created: 20130827075900000
modified: 20161216173541948
tags: Concepts
title: TextReference
type: text/vnd.tiddlywiki

A TextReference is a general purpose way to describe a fragment of text as either a field of a tiddler, or an index within a [[data tiddler|DataTiddlers]].

In different situations, text references can be used to retrieve values, or to specify a value that should be modified.

A TextReference consists of several parts:

* The title of the target tiddler. If omitted, it defaults to the [[Current Tiddler]]
* Either one of:
** The name of a field (marked with `!!`)
** The name of an index within a [[data tiddler|DataTiddlers]] (marked with `##`)
* If both the field and index are omitted, the text field is used as the default

Most of the parts of a text reference can be optional:

* `tiddlerTitle` - the title [[field|TiddlerFields]] of the specified tiddler
* `tiddlerTitle!!field` - a [[tiddler field|TiddlerFields]] (eg, `modified`, `modifier`, `type` etc)
* `!!field` - a [[field|TiddlerFields]] of the current tiddler
* `tiddlerTitle##propertyIndex` - extracts a named property from DataTiddlers

Text references can be used in several places:

* As [[indirect parameters|Filter Parameter]] within [[Filters]] (eg, `<$list filter="[tag{MyTag!!name}]"/>`)
* As [[indirect attributes|HTML in WikiText]] of an element or widget (eg, `<$widget attrib={{Title!!description}}/>`)
* As the operand of a shortcut transclusion (eg, `{{MyTiddler!!title}}`)
* As the `state` attribute of the RevealWidget and the LinkCatcherWidget

<$macrocall $name=".tip" _="""Note the distinction between a text reference such as `foo!!bar` and a transclusion of a text reference such as `{{foo!!bar}}`"""/>