====== Renderer Plugins ======

[[plugintype>8#extension__table|Renderer plugins]] aka. pluggable renderers, allow to implement different rendering mechanisms for DokuWiki. DokuWiki parses Wiki syntax into an instruction array which then is “rendered” to the desired output format. This output format is usually the XHTML to display a nicely formatted Wiki page. Pluggable renderers allow plugin authors to write their own renderer to output any format they want.

===== Synopsis =====

A Renderer Plugin //Example// needs:
  * class name  ''renderer_plugin_example''
  * which extends [[xref>inc::Doku_Renderer|Doku_Renderer]]((defined in [[xref>inc/parser/renderer.php]])) or one of it's subclasses. 
  * to be stored in a file ''lib/plugins/example/renderer.php''.
Moreover, a [[plugin_info|plugin.info.txt]] file is needed. For full details of plugins and their files and how to create more renderer components refer to [[plugin file structure]].

===Required implementation===
  * You need to implement all methods of the ''Doku_Renderer'' class to implement full output of all DokuWiki's markup.
  * **''getFormat()''** Returns format of the renderer

===Optional implementation===
  * **''canRender($format)''** Needs to return true for ''%%$format = 'xhtml'%%''. This function is needed for a replacement renderer, so DokuWiki knows that it should be displayed in its configuration manager as a xhtml replacement.


==== Inherited methods ====
  * **''nocache()''** Switches off the caching
  * **''notoc()''** Switches off the Table of Contents
  * **''isSingleton()''** Returns default false, so the plugin has to be instantiated every use.

  * **''_simpleTitle($name)''** Removes any namespace from ''$name'' but keeps casing and special chars.
  * **''_resolveInterWiki(&$shortcut, $reference)''** Resolves an interwikilink

  * See [[devel:common plugin functions]] for inherited function available to all plugins. e.g. localisation, configuration and introspection.



===== Calling a Renderer Plugin =====

There are two mechanisms for calling a renderer plugin.

==== Export ====

All renderers can be accessed through the **export** command. This is primarily used to [[:export]] wiki pages to usually non-xhtml formats.

The output of the plugin is accessed by appending **''do=export_<plugin name>''** to the page URL.\\ e.g. ''%%http://www.mywiki.com/doku.php?id=somepage&do=export_s5%%''\\
 or with [[:rewrite|URL rewriting]] ''%%http://www.mywiki.com/somepage?do=export_s5%%''.

To make the plugin's export mode accessible to the wiki user, add a button or link somewhere using a [[devel:Syntax Plugins|syntax plugin]] or [[devel:Action Plugins|action plugin]]. To create the correct link you should use the [[xref>exportlink|exportlink()]] function.

When your plugin creates a different output format than ''text/html'', you need to set all needed HTTP headers in the metadata of the page. This is best done in the [[xref>document_start|document_start()]] method of your renderer. Here is an example from the [[plugin:ODT]] plugin (''[[https://codesearch.dokuwiki.org/xref/plugin/odt/renderer/page.php|odt/renderer/page.php]]''):

<code php>
public function document_start() {
    ...
    ...
    $filename = noNS($ID) . '.odt';
    $headers = [
        'Content-Type' => 'application/vnd.oasis.opendocument.text',
        'Content-Disposition' => 'attachment; filename="' . $filename . '";'
    [;
    p_set_metadata($ID, ['format' => ['odt' => $headers]]);
}
</code>

Typical examples of export renderer plugins are:

  * [[plugin:S5]]
  * [[plugin:ODT]]
  * [[plugin:slideshow]]


==== Replacement Default Renderer ====

The [[config:renderer_xhtml]] configuration setting allows you to replace DokuWiki's default renderer with your own. Only xhtml renderer plugins should be used for this. Also it's only possible to have one render at a time with this method. For example you have to choose between [[plugin:noblankcells]] and [[plugin:purplenumbers]]. 

Plugins which wish to use this method should also implement the ''canRender()'' method:

<code php>
public function canRender($format) {
    return ($format == 'xhtml');
}
</code>

This method allows DokuWiki to list the plugin in the options for renderer_xhtml setting in its Configuration Manager.

:!: Don't forget to mention the [[config:renderer_xhtml]] setting on the plugin page.

Typical examples of a replacement renderer plugin are:

  * [[plugin:XBR]]
  * [[plugin:noblankcells]]
  * [[plugin:purplenumbers]]
  * [[plugin:nodetailsxhtml]]

When a renderer plugin is disabled or uninstalled, it falls back to the default bundled renderer of the requested output format.

===== Further reading =====

  * [[Plugin programming tips]]
  * [[parser|The DokuWiki Parser]]
  * [[plugins|Plugin Development]]
  * [[plugintype>8#extension__table|Available renderer plugins]]