add related component per feature request dokufreaks#184

syntax/related.php

@@ -0,0 +1,155 @@
+<?php
+/**
+ * Tag Plugin, related component: displays links to all wiki pages with related tags
+ * 
+ * @license  GPL 2 (http://www.gnu.org/licenses/gpl.html)
+ * @author   Esther Brunner <[email protected]>
+ */
+
+// must be run within Dokuwiki
+if (!defined('DOKU_INC')) die();
+
+if (!defined('DOKU_PLUGIN')) define('DOKU_PLUGIN',DOKU_INC.'lib/plugins/');
+
+/**
+ * Topic syntax, displays links to all wiki pages with a certain tag
+ */
+class syntax_plugin_tag_related extends DokuWiki_Syntax_Plugin {
+
+    /**
+     * @return string Syntax type
+     */
+    function getType() { return 'substition'; }
+
+    /**
+     * @return string Paragraph type
+     */
+    function getPType() { return 'block'; }
+
+    /**
+     * @return int Sort order
+     */
+    function getSort() { return 295; }
+
+    /**
+     * @param string $mode Parser mode
+     */
+    function connectTo($mode) {
+        $this->Lexer->addSpecialPattern('\{\{related>.+?\}\}',$mode,'plugin_tag_related');
+    }
+
+    /**
+     * Handle matches of the topic syntax
+     *
+     * @param string $match The match of the syntax
+     * @param int    $state The state of the handler
+     * @param int    $pos The position in the document
+     * @param Doku_Handler    $handler The handler
+     * @return array Data for the renderer
+     */
+    function handle($match, $state, $pos, Doku_Handler $handler) {
+        global $ID, $INFO;
+
+        $match = substr($match, 10, -2); // strip {{related> from start and }} from end
+        list($match, $flags) = explode('&', $match, 2);
+        $flags = explode('&', $flags);
+        list($ns, $tag) = explode('?', $match);
+
+        if (!$tag) {
+            $tag = $ns;
+            $ns   = '';
+        }
+
+                $num = $tag;
+                if (!is_numeric($num)) {
+                        $num = 5;
+                }
+
+        if (($ns == '*') || ($ns == ':')) $ns = '';
+        elseif ($ns == '.') $ns = getNS($INFO['id']);
+        else $ns = cleanID($ns);
+
+                if (is_array(p_get_metadata($INFO['id'], 'subject'))) {
+                        $tag = implode(" ", p_get_metadata($INFO['id'], 'subject'));
+                } else {
+                        $tag = '';
+                }
+
+        return array($ns, trim($tag), $flags, $num);
+    }
+
+    /**
+     * Render xhtml output or metadata
+     *
+     * @param string         $mode      Renderer mode (supported modes: xhtml and metadata)
+     * @param Doku_Renderer  $renderer  The renderer
+     * @param array          $data      The data from the handler function
+     * @return bool If rendering was successful.
+     */
+    function render($mode, Doku_Renderer $renderer, $data) {
+                global $ID, $INFO;
+        list($ns, $tag, $flags, $num) = $data;
+
+        /* @var helper_plugin_tag $my */
+        if ($my = $this->loadHelper('tag')) $pages = $my->getTopic($ns, '', $tag);
+        if (!isset($pages) || !$pages) return true; // nothing to display
+
+        if ($mode == 'xhtml') {
+            /* @var Doku_Renderer_xhtml $renderer */
+
+            // prevent caching to ensure content is always fresh
+            $renderer->info['cache'] = false;
+
+            /* @var helper_plugin_pagelist $pagelist */
+            // let Pagelist Plugin do the work for us
+            if ((!$pagelist = $this->loadHelper('pagelist'))) {
+                return false;
+            }
+            $pagelist->sort = false;
+            $pagelist->rsort = false;
+
+            $configflags = explode(',', str_replace(" ", "", $this->getConf('pagelist_flags')));
+                $flags = array_merge($configflags, $flags);
+                foreach($flags as $key => $flag) {
+                        if($flag == "") unset($flags[$key]);
+                }     
+                        $subject1 = p_get_metadata($INFO['id'], 'subject');
+                        if (!is_array($subject1)) { return false; }
+                        foreach ($pages as &$page) {
+                $count = count(array_intersect($subject1, p_get_metadata($page['id'], 'subject')));
+                                $page['count'] = $count;
+                        }
+                        foreach ($pages as $key => $page) {
+                if ($page['id'] == $INFO['id']) { unset($pages[$key]); }
+                                if ($page['count'] == 0) { unset($pages[$key]); }
+                        }
+                        // remove duplicates
+            $pages = array_map("unserialize", array_unique(array_map("serialize", $pages)));
+                        $pagelist->setFlags($flags);
+            $pagelist->startList('related');
+
+            // Sort pages by pagename if required by flags
+            $fnc = create_function('$a, $b', 'return strcmp($a["count"], $b["count"]); ');
+                usort($pages, $fnc);
+                // reverse sort the pages
+                krsort($pages);
+                        $pages = array_slice($pages, 0, $num, true);
+
+            foreach ($pages as $page) {
+                $pagelist->addPage($page);
+            }
+            $renderer->doc .= $pagelist->finishList();      
+            return true;
+
+        // for metadata renderer
+/*        } elseif ($mode == 'metadata') {
+            foreach ($pages as $page) {
+                $renderer->meta['relation']['references'][$page['id']] = true;
+            }
+
+            return true;*/ // causes issues with backlinks
+        }
+        return false;
+    }
+}
+// vim:ts=4:sw=4:et: