A class to safely registering scripts in WordPress

class-safe_register_scripts.php

<?php
/**
 * Safely registering scripts without script collisions
 * @package WordPress
 * @author Ralf Albert
 *
 */
class Safe_Registering_Scripts
{

	/**
	 * Set to true if registered scripts should be overwritten
	 * @var bool
	 */
	public $overwrite_scripts = false;

	/**
	 * Scripts to be registered
	 * @var unknown
	 */
	public $scripts = array();

	/**
	 * Array with scripts that have to be registered
	 * @var array
	 */
	public $todo_handles = array();

	/**
	 * Scripts to be unregistered when scripts should be overwritten
	 * @var array
	 */
	public $deregister_handles = array();

	/**
	 * Constructor setup the arrays and start the tests
	 * @param array $scripts Scripts to be registered
	 * @param bool $overwrite Flag if a already registered handle should be overwritten by a handle with the same name
	 */
	public function __construct( $scripts = array(), $overwrite = false ) {

		$this->scripts = $scripts;
		$this->overwrite_scripts = $overwrite;

		$this->check_scripts();

		$this->register_scripts();

	}

	/**
	 * Create an array with all handle and sources that can be safely registered without any collision
	 * @param array $scripts Scripts to be registered if not already set by constructor
	 * @return array $todo_handles Array with all handles and data that can be safely registered
	 */
	public function check_scripts( $scripts = array() ) {

		global $wp_scripts;

		if ( ! empty( $scripts ) )
			$this->scripts = array_merge( $this->scripts, $scripts );

		$registered_sources = array();

		// copy all registered sources to an array
		foreach ( $wp_scripts->registered as $script )
			$registered_sources[] = $this->extract_source_filename( $script->src );


		// check if our source is already registered
		foreach ( $this->scripts as $handle => $data ){

			// if no source for this handle is available, continue with the next script
			if( isset( $data['src'] ) && ! empty( $data['src'] ) )
				$src = $this->extract_source_filename( $data['src'] );
			else
				continue;

			// add the handle and data to the todo-array if the script source isn't already registered
			if ( ! in_array( $src, $registered_sources ) ) {

				$this->todo_handles[ $handle ] = $data;

				// remove the handle and data from the todo-array if a handle with the same name is already registered
				// and scripts should not be overwritten
				if ( false === $this->overwrite_scripts && isset( $wp_scripts->registered[ $handle ] ) )
					unset( $this->todo_handles[ $handle ] );
				else
					$this->deregister_handles[] = $handle;

			}

		}

		return $this->todo_handles;

	}

	/**
	 * Registering the tested scripts
	 * @return array $res Array with the result of each handle (true if the script was successfully registered, else false)
	 */
	public function register_scripts() {

		// deregister registered handles first before re-register this handle
		if ( true === $this->overwrite_scripts )
			$this->deregister_scripts();
		
		// registering the scripts
		foreach ( $this->todo_handles as $handle => $data ) {

			$res[ $handle ] = wp_register_script(
				$handle,
				$data['src'],
				$data['deps'],
				$data['version'],
				$data['in_footer']
			);

		}

		return $res;

	}

	/**
	 * Deregister registered scripts
	 * @return array Result array handle->success [bool]
	 */
	public function deregister_scripts() {

		if ( ! empty( $this->deregister_handles ) && true === $this->overwrite_scripts ) {

			foreach ( $this->deregister_handles as $handle )
				$res[ $handle ] = wp_deregister_script( $handle );

		}

		return $res;
	}

	/**
	 * Extracting the filename from a give ressource
	 * @param string $src Complete ressource
	 * @return string Extracted filename of the ressource
	 */
	public function extract_source_filename( $src = '' ){

		$src_parts = parse_url( $src );

		return ( isset( $src_parts['path'] ) && ! empty( $src_parts['path'] ) ) ?
			array_pop( explode( '/', $src_parts['path'] ) ):
			$src;

	}

}