Expand or contract repeating group conditionally

[laurence]

In my database there is a nesting of data types: GoalType, GoalCategory and Goal.

I want to reflect this in nested repeating groups similarly to how nested folders are reflected in Windows Explorer.

In this example, I want to be able to click on the arrow icon to show or hide the nesting. Along with this, I want to change the icon and bolding of the Type or Category name.

I have the icon and bolding working based on custom state in the icon element.
I don’t see a way of accessing the custom state from the repeating group so I can control its selection or appearance. Apparently custom states aren’t accessible from outside the group containing them.

How can I get the UI effect I need?

[laurence]

Here’s an approach that works.

Put a group around each child rg. This group can reference the icon’s custom state in the containing cell to determine if the group should be visible.

From the UI perspective, this looks good, with minimal delay for any expansion, and the initial page load is quick, suggesting that searching is not done for the child rgs until they are made visible.