hash-generator

Hash_Generator.php

<?php
class Hash_Generator {

	/**
	 * The generated hash.
	 *
	 * @var string
	 */
	private $hash = false;

	/**
	 * Hash_Generator constructor.
	 *
	 * @param mixed      $item      data from which to generate the hash
	 * @param array|bool $whitelist Whitelist of allowed data in the hash. Optional.
	 */
	public function __construct( $item, $whitelist = false ) {
		if ( is_array( $whitelist ) ) {
			$this->item = array_intersect_key( $item, array_flip( $whitelist ) );
		} else {
			$this->item = $item;
		}
	}

	/**
	 * Retrieves the hash.
	 *
	 * @since 1.2.4
	 *
	 * @return string
	 */
	public function get() {
		if ( false === $this->hash ) {
			$sorted = $this->sort( $this->item );

			$this->hash = md5( maybe_serialize( $sorted ) );
		}

		return $this->hash;
	}

	/**
	 * Recursively sorts the data, if it needs to-be sorted.
	 *
	 * @param mixed $item The item to sort.
	 * @return mixed The sorted data. If the item is not an array or object, this will simply return the item, untouched.
	 */
	private function sort( $item ) {
		if ( is_array( $item ) || is_object( $item ) ) {

			$item   = get_object_vars( (object) $item );
			$result = [];

			foreach ( $item as $key => $value ) {

				$result[ $key ] = $this->sort( $value );
			}

			ksort( $item );
		}

		return $item;
	}
}
?>