diff --git a/README.md b/README.md index cff9bc8..70a5a13 100644 --- a/README.md +++ b/README.md @@ -52,6 +52,7 @@ Gin is a web framework written in Go (Golang). It features a martini-like API wi - [Graceful restart or stop](#graceful-restart-or-stop) - [Build a single binary with templates](#build-a-single-binary-with-templates) - [Bind form-data request with custom struct](#bind-form-data-request-with-custom-struct) + - [Try to bind body into different structs](#try-to-bind-body-into-different-structs) - [Testing](#testing) - [Users](#users--) @@ -1554,6 +1555,64 @@ type StructZ struct { 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 +cannot be called multiple times. + +```go +type formA struct { + Foo string `json:"foo" xml:"foo" binding:"required"` +} + +type formB struct { + Bar string `json:"bar" xml:"bar" binding:"required"` +} + +func SomeHandler(c *gin.Context) { + objA := formA{} + objB := formB{} + // This c.ShouldBind consumes c.Request.Body and it cannot be reused. + if errA := c.ShouldBind(&objA); errA == nil { + c.String(http.StatusOK, `the body should be formA`) + // Always an error is occurred by this because c.Request.Body is EOF now. + } else if errB := c.ShouldBind(&objB); errB == nil { + c.String(http.StatusOK, `the body should be formB`) + } else { + ... + } +} +``` + +For this, you can use `c.ShouldBindBodyWith`. + +```go +func SomeHandler(c *gin.Context) { + objA := formA{} + objB := formB{} + // This reads c.Request.Body and stores the result into the context. + if errA := c.ShouldBindBodyWith(&objA, binding.JSON); errA == nil { + c.String(http.StatusOK, `the body should be formA`) + // At this time, it reuses body stored in the context. + } else if errB := c.ShouldBindBodyWith(&objB, binding.JSON); errB == nil { + c.String(http.StatusOK, `the body should be formB JSON`) + // And it can accepts other formats + } else if errB2 := c.ShouldBindBodyWith(&objB, binding.XML); errB2 == nil { + c.String(http.StatusOK, `the body should be formB XML`) + } else { + ... + } +} +``` + +* `c.ShouldBindBodyWith` stores body into the context before binding. This has +a slight impact to performance, so you should not use this method if you are +enough to call binding at once. +* This feature is only needed for some formats -- `JSON`, `XML`, `MsgPack`, +`ProtoBuf`. For other formats, `Query`, `Form`, `FormPost`, `FormMultipart`, +can be called by `c.ShouldBind()` multiple times without any damage to +performance (See [#1341](https://github.com/gin-gonic/gin/pull/1341)). + ## Testing The `net/http/httptest` package is preferable way for HTTP testing. diff --git a/binding/binding.go b/binding/binding.go index 646eb80..1a98477 100644 --- a/binding/binding.go +++ b/binding/binding.go @@ -29,6 +29,13 @@ type Binding interface { Bind(*http.Request, interface{}) error } +// BindingBody adds BindBody method to Binding. BindBody is similar with Bind, +// but it reads the body from supplied bytes instead of req.Body. +type BindingBody interface { + Binding + BindBody([]byte, interface{}) error +} + // StructValidator is the minimal interface which needs to be implemented in // order for it to be used as the validator engine for ensuring the correctness // of the reqest. Gin provides a default implementation for this using diff --git a/binding/binding_body_test.go b/binding/binding_body_test.go new file mode 100644 index 0000000..c41d9f8 --- /dev/null +++ b/binding/binding_body_test.go @@ -0,0 +1,67 @@ +package binding + +import ( + "bytes" + "io/ioutil" + "testing" + + "github.com/gin-gonic/gin/binding/example" + "github.com/golang/protobuf/proto" + "github.com/stretchr/testify/assert" + "github.com/ugorji/go/codec" +) + +func TestBindingBody(t *testing.T) { + for _, tt := range []struct { + name string + binding BindingBody + body string + want string + }{ + { + name: "JSON bidning", + binding: JSON, + body: `{"foo":"FOO"}`, + }, + { + name: "XML bidning", + binding: XML, + body: ` + + FOO +`, + }, + { + name: "MsgPack binding", + binding: MsgPack, + body: msgPackBody(t), + }, + } { + t.Logf("testing: %s", tt.name) + req := requestWithBody("POST", "/", tt.body) + form := FooStruct{} + body, _ := ioutil.ReadAll(req.Body) + assert.NoError(t, tt.binding.BindBody(body, &form)) + assert.Equal(t, FooStruct{"FOO"}, form) + } +} + +func msgPackBody(t *testing.T) string { + test := FooStruct{"FOO"} + h := new(codec.MsgpackHandle) + buf := bytes.NewBuffer(nil) + assert.NoError(t, codec.NewEncoder(buf, h).Encode(test)) + return buf.String() +} + +func TestBindingBodyProto(t *testing.T) { + test := example.Test{ + Label: proto.String("FOO"), + } + data, _ := proto.Marshal(&test) + req := requestWithBody("POST", "/", string(data)) + form := example.Test{} + body, _ := ioutil.ReadAll(req.Body) + assert.NoError(t, ProtoBuf.BindBody(body, &form)) + assert.Equal(t, test, form) +} diff --git a/binding/json.go b/binding/json.go index e928a8c..fea17bb 100644 --- a/binding/json.go +++ b/binding/json.go @@ -5,6 +5,8 @@ package binding import ( + "bytes" + "io" "net/http" "github.com/gin-gonic/gin/json" @@ -22,7 +24,15 @@ func (jsonBinding) Name() string { } func (jsonBinding) Bind(req *http.Request, obj interface{}) error { - decoder := json.NewDecoder(req.Body) + return decodeJSON(req.Body, obj) +} + +func (jsonBinding) BindBody(body []byte, obj interface{}) error { + return decodeJSON(bytes.NewReader(body), obj) +} + +func decodeJSON(r io.Reader, obj interface{}) error { + decoder := json.NewDecoder(r) if EnableDecoderUseNumber { decoder.UseNumber() } diff --git a/binding/msgpack.go b/binding/msgpack.go index 7faea4b..b7f7319 100644 --- a/binding/msgpack.go +++ b/binding/msgpack.go @@ -5,6 +5,8 @@ package binding import ( + "bytes" + "io" "net/http" "github.com/ugorji/go/codec" @@ -17,7 +19,16 @@ func (msgpackBinding) Name() string { } func (msgpackBinding) Bind(req *http.Request, obj interface{}) error { - if err := codec.NewDecoder(req.Body, new(codec.MsgpackHandle)).Decode(&obj); err != nil { + return decodeMsgPack(req.Body, obj) +} + +func (msgpackBinding) BindBody(body []byte, obj interface{}) error { + return decodeMsgPack(bytes.NewReader(body), obj) +} + +func decodeMsgPack(r io.Reader, obj interface{}) error { + cdc := new(codec.MsgpackHandle) + if err := codec.NewDecoder(r, cdc).Decode(&obj); err != nil { return err } return validate(obj) diff --git a/binding/protobuf.go b/binding/protobuf.go index c7eb84e..540e9c1 100644 --- a/binding/protobuf.go +++ b/binding/protobuf.go @@ -17,19 +17,20 @@ func (protobufBinding) Name() string { return "protobuf" } -func (protobufBinding) Bind(req *http.Request, obj interface{}) error { - +func (b protobufBinding) Bind(req *http.Request, obj interface{}) error { buf, err := ioutil.ReadAll(req.Body) if err != nil { return err } + return b.BindBody(buf, obj) +} - if err = proto.Unmarshal(buf, obj.(proto.Message)); err != nil { +func (protobufBinding) BindBody(body []byte, obj interface{}) error { + if err := proto.Unmarshal(body, obj.(proto.Message)); err != nil { return err } - - //Here it's same to return validate(obj), but util now we cann't add `binding:""` to the struct - //which automatically generate by gen-proto + // Here it's same to return validate(obj), but util now we cann't add + // `binding:""` to the struct which automatically generate by gen-proto return nil - //return validate(obj) + // return validate(obj) } diff --git a/binding/xml.go b/binding/xml.go index f84a6b7..4e90114 100644 --- a/binding/xml.go +++ b/binding/xml.go @@ -5,7 +5,9 @@ package binding import ( + "bytes" "encoding/xml" + "io" "net/http" ) @@ -16,7 +18,14 @@ func (xmlBinding) Name() string { } func (xmlBinding) Bind(req *http.Request, obj interface{}) error { - decoder := xml.NewDecoder(req.Body) + return decodeXML(req.Body, obj) +} + +func (xmlBinding) BindBody(body []byte, obj interface{}) error { + return decodeXML(bytes.NewReader(body), obj) +} +func decodeXML(r io.Reader, obj interface{}) error { + decoder := xml.NewDecoder(r) if err := decoder.Decode(obj); err != nil { return err } diff --git a/context.go b/context.go index be205f4..9a51e46 100755 --- a/context.go +++ b/context.go @@ -31,6 +31,7 @@ const ( MIMEPlain = binding.MIMEPlain MIMEPOSTForm = binding.MIMEPOSTForm MIMEMultipartPOSTForm = binding.MIMEMultipartPOSTForm + BodyBytesKey = "_gin-gonic/gin/bodybyteskey" ) const abortIndex int8 = math.MaxInt8 / 2 @@ -508,6 +509,30 @@ func (c *Context) ShouldBindWith(obj interface{}, b binding.Binding) error { return b.Bind(c.Request, obj) } +// ShouldBindBodyWith is similar with ShouldBindWith, but it stores the request +// body into the context, and reuse when it is called again. +// +// NOTE: This method reads the body before binding. So you should use +// ShouldBindWith for better performance if you need to call only once. +func (c *Context) ShouldBindBodyWith( + obj interface{}, bb binding.BindingBody, +) (err error) { + var body []byte + if cb, ok := c.Get(BodyBytesKey); ok { + if cbb, ok := cb.([]byte); ok { + body = cbb + } + } + if body == nil { + body, err = ioutil.ReadAll(c.Request.Body) + if err != nil { + return err + } + c.Set(BodyBytesKey, body) + } + return bb.BindBody(body, obj) +} + // ClientIP implements a best effort algorithm to return the real client IP, it parses // X-Real-IP and X-Forwarded-For in order to work properly with reverse-proxies such us: nginx or haproxy. // Use X-Forwarded-For before X-Real-Ip as nginx uses X-Real-Ip with the proxy's IP. diff --git a/context_test.go b/context_test.go index 841d8af..e94866b 100644 --- a/context_test.go +++ b/context_test.go @@ -18,6 +18,7 @@ import ( "time" "github.com/gin-contrib/sse" + "github.com/gin-gonic/gin/binding" "github.com/stretchr/testify/assert" "golang.org/x/net/context" ) @@ -1334,6 +1335,85 @@ func TestContextBadAutoShouldBind(t *testing.T) { assert.False(t, c.IsAborted()) } +func TestContextShouldBindBodyWith(t *testing.T) { + type typeA struct { + Foo string `json:"foo" xml:"foo" binding:"required"` + } + type typeB struct { + Bar string `json:"bar" xml:"bar" binding:"required"` + } + for _, tt := range []struct { + name string + bindingA, bindingB binding.BindingBody + bodyA, bodyB string + }{ + { + name: "JSON & JSON", + bindingA: binding.JSON, + bindingB: binding.JSON, + bodyA: `{"foo":"FOO"}`, + bodyB: `{"bar":"BAR"}`, + }, + { + name: "JSON & XML", + bindingA: binding.JSON, + bindingB: binding.XML, + bodyA: `{"foo":"FOO"}`, + bodyB: ` + + BAR +`, + }, + { + name: "XML & XML", + bindingA: binding.XML, + bindingB: binding.XML, + bodyA: ` + + FOO +`, + bodyB: ` + + BAR +`, + }, + } { + t.Logf("testing: %s", tt.name) + // bodyA to typeA and typeB + { + w := httptest.NewRecorder() + c, _ := CreateTestContext(w) + c.Request, _ = http.NewRequest( + "POST", "http://example.com", bytes.NewBufferString(tt.bodyA), + ) + // When it binds to typeA and typeB, it finds the body is + // not typeB but typeA. + objA := typeA{} + assert.NoError(t, c.ShouldBindBodyWith(&objA, tt.bindingA)) + assert.Equal(t, typeA{"FOO"}, objA) + objB := typeB{} + assert.Error(t, c.ShouldBindBodyWith(&objB, tt.bindingB)) + assert.NotEqual(t, typeB{"BAR"}, objB) + } + // bodyB to typeA and typeB + { + // When it binds to typeA and typeB, it finds the body is + // not typeA but typeB. + w := httptest.NewRecorder() + c, _ := CreateTestContext(w) + c.Request, _ = http.NewRequest( + "POST", "http://example.com", bytes.NewBufferString(tt.bodyB), + ) + objA := typeA{} + assert.Error(t, c.ShouldBindBodyWith(&objA, tt.bindingA)) + assert.NotEqual(t, typeA{"FOO"}, objA) + objB := typeB{} + assert.NoError(t, c.ShouldBindBodyWith(&objB, tt.bindingB)) + assert.Equal(t, typeB{"BAR"}, objB) + } + } +} + func TestContextGolangContext(t *testing.T) { c, _ := CreateTestContext(httptest.NewRecorder()) c.Request, _ = http.NewRequest("POST", "/", bytes.NewBufferString("{\"foo\":\"bar\", \"bar\":\"foo\"}"))