[TW5] Conditional content based on filter results

[Tobias Beer]

Hi everyone,

Hope I didn't get too rusty since March.

I am struggling to formulate a filter logic for batch operations

that allows to specify a filter whereas when the filter yields...

• results => shows a button to delete all those tiddlers
  
• no results => does not show a button since there are not tiddlers to be deleted
  

The filter is specified by the user in an input field.

Feels like a filter to model this conditional logic isn't quite there yet, is it?

 

<$list filter="[foo[bar]is[emptyList]]">
<$button>foo</$button>
</$list>

What I am not looking for is to just

see if some value in a tiddler field is empty or not,

although I am not sure that that would exist either (in a simple solution).

Best wishes,

Tobias.

[Eric Shulman]

To conditionalize output based the empty/non-empty state of the filter results, use the *emptyMessage* param in the $list widget.

To make things more readable, I tend to put the output rendering code into separate macros, thus:

\define showitem() <$button>{{!!title}}</$button>
\define showempty() no items
\define filter() [foo[bar]]
<$list filter=<<filter>> emptyMessage=<<showempty>>> <<showitem>> </$list>

enjoy,

-e

P.S. welcome back

[Mat]

Reminds of #2202 Add preMessage parameter to ListWidget

<:-)

[Tobias Beer]

Hi Eric,

 

To conditionalize output based the empty/non-empty state of the filter results, use the *emptyMessage* param in the $list widget.

Thanks for your feedback. There remains an issue though.

The user can input any filter that may or may not yield matches.

If there are any matches, I want to display a single button,

followed by a list of all matches.

I guess I will have to use a variable and a helper macro to append a

+[limit[1]]

to the filter string being tested so as to check (once) if there are any results.

Best wishes,

Tobias.

[Mat]

@Tobias

+[limit[1]]

If you could put up a solution on tb5 it would be appreciated!

<:-)