Determine the status of a script - WordPress

When making new plugin or customizing WordPress themes in deep, we want to check that if a script has been registered, enqueued, printed, or is waiting to be printed.

This method is very useful to avoid conflicts between scripts during registering/enqueing scripts in our plugins and themes.

The WordPress have a default function to check the status of script.

wp_script_is( $handle, $list );

Parameters

• $handle :- Name of the script (string & required).

Default value: None

• $list :- The list to query (string & optional).

  1. registered - script was registered through wp_register_script()
  2. enqueued / queue - script was enqueued
  3. done - script has been printed
  4. to_do - script has not yet been printed

Default: enqueued

Return Values

True or false.

Example 1

$handle = 'fluidVids.js';
$list = 'enqueued';
if (wp_script_is( $handle, $list )) {
	return;
} else {
	wp_register_script( 'fluidVids.js', plugin_dir_url(__FILE__).'js/fluidvids.min.js');
	wp_enqueue_script( 'fluidVids.js' );
}

Example 2

On the below example, we are going to check that if jQuery is printed & if so, we will add a custom jQuery snippet to our footer from our theme’s functions.php.

function myscript() {
	if( wp_script_is( 'jquery', 'done' ) ) {
	?>
	<script type="text/javascript">
	  // script dependent on jQuery
	</script>
	<?php
	}
}
add_action( 'wp_footer', 'myscript' );