created: 20150220152540000
modified: 20210629215024053
tags: [[Filter Syntax]]
title: Filter Parameter
type: text/vnd.tiddlywiki

<$railroad text="""
( "[" [:{/"anything but ]"/}] "]"
  |
  "{" [:{/"anything but }"/}] "}"
  |
  "<" [:{/"anything but >"/}] ">"
)
"""/>

The parameter to a [[filter operator|Filter Operators]] can be:

;<<.def hard>>
: `[like this]`
: The parameter is the exact text that appears between the square brackets.
;<<.def soft>>
: <<.def indirect>>
:: `{like this}`
:: The parameter is the text indicated by the [[text reference|TextReference]] whose name appears between the curly brackets, i.e. a [[field|TiddlerFields]] of a specified tiddler, or the value of a property of a specified [[data tiddler|DataTiddlers]].
: <<.def variable>>
:: `<like this>`
:: The parameter is the current value of the [[variable|Variables]] whose name appears between the angle brackets. Macro parameters are <<.em not>> supported up to and including ~TiddlyWiki v5.1.23.
::<<.from-version "5.2.0">> Literal macro parameters are supported. For example: `[<now [UTC]YYYY0MM0DD0hh0mm0ssXXX>]`.

<<.from-version "5.1.23">> Filter operators support multiple parameters which are separated by a ` , ` character.

For example: `[param1],[param2]` or `<param1>,{param2}`