Flow

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A delightfully tiny but powerful HTTP router for Go web applications

Project status

Installation

$ go get github.com/alexedwards/flow@latest

Basic example

package main
import (
 "fmt"
 "log"
 "net/http"
 "github.com/alexedwards/flow"
)
func main() {
 // Initialize a new router.
 mux := flow.New()
 // Add a `GET /greet/:name` route. The : character is used to denote a 
 // named parameter in the URL path, which acts like a 'wildcard'.
 mux.HandleFunc("/greet/:name", greet, "GET")
 err := http.ListenAndServe(":2323", mux)
 log.Fatal(err)
}
func greet(w http.ResponseWriter, r *http.Request) {
 // Retrieve the value of the named parameter from the request.
 name := r.PathValue("name")
 fmt.Fprintf(w, "Hello %s", name)
}

Kitchen-sink example

mux := flow.New()
// The Use() method can be used to register middleware. Middleware declared at
// the top level will be used on all routes (including error handlers and OPTIONS
// responses).
mux.Use(exampleMiddleware1)
// Routes can use multiple HTTP methods.
mux.HandleFunc("/profile/:name", exampleHandlerFunc1, "GET", "POST")
// Optionally, regular expressions can be used to enforce a specific pattern
// for a named parameter.
mux.HandleFunc("/profile/:name/:age|^[0-9]{1,3}$", exampleHandlerFunc2, "GET")
// The wildcard ... can be used to match the remainder of a request path.
// Notice that HTTP methods are also optional (if not provided, all HTTP
// methods will match the route). The value of the wildcard can be retrieved 
// by calling r.PathValue("...").
mux.Handle("/static/...", exampleHandler)
// You can create route 'groups'.
mux.Group(func(mux *flow.Mux) {
 // Middleware declared within the group will only be used on the routes
 // in the group.
 mux.Use(exampleMiddleware2)
 mux.HandleFunc("/admin", exampleHandlerFunc3, "GET")
 // Groups can be nested.
 mux.Group(func(mux *flow.Mux) {
 mux.Use(exampleMiddleware3)
 mux.HandleFunc("/admin/passwords", exampleHandlerFunc4, "GET")
 })
})

Notes

mux := flow.New()
mux.Use(middleware1)
mux.HandleFunc("/foo", ...) // This route will use middleware1 only.
mux.Use(middleware2)
mux.HandleFunc("/bar", ...) // This route will use both middleware1 and middleware2.

Thanks