refactor(form_mapping.go): mapping ptr, struct and map (#1749)

* refactor(form_mapping.go): mapping ptr, struct and map

* fix #1672 correct work with ptr - not create value if field is not set
* avoid allocations on strings.Split() - change to strings.Index()
* fix #610 tag value "-" is mean ignoring field
* struct fields mapped like json.Unmarshal
* map fields mapped like json.Unmarshal

* fix after @thinkerou review

README.md

@@ -1836,24 +1836,6 @@ $ curl "http://localhost:8080/getd?field_x=hello&field_d=world"
 {"d":"world","x":{"FieldX":"hello"}}
 ```
 
-**NOTE**: NOT support the follow style struct:
-
-```go
-type StructX struct {
-    X struct {} `form:"name_x"` // HERE have form
-}
-
-type StructY struct {
-    Y StructX `form:"name_y"` // HERE have form
-}
-
-type StructZ struct {
-    Z *StructZ `form:"name_z"` // HERE have form
-}
-```
-
-In a word, only support nested custom struct which have no `form` now.
-
 ### Try to bind body into different structs
 
 The normal methods for binding request body consumes `c.Request.Body` and they

binding/binding_test.go

@@ -12,6 +12,7 @@ import (
 	"mime/multipart"
 	"net/http"
 	"strconv"
+	"strings"
 	"testing"
 	"time"
 
@@ -57,7 +58,6 @@ type FooStructForTimeTypeFailLocation struct {
 }
 
 type FooStructForMapType struct {
-	// Unknown type: not support map
 	MapFoo map[string]interface{} `form:"map_foo"`
 }
 
@@ -303,7 +303,7 @@ func TestBindingFormInvalidName2(t *testing.T) {
 func TestBindingFormForType(t *testing.T) {
 	testFormBindingForType(t, "POST",
 		"/", "/",
-		"map_foo=", "bar2=1", "Map")
+		"map_foo={\"bar\":123}", "map_foo=1", "Map")
 
 	testFormBindingForType(t, "POST",
 		"/", "/",
@@ -508,20 +508,30 @@ func TestBindingYAMLFail(t *testing.T) {
 		`foo:\nbar`, `bar: foo`)
 }
 
-func createFormPostRequest() *http.Request {
-	req, _ := http.NewRequest("POST", "/?foo=getfoo&bar=getbar", bytes.NewBufferString("foo=bar&bar=foo"))
+func createFormPostRequest(t *testing.T) *http.Request {
+	req, err := http.NewRequest("POST", "/?foo=getfoo&bar=getbar", bytes.NewBufferString("foo=bar&bar=foo"))
+	assert.NoError(t, err)
 	req.Header.Set("Content-Type", MIMEPOSTForm)
 	return req
 }
 
-func createDefaultFormPostRequest() *http.Request {
-	req, _ := http.NewRequest("POST", "/?foo=getfoo&bar=getbar", bytes.NewBufferString("foo=bar"))
+func createDefaultFormPostRequest(t *testing.T) *http.Request {
+	req, err := http.NewRequest("POST", "/?foo=getfoo&bar=getbar", bytes.NewBufferString("foo=bar"))
+	assert.NoError(t, err)
 	req.Header.Set("Content-Type", MIMEPOSTForm)
 	return req
 }
 
-func createFormPostRequestFail() *http.Request {
-	req, _ := http.NewRequest("POST", "/?map_foo=getfoo", bytes.NewBufferString("map_foo=bar"))
+func createFormPostRequestForMap(t *testing.T) *http.Request {
+	req, err := http.NewRequest("POST", "/?map_foo=getfoo", bytes.NewBufferString("map_foo={\"bar\":123}"))
+	assert.NoError(t, err)
+	req.Header.Set("Content-Type", MIMEPOSTForm)
+	return req
+}
+
+func createFormPostRequestForMapFail(t *testing.T) *http.Request {
+	req, err := http.NewRequest("POST", "/?map_foo=getfoo", bytes.NewBufferString("map_foo=hello"))
+	assert.NoError(t, err)
 	req.Header.Set("Content-Type", MIMEPOSTForm)
 	return req
 }
@@ -535,26 +545,42 @@ func createFormMultipartRequest(t *testing.T) *http.Request {
 	assert.NoError(t, mw.SetBoundary(boundary))
 	assert.NoError(t, mw.WriteField("foo", "bar"))
 	assert.NoError(t, mw.WriteField("bar", "foo"))
-	req, _ := http.NewRequest("POST", "/?foo=getfoo&bar=getbar", body)
+	req, err := http.NewRequest("POST", "/?foo=getfoo&bar=getbar", body)
+	assert.NoError(t, err)
 	req.Header.Set("Content-Type", MIMEMultipartPOSTForm+"; boundary="+boundary)
 	return req
 }
 
-func createFormMultipartRequestFail(t *testing.T) *http.Request {
+func createFormMultipartRequestForMap(t *testing.T) *http.Request {
 	boundary := "--testboundary"
 	body := new(bytes.Buffer)
 	mw := multipart.NewWriter(body)
 	defer mw.Close()
 
 	assert.NoError(t, mw.SetBoundary(boundary))
-	assert.NoError(t, mw.WriteField("map_foo", "bar"))
-	req, _ := http.NewRequest("POST", "/?map_foo=getfoo", body)
+	assert.NoError(t, mw.WriteField("map_foo", "{\"bar\":123, \"name\":\"thinkerou\", \"pai\": 3.14}"))
+	req, err := http.NewRequest("POST", "/?map_foo=getfoo", body)
+	assert.NoError(t, err)
+	req.Header.Set("Content-Type", MIMEMultipartPOSTForm+"; boundary="+boundary)
+	return req
+}
+
+func createFormMultipartRequestForMapFail(t *testing.T) *http.Request {
+	boundary := "--testboundary"
+	body := new(bytes.Buffer)
+	mw := multipart.NewWriter(body)
+	defer mw.Close()
+
+	assert.NoError(t, mw.SetBoundary(boundary))
+	assert.NoError(t, mw.WriteField("map_foo", "3.14"))
+	req, err := http.NewRequest("POST", "/?map_foo=getfoo", body)
+	assert.NoError(t, err)
 	req.Header.Set("Content-Type", MIMEMultipartPOSTForm+"; boundary="+boundary)
 	return req
 }
 
 func TestBindingFormPost(t *testing.T) {
-	req := createFormPostRequest()
+	req := createFormPostRequest(t)
 	var obj FooBarStruct
 	assert.NoError(t, FormPost.Bind(req, &obj))
 
@@ -564,7 +590,7 @@ func TestBindingFormPost(t *testing.T) {
 }
 
 func TestBindingDefaultValueFormPost(t *testing.T) {
-	req := createDefaultFormPostRequest()
+	req := createDefaultFormPostRequest(t)
 	var obj FooDefaultBarStruct
 	assert.NoError(t, FormPost.Bind(req, &obj))
 
@@ -572,8 +598,16 @@ func TestBindingDefaultValueFormPost(t *testing.T) {
 	assert.Equal(t, "hello", obj.Bar)
 }
 
-func TestBindingFormPostFail(t *testing.T) {
-	req := createFormPostRequestFail()
+func TestBindingFormPostForMap(t *testing.T) {
+	req := createFormPostRequestForMap(t)
+	var obj FooStructForMapType
+	err := FormPost.Bind(req, &obj)
+	assert.NoError(t, err)
+	assert.Equal(t, float64(123), obj.MapFoo["bar"].(float64))
+}
+
+func TestBindingFormPostForMapFail(t *testing.T) {
+	req := createFormPostRequestForMapFail(t)
 	var obj FooStructForMapType
 	err := FormPost.Bind(req, &obj)
 	assert.Error(t, err)
@@ -589,8 +623,18 @@ func TestBindingFormMultipart(t *testing.T) {
 	assert.Equal(t, "foo", obj.Bar)
 }
 
-func TestBindingFormMultipartFail(t *testing.T) {
-	req := createFormMultipartRequestFail(t)
+func TestBindingFormMultipartForMap(t *testing.T) {
+	req := createFormMultipartRequestForMap(t)
+	var obj FooStructForMapType
+	err := FormMultipart.Bind(req, &obj)
+	assert.NoError(t, err)
+	assert.Equal(t, float64(123), obj.MapFoo["bar"].(float64))
+	assert.Equal(t, "thinkerou", obj.MapFoo["name"].(string))
+	assert.Equal(t, float64(3.14), obj.MapFoo["pai"].(float64))
+}
+
+func TestBindingFormMultipartForMapFail(t *testing.T) {
+	req := createFormMultipartRequestForMapFail(t)
 	var obj FooStructForMapType
 	err := FormMultipart.Bind(req, &obj)
 	assert.Error(t, err)
@@ -773,6 +817,17 @@ func TestFormBindingFail(t *testing.T) {
 	assert.Error(t, err)
 }
 
+func TestFormBindingMultipartFail(t *testing.T) {
+	obj := FooBarStruct{}
+	req, err := http.NewRequest("POST", "/", strings.NewReader("foo=bar"))
+	assert.NoError(t, err)
+	req.Header.Set("Content-Type", MIMEMultipartPOSTForm+";boundary=testboundary")
+	_, err = req.MultipartReader()
+	assert.NoError(t, err)
+	err = Form.Bind(req, &obj)
+	assert.Error(t, err)
+}
+
 func TestFormPostBindingFail(t *testing.T) {
 	b := FormPost
 	assert.Equal(t, "form-urlencoded", b.Name())
@@ -1109,7 +1164,8 @@ func testFormBindingForType(t *testing.T, method, path, badPath, body, badBody s
 	case "Map":
 		obj := FooStructForMapType{}
 		err := b.Bind(req, &obj)
-		assert.Error(t, err)
+		assert.NoError(t, err)
+		assert.Equal(t, float64(123), obj.MapFoo["bar"].(float64))
 	case "SliceMap":
 		obj := FooStructForSliceMapType{}
 		err := b.Bind(req, &obj)
@@ -1317,3 +1373,43 @@ func TestCanSet(t *testing.T) {
 	var c CanSetStruct
 	assert.Nil(t, mapForm(&c, nil))
 }
+
+func formPostRequest(path, body string) *http.Request {
+	req := requestWithBody("POST", path, body)
+	req.Header.Add("Content-Type", MIMEPOSTForm)
+	return req
+}
+
+func TestBindingSliceDefault(t *testing.T) {
+	var s struct {
+		Friends []string `form:"friends,default=mike"`
+	}
+	req := formPostRequest("", "")
+	err := Form.Bind(req, &s)
+	assert.NoError(t, err)
+
+	assert.Len(t, s.Friends, 1)
+	assert.Equal(t, "mike", s.Friends[0])
+}
+
+func TestBindingStructField(t *testing.T) {
+	var s struct {
+		Opts struct {
+			Port int
+		} `form:"opts"`
+	}
+	req := formPostRequest("", `opts={"Port": 8000}`)
+	err := Form.Bind(req, &s)
+	assert.NoError(t, err)
+	assert.Equal(t, 8000, s.Opts.Port)
+}
+
+func TestBindingUnknownTypeChan(t *testing.T) {
+	var s struct {
+		Stop chan bool `form:"stop"`
+	}
+	req := formPostRequest("", "stop=true")
+	err := Form.Bind(req, &s)
+	assert.Error(t, err)
+	assert.Equal(t, errUnknownType, err)
+}

binding/form_mapping.go

@@ -5,6 +5,7 @@
 package binding
 
 import (
+	"encoding/json"
 	"errors"
 	"reflect"
 	"strconv"
@@ -12,6 +13,8 @@ import (
 	"time"
 )
 
+var errUnknownType = errors.New("Unknown type")
+
 func mapUri(ptr interface{}, m map[string][]string) error {
 	return mapFormByTag(ptr, m, "uri")
 }
@@ -20,124 +23,153 @@ func mapForm(ptr interface{}, form map[string][]string) error {
 	return mapFormByTag(ptr, form, "form")
 }
 
+var emptyField = reflect.StructField{}
+
 func mapFormByTag(ptr interface{}, form map[string][]string, tag string) error {
-	typ := reflect.TypeOf(ptr).Elem()
-	val := reflect.ValueOf(ptr).Elem()
-	for i := 0; i < typ.NumField(); i++ {
-		typeField := typ.Field(i)
-		structField := val.Field(i)
-		if !structField.CanSet() {
-			continue
-		}
+	_, err := mapping(reflect.ValueOf(ptr), emptyField, form, tag)
+	return err
+}
 
-		structFieldKind := structField.Kind()
-		inputFieldName := typeField.Tag.Get(tag)
-		inputFieldNameList := strings.Split(inputFieldName, ",")
-		inputFieldName = inputFieldNameList[0]
-		var defaultValue string
-		if len(inputFieldNameList) > 1 {
-			defaultList := strings.SplitN(inputFieldNameList[1], "=", 2)
-			if defaultList[0] == "default" {
-				defaultValue = defaultList[1]
-			}
+func mapping(value reflect.Value, field reflect.StructField, form map[string][]string, tag string) (bool, error) {
+	var vKind = value.Kind()
+
+	if vKind == reflect.Ptr {
+		var isNew bool
+		vPtr := value
+		if value.IsNil() {
+			isNew = true
+			vPtr = reflect.New(value.Type().Elem())
 		}
-		if inputFieldName == "-" {
-			continue
+		isSetted, err := mapping(vPtr.Elem(), field, form, tag)
+		if err != nil {
+			return false, err
 		}
-		if inputFieldName == "" {
-			inputFieldName = typeField.Name
-
-			// if "form" tag is nil, we inspect if the field is a struct or struct pointer.
-			// this would not make sense for JSON parsing but it does for a form
-			// since data is flatten
-			if structFieldKind == reflect.Ptr {
-				if !structField.Elem().IsValid() {
-					structField.Set(reflect.New(structField.Type().Elem()))
-				}
-				structField = structField.Elem()
-				structFieldKind = structField.Kind()
-			}
-			if structFieldKind == reflect.Struct {
-				err := mapFormByTag(structField.Addr().Interface(), form, tag)
-				if err != nil {
-					return err
-				}
-				continue
-			}
+		if isNew && isSetted {
+			value.Set(vPtr)
 		}
-		inputValue, exists := form[inputFieldName]
+		return isSetted, nil
+	}
 
-		if !exists {
-			if defaultValue == "" {
+	ok, err := tryToSetValue(value, field, form, tag)
+	if err != nil {
+		return false, err
+	}
+	if ok {
+		return true, nil
+	}
+
+	if vKind == reflect.Struct {
+		tValue := value.Type()
+
+		var isSetted bool
+		for i := 0; i < value.NumField(); i++ {
+			if !value.Field(i).CanSet() {
 				continue
 			}
-			inputValue = make([]string, 1)
-			inputValue[0] = defaultValue
+			ok, err := mapping(value.Field(i), tValue.Field(i), form, tag)
+			if err != nil {
+				return false, err
+			}
+			isSetted = isSetted || ok
 		}
+		return isSetted, nil
+	}
+	return false, nil
+}
 
-		numElems := len(inputValue)
-		if structFieldKind == reflect.Slice && numElems > 0 {
-			sliceOf := structField.Type().Elem().Kind()
-			slice := reflect.MakeSlice(structField.Type(), numElems, numElems)
-			for i := 0; i < numElems; i++ {
-				if err := setWithProperType(sliceOf, inputValue[i], slice.Index(i)); err != nil {
-					return err
-				}
-			}
-			val.Field(i).Set(slice)
-			continue
+func tryToSetValue(value reflect.Value, field reflect.StructField, form map[string][]string, tag string) (bool, error) {
+	var tagValue, defaultValue string
+	var isDefaultExists bool
+
+	tagValue = field.Tag.Get(tag)
+	tagValue, opts := head(tagValue, ",")
+
+	if tagValue == "-" { // just ignoring this field
+		return false, nil
+	}
+	if tagValue == "" { // default value is FieldName
+		tagValue = field.Name
+	}
+	if tagValue == "" { // when field is "emptyField" variable
+		return false, nil
+	}
+
+	var opt string
+	for len(opts) > 0 {
+		opt, opts = head(opts, ",")
+
+		k, v := head(opt, "=")
+		switch k {
+		case "default":
+			isDefaultExists = true
+			defaultValue = v
 		}
-		if _, isTime := structField.Interface().(time.Time); isTime {
-			if err := setTimeField(inputValue[0], typeField, structField); err != nil {
-				return err
-			}
-			continue
+	}
+
+	vs, ok := form[tagValue]
+	if !ok && !isDefaultExists {
+		return false, nil
+	}
+
+	switch value.Kind() {
+	case reflect.Slice:
+		if !ok {
+			vs = []string{defaultValue}
 		}
-		if err := setWithProperType(typeField.Type.Kind(), inputValue[0], structField); err != nil {
-			return err
+		return true, setSlice(vs, value, field)
+	default:
+		var val string
+		if !ok {
+			val = defaultValue
+		}
+
+		if len(vs) > 0 {
+			val = vs[0]
 		}
+		return true, setWithProperType(val, value, field)
 	}
-	return nil
 }
 
-func setWithProperType(valueKind reflect.Kind, val string, structField reflect.Value) error {
-	switch valueKind {
+func setWithProperType(val string, value reflect.Value, field reflect.StructField) error {
+	switch value.Kind() {
 	case reflect.Int:
-		return setIntField(val, 0, structField)
+		return setIntField(val, 0, value)
 	case reflect.Int8:
-		return setIntField(val, 8, structField)
+		return setIntField(val, 8, value)
 	case reflect.Int16:
-		return setIntField(val, 16, structField)
+		return setIntField(val, 16, value)
 	case reflect.Int32:
-		return setIntField(val, 32, structField)
+		return setIntField(val, 32, value)
 	case reflect.Int64:
-		return setIntField(val, 64, structField)
+		return setIntField(val, 64, value)
 	case reflect.Uint:
-		return setUintField(val, 0, structField)
+		return setUintField(val, 0, value)
 	case reflect.Uint8:
-		return setUintField(val, 8, structField)
+		return setUintField(val, 8, value)
 	case reflect.Uint16:
-		return setUintField(val, 16, structField)
+		return setUintField(val, 16, value)
 	case reflect.Uint32:
-		return setUintField(val, 32, structField)
+		return setUintField(val, 32, value)
 	case reflect.Uint64:
-		return setUintField(val, 64, structField)
+		return setUintField(val, 64, value)
 	case reflect.Bool:
-		return setBoolField(val, structField)
+		return setBoolField(val, value)
 	case reflect.Float32:
-		return setFloatField(val, 32, structField)
+		return setFloatField(val, 32, value)
 	case reflect.Float64:
-		return setFloatField(val, 64, structField)
+		return setFloatField(val, 64, value)
 	case reflect.String:
-		structField.SetString(val)
-	case reflect.Ptr:
-		if !structField.Elem().IsValid() {
-			structField.Set(reflect.New(structField.Type().Elem()))
+		value.SetString(val)
+	case reflect.Struct:
+		switch value.Interface().(type) {
+		case time.Time:
+			return setTimeField(val, field, value)
 		}
-		structFieldElem := structField.Elem()
-		return setWithProperType(structFieldElem.Kind(), val, structFieldElem)
+		return json.Unmarshal([]byte(val), value.Addr().Interface())
+	case reflect.Map:
+		return json.Unmarshal([]byte(val), value.Addr().Interface())
 	default:
-		return errors.New("Unknown type")
+		return errUnknownType
 	}
 	return nil
 }
@@ -218,3 +250,23 @@ func setTimeField(val string, structField reflect.StructField, value reflect.Val
 	value.Set(reflect.ValueOf(t))
 	return nil
 }
+
+func setSlice(vals []string, value reflect.Value, field reflect.StructField) error {
+	slice := reflect.MakeSlice(value.Type(), len(vals), len(vals))
+	for i, s := range vals {
+		err := setWithProperType(s, slice.Index(i), field)
+		if err != nil {
+			return err
+		}
+	}
+	value.Set(slice)
+	return nil
+}
+
+func head(str, sep string) (head string, tail string) {
+	idx := strings.Index(str, sep)
+	if idx < 0 {
+		return str, ""
+	}
+	return str[:idx], str[idx+len(sep):]
+}

binding/form_mapping_benchmark_test.go

@@ -0,0 +1,61 @@
+// Copyright 2019 Gin Core Team.  All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package binding
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var form = map[string][]string{
+	"name":      {"mike"},
+	"friends":   {"anna", "nicole"},
+	"id_number": {"12345678"},
+	"id_date":   {"2018-01-20"},
+}
+
+type structFull struct {
+	Name    string   `form:"name"`
+	Age     int      `form:"age,default=25"`
+	Friends []string `form:"friends"`
+	ID      *struct {
+		Number      string    `form:"id_number"`
+		DateOfIssue time.Time `form:"id_date" time_format:"2006-01-02" time_utc:"true"`
+	}
+	Nationality *string `form:"nationality"`
+}
+
+func BenchmarkMapFormFull(b *testing.B) {
+	var s structFull
+	for i := 0; i < b.N; i++ {
+		mapForm(&s, form)
+	}
+	b.StopTimer()
+
+	t := b
+	assert.Equal(t, "mike", s.Name)
+	assert.Equal(t, 25, s.Age)
+	assert.Equal(t, []string{"anna", "nicole"}, s.Friends)
+	assert.Equal(t, "12345678", s.ID.Number)
+	assert.Equal(t, time.Date(2018, 1, 20, 0, 0, 0, 0, time.UTC), s.ID.DateOfIssue)
+	assert.Nil(t, s.Nationality)
+}
+
+type structName struct {
+	Name string `form:"name"`
+}
+
+func BenchmarkMapFormName(b *testing.B) {
+	var s structName
+	for i := 0; i < b.N; i++ {
+		mapForm(&s, form)
+	}
+	b.StopTimer()
+
+	t := b
+	assert.Equal(t, "mike", s.Name)
+}