TiddlyWiki5/editions/tw5.com/tiddlers/wikitext/Variables in WikiText.tid

caption: Variables
created: 20141002141231992
modified: 20150221221850000
tags: WikiText
title: Variables in WikiText
type: text/vnd.tiddlywiki

See also the [[introduction to the concept of variables|Variables]].

To transclude the value of a variable, use the [[macro call syntax|Macro Calls in WikiText]] with no parameters. You can also use a <<.wlink MacroCallWidget>> widget.

A [[macro|Macros]] snippet can contain `$(name)$` as a [[placeholder|Macro Definitions in WikiText]] for which the value of the variable of that name will be substituted.

A variable's value can be used as a [[filter parameter|Filter Parameter]], or as a [[widget attribute|Widgets in WikiText]]. The latter supports macro parameters.

!! Example: defining a variable

<$macrocall $name=".example" n="1"
eg="""<$set name=animal value=zebra>
<<animal>>
</$set>"""/>

!! Example: defining a macro

The `\define` pragma below [[defines a macro|Macros in WikiText]] called <<.var tags-of-current-tiddler>>. The macro returns the value of the tiddler's <<.field tags>> field, and can be accessed from anywhere else in the same tiddler (or in any tiddler that [[imports|ImportVariablesWidget]] it).

<$importvariables filter="$:/editions/tw5.com/macro-examples/tags-of-current-tiddler">
<$codeblock code={{$:/editions/tw5.com/macro-examples/tags-of-current-tiddler}}/>
<$macrocall $name=".example" n="2" eg="""The tags are: <<tags-of-current-tiddler>>"""/>
</$importvariables>

!! Example: using a variable as a filter parameter

This example uses the <<.olink backlinks>> [[operator|Filter Operators]] to list all tiddlers that link to this one.

<$macrocall $name=".example" n="3" eg="""<<list-links filter:"[<currentTiddler>backlinks[]]">>"""/>
update WidgetVariable documentation 2014-10-02 23:15:06 +00:00			`caption: Variables`
add WidgetVariable documentation 2014-10-02 15:02:48 +00:00			`created: 20141002141231992`
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`modified: 20150221221850000`
add WidgetVariable documentation 2014-10-02 15:02:48 +00:00			`tags: WikiText`
			`title: Variables in WikiText`
			`type: text/vnd.tiddlywiki`

Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`See also the [[introduction to the concept of variables\|Variables]].`
add WidgetVariable documentation 2014-10-02 15:02:48 +00:00
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`To transclude the value of a variable, use the [[macro call syntax\|Macro Calls in WikiText]] with no parameters. You can also use a <<.wlink MacroCallWidget>> widget.`
add WidgetVariable documentation 2014-10-02 15:02:48 +00:00
Update Variables in WikiText.tid swapped `$(name$)` for `$(name)$` in line 12 2015-05-22 00:24:39 +00:00			A [[macro\|Macros]] snippet can contain `$(name)$` as a [[placeholder\|Macro Definitions in WikiText]] for which the value of the variable of that name will be substituted.
add WidgetVariable documentation 2014-10-02 15:02:48 +00:00
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`A variable's value can be used as a [[filter parameter\|Filter Parameter]], or as a [[widget attribute\|Widgets in WikiText]]. The latter supports macro parameters.`
add WidgetVariable documentation 2014-10-02 15:02:48 +00:00
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`!! Example: defining a variable`
add WidgetVariable documentation 2014-10-02 15:02:48 +00:00
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`<$macrocall $name=".example" n="1"`
			`eg="""<$set name=animal value=zebra>`
			`<<animal>>`
			`</$set>"""/>`
add WidgetVariable documentation 2014-10-02 15:02:48 +00:00
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`!! Example: defining a macro`
updates to variable documentation 2015-01-07 15:18:36 +00:00
Wrong macro name in example description The \define pragma below defines a macro called tags. should be: The \define pragma below defines a macro called tags-of-current-tiddler. 2015-06-30 09:01:49 +00:00			The `\define` pragma below [[defines a macro\|Macros in WikiText]] called <<.var tags-of-current-tiddler>>. The macro returns the value of the tiddler's <<.field tags>> field, and can be accessed from anywhere else in the same tiddler (or in any tiddler that [[imports\|ImportVariablesWidget]] it).
updates to variable documentation 2015-01-07 15:18:36 +00:00
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`<$importvariables filter="$:/editions/tw5.com/macro-examples/tags-of-current-tiddler">`
			`<$codeblock code={{$:/editions/tw5.com/macro-examples/tags-of-current-tiddler}}/>`
			`<$macrocall $name=".example" n="2" eg="""The tags are: <<tags-of-current-tiddler>>"""/>`
			`</$importvariables>`
updates to variable documentation 2015-01-07 15:18:36 +00:00
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`!! Example: using a variable as a filter parameter`
updates to variable documentation 2015-01-07 15:18:36 +00:00
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`This example uses the <<.olink backlinks>> [[operator\|Filter Operators]] to list all tiddlers that link to this one.`
updates to variable documentation 2015-01-07 15:18:36 +00:00
Overhaul the macro and variable documentation #1519 2015-02-24 16:41:16 +00:00			`<$macrocall $name=".example" n="3" eg="""<<list-links filter:"[<currentTiddler>backlinks[]]">>"""/>`