store references in the renderer

The plugin gets reused for multiple renderers, but we need independend
references for each one. So we put them into the meta array of the
renderer.

syntax.php

@@ -15,12 +15,6 @@ require_once(__DIR__ . '/lib/grammar.php');
 
 class syntax_plugin_ifauthex extends DokuWiki_Syntax_Plugin
 {
-    /** @var null|string The original document */
-    protected $originalDoc = null;
-    /** @var bool is the current document diverted? */
-    protected $isDiverted = false;
-
-
     /** @inheritDoc */
     public function getType()
     {
@@ -118,10 +112,10 @@ class syntax_plugin_ifauthex extends DokuWiki_Syntax_Plugin
                     $shouldRender = (bool) $exprOrMatch->evaluate();
                     if(!$shouldRender) {
                         // point the renderer's doc to something else, remembering the old one
-                        $this->originalDoc = &$renderer->doc;
+                        $renderer->meta['ifauthex.originalDoc'] = &$renderer->doc;
                         $ignoredDoc = '';
                         $renderer->doc = &$ignoredDoc;
-                        $this->isDiverted = true;
+                        $renderer->meta['ifauthex.isDiverted'] = true;
                     }
                 } catch (Exception $e) {
                     // something went wrong parsing the expression
@@ -134,8 +128,9 @@ class syntax_plugin_ifauthex extends DokuWiki_Syntax_Plugin
                 break;
             case DOKU_LEXER_EXIT:
                 // point the renderer's doc back to the original
-                if($this->isDiverted) {
-                    $renderer->doc = &$this->originalDoc;
+                if($renderer->meta['ifauthex.isDiverted']) {
+                    $renderer->doc = &$renderer->meta['ifauthex.originalDoc'];
+                    $renderer->meta['ifauthex.isDiverted'] = false;
                 }
                 break;
         }