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// Copyright 2012 The Gorilla Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package mux
import (
"errors"
"fmt"
"net/http"
"net/url"
"regexp"
"strings"
)
// Route stores information to match a request and build URLs.
type Route struct {
// Parent where the route was registered (a Router).
parent parentRoute
// Request handler for the route.
handler http.Handler
// List of matchers.
matchers []matcher
// Manager for the variables from host and path.
regexp *routeRegexpGroup
// If true, when the path pattern is "/path/", accessing "/path" will
// redirect to the former and vice versa.
strictSlash bool
// If true, when the path pattern is "/path//to", accessing "/path//to"
// will not redirect
skipClean bool
// If true, "/path/foo%2Fbar/to" will match the path "/path/{var}/to"
useEncodedPath bool
// The scheme used when building URLs.
buildScheme string
// If true, this route never matches: it is only used to build URLs.
buildOnly bool
// The name used to build URLs.
name string
// Error resulted from building a route.
err error
buildVarsFunc BuildVarsFunc
}
// SkipClean reports whether path cleaning is enabled for this route via
// Router.SkipClean.
func (r *Route) SkipClean() bool {
return r.skipClean
}
// Match matches the route against the request.
func (r *Route) Match(req *http.Request, match *RouteMatch) bool {
if r.buildOnly || r.err != nil {
return false
}
var matchErr error
// Match everything.
for _, m := range r.matchers {
if matched := m.Match(req, match); !matched {
if _, ok := m.(methodMatcher); ok {
matchErr = ErrMethodMismatch
continue
}
matchErr = nil
return false
}
}
if matchErr != nil {
match.MatchErr = matchErr
return false
}
if match.MatchErr == ErrMethodMismatch {
// We found a route which matches request method, clear MatchErr
match.MatchErr = nil
// Then override the mis-matched handler
match.Handler = r.handler
}
// Yay, we have a match. Let's collect some info about it.
if match.Route == nil {
match.Route = r
}
if match.Handler == nil {
match.Handler = r.handler
}
if match.Vars == nil {
match.Vars = make(map[string]string)
}
// Set variables.
if r.regexp != nil {
r.regexp.setMatch(req, match, r)
}
return true
}
// ----------------------------------------------------------------------------
// Route attributes
// ----------------------------------------------------------------------------
// GetError returns an error resulted from building the route, if any.
func (r *Route) GetError() error {
return r.err
}
// BuildOnly sets the route to never match: it is only used to build URLs.
func (r *Route) BuildOnly() *Route {
r.buildOnly = true
return r
}
// Handler --------------------------------------------------------------------
// Handler sets a handler for the route.
func (r *Route) Handler(handler http.Handler) *Route {
if r.err == nil {
r.handler = handler
}
return r
}
// HandlerFunc sets a handler function for the route.
func (r *Route) HandlerFunc(f func(http.ResponseWriter, *http.Request)) *Route {
return r.Handler(http.HandlerFunc(f))
}
// GetHandler returns the handler for the route, if any.
func (r *Route) GetHandler() http.Handler {
return r.handler
}
// Name -----------------------------------------------------------------------
// Name sets the name for the route, used to build URLs.
// It is an error to call Name more than once on a route.
func (r *Route) Name(name string) *Route {
if r.name != "" {
r.err = fmt.Errorf("mux: route already has name %q, can't set %q",
r.name, name)
}
if r.err == nil {
r.name = name
r.getNamedRoutes()[name] = r
}
return r
}
// GetName returns the name for the route, if any.
func (r *Route) GetName() string {
return r.name
}
// ----------------------------------------------------------------------------
// Matchers
// ----------------------------------------------------------------------------
// matcher types try to match a request.
type matcher interface {
Match(*http.Request, *RouteMatch) bool
}
// addMatcher adds a matcher to the route.
func (r *Route) addMatcher(m matcher) *Route {
if r.err == nil {
r.matchers = append(r.matchers, m)
}
return r
}
// addRegexpMatcher adds a host or path matcher and builder to a route.
func (r *Route) addRegexpMatcher(tpl string, typ regexpType) error {
if r.err != nil {
return r.err
}
r.regexp = r.getRegexpGroup()
if typ == regexpTypePath || typ == regexpTypePrefix {
if len(tpl) > 0 && tpl[0] != '/' {
return fmt.Errorf("mux: path must start with a slash, got %q", tpl)
}
if r.regexp.path != nil {
tpl = strings.TrimRight(r.regexp.path.template, "/") + tpl
}
}
rr, err := newRouteRegexp(tpl, typ, routeRegexpOptions{
strictSlash: r.strictSlash,
useEncodedPath: r.useEncodedPath,
})
if err != nil {
return err
}
for _, q := range r.regexp.queries {
if err = uniqueVars(rr.varsN, q.varsN); err != nil {
return err
}
}
if typ == regexpTypeHost {
if r.regexp.path != nil {
if err = uniqueVars(rr.varsN, r.regexp.path.varsN); err != nil {
return err
}
}
r.regexp.host = rr
} else {
if r.regexp.host != nil {
if err = uniqueVars(rr.varsN, r.regexp.host.varsN); err != nil {
return err
}
}
if typ == regexpTypeQuery {
r.regexp.queries = append(r.regexp.queries, rr)
} else {
r.regexp.path = rr
}
}
r.addMatcher(rr)
return nil
}
// Headers --------------------------------------------------------------------
// headerMatcher matches the request against header values.
type headerMatcher map[string]string
func (m headerMatcher) Match(r *http.Request, match *RouteMatch) bool {
return matchMapWithString(m, r.Header, true)
}
// Headers adds a matcher for request header values.
// It accepts a sequence of key/value pairs to be matched. For example:
//
// r := mux.NewRouter()
// r.Headers("Content-Type", "application/json",
// "X-Requested-With", "XMLHttpRequest")
//
// The above route will only match if both request header values match.
// If the value is an empty string, it will match any value if the key is set.
func (r *Route) Headers(pairs ...string) *Route {
if r.err == nil {
var headers map[string]string
headers, r.err = mapFromPairsToString(pairs...)
return r.addMatcher(headerMatcher(headers))
}
return r
}
// headerRegexMatcher matches the request against the route given a regex for the header
type headerRegexMatcher map[string]*regexp.Regexp
func (m headerRegexMatcher) Match(r *http.Request, match *RouteMatch) bool {
return matchMapWithRegex(m, r.Header, true)
}
// HeadersRegexp accepts a sequence of key/value pairs, where the value has regex
// support. For example:
//
// r := mux.NewRouter()
// r.HeadersRegexp("Content-Type", "application/(text|json)",
// "X-Requested-With", "XMLHttpRequest")
//
// The above route will only match if both the request header matches both regular expressions.
// If the value is an empty string, it will match any value if the key is set.
// Use the start and end of string anchors (^ and $) to match an exact value.
func (r *Route) HeadersRegexp(pairs ...string) *Route {
if r.err == nil {
var headers map[string]*regexp.Regexp
headers, r.err = mapFromPairsToRegex(pairs...)
return r.addMatcher(headerRegexMatcher(headers))
}
return r
}
// Host -----------------------------------------------------------------------
// Host adds a matcher for the URL host.
// It accepts a template with zero or more URL variables enclosed by {}.
// Variables can define an optional regexp pattern to be matched:
//
// - {name} matches anything until the next dot.
//
// - {name:pattern} matches the given regexp pattern.
//
// For example:
//
// r := mux.NewRouter()
// r.Host("www.example.com")
// r.Host("{subdomain}.domain.com")
// r.Host("{subdomain:[a-z]+}.domain.com")
//
// Variable names must be unique in a given route. They can be retrieved
// calling mux.Vars(request).
func (r *Route) Host(tpl string) *Route {
r.err = r.addRegexpMatcher(tpl, regexpTypeHost)
return r
}
// MatcherFunc ----------------------------------------------------------------
// MatcherFunc is the function signature used by custom matchers.
type MatcherFunc func(*http.Request, *RouteMatch) bool
// Match returns the match for a given request.
func (m MatcherFunc) Match(r *http.Request, match *RouteMatch) bool {
return m(r, match)
}
// MatcherFunc adds a custom function to be used as request matcher.
func (r *Route) MatcherFunc(f MatcherFunc) *Route {
return r.addMatcher(f)
}
// Methods --------------------------------------------------------------------
// methodMatcher matches the request against HTTP methods.
type methodMatcher []string
func (m methodMatcher) Match(r *http.Request, match *RouteMatch) bool {
return matchInArray(m, r.Method)
}
// Methods adds a matcher for HTTP methods.
// It accepts a sequence of one or more methods to be matched, e.g.:
// "GET", "POST", "PUT".
func (r *Route) Methods(methods ...string) *Route {
for k, v := range methods {
methods[k] = strings.ToUpper(v)
}
return r.addMatcher(methodMatcher(methods))
}
// Path -----------------------------------------------------------------------
// Path adds a matcher for the URL path.
// It accepts a template with zero or more URL variables enclosed by {}. The
// template must start with a "/".
// Variables can define an optional regexp pattern to be matched:
//
// - {name} matches anything until the next slash.
//
// - {name:pattern} matches the given regexp pattern.
//
// For example:
//
// r := mux.NewRouter()
// r.Path("/products/").Handler(ProductsHandler)
// r.Path("/products/{key}").Handler(ProductsHandler)
// r.Path("/articles/{category}/{id:[0-9]+}").
// Handler(ArticleHandler)
//
// Variable names must be unique in a given route. They can be retrieved
// calling mux.Vars(request).
func (r *Route) Path(tpl string) *Route {
r.err = r.addRegexpMatcher(tpl, regexpTypePath)
return r
}
// PathPrefix -----------------------------------------------------------------
// PathPrefix adds a matcher for the URL path prefix. This matches if the given
// template is a prefix of the full URL path. See Route.Path() for details on
// the tpl argument.
//
// Note that it does not treat slashes specially ("/foobar/" will be matched by
// the prefix "/foo") so you may want to use a trailing slash here.
//
// Also note that the setting of Router.StrictSlash() has no effect on routes
// with a PathPrefix matcher.
func (r *Route) PathPrefix(tpl string) *Route {
r.err = r.addRegexpMatcher(tpl, regexpTypePrefix)
return r
}
// Query ----------------------------------------------------------------------
// Queries adds a matcher for URL query values.
// It accepts a sequence of key/value pairs. Values may define variables.
// For example:
//
// r := mux.NewRouter()
// r.Queries("foo", "bar", "id", "{id:[0-9]+}")
//
// The above route will only match if the URL contains the defined queries
// values, e.g.: ?foo=bar&id=42.
//
// It the value is an empty string, it will match any value if the key is set.
//
// Variables can define an optional regexp pattern to be matched:
//
// - {name} matches anything until the next slash.
//
// - {name:pattern} matches the given regexp pattern.
func (r *Route) Queries(pairs ...string) *Route {
length := len(pairs)
if length%2 != 0 {
r.err = fmt.Errorf(
"mux: number of parameters must be multiple of 2, got %v", pairs)
return nil
}
for i := 0; i < length; i += 2 {
if r.err = r.addRegexpMatcher(pairs[i]+"="+pairs[i+1], regexpTypeQuery); r.err != nil {
return r
}
}
return r
}
// Schemes --------------------------------------------------------------------
// schemeMatcher matches the request against URL schemes.
type schemeMatcher []string
func (m schemeMatcher) Match(r *http.Request, match *RouteMatch) bool {
return matchInArray(m, r.URL.Scheme)
}
// Schemes adds a matcher for URL schemes.
// It accepts a sequence of schemes to be matched, e.g.: "http", "https".
func (r *Route) Schemes(schemes ...string) *Route {
for k, v := range schemes {
schemes[k] = strings.ToLower(v)
}
if r.buildScheme == "" && len(schemes) > 0 {
r.buildScheme = schemes[0]
}
return r.addMatcher(schemeMatcher(schemes))
}
// BuildVarsFunc --------------------------------------------------------------
// BuildVarsFunc is the function signature used by custom build variable
// functions (which can modify route variables before a route's URL is built).
type BuildVarsFunc func(map[string]string) map[string]string
// BuildVarsFunc adds a custom function to be used to modify build variables
// before a route's URL is built.
func (r *Route) BuildVarsFunc(f BuildVarsFunc) *Route {
r.buildVarsFunc = f
return r
}
// Subrouter ------------------------------------------------------------------
// Subrouter creates a subrouter for the route.
//
// It will test the inner routes only if the parent route matched. For example:
//
// r := mux.NewRouter()
// s := r.Host("www.example.com").Subrouter()
// s.HandleFunc("/products/", ProductsHandler)
// s.HandleFunc("/products/{key}", ProductHandler)
// s.HandleFunc("/articles/{category}/{id:[0-9]+}"), ArticleHandler)
//
// Here, the routes registered in the subrouter won't be tested if the host
// doesn't match.
func (r *Route) Subrouter() *Router {
router := &Router{parent: r, strictSlash: r.strictSlash}
r.addMatcher(router)
return router
}
// ----------------------------------------------------------------------------
// URL building
// ----------------------------------------------------------------------------
// URL builds a URL for the route.
//
// It accepts a sequence of key/value pairs for the route variables. For
// example, given this route:
//
// r := mux.NewRouter()
// r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
// Name("article")
//
// ...a URL for it can be built using:
//
// url, err := r.Get("article").URL("category", "technology", "id", "42")
//
// ...which will return an url.URL with the following path:
//
// "/articles/technology/42"
//
// This also works for host variables:
//
// r := mux.NewRouter()
// r.Host("{subdomain}.domain.com").
// HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
// Name("article")
//
// // url.String() will be "http://news.domain.com/articles/technology/42"
// url, err := r.Get("article").URL("subdomain", "news",
// "category", "technology",
// "id", "42")
//
// All variables defined in the route are required, and their values must
// conform to the corresponding patterns.
func (r *Route) URL(pairs ...string) (*url.URL, error) {
if r.err != nil {
return nil, r.err
}
if r.regexp == nil {
return nil, errors.New("mux: route doesn't have a host or path")
}
values, err := r.prepareVars(pairs...)
if err != nil {
return nil, err
}
var scheme, host, path string
queries := make([]string, 0, len(r.regexp.queries))
if r.regexp.host != nil {
if host, err = r.regexp.host.url(values); err != nil {
return nil, err
}
scheme = "http"
if s := r.getBuildScheme(); s != "" {
scheme = s
}
}
if r.regexp.path != nil {
if path, err = r.regexp.path.url(values); err != nil {
return nil, err
}
}
for _, q := range r.regexp.queries {
var query string
if query, err = q.url(values); err != nil {
return nil, err
}
queries = append(queries, query)
}
return &url.URL{
Scheme: scheme,
Host: host,
Path: path,
RawQuery: strings.Join(queries, "&"),
}, nil
}
// URLHost builds the host part of the URL for a route. See Route.URL().
//
// The route must have a host defined.
func (r *Route) URLHost(pairs ...string) (*url.URL, error) {
if r.err != nil {
return nil, r.err
}
if r.regexp == nil || r.regexp.host == nil {
return nil, errors.New("mux: route doesn't have a host")
}
values, err := r.prepareVars(pairs...)
if err != nil {
return nil, err
}
host, err := r.regexp.host.url(values)
if err != nil {
return nil, err
}
u := &url.URL{
Scheme: "http",
Host: host,
}
if s := r.getBuildScheme(); s != "" {
u.Scheme = s
}
return u, nil
}
// URLPath builds the path part of the URL for a route. See Route.URL().
//
// The route must have a path defined.
func (r *Route) URLPath(pairs ...string) (*url.URL, error) {
if r.err != nil {
return nil, r.err
}
if r.regexp == nil || r.regexp.path == nil {
return nil, errors.New("mux: route doesn't have a path")
}
values, err := r.prepareVars(pairs...)
if err != nil {
return nil, err
}
path, err := r.regexp.path.url(values)
if err != nil {
return nil, err
}
return &url.URL{
Path: path,
}, nil
}
// GetPathTemplate returns the template used to build the
// route match.
// This is useful for building simple REST API documentation and for instrumentation
// against third-party services.
// An error will be returned if the route does not define a path.
func (r *Route) GetPathTemplate() (string, error) {
if r.err != nil {
return "", r.err
}
if r.regexp == nil || r.regexp.path == nil {
return "", errors.New("mux: route doesn't have a path")
}
return r.regexp.path.template, nil
}
// GetPathRegexp returns the expanded regular expression used to match route path.
// This is useful for building simple REST API documentation and for instrumentation
// against third-party services.
// An error will be returned if the route does not define a path.
func (r *Route) GetPathRegexp() (string, error) {
if r.err != nil {
return "", r.err
}
if r.regexp == nil || r.regexp.path == nil {
return "", errors.New("mux: route does not have a path")
}
return r.regexp.path.regexp.String(), nil
}
// GetQueriesRegexp returns the expanded regular expressions used to match the
// route queries.
// This is useful for building simple REST API documentation and for instrumentation
// against third-party services.
// An error will be returned if the route does not have queries.
func (r *Route) GetQueriesRegexp() ([]string, error) {
if r.err != nil {
return nil, r.err
}
if r.regexp == nil || r.regexp.queries == nil {
return nil, errors.New("mux: route doesn't have queries")
}
var queries []string
for _, query := range r.regexp.queries {
queries = append(queries, query.regexp.String())
}
return queries, nil
}
// GetQueriesTemplates returns the templates used to build the
// query matching.
// This is useful for building simple REST API documentation and for instrumentation
// against third-party services.
// An error will be returned if the route does not define queries.
func (r *Route) GetQueriesTemplates() ([]string, error) {
if r.err != nil {
return nil, r.err
}
if r.regexp == nil || r.regexp.queries == nil {
return nil, errors.New("mux: route doesn't have queries")
}
var queries []string
for _, query := range r.regexp.queries {
queries = append(queries, query.template)
}
return queries, nil
}
// GetMethods returns the methods the route matches against
// This is useful for building simple REST API documentation and for instrumentation
// against third-party services.
// An error will be returned if route does not have methods.
func (r *Route) GetMethods() ([]string, error) {
if r.err != nil {
return nil, r.err
}
for _, m := range r.matchers {
if methods, ok := m.(methodMatcher); ok {
return []string(methods), nil
}
}
return nil, errors.New("mux: route doesn't have methods")
}
// GetHostTemplate returns the template used to build the
// route match.
// This is useful for building simple REST API documentation and for instrumentation
// against third-party services.
// An error will be returned if the route does not define a host.
func (r *Route) GetHostTemplate() (string, error) {
if r.err != nil {
return "", r.err
}
if r.regexp == nil || r.regexp.host == nil {
return "", errors.New("mux: route doesn't have a host")
}
return r.regexp.host.template, nil
}
// prepareVars converts the route variable pairs into a map. If the route has a
// BuildVarsFunc, it is invoked.
func (r *Route) prepareVars(pairs ...string) (map[string]string, error) {
m, err := mapFromPairsToString(pairs...)
if err != nil {
return nil, err
}
return r.buildVars(m), nil
}
func (r *Route) buildVars(m map[string]string) map[string]string {
if r.parent != nil {
m = r.parent.buildVars(m)
}
if r.buildVarsFunc != nil {
m = r.buildVarsFunc(m)
}
return m
}
// ----------------------------------------------------------------------------
// parentRoute
// ----------------------------------------------------------------------------
// parentRoute allows routes to know about parent host and path definitions.
type parentRoute interface {
getBuildScheme() string
getNamedRoutes() map[string]*Route
getRegexpGroup() *routeRegexpGroup
buildVars(map[string]string) map[string]string
}
func (r *Route) getBuildScheme() string {
if r.buildScheme != "" {
return r.buildScheme
}
if r.parent != nil {
return r.parent.getBuildScheme()
}
return ""
}
// getNamedRoutes returns the map where named routes are registered.
func (r *Route) getNamedRoutes() map[string]*Route {
if r.parent == nil {
// During tests router is not always set.
r.parent = NewRouter()
}
return r.parent.getNamedRoutes()
}
// getRegexpGroup returns regexp definitions from this route.
func (r *Route) getRegexpGroup() *routeRegexpGroup {
if r.regexp == nil {
if r.parent == nil {
// During tests router is not always set.
r.parent = NewRouter()
}
regexp := r.parent.getRegexpGroup()
if regexp == nil {
r.regexp = new(routeRegexpGroup)
} else {
// Copy.
r.regexp = &routeRegexpGroup{
host: regexp.host,
path: regexp.path,
queries: regexp.queries,
}
}
}
return r.regexp
}