How to Initialize Default Values with Select2 and Trigger AJAX Requests

Описание: Discover the step-by-step guide on how to set a default value for Select2 and trigger AJAX requests seamlessly using jQuery.
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This video is based on the question https://stackoverflow.com/q/65393006/ asked by the user 'yunusunver' ( https://stackoverflow.com/u/5902309/ ) and on the answer https://stackoverflow.com/a/65393322/ provided by the user 'Swati' ( https://stackoverflow.com/u/10606400/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Initialize Default Values with Select2 and Trigger AJAX Requests

When working with dynamic form elements, especially when using libraries like Select2, it’s common to encounter the need to set default values that also trigger AJAX requests. If you’ve found yourself in a situation where the first element of a Select2 dropdown is pre-selected but doesn’t automatically send an AJAX request, don’t worry! In this post, we’ll explore how to handle this correctly.

The Problem

You might have a situation where you want to have the first option of a Select2 dropdown pre-selected when the page loads. However, just selecting that option doesn’t execute the intended AJAX request. Here’s a common piece of code that might resemble your current setup:

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While this might appear to set the first element correctly, it does not trigger the select2:select event, which is necessary to make that AJAX request run.

The Solution: Triggering the Event Correctly

To ensure that your AJAX call is made whenever the default option is selected, you need to initiate the proper event. Here are the steps to achieve that.

Step 1: Initialize Select2

Make sure that you properly initialize the Select2 on your select dropdown. Here is how you can do it:

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Step 2: Handling the Event

Next, you need to attach event handlers for both the change event and the select2:select event. This allows you to execute your AJAX request regardless of how the selection is triggered.

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Step 3: Triggering the Events

Finally, once you’ve set up your Select2 dropdown and the event handlers, you need to programmatically select the first option and ensure that both events trigger as intended.

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Complete Demo Code

Here’s a complete setup that combines everything we’ve discussed:

HTML

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JavaScript

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Conclusion

By following these steps, you'll not only initialize Select2 with a default value but also ensure that your AJAX requests are triggered seamlessly. With the correct event handling in place, your users will have a better experience with your forms, functioning as intended right from the start.

Now you have the knowledge to master Select2 and make the most out of its capabilities. Happy coding!