Dokuwiki - Metadata Renderer

About

A metadata is a renderer type (parsing mode) that is used to create metadata.

See:

• Metadata Caching
• Metadata

Articles Related

Type

Internally DokuWiki maintains two arrays of metadata

• current (current metadata should only be set in the context of the renderer as it will be overwritten the next time metadata is rendered)
• persistent. (The persistent array holds duplicates of those key/values which should not be cleared during the rendering process.)

If you want to create logic that persists:

• only in the scope of a session (example, add a library at the end of a template if a syntax is present): use current
• for all scope that is data dependent: use persistent

Management

Start

Metadata: The metadata rendering is only started by the p_get_metadata() and p_set_metadata().

with the render option possible values:

• METADATA_RENDER_USING_CACHE (default)
• METADATA_DONT_RENDER,
• METADATA_RENDER_USING_SIMPLE_CACHE,
• METADATA_RENDER_UNLIMITED (also combined with the previous two options),

Set

Persisent:

• renderer→persistent
• p_set_metadata set metadata.

Current:

• renderer→meta

Example

global $ID
p_set_metadata(
    $ID,
    array($key => $value),
    $render = false,
    $persistent = true
);

Event

https://www.dokuwiki.org/devel:event:parser_metadata_render - Signalled by p_render_metadata() in inc/parserutils.php before instantiating the metadata renderer.

Get

To get persistent metadata

• p_get_metadata
• or the array renderer→persistent

To get volatile meta:

• renderer→meta

Update

Metadata update happens asynchronously via the taskrunner

The task runner is located in lib/exe/taskrunner.php and is included as hidden image by the tpl_indexerWebBug() function.