// Copyright 2014 Manu Martinez-Almeida. All rights reserved. // Use of this source code is governed by a MIT style // license that can be found in the LICENSE file. package gin import ( "errors" "io" "log" "math" "mime/multipart" "net" "net/http" "net/url" "os" "path/filepath" "strings" "sync" "time" "github.com/gin-contrib/sse" "github.com/gin-gonic/gin/binding" "github.com/gin-gonic/gin/render" ) // Content-Type MIME of the most common data formats. const ( MIMEJSON = binding.MIMEJSON MIMEHTML = binding.MIMEHTML MIMEXML = binding.MIMEXML MIMEXML2 = binding.MIMEXML2 MIMEPlain = binding.MIMEPlain MIMEPOSTForm = binding.MIMEPOSTForm MIMEMultipartPOSTForm = binding.MIMEMultipartPOSTForm MIMEYAML = binding.MIMEYAML MIMEYAML2 = binding.MIMEYAML2 MIMETOML = binding.MIMETOML ) // BodyBytesKey indicates a default body bytes key. const BodyBytesKey = "_gin-gonic/gin/bodybyteskey" // ContextKey is the key that a Context returns itself for. const ContextKey = "_gin-gonic/gin/contextkey" type ContextKeyType int const ContextRequestKey ContextKeyType = 0 // abortIndex represents a typical value used in abort functions. const abortIndex int8 = math.MaxInt8 >> 1 // Context is the most important part of gin. It allows us to pass variables between middleware, // manage the flow, validate the JSON of a request and render a JSON response for example. type Context struct { writermem responseWriter Request *http.Request Writer ResponseWriter Params Params handlers HandlersChain index int8 fullPath string engine *Engine params *Params skippedNodes *[]skippedNode // This mutex protects Keys map. mu sync.RWMutex // Keys is a key/value pair exclusively for the context of each request. Keys map[string]any // Errors is a list of errors attached to all the handlers/middlewares who used this context. Errors errorMsgs // Accepted defines a list of manually accepted formats for content negotiation. Accepted []string // queryCache caches the query result from c.Request.URL.Query(). queryCache url.Values // formCache caches c.Request.PostForm, which contains the parsed form data from POST, PATCH, // or PUT body parameters. formCache url.Values // SameSite allows a server to define a cookie attribute making it impossible for // the browser to send this cookie along with cross-site requests. sameSite http.SameSite } /************************************/ /********** CONTEXT CREATION ********/ /************************************/ func (c *Context) reset() { c.Writer = &c.writermem c.Params = c.Params[:0] c.handlers = nil c.index = -1 c.fullPath = "" c.Keys = nil c.Errors = c.Errors[:0] c.Accepted = nil c.queryCache = nil c.formCache = nil c.sameSite = 0 *c.params = (*c.params)[:0] *c.skippedNodes = (*c.skippedNodes)[:0] } // Copy returns a copy of the current context that can be safely used outside the request's scope. // This has to be used when the context has to be passed to a goroutine. func (c *Context) Copy() *Context { cp := Context{ writermem: c.writermem, Request: c.Request, engine: c.engine, } cp.writermem.ResponseWriter = nil cp.Writer = &cp.writermem cp.index = abortIndex cp.handlers = nil cp.fullPath = c.fullPath cKeys := c.Keys cp.Keys = make(map[string]any, len(cKeys)) c.mu.RLock() for k, v := range cKeys { cp.Keys[k] = v } c.mu.RUnlock() cParams := c.Params cp.Params = make([]Param, len(cParams)) copy(cp.Params, cParams) return &cp } // HandlerName returns the main handler's name. For example if the handler is "handleGetUsers()", // this function will return "main.handleGetUsers". func (c *Context) HandlerName() string { return nameOfFunction(c.handlers.Last()) } // HandlerNames returns a list of all registered handlers for this context in descending order, // following the semantics of HandlerName() func (c *Context) HandlerNames() []string { hn := make([]string, 0, len(c.handlers)) for _, val := range c.handlers { if val == nil { continue } hn = append(hn, nameOfFunction(val)) } return hn } // Handler returns the main handler. func (c *Context) Handler() HandlerFunc { return c.handlers.Last() } // FullPath returns a matched route full path. For not found routes // returns an empty string. // // router.GET("/user/:id", func(c *gin.Context) { // c.FullPath() == "/user/:id" // true // }) func (c *Context) FullPath() string { return c.fullPath } /************************************/ /*********** FLOW CONTROL ***********/ /************************************/ // Next should be used only inside middleware. // It executes the pending handlers in the chain inside the calling handler. // See example in GitHub. func (c *Context) Next() { c.index++ for c.index < int8(len(c.handlers)) { if c.handlers[c.index] == nil { continue } c.handlers[c.index](c) c.index++ } } // IsAborted returns true if the current context was aborted. func (c *Context) IsAborted() bool { return c.index >= abortIndex } // Abort prevents pending handlers from being called. Note that this will not stop the current handler. // Let's say you have an authorization middleware that validates that the current request is authorized. // If the authorization fails (ex: the password does not match), call Abort to ensure the remaining handlers // for this request are not called. func (c *Context) Abort() { c.index = abortIndex } // AbortWithStatus calls `Abort()` and writes the headers with the specified status code. // For example, a failed attempt to authenticate a request could use: context.AbortWithStatus(401). func (c *Context) AbortWithStatus(code int) { c.Status(code) c.Writer.WriteHeaderNow() c.Abort() } // AbortWithStatusJSON calls `Abort()` and then `JSON` internally. // This method stops the chain, writes the status code and return a JSON body. // It also sets the Content-Type as "application/json". func (c *Context) AbortWithStatusJSON(code int, jsonObj any) { c.Abort() c.JSON(code, jsonObj) } // AbortWithError calls `AbortWithStatus()` and `Error()` internally. // This method stops the chain, writes the status code and pushes the specified error to `c.Errors`. // See Context.Error() for more details. func (c *Context) AbortWithError(code int, err error) *Error { c.AbortWithStatus(code) return c.Error(err) } /************************************/ /********* ERROR MANAGEMENT *********/ /************************************/ // Error attaches an error to the current context. The error is pushed to a list of errors. // It's a good idea to call Error for each error that occurred during the resolution of a request. // A middleware can be used to collect all the errors and push them to a database together, // print a log, or append it in the HTTP response. // Error will panic if err is nil. func (c *Context) Error(err error) *Error { if err == nil { panic("err is nil") } var parsedError *Error ok := errors.As(err, &parsedError) if !ok { parsedError = &Error{ Err: err, Type: ErrorTypePrivate, } } c.Errors = append(c.Errors, parsedError) return parsedError } /************************************/ /******** METADATA MANAGEMENT********/ /************************************/ // Set is used to store a new key/value pair exclusively for this context. // It also lazy initializes c.Keys if it was not used previously. func (c *Context) Set(key string, value any) { c.mu.Lock() defer c.mu.Unlock() if c.Keys == nil { c.Keys = make(map[string]any) } c.Keys[key] = value } // Get returns the value for the given key, ie: (value, true). // If the value does not exist it returns (nil, false) func (c *Context) Get(key string) (value any, exists bool) { c.mu.RLock() defer c.mu.RUnlock() value, exists = c.Keys[key] return } // MustGet returns the value for the given key if it exists, otherwise it panics. func (c *Context) MustGet(key string) any { if value, exists := c.Get(key); exists { return value } panic("Key \"" + key + "\" does not exist") } // GetString returns the value associated with the key as a string. func (c *Context) GetString(key string) (s string) { if val, ok := c.Get(key); ok && val != nil { s, _ = val.(string) } return } // GetBool returns the value associated with the key as a boolean. func (c *Context) GetBool(key string) (b bool) { if val, ok := c.Get(key); ok && val != nil { b, _ = val.(bool) } return } // GetInt returns the value associated with the key as an integer. func (c *Context) GetInt(key string) (i int) { if val, ok := c.Get(key); ok && val != nil { i, _ = val.(int) } return } // GetInt8 returns the value associated with the key as an integer 8. func (c *Context) GetInt8(key string) (i8 int8) { if val, ok := c.Get(key); ok && val != nil { i8, _ = val.(int8) } return } // GetInt16 returns the value associated with the key as an integer 16. func (c *Context) GetInt16(key string) (i16 int16) { if val, ok := c.Get(key); ok && val != nil { i16, _ = val.(int16) } return } // GetInt32 returns the value associated with the key as an integer 32. func (c *Context) GetInt32(key string) (i32 int32) { if val, ok := c.Get(key); ok && val != nil { i32, _ = val.(int32) } return } // GetInt64 returns the value associated with the key as an integer 64. func (c *Context) GetInt64(key string) (i64 int64) { if val, ok := c.Get(key); ok && val != nil { i64, _ = val.(int64) } return } // GetUint returns the value associated with the key as an unsigned integer. func (c *Context) GetUint(key string) (ui uint) { if val, ok := c.Get(key); ok && val != nil { ui, _ = val.(uint) } return } // GetUint8 returns the value associated with the key as an unsigned integer 8. func (c *Context) GetUint8(key string) (ui8 uint8) { if val, ok := c.Get(key); ok && val != nil { ui8, _ = val.(uint8) } return } // GetUint16 returns the value associated with the key as an unsigned integer 16. func (c *Context) GetUint16(key string) (ui16 uint16) { if val, ok := c.Get(key); ok && val != nil { ui16, _ = val.(uint16) } return } // GetUint32 returns the value associated with the key as an unsigned integer 32. func (c *Context) GetUint32(key string) (ui32 uint32) { if val, ok := c.Get(key); ok && val != nil { ui32, _ = val.(uint32) } return } // GetUint64 returns the value associated with the key as an unsigned integer 64. func (c *Context) GetUint64(key string) (ui64 uint64) { if val, ok := c.Get(key); ok && val != nil { ui64, _ = val.(uint64) } return } // GetFloat32 returns the value associated with the key as a float32. func (c *Context) GetFloat32(key string) (f32 float32) { if val, ok := c.Get(key); ok && val != nil { f32, _ = val.(float32) } return } // GetFloat64 returns the value associated with the key as a float64. func (c *Context) GetFloat64(key string) (f64 float64) { if val, ok := c.Get(key); ok && val != nil { f64, _ = val.(float64) } return } // GetTime returns the value associated with the key as time. func (c *Context) GetTime(key string) (t time.Time) { if val, ok := c.Get(key); ok && val != nil { t, _ = val.(time.Time) } return } // GetDuration returns the value associated with the key as a duration. func (c *Context) GetDuration(key string) (d time.Duration) { if val, ok := c.Get(key); ok && val != nil { d, _ = val.(time.Duration) } return } func (c *Context) GetIntSlice(key string) (is []int) { if val, ok := c.Get(key); ok && val != nil { is, _ = val.([]int) } return } func (c *Context) GetInt8Slice(key string) (i8s []int8) { if val, ok := c.Get(key); ok && val != nil { i8s, _ = val.([]int8) } return } func (c *Context) GetInt16Slice(key string) (i16s []int16) { if val, ok := c.Get(key); ok && val != nil { i16s, _ = val.([]int16) } return } func (c *Context) GetInt32Slice(key string) (i32s []int32) { if val, ok := c.Get(key); ok && val != nil { i32s, _ = val.([]int32) } return } func (c *Context) GetInt64Slice(key string) (i64s []int64) { if val, ok := c.Get(key); ok && val != nil { i64s, _ = val.([]int64) } return } func (c *Context) GetUintSlice(key string) (uis []uint) { if val, ok := c.Get(key); ok && val != nil { uis, _ = val.([]uint) } return } func (c *Context) GetUint8Slice(key string) (ui8s []uint8) { if val, ok := c.Get(key); ok && val != nil { ui8s, _ = val.([]uint8) } return } func (c *Context) GetUint16Slice(key string) (ui16s []uint16) { if val, ok := c.Get(key); ok && val != nil { ui16s, _ = val.([]uint16) } return } func (c *Context) GetUint32Slice(key string) (ui32s []uint32) { if val, ok := c.Get(key); ok && val != nil { ui32s, _ = val.([]uint32) } return } func (c *Context) GetUint64Slice(key string) (ui64s []uint64) { if val, ok := c.Get(key); ok && val != nil { ui64s, _ = val.([]uint64) } return } func (c *Context) GetFloat32Slice(key string) (f32s []float32) { if val, ok := c.Get(key); ok && val != nil { f32s, _ = val.([]float32) } return } func (c *Context) GetFloat64Slice(key string) (f64s []float64) { if val, ok := c.Get(key); ok && val != nil { f64s, _ = val.([]float64) } return } // GetStringSlice returns the value associated with the key as a slice of strings. func (c *Context) GetStringSlice(key string) (ss []string) { if val, ok := c.Get(key); ok && val != nil { ss, _ = val.([]string) } return } // GetStringMap returns the value associated with the key as a map of interfaces. func (c *Context) GetStringMap(key string) (sm map[string]any) { if val, ok := c.Get(key); ok && val != nil { sm, _ = val.(map[string]any) } return } // GetStringMapString returns the value associated with the key as a map of strings. func (c *Context) GetStringMapString(key string) (sms map[string]string) { if val, ok := c.Get(key); ok && val != nil { sms, _ = val.(map[string]string) } return } // GetStringMapStringSlice returns the value associated with the key as a map to a slice of strings. func (c *Context) GetStringMapStringSlice(key string) (smss map[string][]string) { if val, ok := c.Get(key); ok && val != nil { smss, _ = val.(map[string][]string) } return } /************************************/ /************ INPUT DATA ************/ /************************************/ // Param returns the value of the URL param. // It is a shortcut for c.Params.ByName(key) // // router.GET("/user/:id", func(c *gin.Context) { // // a GET request to /user/john // id := c.Param("id") // id == "john" // // a GET request to /user/john/ // id := c.Param("id") // id == "/john/" // }) func (c *Context) Param(key string) string { return c.Params.ByName(key) } // AddParam adds param to context and // replaces path param key with given value for e2e testing purposes // Example Route: "/user/:id" // AddParam("id", 1) // Result: "/user/1" func (c *Context) AddParam(key, value string) { c.Params = append(c.Params, Param{Key: key, Value: value}) } // Query returns the keyed url query value if it exists, // otherwise it returns an empty string `("")`. // It is shortcut for `c.Request.URL.Query().Get(key)` // // GET /path?id=1234&name=Manu&value= // c.Query("id") == "1234" // c.Query("name") == "Manu" // c.Query("value") == "" // c.Query("wtf") == "" func (c *Context) Query(key string) (value string) { value, _ = c.GetQuery(key) return } // DefaultQuery returns the keyed url query value if it exists, // otherwise it returns the specified defaultValue string. // See: Query() and GetQuery() for further information. // // GET /?name=Manu&lastname= // c.DefaultQuery("name", "unknown") == "Manu" // c.DefaultQuery("id", "none") == "none" // c.DefaultQuery("lastname", "none") == "" func (c *Context) DefaultQuery(key, defaultValue string) string { if value, ok := c.GetQuery(key); ok { return value } return defaultValue } // GetQuery is like Query(), it returns the keyed url query value // if it exists `(value, true)` (even when the value is an empty string), // otherwise it returns `("", false)`. // It is shortcut for `c.Request.URL.Query().Get(key)` // // GET /?name=Manu&lastname= // ("Manu", true) == c.GetQuery("name") // ("", false) == c.GetQuery("id") // ("", true) == c.GetQuery("lastname") func (c *Context) GetQuery(key string) (string, bool) { if values, ok := c.GetQueryArray(key); ok { return values[0], ok } return "", false } // QueryArray returns a slice of strings for a given query key. // The length of the slice depends on the number of params with the given key. func (c *Context) QueryArray(key string) (values []string) { values, _ = c.GetQueryArray(key) return } func (c *Context) initQueryCache() { if c.queryCache == nil { if c.Request != nil && c.Request.URL != nil { c.queryCache = c.Request.URL.Query() } else { c.queryCache = url.Values{} } } } // GetQueryArray returns a slice of strings for a given query key, plus // a boolean value whether at least one value exists for the given key. func (c *Context) GetQueryArray(key string) (values []string, ok bool) { c.initQueryCache() values, ok = c.queryCache[key] return } // QueryMap returns a map for a given query key. func (c *Context) QueryMap(key string) (dicts map[string]string) { dicts, _ = c.GetQueryMap(key) return } // GetQueryMap returns a map for a given query key, plus a boolean value // whether at least one value exists for the given key. func (c *Context) GetQueryMap(key string) (map[string]string, bool) { c.initQueryCache() return c.get(c.queryCache, key) } // PostForm returns the specified key from a POST urlencoded form or multipart form // when it exists, otherwise it returns an empty string `("")`. func (c *Context) PostForm(key string) (value string) { value, _ = c.GetPostForm(key) return } // DefaultPostForm returns the specified key from a POST urlencoded form or multipart form // when it exists, otherwise it returns the specified defaultValue string. // See: PostForm() and GetPostForm() for further information. func (c *Context) DefaultPostForm(key, defaultValue string) string { if value, ok := c.GetPostForm(key); ok { return value } return defaultValue } // GetPostForm is like PostForm(key). It returns the specified key from a POST urlencoded // form or multipart form when it exists `(value, true)` (even when the value is an empty string), // otherwise it returns ("", false). // For example, during a PATCH request to update the user's email: // // email=mail@example.com --> ("mail@example.com", true) := GetPostForm("email") // set email to "mail@example.com" // email= --> ("", true) := GetPostForm("email") // set email to "" // --> ("", false) := GetPostForm("email") // do nothing with email func (c *Context) GetPostForm(key string) (string, bool) { if values, ok := c.GetPostFormArray(key); ok { return values[0], ok } return "", false } // PostFormArray returns a slice of strings for a given form key. // The length of the slice depends on the number of params with the given key. func (c *Context) PostFormArray(key string) (values []string) { values, _ = c.GetPostFormArray(key) return } func (c *Context) initFormCache() { if c.formCache == nil { c.formCache = make(url.Values) req := c.Request if err := req.ParseMultipartForm(c.engine.MaxMultipartMemory); err != nil { if !errors.Is(err, http.ErrNotMultipart) { debugPrint("error on parse multipart form array: %v", err) } } c.formCache = req.PostForm } } // GetPostFormArray returns a slice of strings for a given form key, plus // a boolean value whether at least one value exists for the given key. func (c *Context) GetPostFormArray(key string) (values []string, ok bool) { c.initFormCache() values, ok = c.formCache[key] return } // PostFormMap returns a map for a given form key. func (c *Context) PostFormMap(key string) (dicts map[string]string) { dicts, _ = c.GetPostFormMap(key) return } // GetPostFormMap returns a map for a given form key, plus a boolean value // whether at least one value exists for the given key. func (c *Context) GetPostFormMap(key string) (map[string]string, bool) { c.initFormCache() return c.get(c.formCache, key) } // get is an internal method and returns a map which satisfies conditions. func (c *Context) get(m map[string][]string, key string) (map[string]string, bool) { dicts := make(map[string]string) exist := false for k, v := range m { if i := strings.IndexByte(k, '['); i >= 1 && k[0:i] == key { if j := strings.IndexByte(k[i+1:], ']'); j >= 1 { exist = true dicts[k[i+1:][:j]] = v[0] } } } return dicts, exist } // FormFile returns the first file for the provided form key. func (c *Context) FormFile(name string) (*multipart.FileHeader, error) { if c.Request.MultipartForm == nil { if err := c.Request.ParseMultipartForm(c.engine.MaxMultipartMemory); err != nil { return nil, err } } f, fh, err := c.Request.FormFile(name) if err != nil { return nil, err } f.Close() return fh, err } // MultipartForm is the parsed multipart form, including file uploads. func (c *Context) MultipartForm() (*multipart.Form, error) { err := c.Request.ParseMultipartForm(c.engine.MaxMultipartMemory) return c.Request.MultipartForm, err } // SaveUploadedFile uploads the form file to specific dst. func (c *Context) SaveUploadedFile(file *multipart.FileHeader, dst string) error { src, err := file.Open() if err != nil { return err } defer src.Close() if err = os.MkdirAll(filepath.Dir(dst), 0o750); err != nil { return err } out, err := os.Create(dst) if err != nil { return err } defer out.Close() _, err = io.Copy(out, src) return err } // Bind checks the Method and Content-Type to select a binding engine automatically, // Depending on the "Content-Type" header different bindings are used, for example: // // "application/json" --> JSON binding // "application/xml" --> XML binding // // It parses the request's body as JSON if Content-Type == "application/json" using JSON or XML as a JSON input. // It decodes the json payload into the struct specified as a pointer. // It writes a 400 error and sets Content-Type header "text/plain" in the response if input is not valid. func (c *Context) Bind(obj any) error { b := binding.Default(c.Request.Method, c.ContentType()) return c.MustBindWith(obj, b) } // BindJSON is a shortcut for c.MustBindWith(obj, binding.JSON). func (c *Context) BindJSON(obj any) error { return c.MustBindWith(obj, binding.JSON) } // BindXML is a shortcut for c.MustBindWith(obj, binding.BindXML). func (c *Context) BindXML(obj any) error { return c.MustBindWith(obj, binding.XML) } // BindQuery is a shortcut for c.MustBindWith(obj, binding.Query). func (c *Context) BindQuery(obj any) error { return c.MustBindWith(obj, binding.Query) } // BindYAML is a shortcut for c.MustBindWith(obj, binding.YAML). func (c *Context) BindYAML(obj any) error { return c.MustBindWith(obj, binding.YAML) } // BindTOML is a shortcut for c.MustBindWith(obj, binding.TOML). func (c *Context) BindTOML(obj any) error { return c.MustBindWith(obj, binding.TOML) } // BindPlain is a shortcut for c.MustBindWith(obj, binding.Plain). func (c *Context) BindPlain(obj any) error { return c.MustBindWith(obj, binding.Plain) } // BindHeader is a shortcut for c.MustBindWith(obj, binding.Header). func (c *Context) BindHeader(obj any) error { return c.MustBindWith(obj, binding.Header) } // BindUri binds the passed struct pointer using binding.Uri. // It will abort the request with HTTP 400 if any error occurs. func (c *Context) BindUri(obj any) error { if err := c.ShouldBindUri(obj); err != nil { c.AbortWithError(http.StatusBadRequest, err).SetType(ErrorTypeBind) //nolint: errcheck return err } return nil } // MustBindWith binds the passed struct pointer using the specified binding engine. // It will abort the request with HTTP 400 if any error occurs. // See the binding package. func (c *Context) MustBindWith(obj any, b binding.Binding) error { if err := c.ShouldBindWith(obj, b); err != nil { c.AbortWithError(http.StatusBadRequest, err).SetType(ErrorTypeBind) //nolint: errcheck return err } return nil } // ShouldBind checks the Method and Content-Type to select a binding engine automatically, // Depending on the "Content-Type" header different bindings are used, for example: // // "application/json" --> JSON binding // "application/xml" --> XML binding // // It parses the request's body as JSON if Content-Type == "application/json" using JSON or XML as a JSON input. // It decodes the json payload into the struct specified as a pointer. // Like c.Bind() but this method does not set the response status code to 400 or abort if input is not valid. func (c *Context) ShouldBind(obj any) error { b := binding.Default(c.Request.Method, c.ContentType()) return c.ShouldBindWith(obj, b) } // ShouldBindJSON is a shortcut for c.ShouldBindWith(obj, binding.JSON). func (c *Context) ShouldBindJSON(obj any) error { return c.ShouldBindWith(obj, binding.JSON) } // ShouldBindXML is a shortcut for c.ShouldBindWith(obj, binding.XML). func (c *Context) ShouldBindXML(obj any) error { return c.ShouldBindWith(obj, binding.XML) } // ShouldBindQuery is a shortcut for c.ShouldBindWith(obj, binding.Query). func (c *Context) ShouldBindQuery(obj any) error { return c.ShouldBindWith(obj, binding.Query) } // ShouldBindYAML is a shortcut for c.ShouldBindWith(obj, binding.YAML). func (c *Context) ShouldBindYAML(obj any) error { return c.ShouldBindWith(obj, binding.YAML) } // ShouldBindTOML is a shortcut for c.ShouldBindWith(obj, binding.TOML). func (c *Context) ShouldBindTOML(obj any) error { return c.ShouldBindWith(obj, binding.TOML) } // ShouldBindPlain is a shortcut for c.ShouldBindWith(obj, binding.Plain). func (c *Context) ShouldBindPlain(obj any) error { return c.ShouldBindWith(obj, binding.Plain) } // ShouldBindHeader is a shortcut for c.ShouldBindWith(obj, binding.Header). func (c *Context) ShouldBindHeader(obj any) error { return c.ShouldBindWith(obj, binding.Header) } // ShouldBindUri binds the passed struct pointer using the specified binding engine. func (c *Context) ShouldBindUri(obj any) error { m := make(map[string][]string, len(c.Params)) for _, v := range c.Params { m[v.Key] = []string{v.Value} } return binding.Uri.BindUri(m, obj) } // ShouldBindWith binds the passed struct pointer using the specified binding engine. // See the binding package. func (c *Context) ShouldBindWith(obj any, 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 any, 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 = io.ReadAll(c.Request.Body) if err != nil { return err } c.Set(BodyBytesKey, body) } return bb.BindBody(body, obj) } // ShouldBindBodyWithJSON is a shortcut for c.ShouldBindBodyWith(obj, binding.JSON). func (c *Context) ShouldBindBodyWithJSON(obj any) error { return c.ShouldBindBodyWith(obj, binding.JSON) } // ShouldBindBodyWithXML is a shortcut for c.ShouldBindBodyWith(obj, binding.XML). func (c *Context) ShouldBindBodyWithXML(obj any) error { return c.ShouldBindBodyWith(obj, binding.XML) } // ShouldBindBodyWithYAML is a shortcut for c.ShouldBindBodyWith(obj, binding.YAML). func (c *Context) ShouldBindBodyWithYAML(obj any) error { return c.ShouldBindBodyWith(obj, binding.YAML) } // ShouldBindBodyWithTOML is a shortcut for c.ShouldBindBodyWith(obj, binding.TOML). func (c *Context) ShouldBindBodyWithTOML(obj any) error { return c.ShouldBindBodyWith(obj, binding.TOML) } // ShouldBindBodyWithJSON is a shortcut for c.ShouldBindBodyWith(obj, binding.JSON). func (c *Context) ShouldBindBodyWithPlain(obj any) error { return c.ShouldBindBodyWith(obj, binding.Plain) } // ClientIP implements one best effort algorithm to return the real client IP. // It calls c.RemoteIP() under the hood, to check if the remote IP is a trusted proxy or not. // If it is it will then try to parse the headers defined in Engine.RemoteIPHeaders (defaulting to [X-Forwarded-For, X-Real-Ip]). // If the headers are not syntactically valid OR the remote IP does not correspond to a trusted proxy, // the remote IP (coming from Request.RemoteAddr) is returned. func (c *Context) ClientIP() string { // Check if we're running on a trusted platform, continue running backwards if error if c.engine.TrustedPlatform != "" { // Developers can define their own header of Trusted Platform or use predefined constants if addr := c.requestHeader(c.engine.TrustedPlatform); addr != "" { return addr } } // Legacy "AppEngine" flag if c.engine.AppEngine { log.Println(`The AppEngine flag is going to be deprecated. Please check issues #2723 and #2739 and use 'TrustedPlatform: gin.PlatformGoogleAppEngine' instead.`) if addr := c.requestHeader("X-Appengine-Remote-Addr"); addr != "" { return addr } } // It also checks if the remoteIP is a trusted proxy or not. // In order to perform this validation, it will see if the IP is contained within at least one of the CIDR blocks // defined by Engine.SetTrustedProxies() remoteIP := net.ParseIP(c.RemoteIP()) if remoteIP == nil { return "" } trusted := c.engine.isTrustedProxy(remoteIP) if trusted && c.engine.ForwardedByClientIP && c.engine.RemoteIPHeaders != nil { for _, headerName := range c.engine.RemoteIPHeaders { ip, valid := c.engine.validateHeader(c.requestHeader(headerName)) if valid { return ip } } } return remoteIP.String() } // RemoteIP parses the IP from Request.RemoteAddr, normalizes and returns the IP (without the port). func (c *Context) RemoteIP() string { ip, _, err := net.SplitHostPort(strings.TrimSpace(c.Request.RemoteAddr)) if err != nil { return "" } return ip } // ContentType returns the Content-Type header of the request. func (c *Context) ContentType() string { return filterFlags(c.requestHeader("Content-Type")) } // IsWebsocket returns true if the request headers indicate that a websocket // handshake is being initiated by the client. func (c *Context) IsWebsocket() bool { if strings.Contains(strings.ToLower(c.requestHeader("Connection")), "upgrade") && strings.EqualFold(c.requestHeader("Upgrade"), "websocket") { return true } return false } func (c *Context) requestHeader(key string) string { return c.Request.Header.Get(key) } /************************************/ /******** RESPONSE RENDERING ********/ /************************************/ // bodyAllowedForStatus is a copy of http.bodyAllowedForStatus non-exported function. func bodyAllowedForStatus(status int) bool { switch { case status >= 100 && status <= 199: return false case status == http.StatusNoContent: return false case status == http.StatusNotModified: return false } return true } // Status sets the HTTP response code. func (c *Context) Status(code int) { c.Writer.WriteHeader(code) } // Header is an intelligent shortcut for c.Writer.Header().Set(key, value). // It writes a header in the response. // If value == "", this method removes the header `c.Writer.Header().Del(key)` func (c *Context) Header(key, value string) { if value == "" { c.Writer.Header().Del(key) return } c.Writer.Header().Set(key, value) } // GetHeader returns value from request headers. func (c *Context) GetHeader(key string) string { return c.requestHeader(key) } // GetRawData returns stream data. func (c *Context) GetRawData() ([]byte, error) { if c.Request.Body == nil { return nil, errors.New("cannot read nil body") } return io.ReadAll(c.Request.Body) } // SetSameSite with cookie func (c *Context) SetSameSite(samesite http.SameSite) { c.sameSite = samesite } // SetCookie adds a Set-Cookie header to the ResponseWriter's headers. // The provided cookie must have a valid Name. Invalid cookies may be // silently dropped. func (c *Context) SetCookie(name, value string, maxAge int, path, domain string, secure, httpOnly bool) { if path == "" { path = "/" } http.SetCookie(c.Writer, &http.Cookie{ Name: name, Value: url.QueryEscape(value), MaxAge: maxAge, Path: path, Domain: domain, SameSite: c.sameSite, Secure: secure, HttpOnly: httpOnly, }) } // Cookie returns the named cookie provided in the request or // ErrNoCookie if not found. And return the named cookie is unescaped. // If multiple cookies match the given name, only one cookie will // be returned. func (c *Context) Cookie(name string) (string, error) { cookie, err := c.Request.Cookie(name) if err != nil { return "", err } val, _ := url.QueryUnescape(cookie.Value) return val, nil } // Render writes the response headers and calls render.Render to render data. func (c *Context) Render(code int, r render.Render) { c.Status(code) if !bodyAllowedForStatus(code) { r.WriteContentType(c.Writer) c.Writer.WriteHeaderNow() return } if err := r.Render(c.Writer); err != nil { // Pushing error to c.Errors _ = c.Error(err) c.Abort() } } // HTML renders the HTTP template specified by its file name. // It also updates the HTTP code and sets the Content-Type as "text/html". // See http://golang.org/doc/articles/wiki/ func (c *Context) HTML(code int, name string, obj any) { instance := c.engine.HTMLRender.Instance(name, obj) c.Render(code, instance) } // IndentedJSON serializes the given struct as pretty JSON (indented + endlines) into the response body. // It also sets the Content-Type as "application/json". // WARNING: we recommend using this only for development purposes since printing pretty JSON is // more CPU and bandwidth consuming. Use Context.JSON() instead. func (c *Context) IndentedJSON(code int, obj any) { c.Render(code, render.IndentedJSON{Data: obj}) } // SecureJSON serializes the given struct as Secure JSON into the response body. // Default prepends "while(1)," to response body if the given struct is array values. // It also sets the Content-Type as "application/json". func (c *Context) SecureJSON(code int, obj any) { c.Render(code, render.SecureJSON{Prefix: c.engine.secureJSONPrefix, Data: obj}) } // JSONP serializes the given struct as JSON into the response body. // It adds padding to response body to request data from a server residing in a different domain than the client. // It also sets the Content-Type as "application/javascript". func (c *Context) JSONP(code int, obj any) { callback := c.DefaultQuery("callback", "") if callback == "" { c.Render(code, render.JSON{Data: obj}) return } c.Render(code, render.JsonpJSON{Callback: callback, Data: obj}) } // JSON serializes the given struct as JSON into the response body. // It also sets the Content-Type as "application/json". func (c *Context) JSON(code int, obj any) { c.Render(code, render.JSON{Data: obj}) } // AsciiJSON serializes the given struct as JSON into the response body with unicode to ASCII string. // It also sets the Content-Type as "application/json". func (c *Context) AsciiJSON(code int, obj any) { c.Render(code, render.AsciiJSON{Data: obj}) } // PureJSON serializes the given struct as JSON into the response body. // PureJSON, unlike JSON, does not replace special html characters with their unicode entities. func (c *Context) PureJSON(code int, obj any) { c.Render(code, render.PureJSON{Data: obj}) } // XML serializes the given struct as XML into the response body. // It also sets the Content-Type as "application/xml". func (c *Context) XML(code int, obj any) { c.Render(code, render.XML{Data: obj}) } // YAML serializes the given struct as YAML into the response body. func (c *Context) YAML(code int, obj any) { c.Render(code, render.YAML{Data: obj}) } // TOML serializes the given struct as TOML into the response body. func (c *Context) TOML(code int, obj any) { c.Render(code, render.TOML{Data: obj}) } // ProtoBuf serializes the given struct as ProtoBuf into the response body. func (c *Context) ProtoBuf(code int, obj any) { c.Render(code, render.ProtoBuf{Data: obj}) } // String writes the given string into the response body. func (c *Context) String(code int, format string, values ...any) { c.Render(code, render.String{Format: format, Data: values}) } // Redirect returns an HTTP redirect to the specific location. func (c *Context) Redirect(code int, location string) { c.Render(-1, render.Redirect{ Code: code, Location: location, Request: c.Request, }) } // Data writes some data into the body stream and updates the HTTP code. func (c *Context) Data(code int, contentType string, data []byte) { c.Render(code, render.Data{ ContentType: contentType, Data: data, }) } // DataFromReader writes the specified reader into the body stream and updates the HTTP code. func (c *Context) DataFromReader(code int, contentLength int64, contentType string, reader io.Reader, extraHeaders map[string]string) { c.Render(code, render.Reader{ Headers: extraHeaders, ContentType: contentType, ContentLength: contentLength, Reader: reader, }) } // File writes the specified file into the body stream in an efficient way. func (c *Context) File(filepath string) { http.ServeFile(c.Writer, c.Request, filepath) } // FileFromFS writes the specified file from http.FileSystem into the body stream in an efficient way. func (c *Context) FileFromFS(filepath string, fs http.FileSystem) { defer func(old string) { c.Request.URL.Path = old }(c.Request.URL.Path) c.Request.URL.Path = filepath http.FileServer(fs).ServeHTTP(c.Writer, c.Request) } var quoteEscaper = strings.NewReplacer("\\", "\\\\", `"`, "\\\"") func escapeQuotes(s string) string { return quoteEscaper.Replace(s) } // FileAttachment writes the specified file into the body stream in an efficient way // On the client side, the file will typically be downloaded with the given filename func (c *Context) FileAttachment(filepath, filename string) { if isASCII(filename) { c.Writer.Header().Set("Content-Disposition", `attachment; filename="`+escapeQuotes(filename)+`"`) } else { c.Writer.Header().Set("Content-Disposition", `attachment; filename*=UTF-8''`+url.QueryEscape(filename)) } http.ServeFile(c.Writer, c.Request, filepath) } // SSEvent writes a Server-Sent Event into the body stream. func (c *Context) SSEvent(name string, message any) { c.Render(-1, sse.Event{ Event: name, Data: message, }) } // Stream sends a streaming response and returns a boolean // indicates "Is client disconnected in middle of stream" func (c *Context) Stream(step func(w io.Writer) bool) bool { w := c.Writer clientGone := w.CloseNotify() for { select { case <-clientGone: return true default: keepOpen := step(w) w.Flush() if !keepOpen { return false } } } } /************************************/ /******** CONTENT NEGOTIATION *******/ /************************************/ // Negotiate contains all negotiations data. type Negotiate struct { Offered []string HTMLName string HTMLData any JSONData any XMLData any YAMLData any Data any TOMLData any } // Negotiate calls different Render according to acceptable Accept format. func (c *Context) Negotiate(code int, config Negotiate) { switch c.NegotiateFormat(config.Offered...) { case binding.MIMEJSON: data := chooseData(config.JSONData, config.Data) c.JSON(code, data) case binding.MIMEHTML: data := chooseData(config.HTMLData, config.Data) c.HTML(code, config.HTMLName, data) case binding.MIMEXML: data := chooseData(config.XMLData, config.Data) c.XML(code, data) case binding.MIMEYAML, binding.MIMEYAML2: data := chooseData(config.YAMLData, config.Data) c.YAML(code, data) case binding.MIMETOML: data := chooseData(config.TOMLData, config.Data) c.TOML(code, data) default: c.AbortWithError(http.StatusNotAcceptable, errors.New("the accepted formats are not offered by the server")) //nolint: errcheck } } // NegotiateFormat returns an acceptable Accept format. func (c *Context) NegotiateFormat(offered ...string) string { assert1(len(offered) > 0, "you must provide at least one offer") if c.Accepted == nil { c.Accepted = parseAccept(c.requestHeader("Accept")) } if len(c.Accepted) == 0 { return offered[0] } for _, accepted := range c.Accepted { for _, offer := range offered { // According to RFC 2616 and RFC 2396, non-ASCII characters are not allowed in headers, // therefore we can just iterate over the string without casting it into []rune i := 0 for ; i < len(accepted) && i < len(offer); i++ { if accepted[i] == '*' || offer[i] == '*' { return offer } if accepted[i] != offer[i] { break } } if i == len(accepted) { return offer } } } return "" } // SetAccepted sets Accept header data. func (c *Context) SetAccepted(formats ...string) { c.Accepted = formats } /************************************/ /***** GOLANG.ORG/X/NET/CONTEXT *****/ /************************************/ // hasRequestContext returns whether c.Request has Context and fallback. func (c *Context) hasRequestContext() bool { hasFallback := c.engine != nil && c.engine.ContextWithFallback hasRequestContext := c.Request != nil && c.Request.Context() != nil return hasFallback && hasRequestContext } // Deadline returns that there is no deadline (ok==false) when c.Request has no Context. func (c *Context) Deadline() (deadline time.Time, ok bool) { if !c.hasRequestContext() { return } return c.Request.Context().Deadline() } // Done returns nil (chan which will wait forever) when c.Request has no Context. func (c *Context) Done() <-chan struct{} { if !c.hasRequestContext() { return nil } return c.Request.Context().Done() } // Err returns nil when c.Request has no Context. func (c *Context) Err() error { if !c.hasRequestContext() { return nil } return c.Request.Context().Err() } // Value returns the value associated with this context for key, or nil // if no value is associated with key. Successive calls to Value with // the same key returns the same result. func (c *Context) Value(key any) any { if key == ContextRequestKey { return c.Request } if key == ContextKey { return c } if keyAsString, ok := key.(string); ok { if val, exists := c.Get(keyAsString); exists { return val } } if !c.hasRequestContext() { return nil } return c.Request.Context().Value(key) }