mux – github.com/gorilla/mux Index | Examples | Files

package mux

import "github.com/gorilla/mux"

Package mux implements a request router and dispatcher.

The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are:

Let's start registering a couple of URL paths and handlers: 

func main() {
	r := mux.NewRouter()
	r.HandleFunc("/", HomeHandler)
	r.HandleFunc("/products", ProductsHandler)
	r.HandleFunc("/articles", ArticlesHandler)
	http.Handle("/", r)
}

Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters.

Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: 

r := mux.NewRouter()
r.HandleFunc("/products/{key}", ProductHandler)
r.HandleFunc("/articles/{category}/", ArticlesCategoryHandler)
r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)

Groups can be used inside patterns, as long as they are non-capturing (?:re). For example: 

r.HandleFunc("/articles/{category}/{sort:(?:asc|desc|new)}", ArticlesCategoryHandler)

The names are used to create a map of route variables which can be retrieved calling mux.Vars(): 

vars := mux.Vars(request)
category := vars["category"]

Note that if any capturing groups are present, mux will panic() during parsing. To prevent this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to "/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably when capturing groups were present.

And this is all you need to know about the basic usage. More advanced options are explained below.

Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: 

r := mux.NewRouter()
// Only matches if domain is "www.example.com".
r.Host("www.example.com")
// Matches a dynamic subdomain.
r.Host("{subdomain:[a-z]+}.domain.com")

There are several other matchers that can be added. To match path prefixes: 

r.PathPrefix("/products/")

...or HTTP methods: 

r.Methods("GET", "POST")

...or URL schemes: 

r.Schemes("https")

...or header values: 

r.Headers("X-Requested-With", "XMLHttpRequest")

...or query values: 

r.Queries("key", "value")

...or to use a custom matcher function: 

r.MatcherFunc(func(r *http.Request, rm *RouteMatch) bool {
	return r.ProtoMajor == 0
})

...and finally, it is possible to combine several matchers in a single route: 

r.HandleFunc("/products", ProductsHandler).
  Host("www.example.com").
  Methods("GET").
  Schemes("http")

Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting".

For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: 

r := mux.NewRouter()
s := r.Host("www.example.com").Subrouter()

Then register routes in the subrouter: 

s.HandleFunc("/products/", ProductsHandler)
s.HandleFunc("/products/{key}", ProductHandler)
s.HandleFunc("/articles/{category}/{id:[0-9]+}"), ArticleHandler)

The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route.

Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter.

There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: 

r := mux.NewRouter()
s := r.PathPrefix("/products").Subrouter()
// "/products/"
s.HandleFunc("/", ProductsHandler)
// "/products/{key}/"
s.HandleFunc("/{key}/", ProductHandler)
// "/products/{key}/details"
s.HandleFunc("/{key}/details", ProductDetailsHandler)

Note that the path provided to PathPrefix() represents a "wildcard": calling PathPrefix("/static/").Handler(...) means that the handler will be passed any request that matches "/static/*". This makes it easy to serve static files with mux: 

func main() {
	var dir string

	flag.StringVar(&dir, "dir", ".", "the directory to serve files from. Defaults to the current dir")
	flag.Parse()
	r := mux.NewRouter()

	// This will serve files under http://localhost:8000/static/<filename>
	r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir(dir))))

	srv := &http.Server{
		Handler:      r,
		Addr:         "127.0.0.1:8000",
		// Good practice: enforce timeouts for servers you create!
		WriteTimeout: 15 * time.Second,
		ReadTimeout:  15 * time.Second,
	}

	log.Fatal(srv.ListenAndServe())
}

Now let's see how to build registered URLs.

Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: 

r := mux.NewRouter()
r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
  Name("article")

To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: 

url, err := r.Get("article").URL("category", "technology", "id", "42")

...and the result will be a url.URL with the following path: 

"/articles/technology/42"

This also works for host and query value variables: 

r := mux.NewRouter()
r.Host("{subdomain}.domain.com").
  Path("/articles/{category}/{id:[0-9]+}").
  Queries("filter", "{filter}").
  HandlerFunc(ArticleHandler).
  Name("article")

// url.String() will be "http://news.domain.com/articles/technology/42?filter=gorilla"
url, err := r.Get("article").URL("subdomain", "news",
                                 "category", "technology",
                                 "id", "42",
                                 "filter", "gorilla")

All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match.

Regex support also exists for matching Headers within a route. For example, we could do: 

r.HeadersRegexp("Content-Type", "application/(text|json)")

...and the route will match both requests with a Content-Type of `application/json` as well as `application/text`

There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: 

// "http://news.domain.com/"
host, err := r.Get("article").URLHost("subdomain", "news")

// "/articles/technology/42"
path, err := r.Get("article").URLPath("category", "technology", "id", "42")

And if you use subrouters, host and path defined separately can be built as well: 

r := mux.NewRouter()
s := r.Host("{subdomain}.domain.com").Subrouter()
s.Path("/articles/{category}/{id:[0-9]+}").
  HandlerFunc(ArticleHandler).
  Name("article")

// "http://news.domain.com/articles/technology/42"
url, err := r.Get("article").URL("subdomain", "news",
                                 "category", "technology",
                                 "id", "42")

Mux supports the addition of middlewares to a Router, which are executed in the order they are added if a match is found, including its subrouters. Middlewares are (typically) small pieces of code which take one request, do something with it, and pass it down to another middleware or the final handler. Some common use cases for middleware are request logging, header manipulation, or ResponseWriter hijacking. 

type MiddlewareFunc func(http.Handler) http.Handler

Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc (closures can access variables from the context where they are created).

A very basic middleware which logs the URI of the request being handled could be written as: 

func simpleMw(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Do stuff here
		log.Println(r.RequestURI)
		// Call the next handler, which can be another middleware in the chain, or the final handler.
		next.ServeHTTP(w, r)
	})
}

Middlewares can be added to a router using `Router.Use()`: 

r := mux.NewRouter()
r.HandleFunc("/", handler)
r.Use(simpleMw)

A more complex authentication middleware, which maps session token to users, could be written as: 

// Define our struct
type authenticationMiddleware struct {
	tokenUsers map[string]string
}

// Initialize it somewhere
func (amw *authenticationMiddleware) Populate() {
	amw.tokenUsers["00000000"] = "user0"
	amw.tokenUsers["aaaaaaaa"] = "userA"
	amw.tokenUsers["05f717e5"] = "randomUser"
	amw.tokenUsers["deadbeef"] = "user0"
}

// Middleware function, which will be called for each request
func (amw *authenticationMiddleware) Middleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		token := r.Header.Get("X-Session-Token")

		if user, found := amw.tokenUsers[token]; found {
			// We found the token in our map
			log.Printf("Authenticated user %s\n", user)
			next.ServeHTTP(w, r)
		} else {
			http.Error(w, "Forbidden", http.StatusForbidden)
		}
	})
}

r := mux.NewRouter()
r.HandleFunc("/", handler)

amw := authenticationMiddleware{tokenUsers: make(map[string]string)}
amw.Populate()

r.Use(amw.Middleware)

Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to.

Example (AuthenticationMiddleware)

Code:play  

package main

import (
	"log"
	"net/http"

	"github.com/gorilla/mux"
)

// Define our struct
type authenticationMiddleware struct {
	tokenUsers map[string]string
}

// Initialize it somewhere
func (amw *authenticationMiddleware) Populate() {
	amw.tokenUsers["00000000"] = "user0"
	amw.tokenUsers["aaaaaaaa"] = "userA"
	amw.tokenUsers["05f717e5"] = "randomUser"
	amw.tokenUsers["deadbeef"] = "user0"
}

// Middleware function, which will be called for each request
func (amw *authenticationMiddleware) Middleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		token := r.Header.Get("X-Session-Token")

		if user, found := amw.tokenUsers[token]; found {
			// We found the token in our map
			log.Printf("Authenticated user %s\n", user)
			next.ServeHTTP(w, r)
		} else {
			http.Error(w, "Forbidden", http.StatusForbidden)
		}
	})
}

func main() {
	r := mux.NewRouter()
	r.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		// Do something here
	})
	amw := authenticationMiddleware{make(map[string]string)}
	amw.Populate()
	r.Use(amw.Middleware)
}

Index

Examples

Variables 

var (
	// ErrMethodMismatch is returned when the method in the request does not match
	// the method defined against the route.
	ErrMethodMismatch = errors.New("method is not allowed")
	// ErrNotFound is returned when no route match is found.
	ErrNotFound = errors.New("no matching route was found")
)
var SkipRouter = errors.New("skip this router")

SkipRouter is used as a return value from WalkFuncs to indicate that the router that walk is about to descend down to should be skipped.

Functions

func SetURLVars 

func SetURLVars(r *http.Request, val map[string]string) *http.Request

SetURLVars sets the URL variables for the given request, to be accessed via mux.Vars for testing route behaviour. Arguments are not modified, a shallow copy is returned.

This API should only be used for testing purposes; it provides a way to inject variables into the request context. Alternatively, URL variables can be set by making a route that captures the required variables, starting a server and sending the request to that server.

Example

Code: 

{
	req, _ := http.NewRequest("GET", "/foo", nil)
	req = SetURLVars(req, map[string]string{"foo": "bar"})

	fmt.Println(Vars(req)["foo"])

	// Output: bar
}

Output:

bar

func Vars 

func Vars(r *http.Request) map[string]string

Vars returns the route variables for the current request, if any.

Types

type BuildVarsFunc 

type BuildVarsFunc func(map[string]string) map[string]string

BuildVarsFunc is the function signature used by custom build variable functions (which can modify route variables before a route's URL is built).

type MatcherFunc 

type MatcherFunc func(*http.Request, *RouteMatch) bool

MatcherFunc is the function signature used by custom matchers.

func (MatcherFunc) Match 

func (m MatcherFunc) Match(r *http.Request, match *RouteMatch) bool

Match returns the match for a given request.

type MiddlewareFunc 

type MiddlewareFunc func(http.Handler) http.Handler

MiddlewareFunc is a function which receives an http.Handler and returns another http.Handler. Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc.

func CORSMethodMiddleware 

func CORSMethodMiddleware(r *Router) MiddlewareFunc

CORSMethodMiddleware automatically sets the Access-Control-Allow-Methods response header on requests for routes that have an OPTIONS method matcher to all the method matchers on the route. Routes that do not explicitly handle OPTIONS requests will not be processed by the middleware. See examples for usage.

Example

Code:play  

package main

import (
	"fmt"
	"net/http"
	"net/http/httptest"

	"github.com/gorilla/mux"
)

func main() {
	r := mux.NewRouter()

	r.HandleFunc("/foo", func(w http.ResponseWriter, r *http.Request) {
		// Handle the request
	}).Methods(http.MethodGet, http.MethodPut, http.MethodPatch)
	r.HandleFunc("/foo", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Access-Control-Allow-Origin", "http://example.com")
		w.Header().Set("Access-Control-Max-Age", "86400")
	}).Methods(http.MethodOptions)

	r.Use(mux.CORSMethodMiddleware(r))

	rw := httptest.NewRecorder()
	req, _ := http.NewRequest("OPTIONS", "/foo", nil)                 // needs to be OPTIONS
	req.Header.Set("Access-Control-Request-Method", "POST")           // needs to be non-empty
	req.Header.Set("Access-Control-Request-Headers", "Authorization") // needs to be non-empty
	req.Header.Set("Origin", "http://example.com")                    // needs to be non-empty

	r.ServeHTTP(rw, req)

	fmt.Println(rw.Header().Get("Access-Control-Allow-Methods"))
	fmt.Println(rw.Header().Get("Access-Control-Allow-Origin"))
}

Output:

GET,PUT,PATCH,OPTIONS
http://example.com

func (MiddlewareFunc) Middleware 

func (mw MiddlewareFunc) Middleware(handler http.Handler) http.Handler

Middleware allows MiddlewareFunc to implement the middleware interface.

type Route 

type Route struct {
	// contains filtered or unexported fields
}

Route stores information to match a request and build URLs.

func CurrentRoute 

func CurrentRoute(r *http.Request) *Route

CurrentRoute returns the matched route for the current request, if any. This only works when called inside the handler of the matched route because the matched route is stored in the request context which is cleared after the handler returns.

func (*Route) BuildOnly 

func (r *Route) BuildOnly() *Route

BuildOnly sets the route to never match: it is only used to build URLs.

func (*Route) BuildVarsFunc 

func (r *Route) BuildVarsFunc(f BuildVarsFunc) *Route

BuildVarsFunc adds a custom function to be used to modify build variables before a route's URL is built.

func (*Route) GetError 

func (r *Route) GetError() error

GetError returns an error resulted from building the route, if any.

func (*Route) GetHandler 

func (r *Route) GetHandler() http.Handler

GetHandler returns the handler for the route, if any.

func (*Route) GetHostTemplate 

func (r *Route) GetHostTemplate() (string, error)

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 (*Route) GetMethods 

func (r *Route) GetMethods() ([]string, error)

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 (*Route) GetName 

func (r *Route) GetName() string

GetName returns the name for the route, if any.

func (*Route) GetPathRegexp 

func (r *Route) GetPathRegexp() (string, error)

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 (*Route) GetPathTemplate 

func (r *Route) GetPathTemplate() (string, error)

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 (*Route) GetQueriesRegexp 

func (r *Route) GetQueriesRegexp() ([]string, error)

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 (*Route) GetQueriesTemplates 

func (r *Route) GetQueriesTemplates() ([]string, error)

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 (*Route) GetVarNames 

func (r *Route) GetVarNames() ([]string, error)

GetVarNames returns the names of all variables added by regexp matchers These can be used to know which route variables should be passed into r.URL()

Example

This example demonstrates building a dynamic URL using required vars and values retrieve from another source

Code:play  

package main

import (
	"fmt"
	"github.com/gorilla/mux"
)

func main() {
	r := mux.NewRouter()

	route := r.Host("{domain}").
		Path("/{group}/{item_id}").
		Queries("some_data1", "{some_data1}").
		Queries("some_data2_and_3", "{some_data2}.{some_data3}")

	dataSource := func(key string) string {
		return "my_value_for_" + key
	}

	varNames, _ := route.GetVarNames()

	pairs := make([]string, 0, len(varNames)*2)

	for _, varName := range varNames {
		pairs = append(pairs, varName, dataSource(varName))
	}

	url, err := route.URL(pairs...)
	if err != nil {
		panic(err)
	}
	fmt.Println(url.String())
}

func (*Route) Handler 

func (r *Route) Handler(handler http.Handler) *Route

Handler sets a handler for the route.

func (*Route) HandlerFunc 

func (r *Route) HandlerFunc(f func(http.ResponseWriter, *http.Request)) *Route

HandlerFunc sets a handler function for the route.

func (*Route) Headers 

func (r *Route) Headers(pairs ...string) *Route

Headers adds a matcher for request header values. It accepts a sequence of key/value pairs to be matched. For example: 

r := mux.NewRouter().NewRoute()
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 (*Route) HeadersRegexp 

func (r *Route) HeadersRegexp(pairs ...string) *Route

HeadersRegexp accepts a sequence of key/value pairs, where the value has regex support. For example: 

r := mux.NewRouter().NewRoute()
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.

Example

This example demonstrates setting a regular expression matcher for the header value. A plain word will match any value that contains a matching substring as if the pattern was wrapped with `.*`.

Code:play  

package main

import (
	"fmt"
	"net/http"

	"github.com/gorilla/mux"
)

func main() {
	r := mux.NewRouter()
	route := r.NewRoute().HeadersRegexp("Accept", "html")

	req1, _ := http.NewRequest("GET", "example.com", nil)
	req1.Header.Add("Accept", "text/plain")
	req1.Header.Add("Accept", "text/html")

	req2, _ := http.NewRequest("GET", "example.com", nil)
	req2.Header.Set("Accept", "application/xhtml+xml")

	matchInfo := &mux.RouteMatch{}
	fmt.Printf("Match: %v %q\n", route.Match(req1, matchInfo), req1.Header["Accept"])
	fmt.Printf("Match: %v %q\n", route.Match(req2, matchInfo), req2.Header["Accept"])
}

Output:

Match: true ["text/plain" "text/html"]
Match: true ["application/xhtml+xml"]
Example (ExactMatch)

This example demonstrates setting a strict regular expression matcher for the header value. Using the start and end of string anchors, the value must be an exact match.

Code:play  

package main

import (
	"fmt"
	"net/http"

	"github.com/gorilla/mux"
)

func main() {
	r := mux.NewRouter()
	route := r.NewRoute().HeadersRegexp("Origin", "^https://example.co$")

	yes, _ := http.NewRequest("GET", "example.co", nil)
	yes.Header.Set("Origin", "https://example.co")

	no, _ := http.NewRequest("GET", "example.co.uk", nil)
	no.Header.Set("Origin", "https://example.co.uk")

	matchInfo := &mux.RouteMatch{}
	fmt.Printf("Match: %v %q\n", route.Match(yes, matchInfo), yes.Header["Origin"])
	fmt.Printf("Match: %v %q\n", route.Match(no, matchInfo), no.Header["Origin"])
}

Output:

Match: true ["https://example.co"]
Match: false ["https://example.co.uk"]

func (*Route) Host 

func (r *Route) Host(tpl string) *Route

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().NewRoute()
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 (*Route) Match 

func (r *Route) Match(req *http.Request, match *RouteMatch) bool

Match matches the route against the request.

func (*Route) MatcherFunc 

func (r *Route) MatcherFunc(f MatcherFunc) *Route

MatcherFunc adds a custom function to be used as request matcher.

func (*Route) Methods 

func (r *Route) Methods(methods ...string) *Route

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 (*Route) Name 

func (r *Route) Name(name string) *Route

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 (*Route) Path 

func (r *Route) Path(tpl string) *Route

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().NewRoute()
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 (*Route) PathPrefix 

func (r *Route) PathPrefix(tpl string) *Route

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 (*Route) Queries 

func (r *Route) Queries(pairs ...string) *Route

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().NewRoute()
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.

If 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 (*Route) Schemes 

func (r *Route) Schemes(schemes ...string) *Route

Schemes adds a matcher for URL schemes. It accepts a sequence of schemes to be matched, e.g.: "http", "https". If the request's URL has a scheme set, it will be matched against. Generally, the URL scheme will only be set if a previous handler set it, such as the ProxyHeaders handler from gorilla/handlers. If unset, the scheme will be determined based on the request's TLS termination state. The first argument to Schemes will be used when constructing a route URL.

func (*Route) SkipClean 

func (r *Route) SkipClean() bool

SkipClean reports whether path cleaning is enabled for this route via Router.SkipClean.

func (*Route) Subrouter 

func (r *Route) Subrouter() *Router

Subrouter creates a subrouter for the route.

It will test the inner routes only if the parent route matched. For example: 

r := mux.NewRouter().NewRoute()
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 (*Route) URL 

func (r *Route) URL(pairs ...string) (*url.URL, error)

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.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
  Host("{subdomain}.domain.com").
  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")

The scheme of the resulting url will be the first argument that was passed to Schemes: 

// url.String() will be "https://example.com"
r := mux.NewRouter().NewRoute()
url, err := r.Host("example.com")
             .Schemes("https", "http").URL()

All variables defined in the route are required, and their values must conform to the corresponding patterns.

func (*Route) URLHost 

func (r *Route) URLHost(pairs ...string) (*url.URL, error)

URLHost builds the host part of the URL for a route. See Route.URL().

The route must have a host defined.

func (*Route) URLPath 

func (r *Route) URLPath(pairs ...string) (*url.URL, error)

URLPath builds the path part of the URL for a route. See Route.URL().

The route must have a path defined.

type RouteMatch 

type RouteMatch struct {
	Route   *Route
	Handler http.Handler
	Vars    map[string]string

	// MatchErr is set to appropriate matching error
	// It is set to ErrMethodMismatch if there is a mismatch in
	// the request method and route method
	MatchErr error
}

RouteMatch stores information about a matched route.

type Router 

type Router struct {
	// Configurable Handler to be used when no route matches.
	// This can be used to render your own 404 Not Found errors.
	NotFoundHandler http.Handler

	// Configurable Handler to be used when the request method does not match the route.
	// This can be used to render your own 405 Method Not Allowed errors.
	MethodNotAllowedHandler http.Handler

	// If true, do not clear the request context after handling the request.
	//
	// Deprecated: No effect, since the context is stored on the request itself.
	KeepContext bool
	// contains filtered or unexported fields
}

Router registers routes to be matched and dispatches a handler.

It implements the http.Handler interface, so it can be registered to serve requests: 

var router = mux.NewRouter()

func main() {
    http.Handle("/", router)
}

Or, for Google App Engine, register it in a init() function: 

func init() {
    http.Handle("/", router)
}

This will send all incoming requests to the router.

func NewRouter 

func NewRouter() *Router

NewRouter returns a new router instance.

func (*Router) BuildVarsFunc 

func (r *Router) BuildVarsFunc(f BuildVarsFunc) *Route

BuildVarsFunc registers a new route with a custom function for modifying route variables before building a URL.

func (*Router) Get 

func (r *Router) Get(name string) *Route

Get returns a route registered with the given name.

func (*Router) GetRoute 

func (r *Router) GetRoute(name string) *Route

GetRoute returns a route registered with the given name. This method was renamed to Get() and remains here for backwards compatibility.

func (*Router) Handle 

func (r *Router) Handle(path string, handler http.Handler) *Route

Handle registers a new route with a matcher for the URL path. See Route.Path() and Route.Handler().

func (*Router) HandleFunc 

func (r *Router) HandleFunc(path string, f func(http.ResponseWriter,
	*http.Request)) *Route

HandleFunc registers a new route with a matcher for the URL path. See Route.Path() and Route.HandlerFunc().

func (*Router) Headers 

func (r *Router) Headers(pairs ...string) *Route

Headers registers a new route with a matcher for request header values. See Route.Headers().

func (*Router) Host 

func (r *Router) Host(tpl string) *Route

Host registers a new route with a matcher for the URL host. See Route.Host().

func (*Router) Match 

func (r *Router) Match(req *http.Request, match *RouteMatch) bool

Match attempts to match the given request against the router's registered routes.

If the request matches a route of this router or one of its subrouters the Route, Handler, and Vars fields of the the match argument are filled and this function returns true.

If the request does not match any of this router's or its subrouters' routes then this function returns false. If available, a reason for the match failure will be filled in the match argument's MatchErr field. If the match failure type (eg: not found) has a registered handler, the handler is assigned to the Handler field of the match argument.

func (*Router) MatcherFunc 

func (r *Router) MatcherFunc(f MatcherFunc) *Route

MatcherFunc registers a new route with a custom matcher function. See Route.MatcherFunc().

func (*Router) Methods 

func (r *Router) Methods(methods ...string) *Route

Methods registers a new route with a matcher for HTTP methods. See Route.Methods().

func (*Router) Name 

func (r *Router) Name(name string) *Route

Name registers a new route with a name. See Route.Name().

func (*Router) NewRoute 

func (r *Router) NewRoute() *Route

NewRoute registers an empty route.

func (*Router) Path 

func (r *Router) Path(tpl string) *Route

Path registers a new route with a matcher for the URL path. See Route.Path().

func (*Router) PathPrefix 

func (r *Router) PathPrefix(tpl string) *Route

PathPrefix registers a new route with a matcher for the URL path prefix. See Route.PathPrefix().

func (*Router) Queries 

func (r *Router) Queries(pairs ...string) *Route

Queries registers a new route with a matcher for URL query values. See Route.Queries().

func (*Router) Schemes 

func (r *Router) Schemes(schemes ...string) *Route

Schemes registers a new route with a matcher for URL schemes. See Route.Schemes().

func (*Router) ServeHTTP 

func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request)

ServeHTTP dispatches the handler registered in the matched route.

When there is a match, the route variables can be retrieved calling mux.Vars(request).

func (*Router) SkipClean 

func (r *Router) SkipClean(value bool) *Router

SkipClean defines the path cleaning behaviour for new routes. The initial value is false. Users should be careful about which routes are not cleaned

When true, if the route path is "/path//to", it will remain with the double slash. This is helpful if you have a route like: /fetch/http://xkcd.com/534/

When false, the path will be cleaned, so /fetch/http://xkcd.com/534/ will become /fetch/http/xkcd.com/534

func (*Router) StrictSlash 

func (r *Router) StrictSlash(value bool) *Router

StrictSlash defines the trailing slash behavior for new routes. The initial value is false.

When true, if the route path is "/path/", accessing "/path" will perform a redirect to the former and vice versa. In other words, your application will always see the path as specified in the route.

When false, if the route path is "/path", accessing "/path/" will not match this route and vice versa.

The re-direct is a HTTP 301 (Moved Permanently). Note that when this is set for routes with a non-idempotent method (e.g. POST, PUT), the subsequent re-directed request will be made as a GET by most clients. Use middleware or client settings to modify this behaviour as needed.

Special case: when a route sets a path prefix using the PathPrefix() method, strict slash is ignored for that route because the redirect behavior can't be determined from a prefix alone. However, any subrouters created from that route inherit the original StrictSlash setting.

func (*Router) Use 

func (r *Router) Use(mwf ...MiddlewareFunc)

Use appends a MiddlewareFunc to the chain. Middleware can be used to intercept or otherwise modify requests and/or responses, and are executed in the order that they are applied to the Router.

func (*Router) UseEncodedPath 

func (r *Router) UseEncodedPath() *Router

UseEncodedPath tells the router to match the encoded original path to the routes. For eg. "/path/foo%2Fbar/to" will match the path "/path/{var}/to".

If not called, the router will match the unencoded path to the routes. For eg. "/path/foo%2Fbar/to" will match the path "/path/foo/bar/to"

func (*Router) Walk 

func (r *Router) Walk(walkFn WalkFunc) error

Walk walks the router and all its sub-routers, calling walkFn for each route in the tree. The routes are walked in the order they were added. Sub-routers are explored depth-first.

type WalkFunc 

type WalkFunc func(route *Route, router *Router, ancestors []*Route) error

WalkFunc is the type of the function called for each route visited by Walk. At every invocation, it is given the current route, and the current router, and a list of ancestor routes that lead to the current route.

Source Files

doc.go middleware.go mux.go regexp.go route.go test_helpers.go

Version
v1.8.1 (latest)
Published
Oct 18, 2023
Platform
linux/amd64
Imports
10 packages
Last checked
5 days ago –

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