How to Properly Manage Event Listeners in JavaScript: A Guide to removeEventListener скачать в хорошем качестве

How to Properly Manage Event Listeners in JavaScript: A Guide to removeEventListener

Learn how to efficiently manage event listeners in JavaScript, especially how to properly remove them, to avoid unwanted behavior in your applications. --- This video is based on the question https://stackoverflow.com/q/67417411/ asked by the user 'Johnny Kontrolletti' ( https://stackoverflow.com/u/14544753/ ) and on the answer https://stackoverflow.com/a/67417561/ provided by the user 'Ben Wainwright' ( https://stackoverflow.com/u/3104399/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Can't manage to remove event listeners from element Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- How to Properly Manage Event Listeners in JavaScript: A Guide to removeEventListener Managing event listeners in JavaScript can sometimes become tricky, especially when it comes to removing them after they are no longer needed. If you're here, you might be facing a common issue: you're able to successfully add event listeners to your elements, but you're struggling to remove them when necessary. Don’t worry; you're not alone, and we will clarify this topic step-by-step. The Problem You've written a function that initializes event listeners through a structured approach. However, when attempting to destroy these listeners using removed functions, you find that they are still being executed multiple times. Here’s a brief code example illustrating the issue: [[See Video to Reveal this Text or Code Snippet]] In this case, the initialPosition is an array of objects that contain DOM elements (frames) meant to listen for clicks. The goal is to ensure that when the destroy method is called, it successfully removes the event listeners previously attached in the load method. Why the Current Approach Fails The problem arises from the use of this.onClick.bind(...) within both addEventListener and removeEventListener. Each time you call .bind(), it creates a new function object. When you later attempt to remove the listener, you are trying to remove a function instance that does not match the one that was originally added. The Solution: Capturing References to the Event Handlers To effectively manage the event listeners, you should keep a reference to the bound functions when adding them. This way, you can pass the same function reference to the removeEventListener method later. Here’s how to implement this solution: Step 1: Modify the Load Function In your load function, store the references of your event handlers in an array. [[See Video to Reveal this Text or Code Snippet]] Step 2: Update the Destroy Function In your destroy function, you can now iterate over the this.bindings array to remove the event listeners correctly. [[See Video to Reveal this Text or Code Snippet]] Conclusion By modifying your methods to store function references, you can effectively manage event listeners within your JavaScript applications. This approach ensures that event listeners can be added and removed as necessary without causing unexpected behavior such as multiple function calls. Feel free to implement this pattern in your projects to simplify your event listener management. Happy coding!