~TiddlyWiki provides several macros for generating a tree of tiddler links by analysing tiddler [[tagging|Tagging]]. The table of contents is generated as a HTML ordered list. The `<ol>` elements always have the class `tc-toc`. Expandable trees have the additional class `tc-toc-expandable`. Selectively expandable trees (including those in the two-panel browser) have `tc-toc-selective-expandable`.
To make a table of contents appear in the sidebar, see [[How to add a new tab to the sidebar]].
: This optional parameter can be used to exclude tiddlers from the TOC list. It allows a [[Title List]] or a <<.olink subfilter>>. Eg: `exclude:"HelloThere [[Title with spaces]]"` or `exclude:"[has[excludeTOC]]"`. Where the former will exclude two tiddlers and the later would exclude every tiddler that has a field <<.field excludeTOC>> independent of its value.<br>''Be aware'' that eg: `[prefix[H]]` is a shortcut for `[all[tiddlers]prefix[H]]`, which can have a performance impact, if used carelessly. So use $:/AdvancedSearch -> ''Filters'' tab to test the <<.param exclude>> parameter
: The title of the [[state tiddler|StateMechanism]] for noting the currently selected tiddler, defaulting to `$:/temp/toc/selectedTiddler`. It is recommended that this be a [[system tiddler|SystemTiddlers]]
The top level of the tree consists of the tiddlers that carry a particular tag, known as the <<.def "root tag">>. Tiddlers tagged with any of those make up the next level down, and so on.
At each level, the tiddlers can be [[ordered|Order of Tagged Tiddlers]] by means of the <<.field list>> field of the parent tag tiddler. They can also be ordered by the macro's <<.param sort>> parameter.
!!! Tiddler Fields
; caption
: The tree displays the <<.field caption>> field of a tiddler if it has one, or the tiddler's <<.field title>> otherwise.
; toc-link
: Each tiddler in the tree is normally displayed as a link. To suppress this, give the tiddler a <<.field toc-link>> field with the the value <<.value no>>. In the [[examples|Table-of-Contents Macros (Examples)]], the SecondThree tiddler is set up like this. Clicking such a tiddler in the tree causes its branch to expand or collapse.
; target
:<<.from-version "5.1.23">> By default, the links open the tiddlers making up the table of contents. Alternatively, if the tiddler contains a <<.field target>> field then its contents will be used as the target of the link.
To change the icons used by the Table-of-Contents macros, redefine the macros `toc-open-icon` and `toc-closed-icon`. This setting works for all toc-macro variants.
The default settings can be overwritten in your code using the define-pragma or the let-widget. The <<.wlink LetWidget>> widget can be used, if you have multiple table of contents macros in one tiddler, that need different icons.
