Dom Kses

class-dom-kses.php

<?php

trait Dom_Kses {

	/**
	 * wp_kses, but using DOMDocument.
	 *
	 * Clean HTML to allowed_html.
	 * Also restrict attributes by those in whitelist.
	 *
	 * @param  \DOMNode $node         Dom node
	 * @param  array    $allowed_html kses allowed html.
	 *
	 * @return void.
	 */
	function dom_kses( \DOMNode $node, array $allowed_html ) {

		$this->dom_kses_children( $node, $allowed_html );

		// If not allowed, remove node.
		if (
			! ( '#text' === $node->nodeName )
			&& ! ( array_key_exists( $node->nodeName, $allowed_html ) )
		) {

			$fragment = $node->ownerDocument->createDocumentFragment();

			while ( $node->childNodes->length > 0 ) {
				$fragment->appendChild( $node->childNodes->item(0) );
			}

			$node->parentNode->replaceChild( $fragment, $node );

		} elseif ( $node->hasAttributes() ) {

			$this->dom_kses_node_attr( $node, $allowed_html[ $node->nodeName ] );

		}
	}

	/**
	 * Call dom_kses recursively on childNodes.
	 *
	 * Useful for cleaning inner html.
	 *
	 * @param  \DOMNode $node         Dom node
	 * @param  array    $allowed_html kses allowed html.
	 *
	 * @return void.
	 */
	function dom_kses_children( \DOMNode $node, array $allowed_html ) {
		if ( $node->hasChildNodes() ) {
			foreach ( range( $node->childNodes->length - 1, 0 ) as $i ) {
				$this->dom_kses( $node->childNodes->item( $i ), $allowed_html );
			}
		}
	}

	/**
	 * Filter attributes by whitelist
	 *
	 * @param  \DOMNode $node
	 * @param  array    $allowed_attributes
	 * @return [type]                 [description]
	 */
	function dom_kses_node_attr( \DOMNode $node, array $allowed_attr ) {
		if ( $node->hasAttributes() ) {
			foreach ( $node->attributes as $attr ) {
				if ( ! ( isset( $allowed_attr[ $attr->nodeName ] ) && $allowed_attr[ $attr->nodeName ] ) ) {
					$node->removeAttribute( $attr->nodeName );
				}
			}
		}
	}
	
}