package echo
import (
"bytes"
"encoding/json"
"encoding/xml"
"fmt"
"io"
"mime/multipart"
"net"
"net/http"
"net/url"
"os"
"path/filepath"
"strings"
"sync"
)
type (
// Context represents the context of the current HTTP request. It holds request and
// response objects, path, path parameters, data and registered handler.
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.
RealIP() string
// Path returns the registered path for the handler.
Path() string
// SetPath sets the registered path for the handler.
SetPath(p string)
// Param returns path parameter by name.
Param(name string) string
// ParamNames returns path parameter names.
ParamNames() []string
// SetParamNames sets path parameter names.
SetParamNames(names ...string)
// ParamValues returns path parameter values.
ParamValues() []string
// SetParamValues sets path parameter values.
SetParamValues(values ...string)
// QueryParam returns the query param for the provided name.
QueryParam(name 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
// FormParams returns the form parameters as `url.Values`.
FormParams() (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 the request body into provided type `i`. The default binder
// does it 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
// 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 HTTP error handler. Generally used by middleware.
Error(err error)
// Handler returns the matched handler by router.
Handler() HandlerFunc
// SetHandler sets the matched handler by router.
SetHandler(h HandlerFunc)
// Logger returns the `Logger` instance.
Logger() Logger
// Echo returns the `Echo` instance.
Echo() *Echo
// 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)
}
context struct {
request *http.Request
response *Response
path string
pnames []string
pvalues []string
query url.Values
handler HandlerFunc
store Map
echo *Echo
lock sync.RWMutex
}
)
const (
defaultMemory = 32 << 20 // 32 MB
indexPage = "index.html"
defaultIndent = " "
)
func (c *context) writeContentType(value string) {
header := c.Response().Header()
if header.Get(HeaderContentType) == "" {
header.Set(HeaderContentType, value)
}
}
func (c *context) Request() *http.Request {
return c.request
}
func (c *context) SetRequest(r *http.Request) {
c.request = r
}
func (c *context) Response() *Response {
return c.response
}
func (c *context) SetResponse(r *Response) {
c.response = r
}
func (c *context) IsTLS() bool {
return c.request.TLS != nil
}
func (c *context) IsWebSocket() bool {
upgrade := c.request.Header.Get(HeaderUpgrade)
return strings.ToLower(upgrade) == "websocket"
}
func (c *context) 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"
}
func (c *context) RealIP() string {
if ip := c.request.Header.Get(HeaderXForwardedFor); ip != "" {
return strings.Split(ip, ", ")[0]
}
if ip := c.request.Header.Get(HeaderXRealIP); ip != "" {
return ip
}
ra, _, _ := net.SplitHostPort(c.request.RemoteAddr)
return ra
}
func (c *context) Path() string {
return c.path
}
func (c *context) SetPath(p string) {
c.path = p
}
func (c *context) Param(name string) string {
for i, n := range c.pnames {
if i < len(c.pvalues) {
if n == name {
return c.pvalues[i]
}
}
}
return ""
}
func (c *context) ParamNames() []string {
return c.pnames
}
func (c *context) SetParamNames(names ...string) {
c.pnames = names
}
func (c *context) ParamValues() []string {
return c.pvalues[:len(c.pnames)]
}
func (c *context) SetParamValues(values ...string) {
c.pvalues = values
}
func (c *context) QueryParam(name string) string {
if c.query == nil {
c.query = c.request.URL.Query()
}
return c.query.Get(name)
}
func (c *context) QueryParams() url.Values {
if c.query == nil {
c.query = c.request.URL.Query()
}
return c.query
}
func (c *context) QueryString() string {
return c.request.URL.RawQuery
}
func (c *context) FormValue(name string) string {
return c.request.FormValue(name)
}
func (c *context) FormParams() (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
}
func (c *context) FormFile(name string) (*multipart.FileHeader, error) {
_, fh, err := c.request.FormFile(name)
return fh, err
}
func (c *context) MultipartForm() (*multipart.Form, error) {
err := c.request.ParseMultipartForm(defaultMemory)
return c.request.MultipartForm, err
}
func (c *context) Cookie(name string) (*http.Cookie, error) {
return c.request.Cookie(name)
}
func (c *context) SetCookie(cookie *http.Cookie) {
http.SetCookie(c.Response(), cookie)
}
func (c *context) Cookies() []*http.Cookie {
return c.request.Cookies()
}
func (c *context) Get(key string) interface{} {
c.lock.RLock()
defer c.lock.RUnlock()
return c.store[key]
}
func (c *context) Set(key string, val interface{}) {
c.lock.Lock()
defer c.lock.Unlock()
if c.store == nil {
c.store = make(Map)
}
c.store[key] = val
}
func (c *context) Bind(i interface{}) error {
return c.echo.Binder.Bind(i, c)
}
func (c *context) Validate(i interface{}) error {
if c.echo.Validator == nil {
return ErrValidatorNotRegistered
}
return c.echo.Validator.Validate(i)
}
func (c *context) 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())
}
func (c *context) HTML(code int, html string) (err error) {
return c.HTMLBlob(code, []byte(html))
}
func (c *context) HTMLBlob(code int, b []byte) (err error) {
return c.Blob(code, MIMETextHTMLCharsetUTF8, b)
}
func (c *context) String(code int, s string) (err error) {
return c.Blob(code, MIMETextPlainCharsetUTF8, []byte(s))
}
func (c *context) jsonPBlob(code int, callback string, i interface{}) (err error) {
enc := json.NewEncoder(c.response)
_, pretty := c.QueryParams()["pretty"]
if c.echo.Debug || pretty {
enc.SetIndent("", " ")
}
c.writeContentType(MIMEApplicationJavaScriptCharsetUTF8)
c.response.WriteHeader(code)
if _, err = c.response.Write([]byte(callback + "(")); err != nil {
return
}
if err = enc.Encode(i); err != nil {
return
}
if _, err = c.response.Write([]byte(");")); err != nil {
return
}
return
}
func (c *context) json(code int, i interface{}, indent string) error {
enc := json.NewEncoder(c.response)
if indent != "" {
enc.SetIndent("", indent)
}
c.writeContentType(MIMEApplicationJSONCharsetUTF8)
c.response.Status = code
return enc.Encode(i)
}
func (c *context) 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)
}
func (c *context) JSONPretty(code int, i interface{}, indent string) (err error) {
return c.json(code, i, indent)
}
func (c *context) JSONBlob(code int, b []byte) (err error) {
return c.Blob(code, MIMEApplicationJSONCharsetUTF8, b)
}
func (c *context) JSONP(code int, callback string, i interface{}) (err error) {
return c.jsonPBlob(code, callback, i)
}
func (c *context) 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 *context) 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)
}
func (c *context) 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)
}
func (c *context) XMLPretty(code int, i interface{}, indent string) (err error) {
return c.xml(code, i, indent)
}
func (c *context) 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
}
func (c *context) Blob(code int, contentType string, b []byte) (err error) {
c.writeContentType(contentType)
c.response.WriteHeader(code)
_, err = c.response.Write(b)
return
}
func (c *context) Stream(code int, contentType string, r io.Reader) (err error) {
c.writeContentType(contentType)
c.response.WriteHeader(code)
_, err = io.Copy(c.response, r)
return
}
func (c *context) File(file string) (err error) {
f, err := os.Open(file)
if err != nil {
return NotFoundHandler(c)
}
defer f.Close()
fi, _ := f.Stat()
if fi.IsDir() {
file = filepath.Join(file, indexPage)
f, err = os.Open(file)
if err != nil {
return NotFoundHandler(c)
}
defer f.Close()
if fi, err = f.Stat(); err != nil {
return
}
}
http.ServeContent(c.Response(), c.Request(), fi.Name(), fi.ModTime(), f)
return
}
func (c *context) Attachment(file, name string) error {
return c.contentDisposition(file, name, "attachment")
}
func (c *context) Inline(file, name string) error {
return c.contentDisposition(file, name, "inline")
}
func (c *context) contentDisposition(file, name, dispositionType string) error {
c.response.Header().Set(HeaderContentDisposition, fmt.Sprintf("%s; filename=%q", dispositionType, name))
return c.File(file)
}
func (c *context) NoContent(code int) error {
c.response.WriteHeader(code)
return nil
}
func (c *context) 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
}
func (c *context) Error(err error) {
c.echo.HTTPErrorHandler(err, c)
}
func (c *context) Echo() *Echo {
return c.echo
}
func (c *context) Handler() HandlerFunc {
return c.handler
}
func (c *context) SetHandler(h HandlerFunc) {
c.handler = h
}
func (c *context) Logger() Logger {
return c.echo.Logger
}
func (c *context) Reset(r *http.Request, w http.ResponseWriter) {
c.request = r
c.response.reset(w)
c.query = nil
c.handler = NotFoundHandler
c.store = nil
c.path = ""
c.pnames = nil
// NOTE: Don't reset because it has to have length c.echo.maxParam at all times
// c.pvalues = nil
}