Selectionhelper with renderStyle: 'custom' — slot children containing StaticImageViewer are not re-executable; workaround requires placeholder dynamictext

[acarum]

Problem

When a selectionhelper widget uses renderStyle: 'custom', Mendix requires three child slots to be populated:

• customallselected
• customsomeselected
• customnoneselected

Studio Pro places a Forms$StaticImageViewer (static image) inside each slot. When DESCRIBE PAGE is run on such a page, mxcli emits:

customallselected customallselected1 {
-- Forms$StaticImageViewer (staticImage3) -- NOT re-executable: mxcli cannot author this widget, so re-running this script would drop it
}

This means:

1. mxcli cannot generate StaticImageViewer widgets inside selectionhelper slots.
2. If a script is re-executed (idempotent CREATE OR REPLACE PAGE), the static images are silently dropped, leaving the slots empty.
3. Empty slots cause CE0642 at build time:
   [CE0642] "Property 'All selected' is required."
   [CE0642] "Property 'Some selected' is required."
   [CE0642] "Property 'None selected' is required."

Current workaround

Populate each slot with an empty dynamictext to satisfy the structural requirement:

pluggablewidget 'com.mendix.widget.web.selectionhelper.SelectionHelper' selectionHelper1 (
renderStyle: 'custom',
Class: 'command'
) {
customallselected customallselected1 {
dynamictext txtAllSelected (Content: '')
}
customsomeselected customsomeselected1 {
dynamictext txtSomeSelected (Content: '')
}
customnoneselected customnoneselected1 {
dynamictext txtNoneSelected (Content: '')
}
}

This passes the build check but loses the visual icons present in Studio Pro-built pages.

Expected behavior

Either:

• (A) mxcli supports staticimage (or equivalent) inside pluggable widget slots so the slot content round-trips faithfully, or
• (B) DESCRIBE PAGE emits re-executable MDL for the slot content (e.g. using staticimage syntax), so CREATE OR REPLACE PAGE does not drop the children on re-execution.

Reproduction steps

1. Open any Master page that uses selectionhelper with renderStyle: 'custom' (e.g. OpcenterEXFN_ReferenceData.UoMDimension_Master_SingleSelection).
2. Run DESCRIBE PAGE — observe the -- NOT re-executable comment on slot children.
3. Copy the DESCRIBE output into a CREATE OR REPLACE PAGE script and execute it — the static images are dropped.
4. Run mx check — CE0642 errors appear on the three required slots.

Environment

• Mendix version: 11.12.0
• mxcli version: (0.21.0)