fix(odata): read an external entity's OData source, and keep its local-changes flag

.claude/skills/fix-issue.md

@@ -16,6 +16,8 @@ to the symptom table below, so the next similar issue costs fewer reads.
 
 | Symptom | Root cause layer | First file to open | Fix pattern |
 |---------|-----------------|-------------------|-------------|
+| `create or modify external entities` silently resets a per-entity setting the user had changed (e.g. allow-create-change-locally) | `applyExternalEntityFields` stamps every field on both the create and the update path, so anything not derivable from the OData contract was overwritten with a default | `mdl/executor/cmd_contract.go` (`applyExternalEntityFields`) | Separate contract-derived fields (Countable/Creatable/Deletable/Skip/Top — refresh from metadata) from local modelling choices (CreateChangeLocally — leave alone; a new entity arrives zero-valued, which is Mendix's default). Issue #782 |
+| An **external (OData) entity** loses its remote settings on any read-modify-write — `describe external entity` says `is not an external entity (source: )`, and `alter entity … set allow_create_change_locally = true` reports success but the flag stays off. Works under `--engine legacy` | `entityFromGen` recognised only `DomainModels$OqlViewEntitySource`, so the three `Rest$OData*` sources read back as no source at all: `Source` empty, every remote field zeroed. The write path was fine — it switches on `e.Source`, which the read never populated | `mdl/backend/modelsdk/domainmodel.go` (`entityFromGen`'s source switch, `odataKeyFromGen`) | Mirror the legacy parser (`sdk/mpr/parser_domainmodel.go`) for all three flavours: RemoteEntitySource (capabilities + CreateChangeLocally + key), EntityTypeSource (type name + IsOpen + key), PrimitiveCollectionEntitySource (service only). `Updatable` has no gen accessor and the writer does not emit it — leaving it zero is symmetric. **Check the read side first when a write-path field "does not stick"**: a switch on a field the read never fills looks like a write bug. Repro `mdl-examples/bug-tests/782-external-entity-create-change-locally.mdl`. Issue #782 |
 | A pluggable widget's datasource (or child widget, or client action) is **silently dropped at write time** — `exec` prints `Created page` but the widget lands with the piece missing, and only a `log` line mentions `not yet supported — rerun with MXCLI_ENGINE=legacy` | The converter *does* return an error, but it travels through `widgetobj.ChildSerializer`, whose methods return BSON with no error channel (the `TODO(shared-types)` in `mdl/backend/widgetobj/builder.go`), so the caller logged it and returned nil | `mdl/backend/modelsdk/widget_pluggable_write.go` (`recordChildSerializeErr`, `takeChildSerializeErr`) + the drains in `page_write.go` / `snippet_write.go` | Record the failure in a package-level accumulator and drain it at every page/snippet write entry point, so the statement fails instead of the write succeeding with data missing (ADR-0004: refuse, don't drop). The real fix is the deferred `ChildSerializer` interface change; until then, any **new** write entry point that builds pluggable widgets must drain too. Repro `mdl-examples/bug-tests/795b-flow-datasource-context-entity.mdl` |
 | `describe page` reports the wrong context entity under a data container bound to a microflow/nanoflow — `-- Context: $currentObject (Module.GetOrders)` names the *flow* instead of the entity it returns | `widget.EntityContext = widget.DataSource.Reference` is correct for a database source (reference *is* the entity) and wrong for a flow source (reference is the flow's qualified name) | `mdl/executor/cmd_pages_describe_flowcontext.go` (`dataSourceEntityContext`, `flowReturnEntity`) + the five assignment sites in `cmd_pages_describe_parse.go` | Resolve the flow's return type via `ListMicroflows`/`ListNanoflows` + `getHierarchy().GetQualifiedName`, taking the entity from an Object/List return type; fall back to the reference when the flow is unresolvable or returns a scalar, so the result is never worse than before. Note `GetRawUnitByName` is unimplemented on the modelsdk engine — the list+hierarchy path is the one that works |
 | `describe page` omits a **pluggable** widget's `DataSource` when it is bound to a microflow (`datagrid g1 {` with no DataSource), while a `database from` source describes fine — re-applying the output recreates the grid unbound | A `Forms$MicroflowSource` stores the name in the nested `Forms$MicroflowSettings` (`MicroflowSettings` → `Microflow`), which is what the write path and Studio Pro emit; the reader looked up a top-level `Microflow` key, got `""`, and returned no datasource. The describe *formatter* was correct all along — read bug only | `mdl/executor/cmd_pages_describe_pluggable.go` (`microflowSourceRef`, `nanoflowSourceRef`, `extractDataGrid2DataSource`, `extractGalleryDataSource`, `parseCustomWidgetDataSource`) | Read the nested settings with a top-level fallback, via one shared helper — there were four divergent copies of this lookup and two were wrong. `Forms$NanoflowSource` was missing entirely from the DataGrid2/Gallery switches; add it alongside. Do **not** touch `CustomWidgets$CustomWidgetNanoflowSource` (a different metamodel type whose `Nanoflow` really is top-level) or the `Forms$MicroflowAction` reads (actions, not datasources). Repro `mdl-examples/bug-tests/795-datagrid-microflow-datasource-describe.mdl`. Issue #795 |

mdl-examples/bug-tests/782-external-entity-create-change-locally.mdl

@@ -0,0 +1,59 @@
+-- Bug #782: External Entities — allow_create_change_locally doesn't work
+--
+-- Symptom: after importing entities from a consumed OData service, enabling
+-- "Allow creating and changing objects locally" left the flag at false.
+--
+-- Two independent causes, both fixed:
+--
+-- (1) READ. entityFromGen (mdl/backend/modelsdk/domainmodel.go) recognised only
+--     DomainModels$OqlViewEntitySource, so an OData external entity read back
+--     with an empty Source and every remote field zeroed. `describe external
+--     entity` rejected it outright ("is not an external entity (source: )"), and
+--     `alter entity … set allow_create_change_locally = true` wrote the flag onto
+--     a model that no longer knew the entity was external, so it was lost. The
+--     legacy engine parsed all three OData source flavours, so this was a
+--     modelsdk-engine gap — and modelsdk is the default engine.
+--
+-- (2) RE-IMPORT. applyExternalEntityFields (mdl/executor/cmd_contract.go) stamped
+--     CreateChangeLocally = false on every import, including updates of existing
+--     entities, so `create or modify external entities` reset whatever the user
+--     had set. Unlike Countable/Creatable/Deletable it cannot be derived from the
+--     service contract — it is a local modelling choice — so it is now left alone
+--     on the top-level branch.
+--
+-- Manual verification (needs a project; the metadata file ships with the repo):
+--
+--   cp mdl-examples/odata-local-metadata/sample-metadata.xml /path/to/app/
+--   mxcli exec 782-external-entity-create-change-locally.mdl -p app.mpr
+--
+-- Expect the final DESCRIBE to report `AllowCreateChangeLocally: Yes`. Before the
+-- fix the first DESCRIBE errored with "is not an external entity", and after the
+-- re-import the flag was back to No.
+--
+-- Adjust MetadataUrl below to wherever sample-metadata.xml sits.
+
+create module Issue782;
+create module role Issue782.User;
+
+create constant Issue782.SvcUrl
+  type string
+  default 'https://services.odata.org/V4/Northwind/Northwind.svc/';
+
+create odata client Issue782.Sample (
+  MetadataUrl: './mdl-examples/odata-local-metadata/sample-metadata.xml',
+  ServiceUrl: '@Issue782.SvcUrl'
+);
+
+create external entities from Issue782.Sample into Issue782;
+
+-- (1) The entity must read back as external at all.
+describe external entity Issue782.Products;
+
+-- The reported flow: turn the flag on, and it must stick.
+alter entity Issue782.Products set allow_create_change_locally = true;
+describe external entity Issue782.Products;
+
+-- (2) A re-import refreshes the contract-derived capabilities but must not reset
+-- the local-changes flag.
+create or modify external entities from Issue782.Sample into Issue782;
+describe external entity Issue782.Products;

mdl/backend/modelsdk/domainmodel.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/mendixlabs/mxcli/modelsdk/element"
 	genDm "github.com/mendixlabs/mxcli/modelsdk/gen/domainmodels"
+	genRest "github.com/mendixlabs/mxcli/modelsdk/gen/rest"
 	genTexts "github.com/mendixlabs/mxcli/modelsdk/gen/texts"
 	"github.com/mendixlabs/mxcli/modelsdk/mprread"
 
@@ -160,14 +161,52 @@ func entityFromGen(e *genDm.Entity) *domainmodel.Entity {
 
 	out.Location = parseLocation(e.Location())
 
-	// View entities carry an OqlViewEntitySource referencing their source
-	// document by qualified name; surface it so read-modify-write paths (e.g.
-	// MOVE ENTITY, which must reparent the source doc) can see it.
-	if src, ok := e.Source().(*genDm.OqlViewEntitySource); ok {
+	// An entity's Source says where its data comes from. Surface each flavour so
+	// read-modify-write paths (MOVE ENTITY reparenting a source doc, ALTER ENTITY
+	// flipping a remote capability) can see it — without this an external entity
+	// reads back looking local, DESCRIBE EXTERNAL ENTITY rejects it, and an update
+	// rebuilds it with no source at all (mendixlabs/mxcli#782). Mirrors the legacy
+	// parser in sdk/mpr/parser_domainmodel.go.
+	switch src := e.Source().(type) {
+	case *genDm.OqlViewEntitySource:
 		out.Source = "DomainModels$OqlViewEntitySource"
 		out.SourceObjectID = model.ID(src.ID())
 		out.SourceDocumentRef = src.SourceDocumentQualifiedName()
 		out.OqlQuery = src.Oql()
+
+	case *genRest.ODataRemoteEntitySource:
+		// Top-level external entity: has its own entity set, so it carries the
+		// CRUD/paging capabilities and the local-changes flag.
+		out.Source = "Rest$ODataRemoteEntitySource"
+		out.SourceObjectID = model.ID(src.ID())
+		out.RemoteServiceName = src.SourceDocumentQualifiedName()
+		out.RemoteEntitySet = src.EntitySet()
+		out.RemoteEntityName = src.RemoteName()
+		out.Countable = src.Countable()
+		out.Creatable = src.Creatable()
+		out.Deletable = src.Deletable()
+		out.SkipSupported = src.SkipSupported()
+		out.TopSupported = src.TopSupported()
+		out.CreateChangeLocally = src.CreateChangeLocally()
+		out.RemoteKeyParts = odataKeyFromGen(src.Key())
+		// Updatable has no gen accessor because the storage type has no such
+		// field — updatability is per attribute (Rest$ODataMappedValue). The
+		// write path does not emit it either, so leaving it zero is symmetric.
+
+	case *genRest.ODataEntityTypeSource:
+		// Derived / abstract / contained target type: no entity set, no capabilities.
+		out.Source = "Rest$ODataEntityTypeSource"
+		out.SourceObjectID = model.ID(src.ID())
+		out.RemoteServiceName = src.SourceDocumentQualifiedName()
+		out.RemoteEntityName = src.EntityTypeName()
+		out.IsOpen = src.IsOpen()
+		out.RemoteKeyParts = odataKeyFromGen(src.Key())
+
+	case *genRest.ODataPrimitiveCollectionEntitySource:
+		// NPE generated for a Collection(Edm.*) property; carries only the service.
+		out.Source = "Rest$ODataPrimitiveCollectionEntitySource"
+		out.SourceObjectID = model.ID(src.ID())
+		out.RemoteServiceName = src.SourceDocumentQualifiedName()
 	}
 
 	for _, el := range e.AttributesItems() {
@@ -341,6 +380,32 @@ func indexFromGen(idx *genDm.Index) *domainmodel.Index {
 
 // attributeTypeFromGen is the reverse of attributeTypeToGen: a gen attribute-type
 // element back to a domainmodel.AttributeType (with Length / enumeration ref).
+// odataKeyFromGen converts a Rest$ODataKey to the semantic remote-key parts. The
+// inverse of odataKeyToGen in domainmodel_write.go.
+func odataKeyFromGen(key element.Element) []*domainmodel.RemoteKeyPart {
+	k, ok := key.(*genRest.ODataKey)
+	if !ok || k == nil {
+		return nil
+	}
+	var parts []*domainmodel.RemoteKeyPart
+	for _, el := range k.PartsItems() {
+		p, ok := el.(*genRest.ODataKeyPart)
+		if !ok {
+			continue
+		}
+		kp := &domainmodel.RemoteKeyPart{
+			Name:       p.EntityKeyPartName(),
+			RemoteName: p.Name(),
+			RemoteType: p.RemoteType(),
+		}
+		if t := p.Type(); t != nil {
+			kp.Type = attributeTypeFromGen(t)
+		}
+		parts = append(parts, kp)
+	}
+	return parts
+}
+
 func attributeTypeFromGen(t element.Element) domainmodel.AttributeType {
 	switch at := t.(type) {
 	case *genDm.StringAttributeType: