A metadata is a renderer type (parsing mode) that is used to create metadata.
See:
Internally DokuWiki maintains two arrays of metadata
If you want to create logic that persists:
Metadata: The metadata rendering is only started by the p_get_metadata() and p_set_metadata().
with the render option possible values:
Persisent:
Current:
Example
global $ID
p_set_metadata(
$ID,
array($key => $value),
$render = false,
$persistent = true
);
https://www.dokuwiki.org/devel:event:parser_metadata_render - Signalled by p_render_metadata() in inc/parserutils.php before instantiating the metadata renderer.
To get persistent metadata
To get volatile meta:
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.