prometheus/vendor/github.com/emicklei/go-restful/swagger/model_builder.go
2016-10-17 10:32:10 +02:00

450 lines
12 KiB
Go

package swagger
import (
"encoding/json"
"reflect"
"strings"
)
// ModelBuildable is used for extending Structs that need more control over
// how the Model appears in the Swagger api declaration.
type ModelBuildable interface {
PostBuildModel(m *Model) *Model
}
type modelBuilder struct {
Models *ModelList
Config *Config
}
type documentable interface {
SwaggerDoc() map[string]string
}
// Check if this structure has a method with signature func (<theModel>) SwaggerDoc() map[string]string
// If it exists, retrive the documentation and overwrite all struct tag descriptions
func getDocFromMethodSwaggerDoc2(model reflect.Type) map[string]string {
if docable, ok := reflect.New(model).Elem().Interface().(documentable); ok {
return docable.SwaggerDoc()
}
return make(map[string]string)
}
// addModelFrom creates and adds a Model to the builder and detects and calls
// the post build hook for customizations
func (b modelBuilder) addModelFrom(sample interface{}) {
if modelOrNil := b.addModel(reflect.TypeOf(sample), ""); modelOrNil != nil {
// allow customizations
if buildable, ok := sample.(ModelBuildable); ok {
modelOrNil = buildable.PostBuildModel(modelOrNil)
b.Models.Put(modelOrNil.Id, *modelOrNil)
}
}
}
func (b modelBuilder) addModel(st reflect.Type, nameOverride string) *Model {
modelName := b.keyFrom(st)
if nameOverride != "" {
modelName = nameOverride
}
// no models needed for primitive types
if b.isPrimitiveType(modelName) {
return nil
}
// golang encoding/json packages says array and slice values encode as
// JSON arrays, except that []byte encodes as a base64-encoded string.
// If we see a []byte here, treat it at as a primitive type (string)
// and deal with it in buildArrayTypeProperty.
if (st.Kind() == reflect.Slice || st.Kind() == reflect.Array) &&
st.Elem().Kind() == reflect.Uint8 {
return nil
}
// see if we already have visited this model
if _, ok := b.Models.At(modelName); ok {
return nil
}
sm := Model{
Id: modelName,
Required: []string{},
Properties: ModelPropertyList{}}
// reference the model before further initializing (enables recursive structs)
b.Models.Put(modelName, sm)
// check for slice or array
if st.Kind() == reflect.Slice || st.Kind() == reflect.Array {
b.addModel(st.Elem(), "")
return &sm
}
// check for structure or primitive type
if st.Kind() != reflect.Struct {
return &sm
}
fullDoc := getDocFromMethodSwaggerDoc2(st)
modelDescriptions := []string{}
for i := 0; i < st.NumField(); i++ {
field := st.Field(i)
jsonName, modelDescription, prop := b.buildProperty(field, &sm, modelName)
if len(modelDescription) > 0 {
modelDescriptions = append(modelDescriptions, modelDescription)
}
// add if not omitted
if len(jsonName) != 0 {
// update description
if fieldDoc, ok := fullDoc[jsonName]; ok {
prop.Description = fieldDoc
}
// update Required
if b.isPropertyRequired(field) {
sm.Required = append(sm.Required, jsonName)
}
sm.Properties.Put(jsonName, prop)
}
}
// We always overwrite documentation if SwaggerDoc method exists
// "" is special for documenting the struct itself
if modelDoc, ok := fullDoc[""]; ok {
sm.Description = modelDoc
} else if len(modelDescriptions) != 0 {
sm.Description = strings.Join(modelDescriptions, "\n")
}
// update model builder with completed model
b.Models.Put(modelName, sm)
return &sm
}
func (b modelBuilder) isPropertyRequired(field reflect.StructField) bool {
required := true
if jsonTag := field.Tag.Get("json"); jsonTag != "" {
s := strings.Split(jsonTag, ",")
if len(s) > 1 && s[1] == "omitempty" {
return false
}
}
return required
}
func (b modelBuilder) buildProperty(field reflect.StructField, model *Model, modelName string) (jsonName, modelDescription string, prop ModelProperty) {
jsonName = b.jsonNameOfField(field)
if len(jsonName) == 0 {
// empty name signals skip property
return "", "", prop
}
if tag := field.Tag.Get("modelDescription"); tag != "" {
modelDescription = tag
}
prop.setPropertyMetadata(field)
if prop.Type != nil {
return jsonName, modelDescription, prop
}
fieldType := field.Type
// check if type is doing its own marshalling
marshalerType := reflect.TypeOf((*json.Marshaler)(nil)).Elem()
if fieldType.Implements(marshalerType) {
var pType = "string"
if prop.Type == nil {
prop.Type = &pType
}
if prop.Format == "" {
prop.Format = b.jsonSchemaFormat(fieldType.String())
}
return jsonName, modelDescription, prop
}
// check if annotation says it is a string
if jsonTag := field.Tag.Get("json"); jsonTag != "" {
s := strings.Split(jsonTag, ",")
if len(s) > 1 && s[1] == "string" {
stringt := "string"
prop.Type = &stringt
return jsonName, modelDescription, prop
}
}
fieldKind := fieldType.Kind()
switch {
case fieldKind == reflect.Struct:
jsonName, prop := b.buildStructTypeProperty(field, jsonName, model)
return jsonName, modelDescription, prop
case fieldKind == reflect.Slice || fieldKind == reflect.Array:
jsonName, prop := b.buildArrayTypeProperty(field, jsonName, modelName)
return jsonName, modelDescription, prop
case fieldKind == reflect.Ptr:
jsonName, prop := b.buildPointerTypeProperty(field, jsonName, modelName)
return jsonName, modelDescription, prop
case fieldKind == reflect.String:
stringt := "string"
prop.Type = &stringt
return jsonName, modelDescription, prop
case fieldKind == reflect.Map:
// if it's a map, it's unstructured, and swagger 1.2 can't handle it
objectType := "object"
prop.Type = &objectType
return jsonName, modelDescription, prop
}
if b.isPrimitiveType(fieldType.String()) {
mapped := b.jsonSchemaType(fieldType.String())
prop.Type = &mapped
prop.Format = b.jsonSchemaFormat(fieldType.String())
return jsonName, modelDescription, prop
}
modelType := fieldType.String()
prop.Ref = &modelType
if fieldType.Name() == "" { // override type of anonymous structs
nestedTypeName := modelName + "." + jsonName
prop.Ref = &nestedTypeName
b.addModel(fieldType, nestedTypeName)
}
return jsonName, modelDescription, prop
}
func hasNamedJSONTag(field reflect.StructField) bool {
parts := strings.Split(field.Tag.Get("json"), ",")
if len(parts) == 0 {
return false
}
for _, s := range parts[1:] {
if s == "inline" {
return false
}
}
return len(parts[0]) > 0
}
func (b modelBuilder) buildStructTypeProperty(field reflect.StructField, jsonName string, model *Model) (nameJson string, prop ModelProperty) {
prop.setPropertyMetadata(field)
// Check for type override in tag
if prop.Type != nil {
return jsonName, prop
}
fieldType := field.Type
// check for anonymous
if len(fieldType.Name()) == 0 {
// anonymous
anonType := model.Id + "." + jsonName
b.addModel(fieldType, anonType)
prop.Ref = &anonType
return jsonName, prop
}
if field.Name == fieldType.Name() && field.Anonymous && !hasNamedJSONTag(field) {
// embedded struct
sub := modelBuilder{new(ModelList), b.Config}
sub.addModel(fieldType, "")
subKey := sub.keyFrom(fieldType)
// merge properties from sub
subModel, _ := sub.Models.At(subKey)
subModel.Properties.Do(func(k string, v ModelProperty) {
model.Properties.Put(k, v)
// if subModel says this property is required then include it
required := false
for _, each := range subModel.Required {
if k == each {
required = true
break
}
}
if required {
model.Required = append(model.Required, k)
}
})
// add all new referenced models
sub.Models.Do(func(key string, sub Model) {
if key != subKey {
if _, ok := b.Models.At(key); !ok {
b.Models.Put(key, sub)
}
}
})
// empty name signals skip property
return "", prop
}
// simple struct
b.addModel(fieldType, "")
var pType = fieldType.String()
prop.Ref = &pType
return jsonName, prop
}
func (b modelBuilder) buildArrayTypeProperty(field reflect.StructField, jsonName, modelName string) (nameJson string, prop ModelProperty) {
// check for type override in tags
prop.setPropertyMetadata(field)
if prop.Type != nil {
return jsonName, prop
}
fieldType := field.Type
if fieldType.Elem().Kind() == reflect.Uint8 {
stringt := "string"
prop.Type = &stringt
return jsonName, prop
}
var pType = "array"
prop.Type = &pType
isPrimitive := b.isPrimitiveType(fieldType.Elem().Name())
elemTypeName := b.getElementTypeName(modelName, jsonName, fieldType.Elem())
prop.Items = new(Item)
if isPrimitive {
mapped := b.jsonSchemaType(elemTypeName)
prop.Items.Type = &mapped
} else {
prop.Items.Ref = &elemTypeName
}
// add|overwrite model for element type
if fieldType.Elem().Kind() == reflect.Ptr {
fieldType = fieldType.Elem()
}
if !isPrimitive {
b.addModel(fieldType.Elem(), elemTypeName)
}
return jsonName, prop
}
func (b modelBuilder) buildPointerTypeProperty(field reflect.StructField, jsonName, modelName string) (nameJson string, prop ModelProperty) {
prop.setPropertyMetadata(field)
// Check for type override in tags
if prop.Type != nil {
return jsonName, prop
}
fieldType := field.Type
// override type of pointer to list-likes
if fieldType.Elem().Kind() == reflect.Slice || fieldType.Elem().Kind() == reflect.Array {
var pType = "array"
prop.Type = &pType
isPrimitive := b.isPrimitiveType(fieldType.Elem().Elem().Name())
elemName := b.getElementTypeName(modelName, jsonName, fieldType.Elem().Elem())
if isPrimitive {
primName := b.jsonSchemaType(elemName)
prop.Items = &Item{Ref: &primName}
} else {
prop.Items = &Item{Ref: &elemName}
}
if !isPrimitive {
// add|overwrite model for element type
b.addModel(fieldType.Elem().Elem(), elemName)
}
} else {
// non-array, pointer type
var pType = b.jsonSchemaType(fieldType.String()[1:]) // no star, include pkg path
if b.isPrimitiveType(fieldType.String()[1:]) {
prop.Type = &pType
prop.Format = b.jsonSchemaFormat(fieldType.String()[1:])
return jsonName, prop
}
prop.Ref = &pType
elemName := ""
if fieldType.Elem().Name() == "" {
elemName = modelName + "." + jsonName
prop.Ref = &elemName
}
b.addModel(fieldType.Elem(), elemName)
}
return jsonName, prop
}
func (b modelBuilder) getElementTypeName(modelName, jsonName string, t reflect.Type) string {
if t.Kind() == reflect.Ptr {
return t.String()[1:]
}
if t.Name() == "" {
return modelName + "." + jsonName
}
return b.keyFrom(t)
}
func (b modelBuilder) keyFrom(st reflect.Type) string {
key := st.String()
if len(st.Name()) == 0 { // unnamed type
// Swagger UI has special meaning for [
key = strings.Replace(key, "[]", "||", -1)
}
return key
}
// see also https://golang.org/ref/spec#Numeric_types
func (b modelBuilder) isPrimitiveType(modelName string) bool {
if len(modelName) == 0 {
return false
}
return strings.Contains("uint uint8 uint16 uint32 uint64 int int8 int16 int32 int64 float32 float64 bool string byte rune time.Time", modelName)
}
// jsonNameOfField returns the name of the field as it should appear in JSON format
// An empty string indicates that this field is not part of the JSON representation
func (b modelBuilder) jsonNameOfField(field reflect.StructField) string {
if jsonTag := field.Tag.Get("json"); jsonTag != "" {
s := strings.Split(jsonTag, ",")
if s[0] == "-" {
// empty name signals skip property
return ""
} else if s[0] != "" {
return s[0]
}
}
return field.Name
}
// see also http://json-schema.org/latest/json-schema-core.html#anchor8
func (b modelBuilder) jsonSchemaType(modelName string) string {
schemaMap := map[string]string{
"uint": "integer",
"uint8": "integer",
"uint16": "integer",
"uint32": "integer",
"uint64": "integer",
"int": "integer",
"int8": "integer",
"int16": "integer",
"int32": "integer",
"int64": "integer",
"byte": "integer",
"float64": "number",
"float32": "number",
"bool": "boolean",
"time.Time": "string",
}
mapped, ok := schemaMap[modelName]
if !ok {
return modelName // use as is (custom or struct)
}
return mapped
}
func (b modelBuilder) jsonSchemaFormat(modelName string) string {
if b.Config != nil && b.Config.SchemaFormatHandler != nil {
if mapped := b.Config.SchemaFormatHandler(modelName); mapped != "" {
return mapped
}
}
schemaMap := map[string]string{
"int": "int32",
"int32": "int32",
"int64": "int64",
"byte": "byte",
"uint": "integer",
"uint8": "byte",
"float64": "double",
"float32": "float",
"time.Time": "date-time",
"*time.Time": "date-time",
}
mapped, ok := schemaMap[modelName]
if !ok {
return "" // no format
}
return mapped
}