Better preloads

pkg/common/types.go

@@ -43,6 +43,11 @@ type PreloadOption struct {
 	Updatable   *bool             `json:"updateable"`  // if true, the relation can be updated
 	ComputedQL  map[string]string `json:"computed_ql"` // Computed columns as SQL expressions
 	Recursive   bool              `json:"recursive"`   // if true, preload recursively up to 5 levels
+
+	// Relationship keys from XFiles - used to build proper foreign key filters
+	PrimaryKey string `json:"primary_key"` // Primary key of the related table
+	RelatedKey string `json:"related_key"` // For child tables: column in child that references parent
+	ForeignKey string `json:"foreign_key"` // For parent tables: column in current table that references parent
 }
 
 type FilterOption struct {

pkg/reflection/model_utils.go

@@ -756,11 +756,42 @@ func ConvertToNumericType(value string, kind reflect.Kind) (interface{}, error)
 // 2. Bun tag name (if exists)
 // 3. Gorm tag name (if exists)
 // 4. JSON tag name (if exists)
+//
+// Supports recursive field paths using dot notation (e.g., "MAL.MAL.DEF")
+// For nested fields, it traverses through each level of the struct hierarchy
 func GetRelationModel(model interface{}, fieldName string) interface{} {
 	if model == nil || fieldName == "" {
 		return nil
 	}
 
+	// Split the field name by "." to handle nested/recursive relations
+	fieldParts := strings.Split(fieldName, ".")
+
+	// Start with the current model
+	currentModel := model
+
+	// Traverse through each level of the field path
+	for _, part := range fieldParts {
+		if part == "" {
+			continue
+		}
+
+		currentModel = getRelationModelSingleLevel(currentModel, part)
+		if currentModel == nil {
+			return nil
+		}
+	}
+
+	return currentModel
+}
+
+// getRelationModelSingleLevel gets the model type for a single level field (non-recursive)
+// This is a helper function used by GetRelationModel to handle one level at a time
+func getRelationModelSingleLevel(model interface{}, fieldName string) interface{} {
+	if model == nil || fieldName == "" {
+		return nil
+	}
+
 	modelType := reflect.TypeOf(model)
 	if modelType == nil {
 		return nil

pkg/restheadspec/handler.go

@@ -560,11 +560,33 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 
 // applyPreloadWithRecursion applies a preload with support for ComputedQL and recursive preloading
 func (h *Handler) applyPreloadWithRecursion(query common.SelectQuery, preload common.PreloadOption, model interface{}, depth int) common.SelectQuery {
+	// Log relationship keys if they're specified (from XFiles)
+	if preload.RelatedKey != "" || preload.ForeignKey != "" || preload.PrimaryKey != "" {
+		logger.Debug("Preload %s has relationship keys - PK: %s, RelatedKey: %s, ForeignKey: %s",
+			preload.Relation, preload.PrimaryKey, preload.RelatedKey, preload.ForeignKey)
+
+		// Build a WHERE clause using the relationship keys if needed
+		// Note: Bun's PreloadRelation typically handles the relationship join automatically via struct tags
+		// However, if the relationship keys are explicitly provided from XFiles, we can use them
+		// to add additional filtering or validation
+		if preload.RelatedKey != "" && preload.Where == "" {
+			// For child tables: ensure the child's relatedkey column will be matched
+			// The actual parent value is dynamic and handled by Bun's preload mechanism
+			// We just log this for visibility
+			logger.Debug("Child table %s will be filtered by %s matching parent's primary key",
+				preload.Relation, preload.RelatedKey)
+		}
+		if preload.ForeignKey != "" && preload.Where == "" {
+			// For parent tables: ensure the parent's primary key matches the current table's foreign key
+			logger.Debug("Parent table %s will be filtered by primary key matching current table's %s",
+				preload.Relation, preload.ForeignKey)
+		}
+	}
+
 	// Apply the preload
 	query = query.PreloadRelation(preload.Relation, func(sq common.SelectQuery) common.SelectQuery {
 		// Get the related model for column operations
-		relationParts := strings.Split(preload.Relation, ",")
-		relatedModel := reflection.GetRelationModel(model, relationParts[0])
+		relatedModel := reflection.GetRelationModel(model, preload.Relation)
 		if relatedModel == nil {
 			logger.Warn("Could not get related model for preload: %s", preload.Relation)
 			// relatedModel = model // fallback to parent model

pkg/restheadspec/headers.go

@@ -919,6 +919,20 @@ func (h *Handler) addXFilesPreload(xfile *XFiles, options *ExtendedRequestOption
 	// Set recursive flag
 	preloadOpt.Recursive = xfile.Recursive
 
+	// Extract relationship keys for proper foreign key filtering
+	if xfile.PrimaryKey != "" {
+		preloadOpt.PrimaryKey = xfile.PrimaryKey
+		logger.Debug("X-Files: Set primary key for %s: %s", relationPath, xfile.PrimaryKey)
+	}
+	if xfile.RelatedKey != "" {
+		preloadOpt.RelatedKey = xfile.RelatedKey
+		logger.Debug("X-Files: Set related key for %s: %s", relationPath, xfile.RelatedKey)
+	}
+	if xfile.ForeignKey != "" {
+		preloadOpt.ForeignKey = xfile.ForeignKey
+		logger.Debug("X-Files: Set foreign key for %s: %s", relationPath, xfile.ForeignKey)
+	}
+
 	// Add the preload option
 	options.Preload = append(options.Preload, preloadOpt)