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mirror of https://github.com/labstack/echo.git synced 2024-12-22 20:06:21 +02:00
echo/context.go

787 lines
25 KiB
Go

package echo
import (
"bytes"
"encoding/xml"
"errors"
"fmt"
"io"
"io/fs"
"mime/multipart"
"net"
"net/http"
"net/url"
"path/filepath"
"strings"
"sync"
)
// Context represents the context of the current HTTP request. It holds request and
// response objects, path, path parameters, data and registered handler.
type Context interface {
// Request returns `*http.Request`.
Request() *http.Request
// SetRequest sets `*http.Request`.
SetRequest(r *http.Request)
// SetResponse sets `*Response`.
SetResponse(r *Response)
// Response returns `*Response`.
Response() *Response
// IsTLS returns true if HTTP connection is TLS otherwise false.
IsTLS() bool
// IsWebSocket returns true if HTTP connection is WebSocket otherwise false.
IsWebSocket() bool
// Scheme returns the HTTP protocol scheme, `http` or `https`.
Scheme() string
// RealIP returns the client's network address based on `X-Forwarded-For`
// or `X-Real-IP` request header.
// The behavior can be configured using `Echo#IPExtractor`.
RealIP() string
// RouteInfo returns current request route information. Method, Path, Name and params if they exist for matched route.
// In case of 404 (route not found) and 405 (method not allowed) RouteInfo returns generic struct for these cases.
RouteInfo() RouteInfo
// Path returns the registered path for the handler.
Path() string
// PathParam returns path parameter by name.
PathParam(name string) string
// PathParamDefault returns the path parameter or default value for the provided name.
//
// Notes for DefaultRouter implementation:
// Path parameter could be empty for cases like that:
// * route `/release-:version/bin` and request URL is `/release-/bin`
// * route `/api/:version/image.jpg` and request URL is `/api//image.jpg`
// but not when path parameter is last part of route path
// * route `/download/file.:ext` will not match request `/download/file.`
PathParamDefault(name string, defaultValue string) string
// PathParams returns path parameter values.
PathParams() PathParams
// SetPathParams sets path parameters for current request.
SetPathParams(params PathParams)
// QueryParam returns the query param for the provided name.
QueryParam(name string) string
// QueryParamDefault returns the query param or default value for the provided name.
QueryParamDefault(name, defaultValue string) string
// QueryParams returns the query parameters as `url.Values`.
QueryParams() url.Values
// QueryString returns the URL query string.
QueryString() string
// FormValue returns the form field value for the provided name.
FormValue(name string) string
// FormValueDefault returns the form field value or default value for the provided name.
FormValueDefault(name, defaultValue string) string
// FormValues returns the form field values as `url.Values`.
FormValues() (url.Values, error)
// FormFile returns the multipart form file for the provided name.
FormFile(name string) (*multipart.FileHeader, error)
// MultipartForm returns the multipart form.
MultipartForm() (*multipart.Form, error)
// Cookie returns the named cookie provided in the request.
Cookie(name string) (*http.Cookie, error)
// SetCookie adds a `Set-Cookie` header in HTTP response.
SetCookie(cookie *http.Cookie)
// Cookies returns the HTTP cookies sent with the request.
Cookies() []*http.Cookie
// Get retrieves data from the context.
Get(key string) interface{}
// Set saves data in the context.
Set(key string, val interface{})
// Bind binds path params, query params and the request body into provided type `i`. The default binder
// binds body based on Content-Type header.
Bind(i interface{}) error
// Validate validates provided `i`. It is usually called after `Context#Bind()`.
// Validator must be registered using `Echo#Validator`.
Validate(i interface{}) error
// Render renders a template with data and sends a text/html response with status
// code. Renderer must be registered using `Echo.Renderer`.
Render(code int, name string, data interface{}) error
// HTML sends an HTTP response with status code.
HTML(code int, html string) error
// HTMLBlob sends an HTTP blob response with status code.
HTMLBlob(code int, b []byte) error
// String sends a string response with status code.
String(code int, s string) error
// JSON sends a JSON response with status code.
JSON(code int, i interface{}) error
// JSONPretty sends a pretty-print JSON with status code.
JSONPretty(code int, i interface{}, indent string) error
// JSONBlob sends a JSON blob response with status code.
JSONBlob(code int, b []byte) error
// JSONP sends a JSONP response with status code. It uses `callback` to construct
// the JSONP payload.
JSONP(code int, callback string, i interface{}) error
// JSONPBlob sends a JSONP blob response with status code. It uses `callback`
// to construct the JSONP payload.
JSONPBlob(code int, callback string, b []byte) error
// XML sends an XML response with status code.
XML(code int, i interface{}) error
// XMLPretty sends a pretty-print XML with status code.
XMLPretty(code int, i interface{}, indent string) error
// XMLBlob sends an XML blob response with status code.
XMLBlob(code int, b []byte) error
// Blob sends a blob response with status code and content type.
Blob(code int, contentType string, b []byte) error
// Stream sends a streaming response with status code and content type.
Stream(code int, contentType string, r io.Reader) error
// File sends a response with the content of the file.
File(file string) error
// FileFS sends a response with the content of the file from given filesystem.
FileFS(file string, filesystem fs.FS) error
// Attachment sends a response as attachment, prompting client to save the
// file.
Attachment(file string, name string) error
// Inline sends a response as inline, opening the file in the browser.
Inline(file string, name string) error
// NoContent sends a response with no body and a status code.
NoContent(code int) error
// Redirect redirects the request to a provided URL with status code.
Redirect(code int, url string) error
// Error invokes the registered global HTTP error handler. Generally used by middleware.
// A side-effect of calling global error handler is that now Response has been committed (sent to the client) and
// middlewares up in chain can not change Response status code or Response body anymore.
//
// Avoid using this method in handlers as no middleware will be able to effectively handle errors after that.
// Instead of calling this method in handler return your error and let it be handled by middlewares or global error handler.
Error(err error)
// Echo returns the `Echo` instance.
//
// WARNING: Remember that Echo public fields and methods are coroutine safe ONLY when you are NOT mutating them
// anywhere in your code after Echo server has started.
Echo() *Echo
}
// ServableContext is interface that Echo context implementation must implement to be usable in middleware/handlers and
// be able to be routed by Router.
type ServableContext interface {
Context // minimal set of methods for middlewares and handler
RoutableContext // minimal set for routing. These methods should not be accessed in middlewares/handlers
// Reset resets the context after request completes. It must be called along
// with `Echo#AcquireContext()` and `Echo#ReleaseContext()`.
// See `Echo#ServeHTTP()`
Reset(r *http.Request, w http.ResponseWriter)
}
const (
// ContextKeyHeaderAllow is set by Router for getting value for `Allow` header in later stages of handler call chain.
// Allow header is mandatory for status 405 (method not found) and useful for OPTIONS method requests.
// It is added to context only when Router does not find matching method handler for request.
ContextKeyHeaderAllow = "echo_header_allow"
)
const (
defaultMemory = 32 << 20 // 32 MB
indexPage = "index.html"
defaultIndent = " "
)
// DefaultContext is default implementation of Context interface and can be embedded into structs to compose
// new Contexts with extended/modified behaviour.
type DefaultContext struct {
request *http.Request
response *Response
route RouteInfo
path string
// pathParams holds path/uri parameters determined by Router. Lifecycle is handled by Echo to reduce allocations.
pathParams *PathParams
// currentParams hold path parameters set by non-Echo implementation (custom middlewares, handlers) during the lifetime of Request.
// Lifecycle is not handle by Echo and could have excess allocations per served Request
currentParams PathParams
query url.Values
store Map
echo *Echo
lock sync.RWMutex
}
// NewDefaultContext creates new instance of DefaultContext.
// Argument pathParamAllocSize must be value that is stored in Echo.contextPathParamAllocSize field and is used
// to preallocate PathParams slice.
func NewDefaultContext(e *Echo, pathParamAllocSize int) *DefaultContext {
p := make(PathParams, pathParamAllocSize)
return &DefaultContext{
pathParams: &p,
store: make(Map),
echo: e,
}
}
// Reset resets the context after request completes. It must be called along
// with `Echo#AcquireContext()` and `Echo#ReleaseContext()`.
// See `Echo#ServeHTTP()`
func (c *DefaultContext) Reset(r *http.Request, w http.ResponseWriter) {
c.request = r
c.response.reset(w)
c.query = nil
c.store = nil
c.route = nil
c.path = ""
// NOTE: Don't reset because it has to have length of c.echo.contextPathParamAllocSize at all times
*c.pathParams = (*c.pathParams)[:0]
c.currentParams = nil
}
func (c *DefaultContext) writeContentType(value string) {
header := c.Response().Header()
if header.Get(HeaderContentType) == "" {
header.Set(HeaderContentType, value)
}
}
// Request returns `*http.Request`.
func (c *DefaultContext) Request() *http.Request {
return c.request
}
// SetRequest sets `*http.Request`.
func (c *DefaultContext) SetRequest(r *http.Request) {
c.request = r
}
// Response returns `*Response`.
func (c *DefaultContext) Response() *Response {
return c.response
}
// SetResponse sets `*Response`.
func (c *DefaultContext) SetResponse(r *Response) {
c.response = r
}
// IsTLS returns true if HTTP connection is TLS otherwise false.
func (c *DefaultContext) IsTLS() bool {
return c.request.TLS != nil
}
// IsWebSocket returns true if HTTP connection is WebSocket otherwise false.
func (c *DefaultContext) IsWebSocket() bool {
upgrade := c.request.Header.Get(HeaderUpgrade)
return strings.EqualFold(upgrade, "websocket")
}
// Scheme returns the HTTP protocol scheme, `http` or `https`.
func (c *DefaultContext) Scheme() string {
// Can't use `r.Request.URL.Scheme`
// See: https://groups.google.com/forum/#!topic/golang-nuts/pMUkBlQBDF0
if c.IsTLS() {
return "https"
}
if scheme := c.request.Header.Get(HeaderXForwardedProto); scheme != "" {
return scheme
}
if scheme := c.request.Header.Get(HeaderXForwardedProtocol); scheme != "" {
return scheme
}
if ssl := c.request.Header.Get(HeaderXForwardedSsl); ssl == "on" {
return "https"
}
if scheme := c.request.Header.Get(HeaderXUrlScheme); scheme != "" {
return scheme
}
return "http"
}
// RealIP returns the client's network address based on `X-Forwarded-For`
// or `X-Real-IP` request header.
// The behavior can be configured using `Echo#IPExtractor`.
func (c *DefaultContext) RealIP() string {
if c.echo != nil && c.echo.IPExtractor != nil {
return c.echo.IPExtractor(c.request)
}
// Fall back to legacy behavior
if ip := c.request.Header.Get(HeaderXForwardedFor); ip != "" {
i := strings.IndexAny(ip, ",")
if i > 0 {
xffip := strings.TrimSpace(ip[:i])
xffip = strings.TrimPrefix(xffip, "[")
xffip = strings.TrimSuffix(xffip, "]")
return xffip
}
return ip
}
if ip := c.request.Header.Get(HeaderXRealIP); ip != "" {
ip = strings.TrimPrefix(ip, "[")
ip = strings.TrimSuffix(ip, "]")
return ip
}
ra, _, _ := net.SplitHostPort(c.request.RemoteAddr)
return ra
}
// Path returns the registered path for the handler.
func (c *DefaultContext) Path() string {
return c.path
}
// SetPath sets the registered path for the handler.
func (c *DefaultContext) SetPath(p string) {
c.path = p
}
// RouteInfo returns current request route information. Method, Path, Name and params if they exist for matched route.
// In case of 404 (route not found) and 405 (method not allowed) RouteInfo returns generic struct for these cases.
func (c *DefaultContext) RouteInfo() RouteInfo {
return c.route
}
// SetRouteInfo sets the route info of this request to the context.
func (c *DefaultContext) SetRouteInfo(ri RouteInfo) {
c.route = ri
}
// RawPathParams returns raw path pathParams value. Allocation of PathParams is handled by Context.
func (c *DefaultContext) RawPathParams() *PathParams {
return c.pathParams
}
// SetRawPathParams replaces any existing param values with new values for this context lifetime (request).
//
// DO NOT USE!
// Do not set any other value than what you got from RawPathParams as allocation of PathParams is handled by Context.
// If you mess up size of pathParams size your application will panic/crash during routing
func (c *DefaultContext) SetRawPathParams(params *PathParams) {
c.pathParams = params
}
// PathParam returns path parameter by name.
func (c *DefaultContext) PathParam(name string) string {
if c.currentParams != nil {
return c.currentParams.Get(name, "")
}
return c.pathParams.Get(name, "")
}
// PathParamDefault returns the path parameter or default value for the provided name.
func (c *DefaultContext) PathParamDefault(name, defaultValue string) string {
return c.pathParams.Get(name, defaultValue)
}
// PathParams returns path parameter values.
func (c *DefaultContext) PathParams() PathParams {
if c.currentParams != nil {
return c.currentParams
}
result := make(PathParams, len(*c.pathParams))
copy(result, *c.pathParams)
return result
}
// SetPathParams sets path parameters for current request.
func (c *DefaultContext) SetPathParams(params PathParams) {
c.currentParams = params
}
// QueryParam returns the query param for the provided name.
func (c *DefaultContext) QueryParam(name string) string {
if c.query == nil {
c.query = c.request.URL.Query()
}
return c.query.Get(name)
}
// QueryParamDefault returns the query param or default value for the provided name.
// Note: QueryParamDefault does not distinguish if query had no value by that name or value was empty string
// This means URLs `/test?search=` and `/test` would both return `1` for `c.QueryParamDefault("search", "1")`
func (c *DefaultContext) QueryParamDefault(name, defaultValue string) string {
value := c.QueryParam(name)
if value == "" {
value = defaultValue
}
return value
}
// QueryParams returns the query parameters as `url.Values`.
func (c *DefaultContext) QueryParams() url.Values {
if c.query == nil {
c.query = c.request.URL.Query()
}
return c.query
}
// QueryString returns the URL query string.
func (c *DefaultContext) QueryString() string {
return c.request.URL.RawQuery
}
// FormValue returns the form field value for the provided name.
func (c *DefaultContext) FormValue(name string) string {
return c.request.FormValue(name)
}
// FormValueDefault returns the form field value or default value for the provided name.
// Note: FormValueDefault does not distinguish if form had no value by that name or value was empty string
func (c *DefaultContext) FormValueDefault(name, defaultValue string) string {
value := c.FormValue(name)
if value == "" {
value = defaultValue
}
return value
}
// FormValues returns the form field values as `url.Values`.
func (c *DefaultContext) FormValues() (url.Values, error) {
if strings.HasPrefix(c.request.Header.Get(HeaderContentType), MIMEMultipartForm) {
if err := c.request.ParseMultipartForm(defaultMemory); err != nil {
return nil, err
}
} else {
if err := c.request.ParseForm(); err != nil {
return nil, err
}
}
return c.request.Form, nil
}
// FormFile returns the multipart form file for the provided name.
func (c *DefaultContext) FormFile(name string) (*multipart.FileHeader, error) {
f, fh, err := c.request.FormFile(name)
if err != nil {
return nil, err
}
f.Close()
return fh, nil
}
// MultipartForm returns the multipart form.
func (c *DefaultContext) MultipartForm() (*multipart.Form, error) {
err := c.request.ParseMultipartForm(defaultMemory)
return c.request.MultipartForm, err
}
// Cookie returns the named cookie provided in the request.
func (c *DefaultContext) Cookie(name string) (*http.Cookie, error) {
return c.request.Cookie(name)
}
// SetCookie adds a `Set-Cookie` header in HTTP response.
func (c *DefaultContext) SetCookie(cookie *http.Cookie) {
http.SetCookie(c.Response(), cookie)
}
// Cookies returns the HTTP cookies sent with the request.
func (c *DefaultContext) Cookies() []*http.Cookie {
return c.request.Cookies()
}
// Get retrieves data from the context.
func (c *DefaultContext) Get(key string) interface{} {
c.lock.RLock()
defer c.lock.RUnlock()
return c.store[key]
}
// Set saves data in the context.
func (c *DefaultContext) Set(key string, val interface{}) {
c.lock.Lock()
defer c.lock.Unlock()
if c.store == nil {
c.store = make(Map)
}
c.store[key] = val
}
// Bind binds path params, query params and the request body into provided type `i`. The default binder
// binds body based on Content-Type header.
func (c *DefaultContext) Bind(i interface{}) error {
return c.echo.Binder.Bind(c, i)
}
// Validate validates provided `i`. It is usually called after `Context#Bind()`.
// Validator must be registered using `Echo#Validator`.
func (c *DefaultContext) Validate(i interface{}) error {
if c.echo.Validator == nil {
return ErrValidatorNotRegistered
}
return c.echo.Validator.Validate(i)
}
// Render renders a template with data and sends a text/html response with status
// code. Renderer must be registered using `Echo.Renderer`.
func (c *DefaultContext) Render(code int, name string, data interface{}) (err error) {
if c.echo.Renderer == nil {
return ErrRendererNotRegistered
}
buf := new(bytes.Buffer)
if err = c.echo.Renderer.Render(buf, name, data, c); err != nil {
return
}
return c.HTMLBlob(code, buf.Bytes())
}
// HTML sends an HTTP response with status code.
func (c *DefaultContext) HTML(code int, html string) (err error) {
return c.HTMLBlob(code, []byte(html))
}
// HTMLBlob sends an HTTP blob response with status code.
func (c *DefaultContext) HTMLBlob(code int, b []byte) (err error) {
return c.Blob(code, MIMETextHTMLCharsetUTF8, b)
}
// String sends a string response with status code.
func (c *DefaultContext) String(code int, s string) (err error) {
return c.Blob(code, MIMETextPlainCharsetUTF8, []byte(s))
}
func (c *DefaultContext) jsonPBlob(code int, callback string, i interface{}) (err error) {
indent := ""
if _, pretty := c.QueryParams()["pretty"]; c.echo.Debug || pretty {
indent = defaultIndent
}
c.writeContentType(MIMEApplicationJavaScriptCharsetUTF8)
c.response.WriteHeader(code)
if _, err = c.response.Write([]byte(callback + "(")); err != nil {
return
}
if err = c.echo.JSONSerializer.Serialize(c, i, indent); err != nil {
return
}
if _, err = c.response.Write([]byte(");")); err != nil {
return
}
return
}
func (c *DefaultContext) json(code int, i interface{}, indent string) error {
c.writeContentType(MIMEApplicationJSONCharsetUTF8)
c.response.Status = code
return c.echo.JSONSerializer.Serialize(c, i, indent)
}
// JSON sends a JSON response with status code.
func (c *DefaultContext) JSON(code int, i interface{}) (err error) {
indent := ""
if _, pretty := c.QueryParams()["pretty"]; c.echo.Debug || pretty {
indent = defaultIndent
}
return c.json(code, i, indent)
}
// JSONPretty sends a pretty-print JSON with status code.
func (c *DefaultContext) JSONPretty(code int, i interface{}, indent string) (err error) {
return c.json(code, i, indent)
}
// JSONBlob sends a JSON blob response with status code.
func (c *DefaultContext) JSONBlob(code int, b []byte) (err error) {
return c.Blob(code, MIMEApplicationJSONCharsetUTF8, b)
}
// JSONP sends a JSONP response with status code. It uses `callback` to construct
// the JSONP payload.
func (c *DefaultContext) JSONP(code int, callback string, i interface{}) (err error) {
return c.jsonPBlob(code, callback, i)
}
// JSONPBlob sends a JSONP blob response with status code. It uses `callback`
// to construct the JSONP payload.
func (c *DefaultContext) JSONPBlob(code int, callback string, b []byte) (err error) {
c.writeContentType(MIMEApplicationJavaScriptCharsetUTF8)
c.response.WriteHeader(code)
if _, err = c.response.Write([]byte(callback + "(")); err != nil {
return
}
if _, err = c.response.Write(b); err != nil {
return
}
_, err = c.response.Write([]byte(");"))
return
}
func (c *DefaultContext) xml(code int, i interface{}, indent string) (err error) {
c.writeContentType(MIMEApplicationXMLCharsetUTF8)
c.response.WriteHeader(code)
enc := xml.NewEncoder(c.response)
if indent != "" {
enc.Indent("", indent)
}
if _, err = c.response.Write([]byte(xml.Header)); err != nil {
return
}
return enc.Encode(i)
}
// XML sends an XML response with status code.
func (c *DefaultContext) XML(code int, i interface{}) (err error) {
indent := ""
if _, pretty := c.QueryParams()["pretty"]; c.echo.Debug || pretty {
indent = defaultIndent
}
return c.xml(code, i, indent)
}
// XMLPretty sends a pretty-print XML with status code.
func (c *DefaultContext) XMLPretty(code int, i interface{}, indent string) (err error) {
return c.xml(code, i, indent)
}
// XMLBlob sends an XML blob response with status code.
func (c *DefaultContext) XMLBlob(code int, b []byte) (err error) {
c.writeContentType(MIMEApplicationXMLCharsetUTF8)
c.response.WriteHeader(code)
if _, err = c.response.Write([]byte(xml.Header)); err != nil {
return
}
_, err = c.response.Write(b)
return
}
// Blob sends a blob response with status code and content type.
func (c *DefaultContext) Blob(code int, contentType string, b []byte) (err error) {
c.writeContentType(contentType)
c.response.WriteHeader(code)
_, err = c.response.Write(b)
return
}
// Stream sends a streaming response with status code and content type.
func (c *DefaultContext) Stream(code int, contentType string, r io.Reader) (err error) {
c.writeContentType(contentType)
c.response.WriteHeader(code)
_, err = io.Copy(c.response, r)
return
}
// File sends a response with the content of the file.
func (c *DefaultContext) File(file string) error {
return fsFile(c, file, c.echo.Filesystem)
}
// FileFS serves file from given file system.
//
// When dealing with `embed.FS` use `fs := echo.MustSubFS(fs, "rootDirectory") to create sub fs which uses necessary
// prefix for directory path. This is necessary as `//go:embed assets/images` embeds files with paths
// including `assets/images` as their prefix.
func (c *DefaultContext) FileFS(file string, filesystem fs.FS) error {
return fsFile(c, file, filesystem)
}
func fsFile(c Context, file string, filesystem fs.FS) error {
f, err := filesystem.Open(file)
if err != nil {
return ErrNotFound
}
defer f.Close()
fi, _ := f.Stat()
if fi.IsDir() {
file = filepath.ToSlash(filepath.Join(file, indexPage)) // ToSlash is necessary for Windows. fs.Open and os.Open are different in that aspect.
f, err = filesystem.Open(file)
if err != nil {
return ErrNotFound
}
defer f.Close()
if fi, err = f.Stat(); err != nil {
return err
}
}
ff, ok := f.(io.ReadSeeker)
if !ok {
return errors.New("file does not implement io.ReadSeeker")
}
http.ServeContent(c.Response(), c.Request(), fi.Name(), fi.ModTime(), ff)
return nil
}
// Attachment sends a response as attachment, prompting client to save the file.
func (c *DefaultContext) Attachment(file, name string) error {
return c.contentDisposition(file, name, "attachment")
}
// Inline sends a response as inline, opening the file in the browser.
func (c *DefaultContext) Inline(file, name string) error {
return c.contentDisposition(file, name, "inline")
}
func (c *DefaultContext) contentDisposition(file, name, dispositionType string) error {
c.response.Header().Set(HeaderContentDisposition, fmt.Sprintf("%s; filename=%q", dispositionType, name))
return c.File(file)
}
// NoContent sends a response with no body and a status code.
func (c *DefaultContext) NoContent(code int) error {
c.response.WriteHeader(code)
return nil
}
// Redirect redirects the request to a provided URL with status code.
func (c *DefaultContext) Redirect(code int, url string) error {
if code < 300 || code > 308 {
return ErrInvalidRedirectCode
}
c.response.Header().Set(HeaderLocation, url)
c.response.WriteHeader(code)
return nil
}
// Error invokes the registered global HTTP error handler. Generally used by middleware.
// A side-effect of calling global error handler is that now Response has been committed (sent to the client) and
// middlewares up in chain can not change Response status code or Response body anymore.
//
// Avoid using this method in handlers as no middleware will be able to effectively handle errors after that.
// Instead of calling this method in handler return your error and let it be handled by middlewares or global error handler.
func (c *DefaultContext) Error(err error) {
c.echo.HTTPErrorHandler(c, err)
}
// Echo returns the `Echo` instance.
func (c *DefaultContext) Echo() *Echo {
return c.echo
}