router/router.go
2018-08-03 21:32:25 +02:00

149 lines
3.2 KiB
Go

package router
import (
"encoding/json"
"fmt"
"net/http"
"reflect"
"github.com/julienschmidt/httprouter"
)
type route struct {
Method string
Path string
Handle interface{}
}
// GetHandle handles a request that doesn't receive a body
type GetHandle func(*Context) error
// Router is the router itself
type Router struct {
routes []route
Port int
}
// New returns a new Router
func New() *Router {
return &Router{}
}
// GET adds a GET route
func (r *Router) GET(path string, handle GetHandle) {
r.routes = append(r.routes, route{`GET`, path, handle})
}
// POST adds a POST route
func (r *Router) POST(path string, handle interface{}) {
checkInterfaceHandle(handle)
r.routes = append(r.routes, route{`POST`, path, handle})
}
// DELETE adds a DELETE route
func (r *Router) DELETE(path string, handle GetHandle) {
r.routes = append(r.routes, route{`DELETE`, path, handle})
}
// PUT adds a PUT route
func (r *Router) PUT(path string, handle interface{}) {
checkInterfaceHandle(handle)
r.routes = append(r.routes, route{`PUT`, path, handle})
}
// PATCH adds a PATCH route
func (r *Router) PATCH(path string, handle interface{}) {
checkInterfaceHandle(handle)
r.routes = append(r.routes, route{`PATCH`, path, handle})
}
// HEAD adds a HEAD route
func (r *Router) HEAD(path string, handle GetHandle) {
r.routes = append(r.routes, route{`HEAD`, path, handle})
}
// OPTIONS adds a OPTIONS route
func (r *Router) OPTIONS(path string, handle GetHandle) {
r.routes = append(r.routes, route{`OPTIONS`, path, handle})
}
// Start starts the web server and binds to the given address
func (r *Router) Start(addr string) error {
httpr := r.getHttpr()
return http.ListenAndServe(addr, httpr)
}
func (r *Router) getHttpr() *httprouter.Router {
httpr := httprouter.New()
for _, v := range r.routes {
if handle, ok := v.Handle.(GetHandle); ok {
httpr.Handle(v.Method, v.Path, handleGET(handle))
continue
}
httpr.Handle(v.Method, v.Path, handlePOST(v.Handle))
}
return httpr
}
func checkInterfaceHandle(f interface{}) {
if _, ok := f.(GetHandle); ok {
return
}
rt := reflect.TypeOf(f)
if rt.Kind() != reflect.Func {
panic(`non-func handle`)
}
if rt.NumIn() != 2 {
panic(`handle should take 2 arguments`)
}
if rt.NumOut() != 1 || rt.Out(0).Name() != `error` {
panic(`handle should return only error`)
}
if rt.In(0) != reflect.TypeOf(&Context{}) {
panic(`handle should accept Context as first argument`)
}
return
}
func handlePOST(f interface{}) httprouter.Handle {
funcRv, inputRt := reflect.ValueOf(f), reflect.TypeOf(f).In(1)
return func(res http.ResponseWriter, req *http.Request, param httprouter.Params) {
c := newContext(res, req, param)
data := reflect.New(inputRt)
{
err := json.NewDecoder(req.Body).Decode(data.Interface())
req.Body.Close()
if err != nil {
c.NoContent(400) // TODO: send info about error (BindError)
return
}
}
out := funcRv.Call([]reflect.Value{reflect.ValueOf(c), data.Elem()})
err := out[0].Interface()
_ = err
}
}
func handleGET(f GetHandle) httprouter.Handle {
return func(res http.ResponseWriter, req *http.Request, param httprouter.Params) {
c := newContext(res, req, param)
err := f(c)
fmt.Println(err)
}
}