The action-listops widget is an action widget that manipulates user lists in any field or data index. ActionWidgets are used within triggering widgets such as the ButtonWidget.
The action-listops widget is invisible. Any content within it is ignored.
| Attribute | Description |
|---|---|
| $tiddler | The title of the tiddler whose lists are to be modified (if not provided defaults to the current tiddler |
| $field | The name of a field to be manipulated as a list (defaults to 'list') |
| $index | Optional index of a property in a data tiddler index to be manipulated as a list |
| $filter | An optional filter expression, the output of which will be saved to the field/index being manipulated |
| $subfilter | An optional subfilter expression, which takes the list being manipulated as input, and saves the modified list back to the field/index being manipulated |
| $tags | An optional subfilter expression, which takes the 'tags' field of the target tiddler as input, and saves the modified list of tags back to the 'tags' field |
A number of extended filter operators are necessary for the manipulation of lists. These operators have been designed primarily for use in subfilter expressions whereby the modified current list is returned in place of the current list.
| Listops Operators | ||
|---|---|---|
| Operator | Purpose | |
| allafter | discard all items except those after the marker | |
| allbefore | discard all items except those before the marker | |
| append | append a range of items from an array to the list | |
| insertbefore | insert an item T into a list immediately before an item B |
|
| move | move marker N places in the list | |
| prepend | prepend a range of items from an array to the list | |
| putafter | move N trailing items after the marker | |
| putbefore | move N trailing items before the marker | |
| putfirst | move N trailing items to the head of the list | |
| putlast | move N leading items to the tail of the list | |
| remove | remove a list of titles specified in the operand from the input | |
| replace | replace marker with N trailing items | |
| sortby | sort the current list in the order of the list referenced in the operand | |
In this example we shall populate and then clear a list in an ordinary field (myfield) of this tiddler (the default.)
<$button>
<$action-listops $field="myfield" $subfilter="efg hlm pqr"/>
Populate 'myfield'
</$button>
<$button>
<$action-listops $field="myfield" $subfilter="abc xyz"/>
Append More Items
</$button>
<$button>
<$action-listops $field="myfield" $subfilter="-abc -hlm"/>
Remove Items
</$button>
<$button>
<$action-listops $field="myfield" $filter="[[]]"/>
Clear 'myfield'
</$button>
<$list filter="[list[!!myfield]]">
</$list>That renders as:
In this example we shall append and remove items from a list in an ordinary field (myfield) of this tiddler (the default) and sort the resultant list. We shall then remove some of the appended items and sort the resulting list in reverse order.
<$button>
<$action-listops $field="myfield" $subfilter="-efg ijk xyz [[this is a title]] +[sort[]]"/>
Mangle List
</$button>
<$button>
<$action-listops $field="myfield" $subfilter="-xyz -[[this is a title]] +[!sort[]]"/>
Unmangle List
</$button>
<$list filter="[list[!!myfield]]">
</$list>That renders as:
In this example we shall append a few tags to the 'tags' field of this tiddler (the default.) We shall then remove some of the appended tags.
<$button>
<$action-listops $tags="+[append{Days of the Week!!short}] $:/tag1 $:/tag2 $:/tag3"/>
Populate 'tags'
</$button>
<$button>
<$action-listops $tags="+[!remove:2{!!tags}]"/>
Remove Last Two Tags
</$button>
<$button>
<$action-listops $tags="+[!prefix[$:/]]"/>
Remove System Tags
</$button>
<$button>
<$action-listops $tags="-Mon -Tue"/>
Remove Mon and Tue
</$button>
<$button>
<$action-listops $tags="+[prefix[$:/]] ActionWidgets Widgets"/>
Remove User Tags
</$button>
<$button>
<$action-listops $tags="+[[]] ActionWidgets Widgets"/>
Clear Tags
</$button>
<$list filter="[list[!!tags]]">
</$list>That renders as: