Adding basic support for XML structure

examples/petstore/lib/testdata/doc/openapi.golden.json

@@ -7,7 +7,10 @@
 					"detail": {
 						"description": "Human readable error message",
 						"nullable": true,
-						"type": "string"
+						"type": "string",
+						"xml": {
+							"name": "detail"
+						}
 					},
 					"errors": {
 						"items": {
@@ -26,27 +29,42 @@
 							"type": "object"
 						},
 						"nullable": true,
-						"type": "array"
+						"type": "array",
+						"xml": {
+							"name": "errors"
+						}
 					},
 					"instance": {
 						"nullable": true,
-						"type": "string"
+						"type": "string",
+						"xml": {
+							"name": "instance"
+						}
 					},
 					"status": {
 						"description": "HTTP status code",
 						"example": 403,
 						"nullable": true,
-						"type": "integer"
+						"type": "integer",
+						"xml": {
+							"name": "status"
+						}
 					},
 					"title": {
 						"description": "Short title of the error",
 						"nullable": true,
-						"type": "string"
+						"type": "string",
+						"xml": {
+							"name": "title"
+						}
 					},
 					"type": {
 						"description": "URL of the error type. Can be used to lookup the error in a documentation",
 						"nullable": true,
-						"type": "string"
+						"type": "string",
+						"xml": {
+							"name": "type"
+						}
 					}
 				},
 				"type": "object"
@@ -137,7 +155,10 @@
 				"description": "PetsError schema",
 				"properties": {
 					"message": {
-						"type": "string"
+						"type": "string",
+						"xml": {
+							"name": "message"
+						}
 					}
 				},
 				"type": "object"

openapi.go

@@ -21,10 +21,15 @@ import (
 
 func NewOpenAPI() *OpenAPI {
 	desc := NewOpenApiSpec()
+
+	mp := NewMetadataParsers()
+	mp.InitializeMetadataParsers(DefaultParsers)
+
 	return &OpenAPI{
 		description:            &desc,
 		generator:              openapi3gen.NewGenerator(),
 		globalOpenAPIResponses: []openAPIResponse{},
+		metadataParsers:        mp,
 	}
 }
 
@@ -33,6 +38,7 @@ type OpenAPI struct {
 	description            *openapi3.T
 	generator              *openapi3gen.Generator
 	globalOpenAPIResponses []openAPIResponse
+	metadataParsers        *MetadataParsers
 }
 
 func (openAPI *OpenAPI) Description() *openapi3.T {
@@ -403,129 +409,13 @@ func (openapi *OpenAPI) createSchema(key string, v any) *openapi3.SchemaRef {
 		schemaRef.Value.Description = descriptionable.Description()
 	}
 
-	parseStructTags(reflect.TypeOf(v), schemaRef)
+	openapi.metadataParsers.ParseStructTags(reflect.TypeOf(v), schemaRef)
 
 	openapi.Description().Components.Schemas[key] = schemaRef
 
 	return schemaRef
 }
 
-// parseStructTags parses struct tags and modifies the schema accordingly.
-// t must be a struct type.
-// It adds the following struct tags (tag => OpenAPI schema field):
-// - description => description
-// - example => example
-// - json => nullable (if contains omitempty)
-// - validate:
-//   - required => required
-//   - min=1 => min=1 (for integers)
-//   - min=1 => minLength=1 (for strings)
-//   - max=100 => max=100 (for integers)
-//   - max=100 => maxLength=100 (for strings)
-func parseStructTags(t reflect.Type, schemaRef *openapi3.SchemaRef) {
-	if t.Kind() == reflect.Ptr {
-		t = t.Elem()
-	}
-
-	if t.Kind() != reflect.Struct {
-		return
-	}
-
-	for i := range t.NumField() {
-		field := t.Field(i)
-		if field.Anonymous {
-			fieldType := field.Type
-			parseStructTags(fieldType, schemaRef)
-			continue
-		}
-
-		jsonFieldName := field.Tag.Get("json")
-		jsonFieldName = strings.Split(jsonFieldName, ",")[0] // remove omitempty, etc
-		if jsonFieldName == "-" {
-			continue
-		}
-		if jsonFieldName == "" {
-			jsonFieldName = field.Name
-		}
-
-		property := schemaRef.Value.Properties[jsonFieldName]
-		if property == nil {
-			slog.Warn("Property not found in schema", "property", jsonFieldName)
-			continue
-		}
-		if field.Type.Kind() == reflect.Struct {
-			parseStructTags(field.Type, property)
-		}
-		propertyCopy := *property
-		propertyValue := *propertyCopy.Value
-
-		// Example
-		example, ok := field.Tag.Lookup("example")
-		if ok {
-			propertyValue.Example = example
-			if propertyValue.Type.Is(openapi3.TypeInteger) {
-				exNum, err := strconv.Atoi(example)
-				if err != nil {
-					slog.Warn("Example might be incorrect (should be integer)", "error", err)
-				}
-				propertyValue.Example = exNum
-			}
-		}
-
-		// Validation
-		validateTag, ok := field.Tag.Lookup("validate")
-		validateTags := strings.Split(validateTag, ",")
-		if ok && slices.Contains(validateTags, "required") {
-			schemaRef.Value.Required = append(schemaRef.Value.Required, jsonFieldName)
-		}
-		for _, validateTag := range validateTags {
-			if strings.HasPrefix(validateTag, "min=") {
-				min, err := strconv.Atoi(strings.Split(validateTag, "=")[1])
-				if err != nil {
-					slog.Warn("Min might be incorrect (should be integer)", "error", err)
-				}
-
-				if propertyValue.Type.Is(openapi3.TypeInteger) {
-					minPtr := float64(min)
-					propertyValue.Min = &minPtr
-				} else if propertyValue.Type.Is(openapi3.TypeString) {
-					//nolint:gosec // disable G115
-					propertyValue.MinLength = uint64(min)
-				}
-			}
-			if strings.HasPrefix(validateTag, "max=") {
-				max, err := strconv.Atoi(strings.Split(validateTag, "=")[1])
-				if err != nil {
-					slog.Warn("Max might be incorrect (should be integer)", "error", err)
-				}
-				if propertyValue.Type.Is(openapi3.TypeInteger) {
-					maxPtr := float64(max)
-					propertyValue.Max = &maxPtr
-				} else if propertyValue.Type.Is(openapi3.TypeString) {
-					//nolint:gosec // disable G115
-					maxPtr := uint64(max)
-					propertyValue.MaxLength = &maxPtr
-				}
-			}
-		}
-
-		// Description
-		description, ok := field.Tag.Lookup("description")
-		if ok {
-			propertyValue.Description = description
-		}
-		jsonTag, ok := field.Tag.Lookup("json")
-		if ok {
-			if strings.Contains(jsonTag, ",omitempty") {
-				propertyValue.Nullable = true
-			}
-		}
-		propertyCopy.Value = &propertyValue
-
-		schemaRef.Value.Properties[jsonFieldName] = &propertyCopy
-	}
-}
-
 type OpenAPIDescriptioner interface {
 	Description() string
 }