caption: genesis
created: 20221101100729587
modified: 20230115101800345
tags: Widgets
title: GenesisWidget
type: text/vnd.tiddlywiki

! Introduction

<<.from-version "5.2.4">> The <<.wid genesis>> widget allows the dynamic construction of another widget, where the name and attributes of the new widget can be dynamically determined, without needing to be known in advance.

! Content and Attributes

The content of the <<.wid genesis>> widget is used as the content of the dynamically created widget.

|!Attribute |!Description |
|$type |The type of widget or element to create (an initial `$` indicates a widget, otherwise an HTML element will be created) |
|$names |An optional filter evaluating to the names of a list of attributes to be applied to the widget |
|$values |An optional filter evaluating to the values corresponding to the list of names specified in <<.attr $names>> |
|//{other attributes starting with $}// |Other attributes starting with a single dollar sign are reserved for future use |
|//{attributes starting with $$}// |Attributes starting with two dollar signs are applied as attributes to the output widget, but with the attribute name changed to use a single dollar sign |
|//{attributes not starting with $}// |Any other attributes that do not start with a dollar are applied as attributes to the output widget |

<<.tip """Note that attributes explicitly specified take precedence over attributes with the same name specified in the <<.attr $names>> filter.""">>

! Examples

<$macrocall $name="wikitext-example"
src="""<$genesis $type="div" class="tc-thing" label="Squeak">Mouse</$genesis>"""/>

<$macrocall $name="wikitext-example"
src="""\define my-banner(mode:"inline",caption)
<$genesis $type={{{ [<__mode__>match[inline]then[span]else[div]] }}} class="tc-mybanner">
<<__caption__>>
</$genesis>
\end

<<my-banner caption:"I'm in a SPAN">>

<<my-banner mode:"block" caption:"I'm in a DIV">>
"""/>

! Important

<$macrocall $name=".warning" _="""
In the following example the widget attribute named `one` is not present in the HTML output. This is because HTML attributes starting with the prefix `on` are removed for security reasons. See [[HTML in WikiText]] "Security" for more details. This restriction only affects generated HTML elements, and does not prevent the use of attributes prefixed `on` with other widgets"""/>

<<wikitext-example '<$genesis $type="my-element" $names="one two" $values="1 2">Test Genesis Widget</$genesis>'>>