/
router.go
144 lines (129 loc) · 3.61 KB
/
router.go
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package kocha
import (
"fmt"
"reflect"
"strings"
"github.com/naoina/denco"
"github.com/naoina/kocha/util"
)
// The routing table.
type RouteTable []*Route
func (rt RouteTable) buildRouter() (*Router, error) {
router := &Router{routeTable: rt}
if err := router.buildForward(); err != nil {
return nil, err
}
if err := router.buildReverse(); err != nil {
return nil, err
}
return router, nil
}
// Router represents a router of kocha.
type Router struct {
forward *denco.Router
reverse map[string]*Route
routeTable RouteTable
}
func (router *Router) dispatch(req *Request) (name string, handler requestHandler, params denco.Params, found bool) {
path := util.NormPath(req.URL.Path)
data, params, found := router.forward.Lookup(path)
if !found {
return "", nil, nil, false
}
route := data.(*Route)
handler, found = route.dispatch(req.Method)
return route.Name, handler, params, found
}
// buildForward builds forward router.
func (router *Router) buildForward() error {
records := make([]denco.Record, len(router.routeTable))
for i, route := range router.routeTable {
records[i] = denco.NewRecord(route.Path, route)
}
router.forward = denco.New()
return router.forward.Build(records)
}
// buildReverse builds reverse router.
func (router *Router) buildReverse() error {
router.reverse = make(map[string]*Route)
for _, route := range router.routeTable {
router.reverse[route.Name] = route
for i := 0; i < len(route.Path); i++ {
if c := route.Path[i]; c == denco.ParamCharacter || c == denco.WildcardCharacter {
next := denco.NextSeparator(route.Path, i+1)
route.paramNames = append(route.paramNames, route.Path[i:next])
i = next
}
}
}
return nil
}
// Reverse returns path of route by name and any params.
func (router *Router) Reverse(name string, v ...interface{}) (string, error) {
route := router.reverse[name]
if route == nil {
types := make([]string, len(v))
for i, value := range v {
types[i] = reflect.TypeOf(value).Name()
}
return "", fmt.Errorf("kocha: no match route found: %v (%v)", name, strings.Join(types, ", "))
}
return route.reverse(v...)
}
// Route represents a route.
type Route struct {
Name string
Path string
Controller Controller
paramNames []string
}
func (route *Route) dispatch(method string) (handler requestHandler, found bool) {
switch strings.ToUpper(method) {
case "GET":
if h, ok := route.Controller.(Getter); ok {
return h.GET, true
}
case "POST":
if h, ok := route.Controller.(Poster); ok {
return h.POST, true
}
case "PUT":
if h, ok := route.Controller.(Putter); ok {
return h.PUT, true
}
case "DELETE":
if h, ok := route.Controller.(Deleter); ok {
return h.DELETE, true
}
case "HEAD":
if h, ok := route.Controller.(Header); ok {
return h.HEAD, true
}
case "PATCH":
if h, ok := route.Controller.(Patcher); ok {
return h.PATCH, true
}
}
return nil, false
}
// ParamNames returns names of the path parameters.
func (route *Route) ParamNames() []string {
return route.paramNames
}
func (r *Route) reverse(v ...interface{}) (string, error) {
switch vlen, nlen := len(v), len(r.paramNames); {
case vlen < nlen:
return "", fmt.Errorf("kocha: too few arguments: %v (controller is %T)", r.Name, r.Controller)
case vlen > nlen:
return "", fmt.Errorf("kocha: too many arguments: %v (controller is %T)", r.Name, r.Controller)
case vlen+nlen == 0:
return r.Path, nil
}
var oldnew []string
for i := 0; i < len(v); i++ {
oldnew = append(oldnew, r.paramNames[i], fmt.Sprint(v[i]))
}
replacer := strings.NewReplacer(oldnew...)
path := replacer.Replace(r.Path)
return util.NormPath(path), nil
}