feat(cabana): add mltextarea field type

- mltextarea compiles (with size), binds as a writable scalar and goes
  through the mltext lift, translation write and hydrate paths
- preset on or from an mltextarea field stays refused
- tests: compile, Postgres round trip over a nullable host column with
  multi-line text, invalid locale maps, preset refusals

modules/cabana/crud.go

@@ -30,8 +30,8 @@ type CRUDService struct {
 	// commit; tr localizes the file limit messages. Both may be nil.
 	bucket *blob.Bucket
 	tr     *phrasebook.Translator
-	// writer persists non-default locale values for mltext/mlmarkdown fields.
-	// Nil when the translate plugin is not mounted.
+	// writer persists non-default locale values for mltext/mltextarea/mlmarkdown
+	// fields. Nil when the translate plugin is not mounted.
 	writer TranslationWriter
 }
 
@@ -1224,7 +1224,7 @@ func modelColumns(model any) map[string]struct{} {
 func scalarFormField(typ string) bool {
 	switch typ {
 	case "text", "textarea", "number", "checkbox", "switch", "dropdown", "datepicker",
-		"markdown", "mltext", "mlmarkdown":
+		"markdown", "mltext", "mltextarea", "mlmarkdown":
 		return true
 	default:
 		return false

modules/cabana/field_ml.go

@@ -10,6 +10,7 @@ import (
 
 const (
 	mlTextFieldType     = "mltext"
+	mlTextareaFieldType = "mltextarea"
 	mlMarkdownFieldType = "mlmarkdown"
 )
 
@@ -41,11 +42,17 @@ type mlValue struct {
 	values map[string]string
 }
 
+// mlFieldType reports whether typ is a multilingual field type whose value is
+// a locale map: mltext, mltextarea or mlmarkdown.
 func mlFieldType(typ string) bool {
-	return typ == mlTextFieldType || typ == mlMarkdownFieldType
+	switch typ {
+	case mlTextFieldType, mlTextareaFieldType, mlMarkdownFieldType:
+		return true
+	}
+	return false
 }
 
-// liftMLValues takes declared mltext/mlmarkdown maps out of a save body
+// liftMLValues takes declared mltext/mltextarea/mlmarkdown maps out of a save body
 // before ProjectWritableFields drops nested values. Only fields present in
 // the body whose context allows op are lifted. A value must be a JSON object
 // of enabled locale code to string; unknown locales, extra keys, and
@@ -167,8 +174,8 @@ func applyMLTranslations(ctx context.Context, tx *gorm.DB, writer TranslationWri
 	return nil
 }
 
-// hydrateMLRecord replaces host scalars of declared mltext/mlmarkdown fields
-// in a Show/save RecordResult.Data map with a locale→text map for every
+// hydrateMLRecord replaces host scalars of declared mltext/mltextarea/mlmarkdown
+// fields in a Show/save RecordResult.Data map with a locale→text map for every
 // enabled code. The default locale is the projected host column; other codes
 // come from TranslatedExact; a missing non-default code is an empty string,
 // never D-11 fallback. It is a no-op when writer is nil and is not used from

modules/cabana/form_schema.go

@@ -26,7 +26,7 @@ var (
 		"switch": {}, "dropdown": {}, "relation": {}, "relation-manager": {},
 		"widget": {}, "partial": {}, "fileupload": {}, "datepicker": {},
 		"password": {}, "permissioneditor": {},
-		"markdown": {}, "mltext": {}, "mlmarkdown": {},
+		"markdown": {}, "mltext": {}, "mltextarea": {}, "mlmarkdown": {},
 	}
 	formSpans = map[string]struct{}{
 		"left": {}, "right": {}, "full": {}, "auto": {}, "row": {},

modules/cabana/ml_textarea_test.go

@@ -0,0 +1,181 @@
+package cabana
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"strings"
+	"testing"
+	"testing/fstest"
+)
+
+const mlTextareaFields = `fields:
+    title:
+        label: Title
+        type: mltext
+        required: true
+    description:
+        label: Description
+        type: mltextarea
+        size: small
+`
+
+func mlTextareaCompiled(t *testing.T) *CompiledController {
+	t.Helper()
+	fsys := mlFS()
+	fsys["models/post/fields.yaml"] = &fstest.MapFile{Data: []byte(mlTextareaFields)}
+	reg, err := compileRegistry([]controllerRef{{
+		plugin: formPlugin{fsys: fsys},
+		ctl:    mlNullableController{},
+	}})
+	if err != nil {
+		t.Fatalf("registry: %v", err)
+	}
+	cc, ok := reg.Get("acme.demo.posts")
+	if !ok || cc.Form == nil {
+		t.Fatalf("compiled controller missing form: %+v", cc)
+	}
+	return cc
+}
+
+func TestMLTextareaFieldType(t *testing.T) {
+	accepted := `fields:
+    title:
+        type: mltext
+        label: Title
+    excerpt:
+        type: mltextarea
+        label: Excerpt
+        size: small
+`
+	schema, err := CompileForm("acme.demo", schemaController{model: "Widget"}, formFS(formConfig, accepted))
+	if err != nil {
+		t.Fatalf("compile mltextarea: %v", err)
+	}
+	var excerpt *FormField
+	for i := range schema.Fields {
+		if schema.Fields[i].Name == "excerpt" {
+			excerpt = &schema.Fields[i]
+		}
+	}
+	if excerpt == nil {
+		t.Fatal("excerpt field missing")
+	}
+	if excerpt.Type != "mltextarea" || excerpt.Size != "small" {
+		t.Fatalf("excerpt = type %q size %q, want mltextarea small", excerpt.Type, excerpt.Size)
+	}
+	raw, err := json.Marshal(excerpt)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, want := range []string{`"type":"mltextarea"`, `"size":"small"`} {
+		if !strings.Contains(string(raw), want) {
+			t.Fatalf("json %s lacks %s", raw, want)
+		}
+	}
+
+	_, err = CompileForm("acme.demo", schemaController{model: "Widget"}, formFS(formConfig, "fields:\n    excerpt:\n        type: mltextareas\n        label: Excerpt\n"))
+	if err == nil || !strings.Contains(err.Error(), "unsupported type mltextareas") {
+		t.Fatalf("unknown type err = %v", err)
+	}
+
+	if !mlFieldType("mltextarea") {
+		t.Fatal("mlFieldType(mltextarea) = false")
+	}
+	if mlFieldType("textarea") {
+		t.Fatal("mlFieldType(textarea) = true")
+	}
+	if !scalarFormField("mltextarea") {
+		t.Fatal("scalarFormField(mltextarea) = false")
+	}
+}
+
+func TestMLTextareaRoundTrip(t *testing.T) {
+	_, db := newListService(t)
+	if err := db.Migrator().DropTable(&mlNullablePost{}); err != nil {
+		t.Fatal(err)
+	}
+	if err := db.AutoMigrate(&mlNullablePost{}); err != nil {
+		t.Fatal(err)
+	}
+	writer := &recordingWriter{defaultLocale: "en", enabled: []string{"en", "pl"}}
+	svc := CRUDService{DB: db, writer: writer}
+	cc := mlTextareaCompiled(t)
+	ctx := context.Background()
+
+	row := mlNullablePost{Title: "Hello"}
+	if err := db.Create(&row).Error; err != nil {
+		t.Fatal(err)
+	}
+	title := map[string]any{"en": "Hello", "pl": "Witaj"}
+
+	t.Run("nil host hydrates to empty strings", func(t *testing.T) {
+		shown, err := svc.ShowRecord(ctx, cc, row.ID)
+		if err != nil {
+			t.Fatalf("show: %v", err)
+		}
+		got := mlLocaleMap(t, "show", shown.Data, "description")
+		if got["en"] != "" || got["pl"] != "" || len(got) != 2 {
+			t.Fatalf("nil description = %#v, want en and pl empty", got)
+		}
+	})
+
+	t.Run("multi-line text saves per locale", func(t *testing.T) {
+		en := "Line one\nLine two"
+		pl := "Linia pierwsza\nLinia druga"
+		saved, err := svc.UpdateRecord(ctx, cc, row.ID, RecordInput{Body: map[string]any{
+			"title":       title,
+			"description": map[string]any{"en": en, "pl": pl},
+		}})
+		if err != nil {
+			t.Fatalf("update: %v", err)
+		}
+		if got := mlLocaleMap(t, "save", saved.Data, "description"); got["en"] != en || got["pl"] != pl {
+			t.Fatalf("saved description = %#v", got)
+		}
+		shown, err := svc.ShowRecord(ctx, cc, row.ID)
+		if err != nil {
+			t.Fatalf("show: %v", err)
+		}
+		if got := mlLocaleMap(t, "show", shown.Data, "description"); got["en"] != en || got["pl"] != pl || len(got) != 2 {
+			t.Fatalf("shown description = %#v", got)
+		}
+		var stored mlNullablePost
+		if err := db.First(&stored, row.ID).Error; err != nil {
+			t.Fatal(err)
+		}
+		if stored.Description == nil || *stored.Description != en {
+			t.Fatalf("stored description = %v, want %q", stored.Description, en)
+		}
+		if writer.attrs["pl"]["description"] != pl {
+			t.Fatalf("Polish attributes = %#v", writer.attrs)
+		}
+		if _, dup := writer.attrs["en"]["description"]; dup {
+			t.Fatalf("default locale written to the translation store: %#v", writer.attrs)
+		}
+	})
+
+	invalid := []struct {
+		name  string
+		value map[string]any
+	}{
+		{"undeclared locale", map[string]any{"en": "A", "de": "B"}},
+		{"non-string value", map[string]any{"en": "A", "pl": 3}},
+		{"missing default locale", map[string]any{"pl": "B"}},
+	}
+	for _, tc := range invalid {
+		t.Run(tc.name+" is a validation error", func(t *testing.T) {
+			_, err := svc.UpdateRecord(ctx, cc, row.ID, RecordInput{Body: map[string]any{
+				"title":       title,
+				"description": tc.value,
+			}})
+			var verr *ValidationError
+			if !errors.As(err, &verr) {
+				t.Fatalf("err = %v, want *ValidationError", err)
+			}
+			if _, ok := verr.Details["description"]; !ok {
+				t.Fatalf("details = %#v, want description key", verr.Details)
+			}
+		})
+	}
+}

modules/cabana/preset_ml_test.go

@@ -127,6 +127,32 @@ func TestPresetML(t *testing.T) {
 `,
 			checkErr: "field slug: preset field body must be a text or mltext field",
 		},
+		{
+			name: "mltextarea target is refused",
+			yaml: `fields:
+    title:
+        type: mltext
+        label: Title
+    excerpt:
+        type: mltextarea
+        label: Excerpt
+        preset: title
+`,
+			compileErr: "preset is only valid on type: text or mltext",
+		},
+		{
+			name: "mltextarea source is refused",
+			yaml: `fields:
+    excerpt:
+        type: mltextarea
+        label: Excerpt
+    slug:
+        type: mltext
+        label: Slug
+        preset: excerpt
+`,
+			checkErr: "field slug: preset field excerpt must be a text or mltext field",
+		},
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {

modules/cabana/relation.go

@@ -187,7 +187,7 @@ type RelationService struct {
 
 	// bucket deletes the blobs of child files a save removes, after commit;
 	// tr localizes date bound messages. Both may be nil. writer is the same
-	// optional plugin adapter CRUDService uses for mltext/mlmarkdown.
+	// optional plugin adapter CRUDService uses for mltext/mltextarea/mlmarkdown.
 	bucket *blob.Bucket
 	tr     *phrasebook.Translator
 	writer TranslationWriter