[List / List items] Support custom filtering supporting a filter function with a prop

[nwhittaker]

Description

A way to opt in to an stripped-down behavior when clicking a list-item that contains nested list-items.

Originally included selection and filtering asks, now placed in two separate issues:

• Filtering (below)
• Selection via [List item] Child elements behavior can be toggled open without selection change and event dispatch #8515

Acceptance Criteria

Filtering a list of items with nested list-items:

• Parent list-item is visible when it does not match but any leaf items do match.
• Parent list-item is not visible when it does match but no descendent leaf items match.
• Parent list-item is not visible when no descendent leaf items match.
• Consider [calcite-filter] Add support for custom filter function #3454 as part of the upcoming effort

Relevant Info

No response

Which Component

calcite-list-item

Example Use Case

The Field Maps web app would like to use the calcite-list element to display the layers in a map. For group layers, nested layers are shown as child list-items.

Selecting a leaf layer navigates the app for further handling of the layer. However, the app does not provide further handling for group layers. They are treated more like folders that organize sets of layers -- so clicking them in the list should have no effect other than to drill down to leaf layers.

Esri team

ArcGIS Field Apps

[brittneytewks]

Scheduling time with FieldApps to understand use case in more depth, will add priority and estimate after discussion

[nwhittaker]

Added some stripped-down filtering behavior to the issue description that should also be part of any discussion.