How to localize scripts in WordPress using wp_localize_script

The wp_localize_script function in WordPress allows you to pass data from the server side to a JavaScript file. This can be useful for providing dynamic data to your JavaScript code without having to hardcode it directly into the script. It helps to keep your code more organized and maintainable by separating the data from the code logic.

By using wp_localize_script, you can make your JavaScript files more flexible and reusable, as they can adapt to different data without needing to be modified each time. This can be particularly helpful when working with themes and plugins, as it allows for easier customization and extension of functionality.

Parameters Accepted by wp_localize_script function

  • $handle (string, required): Script handle the data will be attached to.
  • $object_name (string, required): Name for the JavaScript object. Passed directly, so it should be a qualified JS variable. For example, it should match the regular expression ‘/[a-zA-Z0-9_]+/’.
  • $l10n (array, required): The data itself. The data can be either a single or multi-dimensional array.

Return Value

The wp_localize_script function returns a boolean value. It returns true if the script was successfully localized, and false otherwise.


How to localize a script in WordPress

Here’s an example of how to use wp_localize_script to localize a script in WordPress:

wp_enqueue_script( 'my-script', 'path/to/my/script.js' );
wp_localize_script( 'my-script', 'myScriptData', array(
 'ajaxUrl' => admin_url( 'admin-ajax.php' ),
 'nonce' => wp_create_nonce( 'my-script-nonce' )
) );

This code snippet enqueues a script called my-script and localizes it with the data provided in the array. This allows the script to access the localized data in the frontend.

How to use localized data in a script

Once the script is localized, you can access the data in the script file. Here’s an example:

(function( $ ) {
 // Use the localized data
 console.log( myScriptData.ajaxUrl );
 console.log( myScriptData.nonce );
})( jQuery );

In this example, the localized data myScriptData is accessed in the script file using the provided variable names.

How to handle localized data in an AJAX request

If you need to use the localized data in an AJAX request, you can access it in the PHP function handling the request. Here’s an example:

function my_ajax_handler() {
 check_ajax_referer( 'my-script-nonce', 'security' );
 // Use the localized data
 $ajax_url = $_POST['ajaxUrl'];
 // ... rest of the AJAX handling code
add_action( 'wp_ajax_my_action', 'my_ajax_handler' );

In this example, the localized data myScriptData is used in the AJAX request handler to perform necessary actions.


In conclusion, the wp_localize_script function is an useful component for passing data from PHP to JavaScript in WordPress. By using this function, developers can easily make their scripts more dynamic and interactive, without having to hardcode data directly into their JavaScript files. This not only improves the maintainability of the code but also enhances the security of the application by preventing direct access to sensitive data. Overall, wp_localize_script is a valuable resource for WordPress developers looking to create more robust and flexible web applications.

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