Add support for the attributes in struct fields

This commit adds support for the following attributes in the struct
fields:

- "minimum": for numeric fields, via `minimum:"value"` struct tag
- "maximum": for numeric fields, via `maximum:"value"` struct tag
- "minLength": for string fields, via `minLength:"value"` struct tag
- "maxLength": for string fields, via `maxLength:"value"` struct tag
- "enums": via `enums:"value1,value2,value3"` struct tag
- "default": via `default:"value"` struct tag

All these tags except "default" are also supported in "array" fields.

README.md

@@ -432,6 +432,16 @@ Make it AND condition
 // @Param default query string false "string default" default(A)
 ```
 
+It also works for the struct fields:
+
+```go
+type Foo struct {
+ Bar string `minLength:"4" maxLength:"16"`
+ Baz int `minimum:"10" maximum:"20" default:"15"`
+ Qux []string `enums:"foo,bar,baz"`
+}
+```
+
 ### Available
 
 Field Name | Type | Description

parser.go

@@ -479,6 +479,12 @@ type structField struct {
  isRequired bool
  crossPkg string
  exampleValue interface{}
+ maximum *float64
+ minimum *float64
+ maxLength *int64
+ minLength *int64
+ enums []interface{}
+ defaultValue interface{}
 }
 
 func (parser *Parser) parseStruct(pkgName string, field *ast.Field) (properties map[string]spec.Schema) {
@@ -542,7 +548,13 @@ func (parser *Parser) parseStruct(pkgName string, field *ast.Field) (properties
  Items: &spec.SchemaOrArray{
  Schema: &spec.Schema{
  SchemaProps: spec.SchemaProps{
- Type: []string{structField.arrayType},
+ Type: []string{structField.arrayType},
+ Maximum: structField.maximum,
+ Minimum: structField.minimum,
+ MaxLength: structField.maxLength,
+ MinLength: structField.minLength,
+ Enum: structField.enums,
+ Default: structField.defaultValue,
  },
  },
  },
@@ -563,6 +575,12 @@ func (parser *Parser) parseStruct(pkgName string, field *ast.Field) (properties
  Description: desc,
  Format: structField.formatType,
  Required: required,
+ Maximum: structField.maximum,
+ Minimum: structField.minimum,
+ MaxLength: structField.maxLength,
+ MinLength: structField.minLength,
+ Enum: structField.enums,
+ Default: structField.defaultValue,
  },
  SwaggerSchemaProps: spec.SwaggerSchemaProps{
  Example: structField.exampleValue,
@@ -590,6 +608,12 @@ func (parser *Parser) parseStruct(pkgName string, field *ast.Field) (properties
  Format: structField.formatType,
  Properties: props,
  Required: nestRequired,
+ Maximum: structField.maximum,
+ Minimum: structField.minimum,
+ MaxLength: structField.maxLength,
+ MinLength: structField.minLength,
+ Enum: structField.enums,
+ Default: structField.defaultValue,
  },
  SwaggerSchemaProps: spec.SwaggerSchemaProps{
  Example: structField.exampleValue,
@@ -655,8 +679,8 @@ func (parser *Parser) parseField(field *ast.Field) *structField {
  return structField
  }
  // `json:"tag"` -> json:"tag"
- structTag := strings.Replace(field.Tag.Value, "`", "", -1)
- jsonTag := reflect.StructTag(structTag).Get("json")
+ structTag := reflect.StructTag(strings.Replace(field.Tag.Value, "`", "", -1))
+ jsonTag := structTag.Get("json")
  // json:"tag,hoge"
  if strings.Contains(jsonTag, ",") {
  // json:",hoge"
@@ -672,8 +696,7 @@ func (parser *Parser) parseField(field *ast.Field) *structField {
  structField.name = jsonTag
  }
 
- typeTag := reflect.StructTag(structTag).Get("swaggertype")
- if typeTag != "" {
+ if typeTag := structTag.Get("swaggertype"); typeTag != "" {
  parts := strings.Split(typeTag, ",")
  if 0 < len(parts) && len(parts) <= 2 {
  newSchemaType := parts[0]
@@ -688,35 +711,82 @@ func (parser *Parser) parseField(field *ast.Field) *structField {
  structField.arrayType = newArrayType
  }
  }
- exampleTag := reflect.StructTag(structTag).Get("example")
- if exampleTag != "" {
+ if exampleTag := structTag.Get("example"); exampleTag != "" {
  structField.exampleValue = defineTypeOfExample(structField.schemaType, structField.arrayType, exampleTag)
  }
- formatTag := reflect.StructTag(structTag).Get("format")
- if formatTag != "" {
+ if formatTag := structTag.Get("format"); formatTag != "" {
  structField.formatType = formatTag
  }
- bindingTag := reflect.StructTag(structTag).Get("binding")
- if bindingTag != "" {
+ if bindingTag := structTag.Get("binding"); bindingTag != "" {
  for _, val := range strings.Split(bindingTag, ",") {
  if val == "required" {
  structField.isRequired = true
  break
  }
  }
  }
- validateTag := reflect.StructTag(structTag).Get("validate")
- if validateTag != "" {
+ if validateTag := structTag.Get("validate"); validateTag != "" {
  for _, val := range strings.Split(validateTag, ",") {
  if val == "required" {
  structField.isRequired = true
  break
  }
  }
  }
+ if enumsTag := structTag.Get("enums"); enumsTag != "" {
+ enumType := structField.schemaType
+ if structField.schemaType == "array" {
+ enumType = structField.arrayType
+ }
+
+ for _, e := range strings.Split(enumsTag, ",") {
+ structField.enums = append(structField.enums, defineType(enumType, e))
+ }
+ }
+ if defaultTag := structTag.Get("default"); defaultTag != "" {
+ structField.defaultValue = defineType(structField.schemaType, defaultTag)
+ }
+
+ if IsNumericType(structField.schemaType) || IsNumericType(structField.arrayType) {
+ structField.maximum = getFloatTag(structTag, "maximum")
+ structField.minimum = getFloatTag(structTag, "minimum")
+ }
+ if structField.schemaType == "string" || structField.arrayType == "string" {
+ structField.maxLength = getIntTag(structTag, "maxLength")
+ structField.minLength = getIntTag(structTag, "minLength")
+ }
+
  return structField
 }
 
+func getFloatTag(structTag reflect.StructTag, tagName string) *float64 {
+ strValue := structTag.Get(tagName)
+ if strValue == "" {
+ return nil
+ }
+
+ value, err := strconv.ParseFloat(strValue, 64)
+ if err != nil {
+ panic(fmt.Errorf("can't parse numeric value of %q tag: %v", tagName, err))
+ }
+
+ return &value
+}
+
+func getIntTag(structTag reflect.StructTag, tagName string) *int64 {
+ strValue := structTag.Get(tagName)
+ if strValue == "" {
+ return nil
+ }
+
+ value, err := strconv.ParseInt(strValue, 10, 64)
+ if err != nil {
+ panic(fmt.Errorf("can't parse numeric value of %q tag: %v", tagName, err))
+ }
+
+ return &value
+}
+
 func toSnakeCase(in string) string {
  runes := []rune(in)
  length := len(runes)

parser_test.go

@@ -524,6 +524,8 @@ func TestParseSimpleApi(t *testing.T) {
  },
  "name": {
  "type": "string",
+ "maxLength": 16,
+ "minLength": 4,
  "example": "detail_category_name"
  },
  "photo_urls": {
@@ -546,6 +548,19 @@ func TestParseSimpleApi(t *testing.T) {
  "decimal": {
  "type": "number"
  },
+ "enum_array": {
+ "type": "array",
+ "items": {
+ "type": "integer",
+ "enum": [
+ 1,
+ 2,
+ 3,
+ 5,
+ 7
+ ]
+ }
+ },
  "id": {
  "type": "integer",
  "format": "int64",
@@ -563,6 +578,7 @@ func TestParseSimpleApi(t *testing.T) {
  },
  "is_alive": {
  "type": "boolean",
+ "default": true,
  "example": true
  },
  "name": {
@@ -593,10 +609,16 @@ func TestParseSimpleApi(t *testing.T) {
  },
  "price": {
  "type": "number",
+ "maximum": 1000,
+ "minimum": 1,
  "example": 3.25
  },
  "status": {
- "type": "string"
+ "type": "string",
+ "enum": [
+ "healthy",
+ "ill"
+ ]
  },
  "tags": {
  "type": "array",

schema.go

@@ -19,6 +19,11 @@ func IsPrimitiveType(typeName string) bool {
  }
 }
 
+// IsNumericType determines whether the swagger type name is a numeric type
+func IsNumericType(typeName string) bool {
+ return typeName == "integer" || typeName == "number"
+}
+
 // TransToValidSchemeType indicates type will transfer golang basic type to swagger supported type.
 func TransToValidSchemeType(typeName string) string {
  switch typeName {

testdata/simple/web/handler.go

@@ -16,7 +16,7 @@ type Pet struct {
  PhotoUrls []string `json:"photo_urls" example:"http://test/image/1.jpg,http://test/image/2.jpg" format:"url"`
  SmallCategory struct {
  ID int `json:"id" example:"1"`
- Name string `json:"name" example:"detail_category_name" binding:"required"`
+ Name string `json:"name" example:"detail_category_name" binding:"required" minLength:"4" maxLength:"16"`
  PhotoUrls []string `json:"photo_urls" example:"http://test/image/1.jpg,http://test/image/2.jpg"`
  } `json:"small_category"`
  } `json:"category"`
@@ -25,14 +25,15 @@ type Pet struct {
  Tags []Tag `json:"tags"`
  Pets *[]Pet2 `json:"pets"`
  Pets2 []*Pet2 `json:"pets2"`
- Status string `json:"status"`
- Price float32 `json:"price" example:"3.25"`
- IsAlive bool `json:"is_alive" example:"true"`
+ Status string `json:"status" enums:"healthy,ill"`
+ Price float32 `json:"price" example:"3.25" minimum:"1.0" maximum:"1000"`
+ IsAlive bool `json:"is_alive" example:"true" default:"true"`
  Data interface{} `json:"data"`
  Hidden string `json:"-"`
  UUID uuid.UUID `json:"uuid"`
  Decimal decimal.Decimal `json:"decimal"`
  IntArray []int `json:"int_array" example:"1,2"`
+ EnumArray []int `json:"enum_array" enums:"1,2,3,5,7"`
 }
 
 type Tag struct {