to the HTML page, is the crucial component of the code above.
Note: Web Employees are often employed for more CPU-intensive tasks rather than such basic scripts.
Create a Web Worker Object
We must call the web Employee file from an HTML page now that we have it.
The code in “demo_Employees.js” is executed after the following lines determine whether the Employee currently exists or not by creating a new web Employee object:
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The web Employee will then be able to send and receive messages.
Give the web Employee a “onmessage” event listener.
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The code inside the event listener is run when the web Employee posts a message. Event.data is where the web Employee’s data is kept.
Terminate a Web Worker
Once a web Employee object is established, it will wait to be terminated and keep listening for notifications until the external script has finished.
Use the terminate() method to end a web Employee and release browser/computer resources:
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Reuse the Web Worker
You can reuse the code after it has been terminated if you set the Employee variable to undefined:
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Full Web Worker Example Code
The Employee code is already included in the.js file. The HTML page code is shown below:
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Web Workers and the DOM
Web workers cannot access the following JavaScript objects because they are in external files:
HTML Web Workers: Unlocking Asynchronous Processing Power
HTML Web Workers are a powerful feature in web development that allow you to run JavaScript code in the background, separate from the main browser thread. This enables asynchronous processing, which can significantly improve the performance and responsiveness of your web applications.
Web Workers provide a way to offload computationally intensive tasks to a separate thread, freeing up the main thread to handle user interactions and other critical operations. This is particularly useful for tasks like data processing, image manipulation, and complex calculations, which can otherwise cause the main thread to become unresponsive.
To use Web Workers, you create a separate JavaScript file that contains the code you want to run in the background. This file is then accessed by the main web page using the `Worker` object. The main page can then communicate with the worker thread using the `postMessage()` method and the `onmessage` event.
One of the key benefits of Web Workers is that they have limited access to the DOM, which means they cannot directly manipulate the user interface. This helps to ensure that the main thread remains responsive and avoids potential race conditions or synchronization issues.
Web Workers are supported in all modern browsers, although the level of support may vary. It’s important to check the browser support for specific features and to provide fallback solutions for older browsers that do not support Web Workers.
By leveraging HTML Web Workers, developers can create more efficient and responsive web applications, with the ability to offload resource-intensive tasks to a separate thread and maintain a smooth user experience.