mirror of
https://github.com/Jermolene/TiddlyWiki5
synced 2024-11-07 18:39:57 +00:00
2bfe522b72
* $let widget added and tested * Documentation for $let, doc improvements for $vars * let properly avoids refreshing when possible * $let Changes as recommended by others * Removed superfluous super method call Also improved $let test
53 lines
1.9 KiB
Plaintext
53 lines
1.9 KiB
Plaintext
title: VarsWidget
|
|
created: 20150426115958020
|
|
modified: 20150426115958020
|
|
tags: Widgets
|
|
caption: vars
|
|
|
|
! Introduction
|
|
|
|
The <<.wid vars>> widget allows multiple variables to be set in one operation. In some situations it can result in simpler code than using the more flexible <<.wlink SetWidget>> widget. It differs from the <<.wlink LetWidget>> in that variables cannot interfere with the evaluation of other variables within the same <<.wid vars>>.
|
|
|
|
! Content and Attributes
|
|
|
|
The content of the <<.wid vars>> widget is the scope for the value assigned to the variable.
|
|
|
|
|!Attribute |!Description |
|
|
|//{attributes not starting with $}// |Each attribute name specifies a variable name. The attribute value is assigned to the variable |
|
|
|
|
Attributes will not interfere with the evaluation of other attributes. So if one attribute sets <<.attr currentTiddler>>, and another attribute uses <<.attr currentTiddler>> in its evaluation, it will use the value of <<.attr currentTiddler>> that exists outside the widget's scope.
|
|
|
|
! Examples
|
|
|
|
Consider a case where you need to set multiple variables.
|
|
|
|
Using the <<.wid vars>> widget, this situation may be handled in the following way:
|
|
|
|
```
|
|
\define helloworld() Hello world!
|
|
|
|
<$vars greeting="Hi" me={{!!title}} sentence=<<helloworld>>>
|
|
<<greeting>>! I am <<me>> and I say: <<sentence>>
|
|
</$vars>
|
|
```
|
|
|
|
In contrast, here is the same example using the <<.wid set>> widget:
|
|
|
|
```
|
|
<$set name="greeting" value="Hi" >
|
|
<$set name="me" value={{!!title}} >
|
|
<$set name="sentence" value=<<helloworld>> >
|
|
<<greeting>>! I am <<me>> and I say: <<sentence>>
|
|
</$set>
|
|
</$set>
|
|
</$set>
|
|
```
|
|
|
|
! Remarks
|
|
|
|
It should be noted that this widget differs from the <<.wid set>> widget in the following ways:
|
|
|
|
* A fallback (also known as "emptyValue") cannot be specified
|
|
* Filters cannot be used to produce a conditional variable assignement
|
|
* Variable names must be literal strings
|