From 5027f479dddde1e7be161a355af93b542a8fa124 Mon Sep 17 00:00:00 2001
From: Ako <andrej@koelewijn.net>
Date: Wed, 11 Nov 2026 21:15:39 +0100
Subject: [PATCH 1/3] fix(check): accept the container names Studio Pro stores
 in grid rows, control bars and combo box options (#2109)

describe page -> exec of four FactoryManagement pages was refused on its own
output (MDL-BUTTON02, MDL-PAGEARG01), although the stored pages build:

- a show page in a selectable data grid's column passing `$grid1`: the
  grid's selection, stored as Variable {Widget: grid1} as from its control
  bar (MxModelReflection.MxObjectType_Select);
- `$dataView3` from the control bar (filters placeholder) of a grid inside
  dataView3: the bar sits inside the grid, so dataView3 is an outer
  container there (OIDC.OIDC_Client_NewEdit);
- `$dataView2` in a combo box's option content: the option is the combo
  box's own context (AgentCommons.Version_NewEdit).

The check walk and the show page argument context model the three, and
the engine enters a data widget through the same constructor
(enteringDataWidgetOf), so check and exec agree. Re-measured on 11.16:
the control-bar case builds with 0 errors in the variable form written
since #2095; two older tests are updated with that evidence.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011oK82ttaGzay5CwiC2V7cf
---
 ...1-11-own-container-name-in-item-slots.json |  1 +
 CHANGELOG.md                                  |  1 +
 .../2109-own-container-name-in-item-slots.mdl | 64 +++++++++++++++
 mdl/executor/cmd_pages_showpage_args.go       | 42 +++++++++-
 ...d_pages_showpage_selection_arg_122_test.go | 12 ++-
 .../validate_own_container_slots_2109_test.go | 81 +++++++++++++++++++
 mdl/executor/validate_page_button_context.go  | 46 ++++++++---
 .../validate_page_own_container_name_test.go  | 10 ++-
 mdl/executor/widget_engine.go                 |  4 +-
 9 files changed, 238 insertions(+), 23 deletions(-)
 create mode 100644 .claude/skills/fix-issue/findings/mdl-executor/2026-11-11-own-container-name-in-item-slots.json
 create mode 100644 mdl-examples/bug-tests/2109-own-container-name-in-item-slots.mdl
 create mode 100644 mdl/executor/validate_own_container_slots_2109_test.go

diff --git a/.claude/skills/fix-issue/findings/mdl-executor/2026-11-11-own-container-name-in-item-slots.json b/.claude/skills/fix-issue/findings/mdl-executor/2026-11-11-own-container-name-in-item-slots.json
new file mode 100644
index 0000000000..f0b8343da1
--- /dev/null
+++ b/.claude/skills/fix-issue/findings/mdl-executor/2026-11-11-own-container-name-in-item-slots.json
@@ -0,0 +1 @@
+{"area": "mdl/executor", "date": "2026-11-11", "refs": ["ako/mxcli#2109", "mendixlabs/mxcli#1324", "mendixlabs/mxcli#122", "ako/mxcli#2095"], "ce": ["CE0117", "CE0115"], "symptom": "describe page -> exec of four FactoryManagement pages (Mendix 11.16) was refused by check on its own output: \"`actionButton1` reads `$grid1` …, but `grid1` is the data container the widget sits in directly\" (MDL-BUTTON02) and \"$grid1 cannot be stored — … an explicit one is rejected as CE0115\" (MDL-PAGEARG01). The stored pages build (untouched app: 4 unrelated errors).", "file": "mdl/executor/validate_page_button_context.go (checkButtonContextTree: control bar nearest \"\", nearestSelectable; isObjectContextContainer + combobox; checkOwnContainerName skips a show page in a selectable grid's rows), mdl/executor/cmd_pages_showpage_args.go (pageArgContext.rowSelectionOf, namesRowSelection, selectableDataGrid, enteringDataWidgetOf shared by argContextForChildren and both engine sites), mdl/executor/widget_engine.go. Tests: validate_own_container_slots_2109_test.go; updated validate_page_own_container_name_test.go (btnCtlBar) and cmd_pages_showpage_selection_arg_122_test.go", "cause": "Three slots open or move an object context that the walks modelled wrong. A selectable data grid's name is its selection in its rows as well as its control bar (Studio Pro stores Variable {Widget: grid1} from column content). A control bar takes its object from above the grid but sits INSIDE it, so the container above is an outer one, not the nearest. A combo box's option content is its own item context. And the pluggable engine entered a data widget's argument context with its own constructor, so a fix in argContextForChildren alone left exec refusing what check accepted.", "insight": "**Dump the stored slot before deciding which side is wrong, and find the property path, not just the widget.** A small walker mapping each CustomWidget TypePointer to its PropertyKey showed `Datagrid:grid1 > [columns] > [content]`, `[filtersPlaceholder]` (printed as controlbar) and `Combobox > [optionsSourceAssociationCustomContent]` - three different reasons in one rule. Then **re-measure an old 'measured' verdict with today's writer before trusting it**: btnCtlBar's CE0117 on 11.14 was an error in an EXPRESSION `$dvP`; since #2095 the argument is written as the variable pair, and a probe on 11.16 builds it - and even a button DIRECTLY in dvP passing $dvP - with 0 errors (positive control in the same build: CE1365), so MDL-BUTTON02's premise for action arguments may be stale beyond this fix. Controls: reverting each of the five edits fails its test; old binary refuses all four pages, new one reports Unchanged page on the three that MDL-WIDGET03 (#2110) does not block."}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1f78b49c01..a688924d3e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,6 +27,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ### Fixed
 
+- **`check` accepts the data-container names Studio Pro stores in a grid row, a control bar and a combo box option** (ako/mxcli#2109) — `describe page` → `exec` of four FactoryManagement pages was refused on its own output (MDL-BUTTON02, MDL-PAGEARG01): a show page in a selectable data grid's column passing the grid's selection (`$grid1`), a control-bar button passing the data view around its grid, and a combo box's option content reading the data view around the combo box. All three build in Studio Pro's own pages. `check` and `exec` now accept them and write what Studio Pro stores, and the pages report `Unchanged page`.
 - **`describe page` → `exec` no longer rewrites a page over formatting and stored keys MDL cannot state** (ako/mxcli#2106) — on FactoryManagement, 8 pages reported `Replaced page` with nothing changed: a dynamic-classes expression's trailing newlines, an XPath constraint's line breaks and spacing, the order of an enumeration condition's values, an association source's null `SourceVariable` key, and an inherited `createdDate` binding requalified to the specialization. The stored value is now kept where only its form differs, the writer stores the key Studio Pro stores, and a system member resolves to the entity that stores it. A full sweep of the app's 229 pages turns those 8 `Unchanged` and changes no other.
 - **`describe page` → `exec` keeps a check box's label position, a radio button group's orientation and a show page action's close count** (ako/mxcli#2106) — none had an MDL spelling, so a round trip of a Studio Pro page reset a check box with its label after the control to the default, turned every vertical radio button group horizontal, and stopped a show page button from closing the page it came from, with `mx check` green. `checkbox` takes `LabelPosition: Default|BeforeControl|AfterControl`, `radiobuttons` takes `RenderHorizontal: false`, and `show page` takes `with (NumberOfPagesToClose: n)`; `describe` prints each when it differs from the default.
 - **`mxcli test --local --watch` keeps applying changes on macOS and Linux mxbuild** (mendixlabs/mxcli#1787, refs mendixlabs/mxcli#1786) — the test runner's rebuild called mxbuild's serve process directly, without the recovery `run --local --watch` has, so the second build of a serve process failed on regenerated pages and every later change reported "could not be applied". The rebuild now goes through the same recovery, which also recognises mxbuild's resource-key form of that failure (`IO_PathNotFound_Path`, as macOS and Linux report it) and skips the web-bundle check, which only matters when a browser is served.
diff --git a/mdl-examples/bug-tests/2109-own-container-name-in-item-slots.mdl b/mdl-examples/bug-tests/2109-own-container-name-in-item-slots.mdl
new file mode 100644
index 0000000000..1fcbdd85b6
--- /dev/null
+++ b/mdl-examples/bug-tests/2109-own-container-name-in-item-slots.mdl
@@ -0,0 +1,64 @@
+mdl 1;
+-- ============================================================================
+-- Bug ako/mxcli#2109: check refused Studio Pro's own data-container names
+-- ============================================================================
+--
+-- Symptom (before fix): describe page -> exec of four FactoryManagement pages
+-- (Mendix 11.16) was refused by check on its own output:
+--   "`actionButton1` reads `$grid1` …, but `grid1` is the data container the
+--   widget sits in directly — its name is a variable only inside a data
+--   container nested below it (CE0117)" [MDL-BUTTON02]
+--   "$grid1 cannot be stored — … an explicit one is rejected as CE0115" [MDL-PAGEARG01]
+-- The stored pages build. Measured shapes:
+--   - a button in a SELECTABLE data grid's column passing `$grid1`: Studio Pro
+--     stores Variable {Widget: grid1}, the grid's selection, as from its
+--     control bar (MxModelReflection.MxObjectType_Select);
+--   - `$dataView3` from the filter bar (control bar) of a grid inside dataView3
+--     (OIDC.OIDC_Client_NewEdit): the bar sits inside the grid, so dataView3 is
+--     an outer container there;
+--   - `$dataView2` in a combo box's option content inside dataView2
+--     (AgentCommons.Version_NewEdit): the option is the combo box's own context.
+--
+-- After fix: check accepts all three; exec writes the variable forms Studio
+-- Pro stores; mx check 0 errors on Mendix 11.16.0 for this script.
+--
+-- Usage:
+--   mxcli exec mdl-examples/bug-tests/2109-own-container-name-in-item-slots.mdl -p app.mpr
+--   mxcli docker check -p app.mpr        -- expect 0 errors
+-- ============================================================================
+
+create module BugTest2109;
+create module role BugTest2109.User;
+
+create persistent entity BugTest2109.Gate (Name: String(100));
+create persistent entity BugTest2109.Item (Name: String(100));
+
+create microflow BugTest2109.ACT_Open ($Gate: BugTest2109.Gate) returns Boolean
+begin
+  return true;
+end;
+grant execute on microflow BugTest2109.ACT_Open to BugTest2109.User;
+
+create page BugTest2109.Item_Details (Params: ($Item: BugTest2109.Item), Title: 'Item', Layout: Atlas_Core.PopupLayout) {
+  dataview dvItem (DataSource: $Item) {
+    dynamictext txtName (Content: '{1}', ContentParams: ({1} = Name))
+  }
+};
+grant view on page BugTest2109.Item_Details to BugTest2109.User;
+
+create page BugTest2109.Overview (Params: ($Gate: BugTest2109.Gate), Title: 'Overview', Layout: Atlas_Core.PopupLayout) {
+  dataview dvGate (DataSource: $Gate) {
+    datagrid dgGates (DataSource: database from BugTest2109.Gate) {
+      controlbar {
+        actionbutton btnOpen (Caption: 'Open', Action: call microflow BugTest2109.ACT_Open(Gate = $dvGate))
+      }
+      column (Attribute: Name)
+    }
+  }
+  datagrid dgItems (DataSource: database from BugTest2109.Item, Selection: Single) {
+    column (Attribute: Name, ShowContentAs: customContent) {
+      actionbutton btnView (Caption: 'View', Action: show page BugTest2109.Item_Details(Item = $dgItems))
+    }
+  }
+};
+grant view on page BugTest2109.Overview to BugTest2109.User;
diff --git a/mdl/executor/cmd_pages_showpage_args.go b/mdl/executor/cmd_pages_showpage_args.go
index 9ada8c67b5..67d7445a8e 100644
--- a/mdl/executor/cmd_pages_showpage_args.go
+++ b/mdl/executor/cmd_pages_showpage_args.go
@@ -62,6 +62,12 @@ type pageArgContext struct {
 	// selection `$<grid>` passes to a page as an explicit mapping naming the
 	// grid (mendixlabs/mxcli#122). The row object is not the control bar's.
 	selectionOf string
+	// rowSelectionOf is set inside a selectable data grid's rows: the grid's
+	// name, whose selection `$<grid>` a show page in a column passes as the
+	// same explicit mapping. Studio Pro stores exactly that (Variable {Widget:
+	// grid1}) on FactoryManagement's MxModelReflection.MxObjectType_Select,
+	// and it builds (ako/mxcli#2109). The row object stays $currentObject.
+	rowSelectionOf string
 }
 
 // inDataWidget names the data widget whose context c is.
@@ -77,12 +83,42 @@ func (c pageArgContext) namesSelection(value string) bool {
 	return ok && c.selectionOf != "" && strings.EqualFold(name, c.selectionOf)
 }
 
+// namesRowSelection reports whether value is `$<grid>` written in that grid's
+// rows, where the grid has a selection: a show page argument only.
+func (c pageArgContext) namesRowSelection(value string) bool {
+	name, ok := strings.CutPrefix(value, "$")
+	return ok && c.rowSelectionOf != "" && strings.EqualFold(name, c.rowSelectionOf)
+}
+
+// selectableDataGrid reports whether w is a data grid with a selection, whose
+// name is then a variable in its rows as well as in its control bar.
+func selectableDataGrid(w *ast.WidgetV3) bool {
+	switch strings.ToLower(w.Type) {
+	case "datagrid", "datagrid2":
+	default:
+		return false
+	}
+	sel := w.GetSelection()
+	return sel != "" && !strings.EqualFold(sel, "None")
+}
+
 // enteringDataWidget is the context below a data-bound widget bound to ds and
 // yielding entity.
 func enteringDataWidget(ds *ast.DataSourceV3, entity string) pageArgContext {
 	return pageArgContext{known: true, present: true, varName: contextVarFor(ds), entity: entity}
 }
 
+// enteringDataWidgetOf is enteringDataWidget for the rows of data widget w, by
+// name: a selectable data grid's name is its selection there too. The one
+// constructor the check walk and both builders use, so the three agree.
+func enteringDataWidgetOf(w *ast.WidgetV3, ds *ast.DataSourceV3, entity string) pageArgContext {
+	c := enteringDataWidget(ds, entity).inDataWidget(w.Name)
+	if selectableDataGrid(w) {
+		c.rowSelectionOf = w.Name
+	}
+	return c
+}
+
 // atDocumentRoot is the context at the top of a page, snippet or layout the pass
 // walks in full: knowable, and empty.
 func atDocumentRoot() pageArgContext {
@@ -126,7 +162,7 @@ func argContextForChildren(w *ast.WidgetV3, parent pageArgContext) pageArgContex
 	if ds := w.GetDataSource(); ds != nil {
 		// The entity is only used to word the refusal; the executor's builder
 		// overwrites this with one that carries it.
-		c := enteringDataWidget(ds, "").inDataWidget(w.Name)
+		c := enteringDataWidgetOf(w, ds, "")
 		c.docParams = parent.docParams
 		return c
 	}
@@ -303,7 +339,7 @@ func refuseShowPageArgument(widgetName, target, argName, argValue string, c page
 func (pb *pageBuilder) namedParameterArgument(value string) (variable, kind string) {
 	variable, kind = pb.classifyFlowArgValue(value)
 	if kind != "parameter" && kind != "snippet" {
-		if pb.argCtx.namesSelection(value) {
+		if pb.argCtx.namesSelection(value) || pb.argCtx.namesRowSelection(value) {
 			variable, kind = value, "widget"
 		} else {
 			return "", ""
@@ -361,7 +397,7 @@ func validateShowPageArguments(w *ast.WidgetV3, c pageArgContext, locationPrefix
 	var out []linter.Violation
 	for _, arg := range action.Args {
 		strVal, ok := arg.Value.(string)
-		if !ok || c.binds(strVal) || c.namesDocumentParameter(strVal) || c.namesSelection(strVal) {
+		if !ok || c.binds(strVal) || c.namesDocumentParameter(strVal) || c.namesSelection(strVal) || c.namesRowSelection(strVal) {
 			continue
 		}
 		out = append(out, linter.Violation{
diff --git a/mdl/executor/cmd_pages_showpage_selection_arg_122_test.go b/mdl/executor/cmd_pages_showpage_selection_arg_122_test.go
index e46c9b95e8..597c03662f 100644
--- a/mdl/executor/cmd_pages_showpage_selection_arg_122_test.go
+++ b/mdl/executor/cmd_pages_showpage_selection_arg_122_test.go
@@ -75,8 +75,12 @@ func TestValidateShowPageArguments_ControlBarPassesGridSelection(t *testing.T) {
 	}
 }
 
-// The selection is the control bar's, not the row's: a column button passing
-// its own grid's name is not the measured shape and stays refused.
+// A column button passing its own selectable grid's name passes the grid's
+// selection too: Studio Pro stores Variable {Widget: grid1} there
+// (FactoryManagement MxModelReflection.MxObjectType_Select, which builds), and
+// so does the builder now, at 0 errors on 11.16 (ako/mxcli#2109). This used to
+// be refused as an unmeasured shape. A grid without a selection still has no
+// `$grid` to pass (TestCheck_GridSelectionFromColumnContent).
 func TestValidateShowPageArguments_GridSelectionOnlyInItsControlBar(t *testing.T) {
 	src := `create page Mod.Overview (title: 'O', layout: Atlas_Core.Atlas_Default) {
   datagrid dgOrders (datasource: database from Mod.Order, selection: single) {
@@ -90,8 +94,8 @@ func TestValidateShowPageArguments_GridSelectionOnlyInItsControlBar(t *testing.T
 		t.Fatalf("parse: %v", errs)
 	}
 	s := prog.Statements[0].(*ast.CreatePageStmtV3)
-	if got := pageArgViolations(t, s.Widgets); len(got) != 1 {
-		t.Errorf("row-scoped button passing $dgOrders: %d MDL-PAGEARG01, want 1", len(got))
+	if got := pageArgViolations(t, s.Widgets); len(got) != 0 {
+		t.Errorf("row-scoped button passing its selectable grid's selection $dgOrders: %d MDL-PAGEARG01, want 0", len(got))
 	}
 }
 
diff --git a/mdl/executor/validate_own_container_slots_2109_test.go b/mdl/executor/validate_own_container_slots_2109_test.go
new file mode 100644
index 0000000000..aa19454569
--- /dev/null
+++ b/mdl/executor/validate_own_container_slots_2109_test.go
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: Apache-2.0
+
+// ako/mxcli#2109: check refused its own describe output on four FactoryManagement
+// pages (Mendix 11.16), which Studio Pro authored and which build clean. The
+// stored shapes, measured:
+//
+//   - MxModelReflection.MxObjectType_Select, OIDC.OIDC_Client_NewEdit,
+//     UserCommons.ClaimsForClaimEntityAttribute: a button in a Data grid 2
+//     column's content, in a grid with `Selection: Single`, whose show page
+//     mapping stores Variable {Widget: grid1} — the grid's SELECTION, the shape
+//     a control bar button stores for `$grid` (mendixlabs/mxcli#122).
+//   - AgentCommons.Version_NewEdit: container5 in a combo box's
+//     optionsSourceAssociationCustomContent, inside dataView2, with
+//     `Visible: $currentObject = $dataView2`. The option content is the combo
+//     box's own item context, so $dataView2 is an OUTER container there.
+//
+// check said: "`actionButton1` reads `$grid1` …, but `grid1` is the data
+// container the widget sits in directly — its name is a variable only inside
+// a data container nested below it" (MDL-BUTTON02), and refused the argument
+// as an explicit mapping (MDL-PAGEARG01, "an explicit one is rejected as CE0115").
+package executor
+
+import (
+	"strings"
+	"testing"
+)
+
+func ownContainerRules(t *testing.T, src string) []string {
+	t.Helper()
+	var out []string
+	for _, v := range ValidateProgram(parseMDL(t, src), "") {
+		if v.RuleID == "MDL-BUTTON02" || v.RuleID == "MDL-PAGEARG01" {
+			out = append(out, v.RuleID+": "+v.Message)
+		}
+	}
+	return out
+}
+
+func gridColumnButtonPage(selection string) string {
+	return `mdl 1;
+create page M.Select ( Title: 'Select', Layout: Atlas_Core.PopupLayout ) {
+  datagrid grid1 ( DataSource: database from M.Item` + selection + ` ) {
+    column ( Attribute: Name, ShowContentAs: customContent ) {
+      actionbutton actionButton1 ( Caption: 'View', Action: show page M.Item_Details(Item = $grid1) )
+    }
+  }
+};`
+}
+
+func TestCheck_GridSelectionFromColumnContent(t *testing.T) {
+	if got := ownContainerRules(t, gridColumnButtonPage(", Selection: Single")); len(got) != 0 {
+		t.Errorf("a selectable grid's selection refused from its column content:\n%s", strings.Join(got, "\n"))
+	}
+	// Control: a grid with no selection has no `$grid1` to pass.
+	if got := ownContainerRules(t, gridColumnButtonPage("")); len(got) == 0 {
+		t.Error("$grid1 accepted in a grid with no selection")
+	}
+}
+
+func comboBoxOptionContentPage(visible string) string {
+	return `mdl 1;
+create page M.Edit ( Title: 'Edit', Layout: Atlas_Core.PopupLayout, Params: ( $Agent: M.Agent ) ) {
+  dataview dataView2 ( DataSource: $Agent ) {
+    combobox comboBox3 ( Attribute: Agent_Version_InUse, DataSource: database from M.Version, optionsSourceAssociationCustomContentType: 'yes' ) {
+      optionssourceassociationcustomcontent {
+        container container5 ( Visible: ` + visible + ` )
+      }
+    }
+    container container9 ( Visible: $currentObject = $dataView2 )
+  }
+};`
+}
+
+func TestCheck_ComboBoxOptionContentIsItsOwnContext(t *testing.T) {
+	got := ownContainerRules(t, comboBoxOptionContentPage("$currentObject = $dataView2"))
+	// container9 sits directly in dataView2 and is still refused (the control);
+	// container5, in the combo box's option content, is not.
+	if len(got) != 1 || !strings.Contains(got[0], "container9") {
+		t.Errorf("want only container9 refused, got:\n%s", strings.Join(got, "\n"))
+	}
+}
diff --git a/mdl/executor/validate_page_button_context.go b/mdl/executor/validate_page_button_context.go
index 5a6b6cdd6e..b8915bf53c 100644
--- a/mdl/executor/validate_page_button_context.go
+++ b/mdl/executor/validate_page_button_context.go
@@ -25,7 +25,7 @@ func ValidatePageButtonContext(prog *ast.Program) []linter.Violation {
 	var out []linter.Violation
 	for _, stmt := range prog.Statements {
 		if label, widgets, ok := documentWidgets(stmt); ok {
-			out = append(out, checkButtonContextTree(widgets, "", false, "", label)...)
+			out = append(out, checkButtonContextTree(widgets, "", false, "", false, label)...)
 		}
 	}
 	return out
@@ -48,9 +48,14 @@ func ValidatePageButtonContext(prog *ast.Program) []linter.Violation {
 // control bar inherits the context from above the grid, not from the grid.
 //
 // nearest is the name of the data container whose object the widget sits in
-// ("" at the top), for MDL-BUTTON02 (mendixlabs/mxcli#1324). It moves with the
-// same rule as inContext: a control bar keeps the context from above its grid.
-func checkButtonContextTree(widgets []*ast.WidgetV3, controlBarOf string, inContext bool, nearest, locationPrefix string) []linter.Violation {
+// ("" at the top), for MDL-BUTTON02 (mendixlabs/mxcli#1324). Inside a control
+// bar it is "": the bar takes its object from above its grid but sits inside
+// the grid, so no container's name is its own there (ako/mxcli#2109).
+//
+// nearestSelectable says the nearest container is a data grid with a
+// selection: its name then is a variable in its rows too, the selection, which
+// a show page argument may pass (ako/mxcli#2109).
+func checkButtonContextTree(widgets []*ast.WidgetV3, controlBarOf string, inContext bool, nearest string, nearestSelectable bool, locationPrefix string) []linter.Violation {
 	var out []linter.Violation
 	for _, w := range widgets {
 		if w == nil {
@@ -60,19 +65,24 @@ func checkButtonContextTree(widgets []*ast.WidgetV3, controlBarOf string, inCont
 			out = append(out, checkControlBarAction(a, w.Name, controlBarOf, locationPrefix)...)
 		}
 		if nearest != "" {
-			out = append(out, checkOwnContainerName(w, nearest, locationPrefix)...)
+			out = append(out, checkOwnContainerName(w, nearest, nearestSelectable, locationPrefix)...)
 		}
 		childContext := inContext || isObjectContextContainer(w)
-		childNearest := nearest
+		childNearest, childSelectable := nearest, nearestSelectable
 		if isObjectContextContainer(w) && w.Name != "" {
-			childNearest = w.Name
+			childNearest, childSelectable = w.Name, selectableDataGrid(w)
 		}
 		for _, c := range w.Children {
-			childOf, ctx, near := controlBarOf, childContext, childNearest
+			childOf, ctx, near, sel := controlBarOf, childContext, childNearest, childSelectable
 			if c != nil && strings.EqualFold(c.Type, "controlbar") {
-				childOf, ctx, near = w.Name, inContext, nearest
+				// The control bar's object comes from above the grid, but the
+				// control bar sits INSIDE the grid, so the container above is
+				// an outer one there: `$dataView3` from the filter bar of a
+				// grid in dataView3 is Studio Pro's own spelling and builds
+				// (FactoryManagement OIDC.OIDC_Client_NewEdit, ako/mxcli#2109).
+				childOf, ctx, near, sel = w.Name, inContext, "", false
 			}
-			out = append(out, checkButtonContextTree([]*ast.WidgetV3{c}, childOf, ctx, near, locationPrefix)...)
+			out = append(out, checkButtonContextTree([]*ast.WidgetV3{c}, childOf, ctx, near, sel, locationPrefix)...)
 		}
 	}
 	return out
@@ -95,7 +105,12 @@ var ownNameExprProps = []struct{ key, written string }{
 // arguments (and a chained THEN action's), a data source's flow arguments,
 // Visible, Editable and DynamicClasses are CE0117 "Error(s) in expression.",
 // and a data source's XPath `where` is CE0161 "Error(s) in XPath constraint.".
-func checkOwnContainerName(w *ast.WidgetV3, nearest, locationPrefix string) []linter.Violation {
+//
+// A selectable data grid's name in its rows is the grid's selection, which a
+// show page argument stores as Variable {Widget: <grid>}: Studio Pro writes it
+// there and it builds (ako/mxcli#2109), so that one slot is not judged. Other
+// slots are, as no stored example shows them reading the selection.
+func checkOwnContainerName(w *ast.WidgetV3, nearest string, nearestSelectable bool, locationPrefix string) []linter.Violation {
 	var out []linter.Violation
 	flag := func(slot, expr, code string) {
 		if !exprReadsVariable(expr, nearest) {
@@ -113,6 +128,9 @@ func checkOwnContainerName(w *ast.WidgetV3, nearest, locationPrefix string) []li
 		})
 	}
 	for a := w.GetAction(); a != nil; a = a.ThenAction {
+		if nearestSelectable && a.Type == "showPage" {
+			continue
+		}
 		for _, arg := range a.Args {
 			if v, ok := arg.Value.(string); ok {
 				flag(a.Type+" action argument", v, "CE0117")
@@ -174,10 +192,12 @@ func isExprIdentByte(c byte) bool {
 
 // isObjectContextContainer reports whether w gives its (non-control-bar)
 // children a current object: a data view's object, a list view or gallery
-// item, a grid row (column content).
+// item, a grid row (column content), a combo box option (its custom content:
+// AgentCommons.Version_NewEdit reads `$dataView2` there, the data view
+// around the combo box, and builds; ako/mxcli#2109).
 func isObjectContextContainer(w *ast.WidgetV3) bool {
 	switch strings.ToLower(w.Type) {
-	case "dataview", "listview", "gallery", "templategrid", "datagrid", "datagrid2":
+	case "dataview", "listview", "gallery", "templategrid", "datagrid", "datagrid2", "combobox":
 		return true
 	}
 	return false
diff --git a/mdl/executor/validate_page_own_container_name_test.go b/mdl/executor/validate_page_own_container_name_test.go
index b922252017..fa2bd1c6b1 100644
--- a/mdl/executor/validate_page_own_container_name_test.go
+++ b/mdl/executor/validate_page_own_container_name_test.go
@@ -56,6 +56,14 @@ func TestValidatePageButtonContext_OwnDataViewName_Issue1324(t *testing.T) {
 // data container decides — a plain container is transparent, a control bar
 // takes the context from ABOVE its grid (so a grid's own selection stays
 // spellable there), and a row or item of a nested list is a new context.
+//
+// btnCtlBar is no longer flagged (ako/mxcli#2109). Its CE0117 was an error in
+// an EXPRESSION `$dvP`; since #2095 the argument is written as the variable
+// pair {Widget: dvP, PageParameter: Gate}, which builds with 0 errors on
+// 11.16 (probe page, with a CE1365 positive control in the same build), and
+// is what Studio Pro stores for a control-bar button there
+// (FactoryManagement OIDC.OIDC_Client_NewEdit actionButton7, which builds).
+// A control bar sits inside its grid, so the container above is an outer one.
 func TestValidatePageButtonContext_OwnContainerName_MeasuredShapes(t *testing.T) {
 	src := `create page G52.Probe (Title: 'Probe', Layout: Atlas_Core.PopupLayout, Params: ( $Gate: G52.Gate )) {
   dataview dvP (DataSource: $Gate) {
@@ -92,7 +100,7 @@ func TestValidatePageButtonContext_OwnContainerName_MeasuredShapes(t *testing.T)
   }
 };`
 	got := strings.Join(ownContainerFlagged(t, src), ",")
-	want := "btnCtlBar,btnDgOwnCol,btnGaOwn,btnInContainer,btnLvOwn,btnOwnPath"
+	want := "btnDgOwnCol,btnGaOwn,btnInContainer,btnLvOwn,btnOwnPath"
 	if got != want {
 		t.Fatalf("flagged %q, want %q (mx check 11.14.0's CE0117 set)", got, want)
 	}
diff --git a/mdl/executor/widget_engine.go b/mdl/executor/widget_engine.go
index b867974c9d..d2184b9ba2 100644
--- a/mdl/executor/widget_engine.go
+++ b/mdl/executor/widget_engine.go
@@ -527,7 +527,7 @@ func (e *PluggableWidgetEngine) Build(def *WidgetDefinition, w *ast.WidgetV3) (*
 				e.recordDataSourceEntity(propKey, entityName)
 				if entityName != "" {
 					e.pageBuilder.entityContext = entityName
-					e.pageBuilder.argCtx = enteringDataWidget(ds, entityName).inDataWidget(w.Name)
+					e.pageBuilder.argCtx = enteringDataWidgetOf(w, ds, entityName)
 				}
 			}
 		}
@@ -1776,7 +1776,7 @@ func (e *PluggableWidgetEngine) resolveMapping(mapping PropertyMapping, w *ast.W
 			e.recordDataSourceEntity(mapping.PropertyKey, entityName)
 			if entityName != "" {
 				e.pageBuilder.entityContext = entityName
-				e.pageBuilder.argCtx = enteringDataWidget(ds, entityName).inDataWidget(w.Name)
+				e.pageBuilder.argCtx = enteringDataWidgetOf(w, ds, entityName)
 				if w.Name != "" {
 					e.pageBuilder.paramEntityNames[w.Name] = entityName
 				}

From dc81d8026706acc246552a2971564fc46df1e05a Mon Sep 17 00:00:00 2001
From: Ako <andrej@koelewijn.net>
Date: Wed, 11 Nov 2026 21:15:39 +0100
Subject: [PATCH 2/3] fix(pages): keep a binding read through an outer data
 view (#2107)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Studio Pro stores a binding to an outer data view's object with the
data-view pair SourceVariable {Widget, PageParameter}, with association
steps for a path. describe printed the bare qualified name, and the rewrite
read it against the nearest data view: CE7247 on five ConversationalUI
markdown viewers, "TraceView has no attribute HasError" on Trace_Details.

`$dvOuter.Attr` and `$dvOuter/Assoc/Attr`, the spelling input widgets
already had (#826, #833), now work on a pluggable widget's attribute
property and in `Visible: … in (…)`: one resolver (namedObjectVariable)
for check, describe and exec, MDL-WIDGET34 accepting an enclosing data
view, the rooted path accepted in the form the parser produces, and
WidgetObjectBuilder.SetAttributeWithSteps to store the steps. All six
pages report Unchanged page; a fresh page with the three forms builds with
mx check 0 errors on 11.16.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011oK82ttaGzay5CwiC2V7cf
---
 ...11-11-binding-through-outer-data-view.json |   1 +
 CHANGELOG.md                                  |   1 +
 docs-site/src/reference/page/create-page.md   |  17 +-
 .../2107-binding-through-outer-data-view.mdl  |  51 +++
 mdl/backend/mcp/widget.go                     |  11 +
 mdl/backend/mutation.go                       |   4 +
 mdl/backend/widgetobj/builder.go              |   9 +
 mdl/executor/cmd_pages_builder_v3.go          |  30 +-
 .../cmd_pages_builder_visible_when.go         |  11 +-
 mdl/executor/cmd_pages_describe_parse.go      |   6 +-
 mdl/executor/cmd_pages_describe_pluggable.go  |  18 +-
 .../cmd_pages_input_binding_context.go        |  12 +-
 ..._pages_outer_dataview_binding_2107_test.go | 307 ++++++++++++++++++
 mdl/executor/cmd_pages_parameter_binding.go   |  30 +-
 .../validate_widget_expression_value.go       |   7 +-
 mdl/executor/widget_engine.go                 |  64 +++-
 mdl/executor/widget_expression_value.go       |   5 +
 17 files changed, 551 insertions(+), 33 deletions(-)
 create mode 100644 .claude/skills/fix-issue/findings/mdl-executor/2026-11-11-binding-through-outer-data-view.json
 create mode 100644 mdl-examples/bug-tests/2107-binding-through-outer-data-view.mdl
 create mode 100644 mdl/executor/cmd_pages_outer_dataview_binding_2107_test.go

diff --git a/.claude/skills/fix-issue/findings/mdl-executor/2026-11-11-binding-through-outer-data-view.json b/.claude/skills/fix-issue/findings/mdl-executor/2026-11-11-binding-through-outer-data-view.json
new file mode 100644
index 0000000000..093b761016
--- /dev/null
+++ b/.claude/skills/fix-issue/findings/mdl-executor/2026-11-11-binding-through-outer-data-view.json
@@ -0,0 +1 @@
+{"area": "mdl/executor", "date": "2026-11-11", "refs": ["ako/mxcli#2107", "ako/mxcli#826", "ako/mxcli#833", "mendixlabs/mxcli#1591"], "ce": ["CE7247"], "symptom": "describe page -> exec of six FactoryManagement pages (Mendix 11.16) failed: a markdown viewer in an inner data view was refused \"`GenAICommons.Span.Output` is an attribute of GenAICommons.Span, not of ConversationalUI.CopyHelper … CE7247\" (and Span_TextGeneration_SlideIn's markdownViewer3 failed \"failed to resolve mapping for stringAttribute\"); an attribute-based visibility condition failed \"ConversationalUI.TraceView has no attribute HasError\".", "file": "mdl/executor/cmd_pages_parameter_binding.go (namedObjectSourceName, isNamedObjectAttributeText), cmd_pages_describe_pluggable.go and cmd_pages_describe_parse.go (print $dv.Attr / $dv/Assoc/Attr), cmd_pages_builder_v3.go (namedObjectVariable, used by resolveRootedAssociationPath), widget_engine.go (parameterBinding takes a data view; rootedAttributeBinding; BuildContext.AttributeSteps), widget_expression_value.go and validate_widget_expression_value.go (rooted data-source form on an attribute property), cmd_pages_builder_visible_when.go, cmd_pages_input_binding_context.go (MDL-WIDGET34 accepts an enclosing data view), mdl/backend (WidgetObjectBuilder.SetAttributeWithSteps in widgetobj and mcp). Tests: cmd_pages_outer_dataview_binding_2107_test.go", "cause": "Studio Pro stores both bindings with the data-view pair SourceVariable {Widget: <outer data view>, PageParameter: …} (markdownViewer3 also with association steps). parameterSourceName returns \"\" when Widget is set, so describe fell back to the qualified name and the rewrite resolved it against the nearest container. The `$dataView1.Attr` spelling existed for built-in inputs only (#826); the pluggable engine, Visible-by-attribute and MDL-WIDGET34 accepted a parameter only, and no pluggable attribute property could store association steps at all.", "insight": "**When a describe falls back to a qualified name, look for a SourceVariable the reader ignored.** Every one of these bindings carried the pair, and the existing spelling for it just had not been wired into every reader and writer: grep the parameter-only helpers (parameterSourceName, parameterVariable) for their callers, and widen them in ONE helper (namedObjectVariable, namedObjectSourceName) so check, describe and exec agree. Also note that `$x/Assoc/Attr` parses as an association data source, not an expression: a fix tested only through the expression form passes its unit test and still fails the real page (MDL-WIDGET42) - feed the engine the parsed shape. Controls: reverting each edit fails its test; the old binary refuses all six pages, the new one reports Unchanged page on all six; a fresh page with $dvOuter.Output, $dvOuter/Span_Trace/SystemPrompt and Visible: $dvOuter.Flag in (true) builds with mx check 0 errors on 11.16."}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a688924d3e..74b4c8aafc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -28,6 +28,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ### Fixed
 
 - **`check` accepts the data-container names Studio Pro stores in a grid row, a control bar and a combo box option** (ako/mxcli#2109) — `describe page` → `exec` of four FactoryManagement pages was refused on its own output (MDL-BUTTON02, MDL-PAGEARG01): a show page in a selectable data grid's column passing the grid's selection (`$grid1`), a control-bar button passing the data view around its grid, and a combo box's option content reading the data view around the combo box. All three build in Studio Pro's own pages. `check` and `exec` now accept them and write what Studio Pro stores, and the pages report `Unchanged page`.
+- **A binding to an outer data view keeps that data view** (ako/mxcli#2107) — a markdown viewer or an attribute-based visibility condition inside a nested data view, bound to the outer one's object, was described as a bare qualified name and rewritten against the nearest data view: CE7247, or "has no attribute". `$dvOuter.Attr` and `$dvOuter/Assoc/Attr` now work on a pluggable widget's attribute property and in `Visible: … in (…)`, as on input widgets, and `describe` prints them; the six FactoryManagement pages report `Unchanged page`.
 - **`describe page` → `exec` no longer rewrites a page over formatting and stored keys MDL cannot state** (ako/mxcli#2106) — on FactoryManagement, 8 pages reported `Replaced page` with nothing changed: a dynamic-classes expression's trailing newlines, an XPath constraint's line breaks and spacing, the order of an enumeration condition's values, an association source's null `SourceVariable` key, and an inherited `createdDate` binding requalified to the specialization. The stored value is now kept where only its form differs, the writer stores the key Studio Pro stores, and a system member resolves to the entity that stores it. A full sweep of the app's 229 pages turns those 8 `Unchanged` and changes no other.
 - **`describe page` → `exec` keeps a check box's label position, a radio button group's orientation and a show page action's close count** (ako/mxcli#2106) — none had an MDL spelling, so a round trip of a Studio Pro page reset a check box with its label after the control to the default, turned every vertical radio button group horizontal, and stopped a show page button from closing the page it came from, with `mx check` green. `checkbox` takes `LabelPosition: Default|BeforeControl|AfterControl`, `radiobuttons` takes `RenderHorizontal: false`, and `show page` takes `with (NumberOfPagesToClose: n)`; `describe` prints each when it differs from the default.
 - **`mxcli test --local --watch` keeps applying changes on macOS and Linux mxbuild** (mendixlabs/mxcli#1787, refs mendixlabs/mxcli#1786) — the test runner's rebuild called mxbuild's serve process directly, without the recovery `run --local --watch` has, so the second build of a serve process failed on regenerated pages and every later change reported "could not be applied". The rebuild now goes through the same recovery, which also recognises mxbuild's resource-key form of that failure (`IO_PathNotFound_Path`, as macOS and Linux report it) and skips the web-bundle check, which only matters when a browser is served.
diff --git a/docs-site/src/reference/page/create-page.md b/docs-site/src/reference/page/create-page.md
index e62da012fc..0d445871b8 100644
--- a/docs-site/src/reference/page/create-page.md
+++ b/docs-site/src/reference/page/create-page.md
@@ -238,7 +238,14 @@ DATAGRID dgOrders (DataSource: DATABASE FROM Sales.Order, Selection: Single) {
 
 A `SHOW PAGE` in the control bar takes the selection the same way —
 `Action: SHOW PAGE Sales.Order_Detail(Order = $dgOrders)` opens the page with
-the selected row, and the button is disabled until a row is selected.
+the selected row, and the button is disabled until a row is selected. In a grid
+with `Selection`, a `SHOW PAGE` in a column's custom content may pass the
+grid's selection by name as well, which is what Studio Pro stores there;
+`$currentObject` is the row.
+
+A control bar takes its object from above its grid, but sits inside the grid,
+so the data view around the grid is an outer one there: `$dvOrder` from the
+control bar of a grid in data view `dvOrder` is valid.
 
 `mxcli check -p <app.mpr>` reports a missing argument before mxbuild does.
 
@@ -288,6 +295,14 @@ attribute property set by its own key too, such as a Custom chart's
 attribute (`Module.Other.Attr`) is refused, because stored without the
 parameter it is mx check CE7247.
 
+An **enclosing data view** is named the same way: inside a data view nested in
+`dvOuter`, `$dvOuter.Attr` reads the outer data view's object, and
+`$dvOuter/Assoc/Attr` reads over an association from it. This works on input
+widgets, on a pluggable widget's attribute property
+(`markdown md (stringAttribute: $dvOuter.Output)`) and in an attribute-based
+visibility condition (`Visible: $dvOuter.HasError in (true)`). It is the form
+Studio Pro stores for these bindings.
+
 ## Parameters
 
 `module.Name`
diff --git a/mdl-examples/bug-tests/2107-binding-through-outer-data-view.mdl b/mdl-examples/bug-tests/2107-binding-through-outer-data-view.mdl
new file mode 100644
index 0000000000..6cd2bcebe9
--- /dev/null
+++ b/mdl-examples/bug-tests/2107-binding-through-outer-data-view.mdl
@@ -0,0 +1,51 @@
+mdl 1;
+-- ============================================================================
+-- Bug ako/mxcli#2107: a binding to an outer data view resolved against the nearest
+-- ============================================================================
+--
+-- Symptom (before fix): describe page -> exec of six FactoryManagement pages
+-- (Mendix 11.16) failed. Studio Pro stores the binding with the data-view pair
+-- SourceVariable {Widget: <outer data view>, PageParameter: …}; describe printed
+-- the bare qualified name and the rewrite read it against the NEAREST data view:
+--   "`GenAICommons.Span.Output` is an attribute of GenAICommons.Span, not of
+--   ConversationalUI.CopyHelper … CE7247" (markdown viewer)
+--   "ConversationalUI.TraceView has no attribute HasError" (Visible by attribute)
+--
+-- After fix: `$dvOuter.Attr`, and the rooted `$dvOuter/Assoc/Attr`, on a
+-- pluggable widget's attribute property and in `Visible: … in (…)`, store the
+-- data-view pair (with the association steps); describe prints them so, and
+-- the six pages report `Unchanged page`. mx check 0 errors on Mendix 11.16.0
+-- for this script (needs the Markdown widget, as Conversational UI ships it).
+--
+-- Usage:
+--   mxcli exec mdl-examples/bug-tests/2107-binding-through-outer-data-view.mdl -p app.mpr
+--   mxcli docker check -p app.mpr        -- expect 0 errors
+-- ============================================================================
+
+create module BugTest2107;
+create module role BugTest2107.User;
+
+create persistent entity BugTest2107.Span (Output: String(unlimited), Flag: Boolean default false);
+create persistent entity BugTest2107.Trace (SystemPrompt: String(unlimited));
+create association BugTest2107.Span_Trace from BugTest2107.Span to BugTest2107.Trace;
+create non-persistent entity BugTest2107.Helper (Note: String(100));
+
+create microflow BugTest2107.DS_Helper () returns BugTest2107.Helper
+begin
+  $Helper = create BugTest2107.Helper (Note = 'x');
+  return $Helper;
+end;
+grant execute on microflow BugTest2107.DS_Helper to BugTest2107.User;
+
+create page BugTest2107.Span_Details (Params: ($Span: BugTest2107.Span), Title: 'Span', Layout: Atlas_Core.PopupLayout) {
+  dataview dvOuter (DataSource: $Span) {
+    dataview dvInner (DataSource: microflow BugTest2107.DS_Helper()) {
+      markdown mdOutput (stringAttribute: $dvOuter.Output)
+      markdown mdPrompt (stringAttribute: $dvOuter/Span_Trace/SystemPrompt)
+      container cFlag (Visible: $dvOuter.Flag in (true)) {
+        dynamictext txtFlag (Content: 'flagged')
+      }
+    }
+  }
+};
+grant view on page BugTest2107.Span_Details to BugTest2107.User;
diff --git a/mdl/backend/mcp/widget.go b/mdl/backend/mcp/widget.go
index 243970a11e..991359b651 100644
--- a/mdl/backend/mcp/widget.go
+++ b/mdl/backend/mcp/widget.go
@@ -165,6 +165,17 @@ func (w *mcpWidgetBuilder) SetAttribute(propertyKey, attributePath string) {
 	}
 }
 
+// SetAttributeWithSteps: the MCP payload's attribute has no association
+// steps, so a path over associations is reported unsupported rather than sent
+// as a direct attribute.
+func (w *mcpWidgetBuilder) SetAttributeWithSteps(propertyKey, attributePath string, steps []pages.AttributeRefStep) {
+	if len(steps) > 0 {
+		w.note("SetAttributeWithSteps(" + propertyKey + ")")
+		return
+	}
+	w.SetAttribute(propertyKey, attributePath)
+}
+
 // SetSourceVariable: the MCP widget payload has no slot for a property's
 // parameter source, so a `$Param.Attr` binding is reported unsupported rather
 // than sent as one read from the enclosing object.
diff --git a/mdl/backend/mutation.go b/mdl/backend/mutation.go
index b4d3f5e80c..37da3f9a42 100644
--- a/mdl/backend/mutation.go
+++ b/mdl/backend/mutation.go
@@ -392,6 +392,10 @@ type WidgetObjectBuilder interface {
 	// and deferred to Finalize, which returns the aggregate result.
 
 	SetAttribute(propertyKey string, attributePath string)
+	// SetAttributeWithSteps is SetAttribute for an attribute reached over
+	// associations: the AttributeRef's EntityRef holds one step per hop, as
+	// a rooted path `$Name/Assoc/Attr` stores it beside its SourceVariable.
+	SetAttributeWithSteps(propertyKey string, attributePath string, steps []pages.AttributeRefStep)
 	SetAssociation(propertyKey string, assocPath string, entityName string)
 	// SetSourceVariable names the object an attribute or association property
 	// reads, when that is not the enclosing data context: a page or snippet
diff --git a/mdl/backend/widgetobj/builder.go b/mdl/backend/widgetobj/builder.go
index b21885a1e5..24f60fd111 100644
--- a/mdl/backend/widgetobj/builder.go
+++ b/mdl/backend/widgetobj/builder.go
@@ -136,6 +136,15 @@ func (ob *Builder) SetAttribute(propertyKey string, attributePath string) {
 	})
 }
 
+func (ob *Builder) SetAttributeWithSteps(propertyKey string, attributePath string, steps []pages.AttributeRefStep) {
+	if attributePath == "" {
+		return
+	}
+	ob.object = updateWidgetPropertyValue(ob.object, ob.propertyTypeIDs, propertyKey, func(val bson.D) bson.D {
+		return setAttributeRefField(val, attributePath, steps)
+	})
+}
+
 func (ob *Builder) SetAssociation(propertyKey string, assocPath string, entityName string) {
 	if assocPath == "" {
 		return
diff --git a/mdl/executor/cmd_pages_builder_v3.go b/mdl/executor/cmd_pages_builder_v3.go
index 7c838f82f5..331ea041cc 100644
--- a/mdl/executor/cmd_pages_builder_v3.go
+++ b/mdl/executor/cmd_pages_builder_v3.go
@@ -2573,13 +2573,8 @@ func (pb *pageBuilder) resolveRootedAssociationPath(attrRef string) (wv pages.Wi
 	if !ok {
 		return pages.WidgetVariable{}, "", nil, false
 	}
-	var start string
-	if v, entity, isParam := pb.parameterVariable(root); isParam {
-		wv, start = v, entity
-	} else if v, isDV := pb.dataViewVariables[root]; isDV {
-		wv, start = v, pb.paramEntityNames[root]
-	}
-	if start == "" {
+	wv, start, named := pb.namedObjectVariable(root)
+	if !named {
 		return pages.WidgetVariable{}, "", nil, false
 	}
 	finalQN, steps, ok = pb.resolveAssociationPathFrom(path, start)
@@ -3017,6 +3012,27 @@ func (pb *pageBuilder) parameterVariable(name string) (pages.WidgetVariable, str
 	return pages.WidgetVariable{Variable: name, Kind: pb.parameterSlotKind(name)}, entity, true
 }
 
+// namedObjectVariable is parameterVariable widened to an enclosing data view:
+// the `$name` of a `$name.Attr` binding read from a page or snippet parameter,
+// or else from a data view the widget sits inside, whose SourceVariable is the
+// data-view pair {Widget: name, PageParameter: …} (ako/mxcli#826, #2107). It
+// returns the SourceVariable to store and the object's entity.
+func (pb *pageBuilder) namedObjectVariable(name string) (pages.WidgetVariable, string, bool) {
+	if wv, entity, ok := pb.parameterVariable(name); ok {
+		return wv, entity, true
+	}
+	name = strings.TrimPrefix(name, "$")
+	wv, known := pb.dataViewVariables[name]
+	if !known || pb.isDeclaredParameter(name) {
+		return pages.WidgetVariable{}, "", false
+	}
+	entity := pb.paramEntityNames[name]
+	if entity == "" {
+		return pages.WidgetVariable{}, "", false
+	}
+	return wv, entity, true
+}
+
 // documentKind names what is being built, for messages.
 func (pb *pageBuilder) documentKind() string {
 	if pb.isSnippet {
diff --git a/mdl/executor/cmd_pages_builder_visible_when.go b/mdl/executor/cmd_pages_builder_visible_when.go
index fbeabf3cba..0be6c22ed2 100644
--- a/mdl/executor/cmd_pages_builder_visible_when.go
+++ b/mdl/executor/cmd_pages_builder_visible_when.go
@@ -70,11 +70,16 @@ func (pb *pageBuilder) visibleWhenSettings(w *ast.WidgetV3, vw *ast.VisibleWhenV
 	// the snippet with no data container around it.
 	entity, attrName := pb.entityContext, vw.Attribute
 	var source *pages.WidgetVariable
+	//
+	// `$dataView1.Attr` reads an enclosing data view's object: the data-view pair
+	// {Widget, PageParameter}, as on FactoryManagement's
+	// ConversationalUI.Trace_Details (ako/mxcli#2107).
 	if name, rest, ok := namedObjectBinding(vw.Attribute); ok {
-		wv, paramEntity, isParam := pb.parameterVariable(name)
+		wv, paramEntity, isParam := pb.namedObjectVariable(name)
 		if !isParam || strings.Contains(rest, ".") {
-			return nil, mdlerrors.NewValidationf("%s: `$%s` is not a parameter of this %s — `Visible: $Param.Attr in (…)` "+
-				"reads an attribute of a page or snippet parameter; inside a data container name the attribute bare",
+			return nil, mdlerrors.NewValidationf("%s: `$%s` is not a parameter of this %s or an enclosing data view — "+
+				"`Visible: $Param.Attr in (…)` reads an attribute of a page or snippet parameter, `$dataView1.Attr` one of "+
+				"a data view the widget is inside; for the nearest data container's object name the attribute bare",
 				where, name, pb.documentKind())
 		}
 		entity, attrName, source = paramEntity, rest, &wv
diff --git a/mdl/executor/cmd_pages_describe_parse.go b/mdl/executor/cmd_pages_describe_parse.go
index bb94b4bb70..947b7b4646 100644
--- a/mdl/executor/cmd_pages_describe_parse.go
+++ b/mdl/executor/cmd_pages_describe_parse.go
@@ -39,8 +39,10 @@ func extractConditionalSettings(ctx *ExecContext, widget *rawWidget, w map[strin
 		if attr, ok := cvs["Attribute"].(string); ok && attr != "" {
 			widget.VisibleAttr = describeAttr(ctx, attr)
 			// Read from a page or snippet parameter (TestApp
-			// Snip_UserTask_NameColumnWithIcon): `$Param.Attr in (…)`.
-			if param := parameterSourceName(cvs["SourceVariable"]); param != "" {
+			// Snip_UserTask_NameColumnWithIcon): `$Param.Attr in (…)`, or from
+			// an enclosing data view (FactoryManagement
+			// ConversationalUI.Trace_Details): `$dataView6.Attr in (…)`.
+			if param := namedObjectSourceName(cvs["SourceVariable"]); param != "" {
 				widget.VisibleAttr = parameterAttributeMDL(param, attr)
 			}
 			for _, c := range getBsonArrayElements(cvs["Conditions"]) {
diff --git a/mdl/executor/cmd_pages_describe_pluggable.go b/mdl/executor/cmd_pages_describe_pluggable.go
index bedac40b17..96f27b936a 100644
--- a/mdl/executor/cmd_pages_describe_pluggable.go
+++ b/mdl/executor/cmd_pages_describe_pluggable.go
@@ -1345,10 +1345,20 @@ func extractExplicitProperties(ctx *ExecContext, w map[string]any, enclosingEnti
 		if attrRef, ok := value["AttributeRef"].(map[string]any); ok && attrRef != nil {
 			if attr := extractString(attrRef["Attribute"]); attr != "" {
 				described := describeAttr(ctx, attr)
-				if param := parameterSourceName(value["SourceVariable"]); param != "" && attrRef["EntityRef"] == nil {
-					// Read from a page or snippet parameter: `$Param.Attr`. The
-					// qualified name re-executes without the SourceVariable —
-					// CE7247 (mendixlabs/mxcli#1591).
+				if root := namedObjectSourceName(value["SourceVariable"]); root != "" && attrRef["EntityRef"] != nil {
+					// The same object, with association steps: `$Root/Assoc/Attr`
+					// (ako/mxcli#833), as FactoryManagement's
+					// ConversationalUI.Span_TextGeneration_SlideIn stores it
+					// (ako/mxcli#2107).
+					if path := columnAttributeFromRef(ctx, attrRef); strings.Contains(path, "/") {
+						described = "$" + root + "/" + path
+					}
+				} else if param := namedObjectSourceName(value["SourceVariable"]); param != "" && attrRef["EntityRef"] == nil {
+					// Read from a page or snippet parameter, `$Param.Attr`, or an
+					// enclosing data view, `$dataView1.Attr`. The qualified name
+					// re-executes without the SourceVariable and binds against
+					// the nearest container — CE7247 (mendixlabs/mxcli#1591,
+					// ako/mxcli#2107).
 					described = parameterAttributeMDL(param, attr)
 				} else if schemas[typePointerID].DataSourceProperty == "" && strings.Contains(enclosing, ".") &&
 					!strings.EqualFold(attributeEntity(attr), enclosing) {
diff --git a/mdl/executor/cmd_pages_input_binding_context.go b/mdl/executor/cmd_pages_input_binding_context.go
index daf351ec10..016d4b5325 100644
--- a/mdl/executor/cmd_pages_input_binding_context.go
+++ b/mdl/executor/cmd_pages_input_binding_context.go
@@ -306,8 +306,10 @@ func validatePageVariableBindings(widgets []*ast.WidgetV3, variables []ast.PageV
 
 // validateNamedObjectBindings is MDL-WIDGET34 for `$name.Attr` on a whole page
 // or snippet, where the parameters are known: a name that is neither one of
-// them nor — on a built-in input — an enclosing data view names nothing, and
-// exec refuses it. `Visible: $name.Attr in (…)` reads a parameter only.
+// them nor — on a built-in input, or in `Visible: $name.Attr in (…)` — an
+// enclosing data view names nothing, and exec refuses it. The visibility
+// setting stores the data-view pair as an input does (FactoryManagement
+// ConversationalUI.Trace_Details, ako/mxcli#2107).
 func validateNamedObjectBindings(widgets []*ast.WidgetV3, params []string, locationPrefix string) []linter.Violation {
 	declared := make(map[string]bool, len(params))
 	for _, p := range params {
@@ -382,9 +384,9 @@ func validateNamedObjectBindings(widgets []*ast.WidgetV3, params []string, locat
 				}
 			}
 			if vw, ok := w.Properties["VisibleWhen"].(*ast.VisibleWhenV3); ok && vw != nil {
-				if name, rest, ok := namedObjectBinding(vw.Attribute); ok && (!declared[name] || strings.Contains(rest, ".")) {
-					report(fmt.Sprintf("%s `%s`: `Visible: %s in (…)` — `$%s` is not a parameter of this document, "+
-						"so the condition would read nothing", kind, w.Name, vw.Attribute, name))
+				if name, rest, ok := namedObjectBinding(vw.Attribute); ok && (!(declared[name] || dataViews[name]) || strings.Contains(rest, ".")) {
+					report(fmt.Sprintf("%s `%s`: `Visible: %s in (…)` — `$%s` is not a parameter of this document "+
+						"or a data view the widget is inside, so the condition would read nothing", kind, w.Name, vw.Attribute, name))
 				}
 			}
 			inner := dataViews
diff --git a/mdl/executor/cmd_pages_outer_dataview_binding_2107_test.go b/mdl/executor/cmd_pages_outer_dataview_binding_2107_test.go
new file mode 100644
index 0000000000..1906e5e144
--- /dev/null
+++ b/mdl/executor/cmd_pages_outer_dataview_binding_2107_test.go
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: Apache-2.0
+
+// ako/mxcli#2107: a widget bound to an attribute of an OUTER data view's object.
+// Studio Pro stores the binding with the data-view pair as its source,
+// SourceVariable {Widget: <outer data view>, PageParameter: <its parameter>}
+// (FactoryManagement, Mendix 11.16):
+//
+//	ConversationalUI.Span_ToolSpan_SlideIn  markdownViewer1.stringAttribute
+//	  AttributeRef GenAICommons.Span.Output, SourceVariable {Widget: dataView1, PageParameter: ToolSpan}
+//	ConversationalUI.Trace_Details  container112 Visible
+//	  Attribute GenAICommons.Trace.HasError, SourceVariable {Widget: dataView6, PageParameter: Trace}
+//
+// describe printed the bare qualified name, which the rewrite resolved against the
+// NEAREST data view: "`GenAICommons.Span.Output` is an attribute of
+// GenAICommons.Span, not of ConversationalUI.CopyHelper … CE7247", and
+// "ConversationalUI.TraceView has no attribute HasError". The pair already has
+// an MDL spelling on input widgets, `$dataView1.Attr` (ako/mxcli#826).
+package executor
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/mendixlabs/mxcli/mdl/ast"
+	modelsdkbackend "github.com/mendixlabs/mxcli/mdl/backend/modelsdk"
+	"github.com/mendixlabs/mxcli/mdl/backend/mock"
+	"github.com/mendixlabs/mxcli/model"
+	"github.com/mendixlabs/mxcli/sdk/domainmodel"
+	"github.com/mendixlabs/mxcli/sdk/pages"
+	"go.mongodb.org/mongo-driver/v2/bson"
+)
+
+func outerDataViewPair(widget, param string) map[string]any {
+	return map[string]any{"$Type": "Forms$PageVariable", "Widget": widget, "PageParameter": param}
+}
+
+func markdownInNestedDataView(sourceVariable any) map[string]any {
+	md := map[string]any{
+		"$Type": "CustomWidgets$CustomWidget",
+		"Name":  "markdownViewer1",
+		"Type": map[string]any{
+			"WidgetId": "com.mendix.widget.web.markdown.Markdown",
+			"ObjectType": map[string]any{"PropertyTypes": []any{
+				map[string]any{"$ID": "pt-str", "PropertyKey": "stringAttribute",
+					"ValueType": map[string]any{"Type": "Attribute"}},
+			}},
+		},
+		"Object": map[string]any{"Properties": []any{
+			map[string]any{"TypePointer": "pt-str", "Value": map[string]any{
+				"AttributeRef":   map[string]any{"Attribute": "GenAICommons.Span.Output"},
+				"SourceVariable": sourceVariable,
+			}},
+		}},
+	}
+	inner := map[string]any{
+		"$Type": "Forms$DataView", "Name": "dataView3",
+		"DataSource": map[string]any{"$Type": "Forms$DataViewSource",
+			"EntityRef": map[string]any{"$Type": "DomainModels$DirectEntityRef", "Entity": "ConversationalUI.CopyHelper"}},
+		"Widgets": []any{md},
+	}
+	return map[string]any{
+		"$Type": "Forms$DataView", "Name": "dataView1",
+		"DataSource": map[string]any{"$Type": "Forms$DataViewSource",
+			"EntityRef":      map[string]any{"$Type": "DomainModels$DirectEntityRef", "Entity": "GenAICommons.ToolSpan"},
+			"SourceVariable": map[string]any{"$Type": "Forms$PageVariable", "PageParameter": "ToolSpan"}},
+		"Widgets": []any{inner},
+	}
+}
+
+func describedMarkdownAttribute(t *testing.T, sourceVariable any) string {
+	t.Helper()
+	ctx, _ := newMockCtx(t)
+	outer := parseRawWidget(ctx, markdownInNestedDataView(sourceVariable))
+	if len(outer) != 1 || len(outer[0].Children) != 1 || len(outer[0].Children[0].Children) != 1 {
+		t.Fatalf("want dataView1 > dataView3 > markdown, got %+v", outer)
+	}
+	for _, p := range outer[0].Children[0].Children[0].ExplicitProperties {
+		if p.Key == "stringAttribute" {
+			return p.Value
+		}
+	}
+	t.Fatal("no stringAttribute described")
+	return ""
+}
+
+func TestDescribePluggableAttributeThroughOuterDataView(t *testing.T) {
+	if got := describedMarkdownAttribute(t, outerDataViewPair("dataView1", "ToolSpan")); got != "$dataView1.Output" {
+		t.Errorf("stringAttribute = %q, want $dataView1.Output (the stored data-view pair)", got)
+	}
+	// Control: with no SourceVariable the qualified name stays, as before.
+	if got := describedMarkdownAttribute(t, nil); got != "GenAICommons.Span.Output" {
+		t.Errorf("stringAttribute without a source = %q, want GenAICommons.Span.Output", got)
+	}
+}
+
+func describedVisibleAttr(t *testing.T, sourceVariable any) string {
+	t.Helper()
+	ctx, _ := newMockCtx(t)
+	var w rawWidget
+	extractConditionalSettings(ctx, &w, map[string]any{"ConditionalVisibilitySettings": map[string]any{
+		"Attribute":      "GenAICommons.Trace.HasError",
+		"SourceVariable": sourceVariable,
+		"Conditions": []any{int32(2),
+			map[string]any{"AttributeValue": "true", "EditableVisible": true},
+			map[string]any{"AttributeValue": "false", "EditableVisible": false}},
+	}})
+	return w.VisibleAttr
+}
+
+func TestDescribeVisibleAttributeThroughOuterDataView(t *testing.T) {
+	if got := describedVisibleAttr(t, outerDataViewPair("dataView6", "Trace")); got != "$dataView6.HasError" {
+		t.Errorf("Visible attribute = %q, want $dataView6.HasError", got)
+	}
+	// Control: a parameter source stays `$Param.Attr`.
+	if got := describedVisibleAttr(t, map[string]any{"$Type": "Forms$PageVariable", "PageParameter": "Trace"}); got != "$Trace.HasError" {
+		t.Errorf("Visible attribute from a parameter = %q, want $Trace.HasError", got)
+	}
+}
+
+// The builder half: `$dataView1.Attr` on a Visible-by-attribute setting and on
+// a pluggable widget's attribute key writes the data-view pair, as it already
+// did on an input widget.
+
+func TestBuildVisibleWhen_ThroughOuterDataView(t *testing.T) {
+	pb := scopedPB(false)
+	pb.paramEntityNames["dataView1"] = "M.Job"
+	defer pb.registerDataViewVariable("dataView1", &pages.DataViewSource{ParameterName: "Task"})()
+	cvs, err := buildVisibleWhen(t, pb, "$dataView1.Status", "Running")
+	if err != nil {
+		t.Fatalf("build: %v", err)
+	}
+	if cvs == nil || cvs.Attribute != "M.Job.Status" {
+		t.Fatalf("settings = %+v, want Attribute M.Job.Status", cvs)
+	}
+	if want := (pages.WidgetVariable{Widget: "dataView1", Variable: "Task"}); cvs.SourceVariable == nil || *cvs.SourceVariable != want {
+		t.Errorf("SourceVariable = %+v, want %+v", cvs.SourceVariable, want)
+	}
+	// Control: a name that is neither a parameter nor an enclosing data view.
+	if _, err := buildVisibleWhen(t, scopedPB(false), "$dataView9.Status", "Running"); err == nil {
+		t.Error("Visible: $dataView9.Status built; want a refusal")
+	}
+}
+
+func TestBuildPluggableAttribute_ThroughOuterDataView(t *testing.T) {
+	e := scopeEngine(t)
+	e.pageBuilder.paramEntityNames["dvOuter"] = "Sales.Customer"
+	defer e.pageBuilder.registerDataViewVariable("dvOuter", &pages.DataViewSource{ParameterName: "Ctx"})()
+	w := twoSourceWidget(map[string]any{"staticAttribute": &ast.WidgetExpressionV3{Text: "$dvOuter.Name"}})
+	widget, err := e.Build(multiSourceDef(), w)
+	if err != nil {
+		t.Fatalf("Build: %v", err)
+	}
+	val := widgetValueFor(widget.RawObject, "Sales.Customer.Name")
+	if val == nil {
+		t.Fatal("no WidgetValue binds Sales.Customer.Name — the binding was dropped")
+	}
+	sv, ok := dGet(val, "SourceVariable").(bson.D)
+	if !ok {
+		t.Fatalf("SourceVariable = %#v, want the data-view pair", dGet(val, "SourceVariable"))
+	}
+	for k, want := range map[string]any{"Widget": "dvOuter", "PageParameter": "Ctx"} {
+		if got := dGet(sv, k); got != want {
+			t.Errorf("SourceVariable.%s = %#v, want %#v", k, got, want)
+		}
+	}
+	// Control: a name that is no data view and no parameter is still refused.
+	w = twoSourceWidget(map[string]any{"staticAttribute": &ast.WidgetExpressionV3{Text: "$dvNope.Name"}})
+	if _, err := scopeEngine(t).Build(multiSourceDef(), w); err == nil {
+		t.Error("staticAttribute: $dvNope.Name built; want a refusal")
+	}
+}
+
+// The check half: MDL-WIDGET34 accepted `Visible: $name.Attr in (…)` for a
+// parameter only, so describe's `$dataView6.HasError` would be refused.
+func TestCheck_VisibleAttributeThroughOuterDataView(t *testing.T) {
+	widget34 := func(src string) int {
+		n := 0
+		for _, v := range ValidateProgram(parseMDL(t, src), "") {
+			if v.RuleID == "MDL-WIDGET34" {
+				n++
+			}
+		}
+		return n
+	}
+	page := func(inner string) string {
+		return `mdl 1;
+create page M.Trace ( Title: 'T', Layout: Atlas_Core.PopupLayout, Params: ( $Trace: M.Job ) ) {
+  dataview dvOuter ( DataSource: $Trace ) {
+    dataview dvInner ( DataSource: microflow M.DS_View() ) {
+      container c1 ( Visible: $dvOuter.Status in (Running) )
+    }
+  }
+  ` + inner + `
+};`
+	}
+	if n := widget34(page("")); n != 0 {
+		t.Errorf("`$dvOuter.Status` inside dvOuter: %d MDL-WIDGET34, want 0", n)
+	}
+	// Control: the same name outside dvOuter reads nothing.
+	if n := widget34(page("container c2 ( Visible: $dvOuter.Status in (Running) )")); n != 1 {
+		t.Errorf("`$dvOuter.Status` outside dvOuter: %d MDL-WIDGET34, want 1", n)
+	}
+}
+
+// The pair with association steps: ConversationalUI.Span_TextGeneration_SlideIn's
+// markdownViewer3 reads GenAICommons.Trace.SystemPrompt over Span_Trace from
+// dataView1's object, SourceVariable {Widget: dataView1, PageParameter:
+// ModelSpan}. The rooted spelling is #833's `$Root/Assoc/Attr`.
+func TestDescribePluggableAttributePathThroughOuterDataView(t *testing.T) {
+	ctx, _ := newMockCtx(t)
+	w := markdownInNestedDataView(outerDataViewPair("dataView1", "ModelSpan"))
+	md := w["Widgets"].([]any)[0].(map[string]any)["Widgets"].([]any)[0].(map[string]any)
+	prop := md["Object"].(map[string]any)["Properties"].([]any)[0].(map[string]any)
+	prop["Value"].(map[string]any)["AttributeRef"] = map[string]any{
+		"Attribute": "GenAICommons.Trace.SystemPrompt",
+		"EntityRef": map[string]any{"$Type": "DomainModels$IndirectEntityRef", "Steps": []any{int32(2),
+			map[string]any{"$Type": "DomainModels$EntityRefStep", "Association": "GenAICommons.Span_Trace", "DestinationEntity": "GenAICommons.Trace"}}},
+	}
+	outer := parseRawWidget(ctx, w)
+	var got string
+	for _, p := range outer[0].Children[0].Children[0].ExplicitProperties {
+		if p.Key == "stringAttribute" {
+			got = p.Value
+		}
+	}
+	if !strings.HasPrefix(got, "$dataView1/") || !strings.HasSuffix(got, "Span_Trace/SystemPrompt") {
+		t.Errorf("stringAttribute = %q, want $dataView1/…Span_Trace/SystemPrompt", got)
+	}
+}
+
+func associationEngine(t *testing.T) *PluggableWidgetEngine {
+	t.Helper()
+	real := &modelsdkbackend.Backend{}
+	mod := &model.Module{BaseElement: model.BaseElement{ID: model.ID("mod-sales")}, Name: "Sales"}
+	b := &mock.MockBackend{
+		LoadWidgetTemplateFunc: real.LoadWidgetTemplate,
+		ListModulesFunc:        func() ([]*model.Module, error) { return []*model.Module{mod}, nil },
+		ListDomainModelsFunc: func() ([]*domainmodel.DomainModel, error) {
+			return []*domainmodel.DomainModel{{
+				BaseElement: model.BaseElement{ID: model.ID("dm-sales")},
+				ContainerID: mod.ID,
+				Entities: []*domainmodel.Entity{
+					{BaseElement: model.BaseElement{ID: model.ID("e-invoice")}, Name: "Invoice",
+						Attributes: []*domainmodel.Attribute{{Name: "Reference"}, {Name: "Label"}}},
+					{BaseElement: model.BaseElement{ID: model.ID("e-order")}, Name: "Order",
+						Attributes: []*domainmodel.Attribute{{Name: "Number"}, {Name: "Label"}}},
+					{BaseElement: model.BaseElement{ID: model.ID("e-customer")}, Name: "Customer",
+						Attributes: []*domainmodel.Attribute{{Name: "Name"}, {Name: "Label"}}},
+				},
+				Associations: []*domainmodel.Association{{Name: "Order_Customer", ParentID: "e-order", ChildID: "e-customer",
+					Type: domainmodel.AssociationTypeReference}},
+			}}, nil
+		},
+	}
+	pb := &pageBuilder{backend: b, entityContext: "Sales.Invoice", paramEntityNames: map[string]string{}, widgetScope: map[string]model.ID{}}
+	e := NewPluggableWidgetEngine(b, pb)
+	pb.pluggableEngine = e
+	return e
+}
+
+func TestBuildPluggableAttributePath_ThroughOuterDataView(t *testing.T) {
+	e := associationEngine(t)
+	e.pageBuilder.paramEntityNames["dvOuter"] = "Sales.Order"
+	defer e.pageBuilder.registerDataViewVariable("dvOuter", &pages.DataViewSource{ParameterName: "Ctx"})()
+	w := twoSourceWidget(map[string]any{"staticAttribute": &ast.WidgetExpressionV3{Text: "$dvOuter/Order_Customer/Name"}})
+	widget, err := e.Build(multiSourceDef(), w)
+	if err != nil {
+		t.Fatalf("Build: %v", err)
+	}
+	val := widgetValueFor(widget.RawObject, "Sales.Customer.Name")
+	if val == nil {
+		t.Fatal("no WidgetValue binds Sales.Customer.Name — the binding was dropped")
+	}
+	ref, _ := dGet(val, "AttributeRef").(bson.D)
+	entityRef, _ := dGet(ref, "EntityRef").(bson.D)
+	steps, _ := dGet(entityRef, "Steps").(bson.A)
+	var step bson.D
+	if len(steps) == 2 {
+		step, _ = steps[1].(bson.D)
+	}
+	if dGet(step, "Association") != "Sales.Order_Customer" {
+		t.Errorf("EntityRef steps = %#v, want one hop over Sales.Order_Customer", dGet(ref, "EntityRef"))
+	}
+	sv, _ := dGet(val, "SourceVariable").(bson.D)
+	if dGet(sv, "Widget") != "dvOuter" || dGet(sv, "PageParameter") != "Ctx" {
+		t.Errorf("SourceVariable = %#v, want the data-view pair", dGet(val, "SourceVariable"))
+	}
+}
+
+// As the parser hands it over: `stringAttribute: $dataView1/Span_Trace/SystemPrompt`
+// parses as an association data source rooted at the data view, which the
+// engine refused as "an attribute property … cannot hold the expression"
+// (MDL-WIDGET42) on Span_TextGeneration_SlideIn.
+func TestBuildPluggableAttributePath_ParsedForm(t *testing.T) {
+	e := associationEngine(t)
+	e.pageBuilder.paramEntityNames["dvOuter"] = "Sales.Order"
+	defer e.pageBuilder.registerDataViewVariable("dvOuter", &pages.DataViewSource{ParameterName: "Ctx"})()
+	w := twoSourceWidget(map[string]any{"staticAttribute": &ast.DataSourceV3{
+		Type: "association", Reference: "Order_Customer/Name", ContextVariable: "dvOuter"}})
+	widget, err := e.Build(multiSourceDef(), w)
+	if err != nil {
+		t.Fatalf("Build: %v", err)
+	}
+	if widgetValueFor(widget.RawObject, "Sales.Customer.Name") == nil {
+		t.Fatal("no WidgetValue binds Sales.Customer.Name")
+	}
+}
diff --git a/mdl/executor/cmd_pages_parameter_binding.go b/mdl/executor/cmd_pages_parameter_binding.go
index dbf9de5ea1..679b15734c 100644
--- a/mdl/executor/cmd_pages_parameter_binding.go
+++ b/mdl/executor/cmd_pages_parameter_binding.go
@@ -48,7 +48,7 @@ func namedObjectBinding(s string) (name, rest string, ok bool) {
 // one shape is still an expression.
 func parameterAttributeValue(raw any) (string, bool) {
 	e, ok := raw.(*ast.WidgetExpressionV3)
-	if !ok || !isParameterAttributeText(e.Text) {
+	if !ok || !isNamedObjectAttributeText(e.Text) {
 		return "", false
 	}
 	return e.Text, true
@@ -89,6 +89,21 @@ func parameterSourceName(sv any) string {
 	return extractString(m["PageParameter"])
 }
 
+// namedObjectSourceName is the `$name` of the object a stored SourceVariable
+// names: the data view of a data-view pair {Widget, PageParameter}, or else a
+// page or snippet parameter — "" for none, or for a page variable. MDL spells
+// the pair `$dataView1.Attr` (ako/mxcli#826, #2107).
+func namedObjectSourceName(sv any) string {
+	m, ok := sv.(map[string]any)
+	if !ok || m == nil || extractString(m["LocalVariable"]) != "" {
+		return ""
+	}
+	if widget := extractString(m["Widget"]); widget != "" {
+		return widget
+	}
+	return parameterSourceName(sv)
+}
+
 // customWidgetPropertyParameter is the parameter a CustomWidget property's
 // WidgetValue reads (its SourceVariable), or "".
 func customWidgetPropertyParameter(w map[string]any, propertyKey string) string {
@@ -114,6 +129,19 @@ func parameterAttributeMDL(name, attrQN string) string {
 	return "$" + name + "." + mdlIdent(shortAttributeName(attrQN))
 }
 
+// isNamedObjectAttributeText reports whether text binds an attribute of a named
+// object: `$Name.Attr`, or the rooted association path `$Name/Assoc/Attr`
+// (ako/mxcli#833), which a pluggable attribute property takes as well
+// (FactoryManagement ConversationalUI.Span_TextGeneration_SlideIn,
+// ako/mxcli#2107). Neither is a Mendix expression to an attribute property.
+func isNamedObjectAttributeText(text string) bool {
+	if isParameterAttributeText(text) {
+		return true
+	}
+	_, _, rooted := rootedAssociationPath(text)
+	return rooted
+}
+
 // isParameterAttributeText reports whether text is the `$Param.Attr` shape.
 // namedObjectBinding alone takes `$Ctx.Name + 'x'` too, which is an expression.
 func isParameterAttributeText(text string) bool {
diff --git a/mdl/executor/validate_widget_expression_value.go b/mdl/executor/validate_widget_expression_value.go
index 4a08a385fe..787d5b62b4 100644
--- a/mdl/executor/validate_widget_expression_value.go
+++ b/mdl/executor/validate_widget_expression_value.go
@@ -58,6 +58,11 @@ func validateWidgetExpressionValuesIn(w *ast.WidgetV3, def *WidgetDefinition, it
 				continue
 			}
 			text = src
+			// `$Name/Assoc/Attr` parses as a data source; on an attribute
+			// property it is a rooted attribute path (ako/mxcli#2107).
+			if root, path, rooted := rootedAttributeValue(v); rooted {
+				text, isExpr = "$"+root+"/"+path, true
+			}
 		default:
 			continue
 		}
@@ -77,7 +82,7 @@ func validateWidgetExpressionValuesIn(w *ast.WidgetV3, def *WidgetDefinition, it
 		switch {
 		case op == "expression":
 			continue
-		case isExpr && isParameterAttributeText(text) && (op == "attribute" || !known):
+		case isExpr && isNamedObjectAttributeText(text) && (op == "attribute" || !known):
 			// `$Param.Attr` reads an attribute of a page or snippet parameter
 			// (mendixlabs/mxcli#1591); exec resolves the parameter. It is no
 			// Mendix expression (that is `$Param/Attr`), so a key whose kind is
diff --git a/mdl/executor/widget_engine.go b/mdl/executor/widget_engine.go
index d2184b9ba2..e5c361b9a2 100644
--- a/mdl/executor/widget_engine.go
+++ b/mdl/executor/widget_engine.go
@@ -278,6 +278,10 @@ type BuildContext struct {
 	// SourceVariable names the parameter an attribute or association binding
 	// reads (`$Param.Attr`); nil for one read from the enclosing object.
 	SourceVariable *pages.WidgetVariable
+	// AttributeSteps are the association hops of a rooted attribute path,
+	// `$Name/Assoc/Attr`, stored as the AttributeRef's EntityRef beside
+	// SourceVariable (ako/mxcli#2107).
+	AttributeSteps []pages.AttributeRefStep
 	// ImageEntity is the entity an image-typed property binds to when it was
 	// written `$currentObject` rather than as a collection entry (#1476).
 	ImageEntity string
@@ -747,6 +751,17 @@ func (e *PluggableWidgetEngine) Build(def *WidgetDefinition, w *ast.WidgetV3) (*
 			// re-applies a property authored by its schema key AFTER every
 			// datasource has run, so the shared context here is always the LAST
 			// datasource's entity, which is what #647 wrote for every name.
+			if _, _, rooted := rootedAssociationPath(strVal); rooted {
+				// `$Name/Assoc/Attr`: an association path read from a named
+				// object (ako/mxcli#833, #2107).
+				wv, finalQN, steps, err := e.rootedAttributeBinding(w, propName, strVal)
+				if err != nil {
+					return nil, err
+				}
+				builder.SetAttributeWithSteps(propName, finalQN, steps)
+				builder.SetSourceVariable(propName, &wv)
+				break
+			}
 			if name, rest, named := namedObjectBinding(strVal); named {
 				// `$Param.Attr`: the attribute of a page or snippet parameter,
 				// whatever encloses the widget — the AttributeRef plus a
@@ -1059,7 +1074,11 @@ var templateAttrPlaceholderRe = regexp.MustCompile(`\{[A-Za-z][A-Za-z0-9_]*\}`)
 func (e *PluggableWidgetEngine) applyOperation(builder backend.WidgetObjectBuilder, opName string, propKey string, ctx *BuildContext) error {
 	switch opName {
 	case "attribute":
-		builder.SetAttribute(propKey, ctx.AttributePath)
+		if len(ctx.AttributeSteps) > 0 {
+			builder.SetAttributeWithSteps(propKey, ctx.AttributePath, ctx.AttributeSteps)
+		} else {
+			builder.SetAttribute(propKey, ctx.AttributePath)
+		}
 		if ctx.SourceVariable != nil && ctx.AttributePath != "" {
 			builder.SetSourceVariable(propKey, ctx.SourceVariable)
 		}
@@ -1497,13 +1516,15 @@ func refuseAmbiguousGenericDataSource(def *WidgetDefinition, w *ast.WidgetV3, ds
 }
 
 // parameterBinding resolves the `$name` of a `$name.Attr` binding on a pluggable
-// widget property to the page or snippet parameter it names: the SourceVariable
-// to store beside the reference, and the parameter's entity. A name that is no
-// parameter is refused — the data-view pair (#826) is measured on the built-in
-// inputs only, and anything else would be written as a binding that reads
+// widget property to the object it names: a page or snippet parameter, or an
+// enclosing data view — the data-view pair Studio Pro stores on a markdown
+// viewer in an inner data view (FactoryManagement ConversationalUI
+// Span_*_SlideIn, ako/mxcli#2107) as on the built-in inputs (#826). It returns
+// the SourceVariable to store beside the reference and the object's entity.
+// Any other name is refused: it would be written as a binding that reads
 // nothing.
 func (e *PluggableWidgetEngine) parameterBinding(w *ast.WidgetV3, propertyKey, attr, name string) (pages.WidgetVariable, string, error) {
-	wv, entity, ok := e.pageBuilder.parameterVariable(name)
+	wv, entity, ok := e.pageBuilder.namedObjectVariable(name)
 	if !ok {
 		return pages.WidgetVariable{}, "", notAParameterError(
 			fmt.Sprintf("%s `%s` property `%s`", strings.ToLower(w.Type), w.Name, propertyKey),
@@ -1512,12 +1533,30 @@ func (e *PluggableWidgetEngine) parameterBinding(w *ast.WidgetV3, propertyKey, a
 	return wv, entity, nil
 }
 
+// rootedAttributeBinding resolves `$Name/Assoc/Attr` on a pluggable widget's
+// attribute property — an association path read from a parameter or an
+// enclosing data view, the shape Studio Pro stores as the AttributeRef's
+// steps beside a SourceVariable naming the object (FactoryManagement
+// ConversationalUI.Span_TextGeneration_SlideIn, ako/mxcli#2107).
+func (e *PluggableWidgetEngine) rootedAttributeBinding(w *ast.WidgetV3, propertyKey, attr string) (pages.WidgetVariable, string, []pages.AttributeRefStep, error) {
+	wv, finalQN, steps, ok := e.pageBuilder.resolveRootedAssociationPath(attr)
+	if !ok {
+		root, _, _ := rootedAssociationPath(attr)
+		return pages.WidgetVariable{}, "", nil, mdlerrors.NewValidationf(
+			"%s `%s` property `%s`: `%s` — `$%s/…` reads an association path from a parameter of this %s or an "+
+				"enclosing data view, and `$%s` is neither, or the path does not resolve from it",
+			strings.ToLower(w.Type), w.Name, propertyKey, attr, root, e.pageBuilder.documentKind(), root)
+	}
+	return wv, finalQN, steps, nil
+}
+
 // notAParameterError refuses a `$name.Attr` binding whose name is no page or
 // snippet parameter. where names the widget property, for the message.
 func notAParameterError(where, attr, name, documentKind string) error {
 	return mdlerrors.NewValidationf(
-		"%s: `%s` — `$%s` is not a parameter of this %s; `$Param.Attr` reads an attribute "+
-			"of a page or snippet parameter. Inside a data container, name the attribute bare",
+		"%s: `%s` — `$%s` is not a parameter of this %s or an enclosing data view; `$Param.Attr` reads an "+
+			"attribute of a page or snippet parameter, `$dataView1.Attr` one of a data view the widget is inside. "+
+			"For the nearest data container's object, name the attribute bare",
 		where, attr, name, documentKind)
 }
 
@@ -1688,7 +1727,14 @@ func (e *PluggableWidgetEngine) resolveMapping(mapping PropertyMapping, w *ast.W
 				}
 			}
 		}
-		if name, rest, named := namedObjectBinding(attr); named {
+		if _, _, rooted := rootedAssociationPath(attr); rooted {
+			// `$Name/Assoc/Attr` (ako/mxcli#833, #2107).
+			wv, finalQN, steps, err := e.rootedAttributeBinding(w, mapping.PropertyKey, attr)
+			if err != nil {
+				return nil, err
+			}
+			ctx.AttributePath, ctx.AttributeSteps, ctx.SourceVariable = finalQN, steps, &wv
+		} else if name, rest, named := namedObjectBinding(attr); named {
 			// `$Param.Attr`: read from a page or snippet parameter, whatever
 			// encloses the widget (see cmd_pages_parameter_binding.go).
 			wv, entity, err := e.parameterBinding(w, mapping.PropertyKey, attr, name)
diff --git a/mdl/executor/widget_expression_value.go b/mdl/executor/widget_expression_value.go
index 3a547423f6..efe752db0e 100644
--- a/mdl/executor/widget_expression_value.go
+++ b/mdl/executor/widget_expression_value.go
@@ -69,6 +69,11 @@ func scalarPropertyText(w *ast.WidgetV3, key string, raw any, op string) (string
 		}
 		return "", expressionInScalarPropertyError(w, key, op, v.Text)
 	case *ast.DataSourceV3:
+		// `$Name/Assoc/Attr` parses as a data source; on an attribute property
+		// it is a rooted attribute path, resolved by the engine (ako/mxcli#2107).
+		if root, path, rooted := rootedAttributeValue(v); rooted && op == "attribute" {
+			return "$" + root + "/" + path, nil
+		}
 		src, hasSrc := w.ExpressionSource(key)
 		if op == "expression" && hasSrc {
 			return src, nil

From 8cbe6d691c506eeda09cced2402547628b8ddc17 Mon Sep 17 00:00:00 2001
From: Ako <andrej@koelewijn.net>
Date: Wed, 11 Nov 2026 22:15:44 +0100
Subject: [PATCH 3/3] style: gofmt the #2107 test

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011oK82ttaGzay5CwiC2V7cf
---
 mdl/executor/cmd_pages_outer_dataview_binding_2107_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mdl/executor/cmd_pages_outer_dataview_binding_2107_test.go b/mdl/executor/cmd_pages_outer_dataview_binding_2107_test.go
index 1906e5e144..ad6793caf0 100644
--- a/mdl/executor/cmd_pages_outer_dataview_binding_2107_test.go
+++ b/mdl/executor/cmd_pages_outer_dataview_binding_2107_test.go
@@ -22,8 +22,8 @@ import (
 	"testing"
 
 	"github.com/mendixlabs/mxcli/mdl/ast"
-	modelsdkbackend "github.com/mendixlabs/mxcli/mdl/backend/modelsdk"
 	"github.com/mendixlabs/mxcli/mdl/backend/mock"
+	modelsdkbackend "github.com/mendixlabs/mxcli/mdl/backend/modelsdk"
 	"github.com/mendixlabs/mxcli/model"
 	"github.com/mendixlabs/mxcli/sdk/domainmodel"
 	"github.com/mendixlabs/mxcli/sdk/pages"