<?php

/**
 * @file classes/xslt/XSLTransformationFilter.inc.php
 *
 * Copyright (c) 2014-2021 Simon Fraser University
 * Copyright (c) 2000-2021 John Willinsky
 * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
 *
 * @class XSLTransformationFilter
 * @ingroup xslt
 *
 * @brief Class that transforms XML via XSL.
 */

import('lib.pkp.classes.filter.PersistableFilter');
import('lib.pkp.classes.xslt.XSLTransformer');

class XSLTransformationFilter extends PersistableFilter {
	/**
	 * Constructor
	 *
	 * @param $filterGroup FilterGroup
	 * @param $displayName string
	 *
	 * NB: The input side of the transformation must always
	 * be an XML format. See the XMLTypeDescription class for
	 * more details how to enable XML validation.
	 */
	function __construct($filterGroup, $displayName = 'XSL Transformation') {
		// Check that we only get xml input, the output type is arbitrary.
		if (!substr($filterGroup->getInputType(), 0, 5) == 'xml::') fatalError('XSL filters need XML as input.');

		// Instantiate the settings of this filter
		import('lib.pkp.classes.filter.FilterSetting');
		$this->addSetting(new FilterSetting('xsl', null, null));
		$this->addSetting(new FilterSetting('xslType', null, null));
		$this->addSetting(new FilterSetting('resultType', null, null, FORM_VALIDATOR_OPTIONAL_VALUE));

		$this->setDisplayName($displayName);

		parent::__construct($filterGroup);
	}


	//
	// Getters and Setters
	//
	/**
	 * Get the XSL
	 * @return DOMDocument|string a document, xsl string or file name
	 */
	function &getXSL() {
		return $this->getData('xsl');
	}

	/**
	 * Get the XSL Type
	 * @return integer
	 */
	function getXSLType() {
		return $this->getData('xslType');
	}

	/**
	 * Set the XSL
	 * @param $xsl DOMDocument|string
	 */
	function setXSL(&$xsl) {
		// Determine the xsl type
		if (is_string($xsl)) {
			$this->setData('xslType', XSL_TRANSFORMER_DOCTYPE_STRING);
		} elseif (is_a($xsl, 'DOMDocument')) {
			$this->setData('xslType', XSL_TRANSFORMER_DOCTYPE_DOM);
		} else assert(false);

		$this->setData('xsl', $xsl);
	}

	/**
	 * Set the XSL as a file name
	 * @param $xslFile string
	 */
	function setXSLFilename($xslFile) {
		$this->setData('xslType', XSL_TRANSFORMER_DOCTYPE_FILE);
		$this->setData('xsl', $xslFile);
	}

	/**
	 * Get the result type
	 * @return integer
	 */
	function getResultType() {
		return $this->getData('resultType');
	}

	/**
	 * Set the result type
	 * @param $resultType integer
	 */
	function setResultType($resultType) {
		$this->setData('resultType', $resultType);
	}


	//
	// Implement template methods from PersistableFilter
	//
	/**
	 * @see PersistableFilter::getClassName()
	 */
	function getClassName() {
		return 'lib.pkp.classes.xslt.XSLTransformationFilter';
	}


	//
	// Implement template methods from Filter
	//
	/**
	 * Process the given XML with the configured XSL
	 * @see Filter::process()
	 * @param $xml DOMDocument|string
	 * @return DOMDocument|string
	 */
	function &process(&$xml) {
		// Determine the input type
		if (is_string($xml)) {
			$xmlType = XSL_TRANSFORMER_DOCTYPE_STRING;
		} elseif (is_a($xml, 'DOMDocument')) {
			$xmlType = XSL_TRANSFORMER_DOCTYPE_DOM;
		} else assert(false);

		// Determine the result type based on
		// the input type if it has not been
		// set explicitly.
		if (is_null($this->getResultType())) {
			$this->setResultType($xmlType);
		}

		// Transform the input
		$xslTransformer = new XSLTransformer();
		$result = $xslTransformer->transform($xml, $xmlType, $this->getXsl(), $this->getXslType(), $this->getResultType());
		return $result;
	}
}