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[grauphel.git] / lib / converter / html.php

diff --git a/lib/converter/html.php b/lib/converter/html.php
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+<?php
+/**
+ * Part of grauphel
+ *
+ * PHP version 5
+ *
+ * @category  Tools
+ * @package   Grauphel
+ * @author    Christian Weiske <cweiske@cweiske.de>
+ * @copyright 2014 Christian Weiske
+ * @license   http://www.gnu.org/licenses/agpl.html GNU AGPL v3
+ * @link      http://cweiske.de/grauphel.htm
+ */
+namespace OCA\Grauphel\Lib\Converter;
+use \XMLReader;
+
+/**
+ * Convert Tomboy note XML to HTML
+ *
+ * Tomboy already ships with a converter:
+ * https://git.gnome.org/browse/tomboy/tree/Tomboy/Addins/ExportToHtml/ExportToHtml.xsl
+ * We cannot use it since we want nice callbacks, and we do not want to rely
+ * on the PHP XSL extension, and we have to fix the links.
+ *
+ * @category  Tools
+ * @package   Grauphel
+ * @author    Christian Weiske <cweiske@cweiske.de>
+ * @copyright 2014 Christian Weiske
+ * @license   http://www.gnu.org/licenses/agpl.html GNU AGPL v3
+ * @version   Release: @package_version@
+ * @link      http://cweiske.de/grauphel.htm
+ */
+class Html
+{
+    protected static $tagMap = array(
+        'list'      => 'ul',
+        'list-item' => 'li',
+        'bold'      => 'b',
+        'italic'    => 'i',
+        'monospace' => 'tt',
+    );
+
+    protected static $styleClassMap = array(
+        'strikethrough' => 'strikethrough',
+        'highlight'  => 'highlight',
+        'size:small' => 'small',
+        'size:large' => 'large',
+        'size:huge'  => 'huge',
+    );
+
+    public $internalLinkHandler;
+
+
+
+    public function __construct()
+    {
+        $this->internalLinkHandler = array($this, 'internalLinkHandler');
+    }
+
+    /**
+     * Converts the tomboy note XML into HTML
+     *
+     * @param string $xmlContent Tomboy note content
+     *
+     * @return string HTML
+     */
+    public function convert($xmlContent)
+    {
+        if (strpos($xmlContent, '</link:internal><link:internal>') !== false) {
+            $xmlContent = $this->fixNastyLinks($xmlContent);
+        }
+
+        $html = '';
+        $reader = new XMLReader();
+        $reader->xml(
+            '<?xml version="1.0" encoding="utf-8"?>' . "\n"
+            . '<content xmlns:size="size" xmlns:link="link">'
+            . $xmlContent
+            . '</content>'
+        );
+
+        $withinLink = false;
+        $store = &$html;
+        while ($reader->read()) {
+            switch ($reader->nodeType) {
+            case XMLReader::ELEMENT:
+                //echo $reader->name . "\n";
+                if (isset(static::$tagMap[$reader->name])) {
+                    $store .= '<' . static::$tagMap[$reader->name] . '>';
+                } else if (isset(static::$styleClassMap[$reader->name])) {
+                    $store .= '<span class="'
+                        . static::$styleClassMap[$reader->name]
+                        . '">';
+                } else if (substr($reader->name, 0, 5) == 'link:') {
+                    $withinLink = true;
+                    $linkText    = '';
+                    $store       = &$linkText;
+                }
+                break;
+            case XMLReader::END_ELEMENT:
+                if (isset(static::$tagMap[$reader->name])) {
+                    $store .= '</' . static::$tagMap[$reader->name] . '>';
+                } else if (isset(static::$styleClassMap[$reader->name])) {
+                    $store .= '</span>';
+                } else if (substr($reader->name, 0, 5) == 'link:') {
+                    $withinLink = false;
+                    $store      = &$html;
+                    $linkUrl = htmlspecialchars_decode(strip_tags($linkText));
+                    if ($reader->name == 'link:internal') {
+                        $linkUrl = call_user_func($this->internalLinkHandler, $linkUrl);
+                    } else {
+                        $linkUrl = $this->fixLinkUrl($linkUrl);
+                    }
+                    $store .= '<a href="' . htmlspecialchars($linkUrl) . '">'
+                        . $linkText
+                        . '</a>';
+                }
+                break;
+            case XMLReader::TEXT:
+            case XMLReader::SIGNIFICANT_WHITESPACE:
+                $store .= nl2br(htmlspecialchars($reader->value));
+                break;
+            default:
+                throw new \Exception(
+                    'Unsupported XML node type: ' . $reader->nodeType
+                );
+            }
+        }
+
+        $html = str_replace("</ul><br />\n", "</ul>\n", $html);
+
+        return $html;
+    }
+
+    /**
+     * Fixes external URLs without a protocol
+     *
+     * @param string $linkUrl URL to fix
+     *
+     * @return string Fixed URL
+     */
+    protected function fixLinkUrl($linkUrl)
+    {
+        if ($linkUrl{0} == '/') {
+            //Unix file path
+            $linkUrl = 'file://' . $linkUrl;
+        }
+        return $linkUrl;
+    }
+
+    /**
+     * Dummy internal link handler that simply adds ".htm" to the note title
+     *
+     * @param string $linkUrl Title of page that is linked
+     *
+     * @return string URL to link to
+     */
+    public function internalLinkHandler($linkUrl)
+    {
+        return $linkUrl . '.htm';
+    }
+
+    /**
+     * Re-arranges the XML of formatted links to that clean link tags can
+     * be generated.
+     *
+     * Tomboy 1.15.2 allows link formatting, and the resulting XML is a
+     * mess of multiple(!) link tags that are within or around other formatting
+     * tags.
+     *
+     * This method tries to re-arrange the links so that only a single link tag
+     * appears with all the formatting inside.
+     * 
+     * @param string $xmlContent Tomboy note content
+     *
+     * @return string XML content, with re-arranged link tags.
+     */
+    protected function fixNastyLinks($xmlContent)
+    {
+        preg_match_all(
+            '#(?:<.*>)?<link:internal>.+</link:internal><link:internal>.+</link:internal>#U',
+            $xmlContent,
+            $matches
+        );
+
+        foreach ($matches[0] as $nastyLink) {
+            $cleaner = str_replace('</link:internal><link:internal>', '', $nastyLink);
+            $cleaner = preg_replace('#<([a-z]+)><(link:internal)>#U', '<\2><\1>', $cleaner);
+            $cleaner = preg_replace('#</(link:internal)></([a-z]+)>#U', '</\2></\1>', $cleaner);
+            $cleaner = str_replace('</link:internal><link:internal>', '', $cleaner);
+            $xmlContent = str_replace($nastyLink, $cleaner, $xmlContent);
+        }
+
+        return $xmlContent;
+    }
+}
+?>