created: 20221007125701001
modified: 20230419103154329
tags: WikiText Procedures
title: Procedure Definitions
type: text/vnd.tiddlywiki

!! Introduction

This tiddler describes the different ways in which [[Procedures|Procedures]] can be defined.

!! Procedure Definition Pragma

Procedures are created using the [[Pragma: \procedure]] at the start of a tiddler. The definitions are available in the rest of the tiddler that defines them, plus any tiddlers that it transcludes.

```
\define my-procedure(param)
This is the procedure text (param=<<param>>)
\end
```

!! Procedure Definition with Set Widget

Procedures are implemented as a special kind of [[variable|Variables]] and so internally are actually defined with a <<.wlink SetWidget>> widget.

```
<$set name="my-procedure" value="This is the procedure text">
...
</$set>
```

<<.note """that it is not currently possible to specify parameters when defining a procedure with the  <<.wlink SetWidget>> widget.""">>

!! Importing Procedure Definitions

The [[Pragma: \import]] or <<.wlink ImportVariablesWidget>> widget can be used to copy procedure definitions from another tiddler.

!! `$:/tags/Global` Tag

Global procedures can be defined using the [[SystemTag: $:/tags/Global]].

The tag [[SystemTag: $:/tags/Global/View]] is used to define procedures that should only be available within the main view template and the preview panel.

The tag [[SystemTag: $:/tags/Global/View/Body]] is used to define procedures that should only be available within the main view template body and the preview panel.
