source: extensions/Piwecard/ws/ws_functions.inc.php

<?php

if (!defined('PHPWG_ROOT_PATH')) die('Hacking attempt!');

$service = &$arr[0];
$service->addMethod('pwg.piwecard.previewEmail', 'piwecard_ws_previewEmail',
        array(
                'format_message'=>array(),
                'message'=>array(),
        ),
        'Preview the email'
);

/**
 * Function called by Javascript
 * @param Array Parameters passed through Javascript
 * @param
 * @return String the preview of the email
 */
function piwecard_ws_previewEmail($params, $service) {
        $format_message = $params['format_message'];
        $message = $params['message'];
        
        return previewEmail($format_message, $message);
}

/**
 * Construct the preview of the email
 * @param String Email format (text or html)
 * @param String the email message
 * @return String the preview of the email
 */
function previewEmail($format_message, $message) {
        $piwecard = new Piwecard();

        $template_mail = new Template(PIWECARD_MAIL_PATH.'template');
        $smarty = $template_mail->smarty;
        
        if ($format_message == 'text') {
                $message_output = nl2br($piwecard->get_text_message(stripslashes(parse($message)), $smarty));
                $style = '';
        } elseif ($format_message == 'html') {
                $output = $piwecard->get_html_message(stripslashes(parse($message)), $smarty);
                $dom_document = new DOMDocument();
                $dom_document->loadHTML($output);
                $styles = piwecard_create_style_array($dom_document->getElementsByTagName('style')->item(0)->nodeValue);
                $message_output = $dom_document->getElementsByTagName('body')->item(0);
                $email_body = $dom_document->createElement('div');
                $email_body->setAttribute('id', 'email_body');
                $message_output->parentNode->insertBefore($email_body, $message_output);
                $email_body->appendChild($message_output);
                foreach ($styles as $id => $style) {
                        $dom_document->getElementById(str_replace('#', '', $id))->setAttribute("style", $style);
                }
                $message_output = $dom_document->saveHTML();
        }

        return array('message' => $message_output);
}

/**
 * Get style from the email template
 * @param String The value of the node "Style"
 * @return Array the styles of the email
 */
function piwecard_create_style_array($style) {
        $style = str_replace(array("\n", "\t"), array('', ''), $style);
        $tok = strtok($style, "{}");
        
        $sarray = array();
        while ($tok !== false) {
                array_push($sarray, trim($tok));
                $tok = strtok("{}");
        }

        $styles = array();

        for($i = 0; $i<count($sarray)-2; $i+=2){
                $styles[$sarray[$i]] = $sarray[$i+1];
        }

        return $styles;
}

/**
 * Parse the email message
 * @param String message to parse
 * @return String parsed message
 */
function parse($data) {
        global $conf;
        
        set_make_full_url();
        $ecard_parse = array(
                        '%yourname%'            => 'Your Name',
                        '%youremail%'           => 'Your email',
                        '%recipientname%'       => 'Recipient name',
                        '%recipientemail%'      => 'Recipient email',
                        '%website%'                     => isset($conf['gallery_title']) ? $conf['gallery_title'] : '' ,
                        '%websiteurl%'          => get_absolute_root_url() ,
                        '%ecardurl%'            => '',
                        '%ecardtitle%'          => 'Ecard title',
                        '%ecardmessage%'        => 'The message of the ecard',
                        '%pictureurl%'          => get_root_url().PIWECARD_PATH.'admin/images/image_thumb.jpg',
                        '%pictureinfos%'        => '<small>Image infos</small>',
                        );
        unset_make_full_url();
        
        $patterns = array();
        $replacements = array();
        foreach ($ecard_parse as $key => $value) {
                array_push($patterns, $key); 
                array_push($replacements, $value);
        }

        return str_replace($patterns, $replacements, $data);
}