listIndex Mode

Using the checkbox widget in index list mode requires the listIndex attribute to specify the the property of a DataTiddler. This property contains a list. The checked attribute specifies the value that should be present or absent in the list when the checkbox is checked or unchecked respectively. If checked is absent (or empty) but unchecked is present, then the logic will be inverted: the checkbox will be checked when the unchecked value is missing from the list, and unchecked when the unchecked value is found in the list. If both checked and unchecked are present, the checkbox will work like a toggle, replacing the checked value with the unchecked value and vice-versa. Finally, if neither checked nor unchecked is specified, the checkbox will be checked if the field has anything in it, but unchecked if the field is missing or empty. (This is rarely useful. Most of the time you want to specify checked or unchecked or both.)

The default attribute is used as a fallback for the checkbox state if the property is undefined.

The following table summarizes the possible combinations:

The example below creates three checkboxes that each control a different value in a property of the ExampleData tiddler.

<$set name=indexName filter="[<currentTiddler>addsuffix[ Colors]]" >
<$checkbox tiddler="ExampleData" listIndex=<<indexName>> checked="green" unchecked="red" default="red"> Green or red?</$checkbox><br/>
<$checkbox tiddler="ExampleData" listIndex=<<indexName>> checked="yellow" unchecked="blue" default="blue"> Yellow or blue?</$checkbox><br/>
<$checkbox tiddler="ExampleData" listIndex=<<indexName>> checked="orange" unchecked="purple" default="purple"> Orange or purple?</$checkbox><br/>
Colors list: <$text text={{{ [[ExampleData]getindex<indexName>] }}} />
</$set>