The [TemplateData extension](https://www.mediawiki.org/wiki/Special:MyLanguage/Extension:TemplateData)
for MediaWiki has two main JavaScript components:

1. **DataGenerator** — a dialog for editing TemplateData blocks on template pages.
2. **TemplateDiscovery** — a widget for searching and favoriting templates (for use in TemplateWizard and VisualEditor).

The latter has [developer documentation on MediaWiki.org](https://www.mediawiki.org/wiki/Special:MyLanguage/Extension:TemplateData/Template_search_widget)
in addition to the docblocks within the code.