Everything we've learned about tiddlers so far can also be applied to the functionality of TiddlyWiki itself, because everything's a tiddler! After completing this chapter, you'll be able to customize TiddlyWiki's interface and behavior in a variety of useful ways, such as by adding buttons to the toolbars, placing predefined content on tiddlers matching some criteria, and creating new forms and interface elements.

We'll start by looking at system tiddlers, plugins, and shadow tiddlers, which are extensions to the normal understanding of tiddlers. Then we'll see how mechanisms built into TiddlyWiki allow us to edit parts of TiddlyWiki's interface and link our own entirely new tiddlers into it – whether that's the sidebar, tiddlers in the story river, or buttons on a toolbar. And we'll work through several example customizations so you can see how these features can be used in real life.

In this chapter

• System Tiddlers – Almost everything in TiddlyWiki is controlled by tiddlers; system tiddlers are those hidden “meta-tiddlers” that control the wiki rather than containing your actual content.
• Plugins – Plugins are bundles of tiddlers that provide new functionality.
• Shadow Tiddlers – Shadow tiddlers are tiddlers that are provided by plugins; they can be overridden if you want to customize a plugin.
• The View Template – The ViewTemplate is a special template TiddlyWiki uses internally to render each story in the story river; you can customize it to add custom content to all tiddlers or a subset of tiddlers.
• Adding to the Sidebar – Arbitrary tiddlers can be added to the sidebar to expose custom navigation options or any other content you like.
• Stamps – Stamps allow quick insertion of commonly-used snippets of text into tiddlers while editing.
• Creating a List of Links and Backlinks – Dive into adding custom tooling to TiddlyWiki by building a list of outbound and inbound links that appears at the bottom of every tiddler.
• Buttons and Input Widgets – Buttons and input widgets allow you to create custom user interfaces that edit fields and take actions in the wiki.
• Creating Tiddlers With Predefined Fields – Explore buttons, system tags, action widgets, and messages by adding new buttons to the toolbar that create tiddlers with some custom field values already in place.
• Overriding Built-In Widgets – Write custom widgets that get transcluded in place of TiddlyWiki's built-in widgets.