github.com/palantir/witchcraft-go-server/v2@v2.76.0/wrouter/whttprouter/routerimpl.go (about)

     1  // Copyright (c) 2018 Palantir Technologies. All rights reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package whttprouter
    16  
    17  import (
    18  	"net/http"
    19  	"strings"
    20  
    21  	"github.com/julienschmidt/httprouter"
    22  	"github.com/palantir/witchcraft-go-server/v2/wrouter"
    23  )
    24  
    25  // New returns a wrouter.RouterImpl backed by a new httprouter.Router configured using the provided parameters.
    26  func New(params ...Param) wrouter.RouterImpl {
    27  	r := httprouter.New()
    28  	for _, p := range params {
    29  		p.apply(r)
    30  	}
    31  	return (*router)(r)
    32  }
    33  
    34  type Param interface {
    35  	apply(*httprouter.Router)
    36  }
    37  
    38  type paramFunc func(*httprouter.Router)
    39  
    40  func (f paramFunc) apply(r *httprouter.Router) {
    41  	f(r)
    42  }
    43  
    44  func RedirectTrailingSlash(redirect bool) Param {
    45  	return paramFunc(func(r *httprouter.Router) {
    46  		r.RedirectTrailingSlash = redirect
    47  	})
    48  }
    49  
    50  func RedirectFixedPath(redirect bool) Param {
    51  	return paramFunc(func(r *httprouter.Router) {
    52  		r.RedirectFixedPath = redirect
    53  	})
    54  }
    55  
    56  func HandleMethodNotAllowed(notAllowed bool) Param {
    57  	return paramFunc(func(r *httprouter.Router) {
    58  		r.HandleMethodNotAllowed = notAllowed
    59  	})
    60  }
    61  
    62  func HandleOPTIONS(handle bool) Param {
    63  	return paramFunc(func(r *httprouter.Router) {
    64  		r.HandleOPTIONS = handle
    65  	})
    66  }
    67  
    68  type router httprouter.Router
    69  
    70  func (r *router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
    71  	(*httprouter.Router)(r).ServeHTTP(w, req)
    72  }
    73  
    74  func (r *router) Register(method string, pathSegments []wrouter.PathSegment, handler http.Handler) {
    75  	(*httprouter.Router)(r).Handler(method, r.convertPathParams(pathSegments), handler)
    76  }
    77  
    78  func (r *router) RegisterNotFoundHandler(handler http.Handler) {
    79  	(*httprouter.Router)(r).NotFound = handler
    80  }
    81  
    82  func (r *router) PathParams(req *http.Request, pathVarNames []string) map[string]string {
    83  	_, vars, _ := (*httprouter.Router)(r).Lookup(req.Method, req.URL.Path)
    84  	if len(vars) == 0 {
    85  		return nil
    86  	}
    87  	params := make(map[string]string)
    88  	for i := range vars {
    89  		// strip preceding forward slashes for trailing match path params. httprouter is implemented such that,
    90  		// for a trailing parameter for the form "/{param*}", the path "/var/foo/bar.txt" will match with a
    91  		// value of "/var/foo/bar.txt". However, the contract of zappermux stipulates that the match should be
    92  		// of the form "var/foo/bar.txt", so strip the preceding slash to fulfill this contract.
    93  		params[vars[i].Key] = strings.TrimPrefix(vars[i].Value, "/")
    94  	}
    95  	return params
    96  }
    97  
    98  func (r *router) convertPathParams(pathSegments []wrouter.PathSegment) string {
    99  	pathParts := make([]string, len(pathSegments))
   100  	for i, segment := range pathSegments {
   101  		switch segment.Type {
   102  		case wrouter.PathParamSegment:
   103  			pathParts[i] = ":" + segment.Value
   104  		case wrouter.TrailingPathParamSegment:
   105  			pathParts[i] = "*" + segment.Value
   106  		default:
   107  			pathParts[i] = segment.Value
   108  		}
   109  	}
   110  	return "/" + strings.Join(pathParts, "/")
   111  }