gin/context.go
Xinyu Kuo 647311aba2
refactor(context): refactor context handling and improve test robustness (#4066)
Use assert.InDelta for float comparison with tolerance in TestContextGetFloat32
Remove unnecessary blank line in TestContextInitQueryCache
Replace anonymous struct with named contextKey type in TestContextWithFallbackValueFromRequestContext
Update context key handling in TestContextWithFallbackValueFromRequestContext to use contextKey type
2024-10-25 09:33:31 +08:00

1430 lines
42 KiB
Go

// 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)
}
// ShouldBindBodyWithPlain is a shortcut for c.ShouldBindBodyWith(obj, binding.Plain).
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)
}