MDL parser does not support pluggable widget slot syntax documented by mxcli widget docs

[acarum]

Version: nightly-20260902-89824921 (2026-09-02T07:23:30Z)

Summary:
mxcli widget docs generates per-widget Markdown files that document a curly-brace slot syntax for pluggable widgets with widgets-typed properties. The parser does not implement this syntax — it rejects it at the mxcli check stage with mismatched input.

Steps to reproduce:

1. Run mxcli widget docs -p <project.mpr> — this generates a .md file for the Selection Helper widget documenting the following MDL syntax:

PLUGGABLEWIDGET 'com.mendix.widget.web.selectionhelper.SelectionHelper' selectionHelper1 {
customallselected {
-- widgets for customAllSelected
}
customsomeselected {
-- widgets for customSomeSelected
}
customnoneselected {
-- widgets for customNoneSelected
}
}

Steps to reproduce:

1. Run mxcli widget docs -p <project.mpr> — this generates a .md file for the Selection Helper widget documenting the following MDL syntax:

PLUGGABLEWIDGET 'com.mendix.widget.web.selectionhelper.SelectionHelper' selectionHelper1 {
customallselected {
-- widgets for customAllSelected
}
customsomeselected {
-- widgets for customSomeSelected
}
customnoneselected {
-- widgets for customNoneSelected
}
}

2. Write an MDL script using that syntax inside a CREATE OR REPLACE PAGE or ALTER PAGE ... REPLACE ... WITH { } block.
3. Run mxcli check script.mdl.

Actual result:

Syntax errors found:
- line 22:14 mismatched input 'customallselected' expecting '}'
- line 25:14 mismatched input 'customsomeselected' expecting '}'
- line 28:14 missing '}' at 'customnoneselected'

The parser rejects the slot block names in both CREATE OR REPLACE PAGE and ALTER PAGE REPLACE contexts.

Expected result:

The parser accepts slot block syntax as documented in the generated widget docs, creates the corresponding CustomWidgets$WidgetProperty entries in the MPR for each slot, and the project compiles without CE0642 ("Property X is required").

Additional context:

• Without slot syntax support, there is no way to use renderStyle: 'custom' on the Selection Helper widget via mxcli. Setting it produces 3× CE0642 errors (one per required slot: All selected, Some selected, None selected).
• The workaround customAllSelected: [] (array property syntax) passes mxcli check and executes, but only updates the widget type schema metadata — it does not create the actual WidgetProperty value entries in Object.Properties. CE0642 still fires.
• mxcli fix widgets (which resyncs widget definitions for CE0463) does not populate the missing slot properties either.
• A page created via Studio Pro with the same widget and renderStyle: custom compiles cleanly. BSON inspection confirms it has 5 CustomWidgets$WidgetProperty entries (one per property type) vs. 2 produced by mxcli.
• Widget ID: com.mendix.widget.web.selectionhelper.SelectionHelper v3.10.0, Mendix 11.12.0.