Скачать или смотреть How to dynamically set the event handler type in JavaScript

Learn how to dynamically set event handler types in JavaScript. This guide provides practical examples using jQuery to improve your coding skills.
---
This video is based on the question https://stackoverflow.com/q/64788982/ asked by the user 'Slim' ( https://stackoverflow.com/u/4362877/ ) and on the answer https://stackoverflow.com/a/64792282/ provided by the user 'Oleg Imanilov' ( https://stackoverflow.com/u/2304204/ ) 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: How to dynamically set the event handler type?

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.
---
Dynamically Setting the Event Handler Type in JavaScript

Have you ever found yourself needing to change the type of an event handler in JavaScript based on a certain condition? This is a common problem that developers face when trying to create flexible and dynamic user interfaces. In this guide, we'll look at how to dynamically set the event handler type using JavaScript and jQuery.

Understanding the Problem

When building interactive applications, you might need to attach different types of events to elements. A typical scenario involves using jQuery's .on() method. However, hardcoding the method means you lose a degree of flexibility. The goal here is to dynamically set the event handler using a variable. For example, instead of deciding at coding time whether you want to use .on(), .live(), or any other event type, you want to choose it on the fly.

Example Scenario

Let's impress this concept with a simple example:

In your jQuery code, you might have:

[[See Video to Reveal this Text or Code Snippet]]

But, what if you want to make it even more flexible? You could imagine something like this pseudo-code:

[[See Video to Reveal this Text or Code Snippet]]

Here, you're hoping to choose the event handler dynamically—an interesting challenge that we'll solve next.

Solution: How to Create a Dynamic Event Handler

To achieve this functionality, we can utilize JavaScript's bracket notation. This allows us to dynamically access properties of objects, including jQuery functions. Below is a step-by-step breakdown and demonstration of the solution.

Step 1: Set Up jQuery

First, ensure you include jQuery in your project. You can do this by linking the jQuery CDN in your HTML:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Create Your HTML Element

Next, create a simple button element in your HTML that will act as our testing element:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Write the JavaScript Code

You can dynamically set the event handler using the following JavaScript code:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Code

Dynamic Event Handler: By defining eventHandler as a string, we can call the desired jQuery method dynamically.

Bracket Notation: The syntax $('.test')[eventHandler] allows you to access the method (in this case, on) as if you were using normal function calls. This gives your code flexibility and cleanliness.

Conclusion

Using this approach, you can easily switch between different event handler types based on your application's needs. It not only makes your code more readable but also significantly enhances its flexibility.

Feel free to experiment with various event handlers by modifying the eventHandler variable as per your requirement. Happy coding!