summaryrefslogtreecommitdiffstats
path: root/vendor/github.com/gorilla/mux/mux.go
blob: 4bbafa51da301690f53a011964769d4eac6d7c84 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
// Copyright 2012 The Gorilla Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package mux

import (
	"errors"
	"fmt"
	"net/http"
	"path"
	"regexp"
)

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")
)

// NewRouter returns a new router instance.
func NewRouter() *Router {
	return &Router{namedRoutes: make(map[string]*Route), KeepContext: false}
}

// 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.
type Router struct {
	// Configurable Handler to be used when no route matches.
	NotFoundHandler http.Handler

	// Configurable Handler to be used when the request method does not match the route.
	MethodNotAllowedHandler http.Handler

	// Parent route, if this is a subrouter.
	parent parentRoute
	// Routes to be matched, in order.
	routes []*Route
	// Routes by name for URL building.
	namedRoutes map[string]*Route
	// See Router.StrictSlash(). This defines the flag for new routes.
	strictSlash bool
	// See Router.SkipClean(). This defines the flag for new routes.
	skipClean bool
	// If true, do not clear the request context after handling the request.
	// This has no effect when go1.7+ is used, since the context is stored
	// on the request itself.
	KeepContext bool
	// see Router.UseEncodedPath(). This defines a flag for all routes.
	useEncodedPath bool
	// Slice of middlewares to be called after a match is found
	middlewares []middleware
}

// 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 (r *Router) Match(req *http.Request, match *RouteMatch) bool {
	for _, route := range r.routes {
		if route.Match(req, match) {
			// Build middleware chain if no error was found
			if match.MatchErr == nil {
				for i := len(r.middlewares) - 1; i >= 0; i-- {
					match.Handler = r.middlewares[i].Middleware(match.Handler)
				}
			}
			return true
		}
	}

	if match.MatchErr == ErrMethodMismatch {
		if r.MethodNotAllowedHandler != nil {
			match.Handler = r.MethodNotAllowedHandler
			return true
		}

		return false
	}

	// Closest match for a router (includes sub-routers)
	if r.NotFoundHandler != nil {
		match.Handler = r.NotFoundHandler
		match.MatchErr = ErrNotFound
		return true
	}

	match.MatchErr = ErrNotFound
	return false
}

// 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 (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	if !r.skipClean {
		path := req.URL.Path
		if r.useEncodedPath {
			path = req.URL.EscapedPath()
		}
		// Clean path to canonical form and redirect.
		if p := cleanPath(path); p != path {

			// Added 3 lines (Philip Schlump) - It was dropping the query string and #whatever from query.
			// This matches with fix in go 1.2 r.c. 4 for same problem.  Go Issue:
			// http://code.google.com/p/go/issues/detail?id=5252
			url := *req.URL
			url.Path = p
			p = url.String()

			w.Header().Set("Location", p)
			w.WriteHeader(http.StatusMovedPermanently)
			return
		}
	}
	var match RouteMatch
	var handler http.Handler
	if r.Match(req, &match) {
		handler = match.Handler
		req = setVars(req, match.Vars)
		req = setCurrentRoute(req, match.Route)
	}

	if handler == nil && match.MatchErr == ErrMethodMismatch {
		handler = methodNotAllowedHandler()
	}

	if handler == nil {
		handler = http.NotFoundHandler()
	}

	if !r.KeepContext {
		defer contextClear(req)
	}

	handler.ServeHTTP(w, req)
}

// Get returns a route registered with the given name.
func (r *Router) Get(name string) *Route {
	return r.getNamedRoutes()[name]
}

// GetRoute returns a route registered with the given name. This method
// was renamed to Get() and remains here for backwards compatibility.
func (r *Router) GetRoute(name string) *Route {
	return r.getNamedRoutes()[name]
}

// 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 (r *Router) StrictSlash(value bool) *Router {
	r.strictSlash = value
	return r
}

// 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 (r *Router) SkipClean(value bool) *Router {
	r.skipClean = value
	return r
}

// 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 (r *Router) UseEncodedPath() *Router {
	r.useEncodedPath = true
	return r
}

// ----------------------------------------------------------------------------
// parentRoute
// ----------------------------------------------------------------------------

func (r *Router) getBuildScheme() string {
	if r.parent != nil {
		return r.parent.getBuildScheme()
	}
	return ""
}

// getNamedRoutes returns the map where named routes are registered.
func (r *Router) getNamedRoutes() map[string]*Route {
	if r.namedRoutes == nil {
		if r.parent != nil {
			r.namedRoutes = r.parent.getNamedRoutes()
		} else {
			r.namedRoutes = make(map[string]*Route)
		}
	}
	return r.namedRoutes
}

// getRegexpGroup returns regexp definitions from the parent route, if any.
func (r *Router) getRegexpGroup() *routeRegexpGroup {
	if r.parent != nil {
		return r.parent.getRegexpGroup()
	}
	return nil
}

func (r *Router) buildVars(m map[string]string) map[string]string {
	if r.parent != nil {
		m = r.parent.buildVars(m)
	}
	return m
}

// ----------------------------------------------------------------------------
// Route factories
// ----------------------------------------------------------------------------

// NewRoute registers an empty route.
func (r *Router) NewRoute() *Route {
	route := &Route{parent: r, strictSlash: r.strictSlash, skipClean: r.skipClean, useEncodedPath: r.useEncodedPath}
	r.routes = append(r.routes, route)
	return route
}

// Handle registers a new route with a matcher for the URL path.
// See Route.Path() and Route.Handler().
func (r *Router) Handle(path string, handler http.Handler) *Route {
	return r.NewRoute().Path(path).Handler(handler)
}

// HandleFunc registers a new route with a matcher for the URL path.
// See Route.Path() and Route.HandlerFunc().
func (r *Router) HandleFunc(path string, f func(http.ResponseWriter,
	*http.Request)) *Route {
	return r.NewRoute().Path(path).HandlerFunc(f)
}

// Headers registers a new route with a matcher for request header values.
// See Route.Headers().
func (r *Router) Headers(pairs ...string) *Route {
	return r.NewRoute().Headers(pairs...)
}

// Host registers a new route with a matcher for the URL host.
// See Route.Host().
func (r *Router) Host(tpl string) *Route {
	return r.NewRoute().Host(tpl)
}

// MatcherFunc registers a new route with a custom matcher function.
// See Route.MatcherFunc().
func (r *Router) MatcherFunc(f MatcherFunc) *Route {
	return r.NewRoute().MatcherFunc(f)
}

// Methods registers a new route with a matcher for HTTP methods.
// See Route.Methods().
func (r *Router) Methods(methods ...string) *Route {
	return r.NewRoute().Methods(methods...)
}

// Path registers a new route with a matcher for the URL path.
// See Route.Path().
func (r *Router) Path(tpl string) *Route {
	return r.NewRoute().Path(tpl)
}

// PathPrefix registers a new route with a matcher for the URL path prefix.
// See Route.PathPrefix().
func (r *Router) PathPrefix(tpl string) *Route {
	return r.NewRoute().PathPrefix(tpl)
}

// Queries registers a new route with a matcher for URL query values.
// See Route.Queries().
func (r *Router) Queries(pairs ...string) *Route {
	return r.NewRoute().Queries(pairs...)
}

// Schemes registers a new route with a matcher for URL schemes.
// See Route.Schemes().
func (r *Router) Schemes(schemes ...string) *Route {
	return r.NewRoute().Schemes(schemes...)
}

// BuildVarsFunc registers a new route with a custom function for modifying
// route variables before building a URL.
func (r *Router) BuildVarsFunc(f BuildVarsFunc) *Route {
	return r.NewRoute().BuildVarsFunc(f)
}

// 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.
func (r *Router) Walk(walkFn WalkFunc) error {
	return r.walk(walkFn, []*Route{})
}

// 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.
var SkipRouter = errors.New("skip this router")

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

func (r *Router) walk(walkFn WalkFunc, ancestors []*Route) error {
	for _, t := range r.routes {
		err := walkFn(t, r, ancestors)
		if err == SkipRouter {
			continue
		}
		if err != nil {
			return err
		}
		for _, sr := range t.matchers {
			if h, ok := sr.(*Router); ok {
				ancestors = append(ancestors, t)
				err := h.walk(walkFn, ancestors)
				if err != nil {
					return err
				}
				ancestors = ancestors[:len(ancestors)-1]
			}
		}
		if h, ok := t.handler.(*Router); ok {
			ancestors = append(ancestors, t)
			err := h.walk(walkFn, ancestors)
			if err != nil {
				return err
			}
			ancestors = ancestors[:len(ancestors)-1]
		}
	}
	return nil
}

// ----------------------------------------------------------------------------
// Context
// ----------------------------------------------------------------------------

// RouteMatch stores information about a matched route.
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
}

type contextKey int

const (
	varsKey contextKey = iota
	routeKey
)

// Vars returns the route variables for the current request, if any.
func Vars(r *http.Request) map[string]string {
	if rv := contextGet(r, varsKey); rv != nil {
		return rv.(map[string]string)
	}
	return nil
}

// 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, unless the KeepContext option is set on the
// Router.
func CurrentRoute(r *http.Request) *Route {
	if rv := contextGet(r, routeKey); rv != nil {
		return rv.(*Route)
	}
	return nil
}

func setVars(r *http.Request, val interface{}) *http.Request {
	return contextSet(r, varsKey, val)
}

func setCurrentRoute(r *http.Request, val interface{}) *http.Request {
	return contextSet(r, routeKey, val)
}

// ----------------------------------------------------------------------------
// Helpers
// ----------------------------------------------------------------------------

// cleanPath returns the canonical path for p, eliminating . and .. elements.
// Borrowed from the net/http package.
func cleanPath(p string) string {
	if p == "" {
		return "/"
	}
	if p[0] != '/' {
		p = "/" + p
	}
	np := path.Clean(p)
	// path.Clean removes trailing slash except for root;
	// put the trailing slash back if necessary.
	if p[len(p)-1] == '/' && np != "/" {
		np += "/"
	}

	return np
}

// uniqueVars returns an error if two slices contain duplicated strings.
func uniqueVars(s1, s2 []string) error {
	for _, v1 := range s1 {
		for _, v2 := range s2 {
			if v1 == v2 {
				return fmt.Errorf("mux: duplicated route variable %q", v2)
			}
		}
	}
	return nil
}

// checkPairs returns the count of strings passed in, and an error if
// the count is not an even number.
func checkPairs(pairs ...string) (int, error) {
	length := len(pairs)
	if length%2 != 0 {
		return length, fmt.Errorf(
			"mux: number of parameters must be multiple of 2, got %v", pairs)
	}
	return length, nil
}

// mapFromPairsToString converts variadic string parameters to a
// string to string map.
func mapFromPairsToString(pairs ...string) (map[string]string, error) {
	length, err := checkPairs(pairs...)
	if err != nil {
		return nil, err
	}
	m := make(map[string]string, length/2)
	for i := 0; i < length; i += 2 {
		m[pairs[i]] = pairs[i+1]
	}
	return m, nil
}

// mapFromPairsToRegex converts variadic string parameters to a
// string to regex map.
func mapFromPairsToRegex(pairs ...string) (map[string]*regexp.Regexp, error) {
	length, err := checkPairs(pairs...)
	if err != nil {
		return nil, err
	}
	m := make(map[string]*regexp.Regexp, length/2)
	for i := 0; i < length; i += 2 {
		regex, err := regexp.Compile(pairs[i+1])
		if err != nil {
			return nil, err
		}
		m[pairs[i]] = regex
	}
	return m, nil
}

// matchInArray returns true if the given string value is in the array.
func matchInArray(arr []string, value string) bool {
	for _, v := range arr {
		if v == value {
			return true
		}
	}
	return false
}

// matchMapWithString returns true if the given key/value pairs exist in a given map.
func matchMapWithString(toCheck map[string]string, toMatch map[string][]string, canonicalKey bool) bool {
	for k, v := range toCheck {
		// Check if key exists.
		if canonicalKey {
			k = http.CanonicalHeaderKey(k)
		}
		if values := toMatch[k]; values == nil {
			return false
		} else if v != "" {
			// If value was defined as an empty string we only check that the
			// key exists. Otherwise we also check for equality.
			valueExists := false
			for _, value := range values {
				if v == value {
					valueExists = true
					break
				}
			}
			if !valueExists {
				return false
			}
		}
	}
	return true
}

// matchMapWithRegex returns true if the given key/value pairs exist in a given map compiled against
// the given regex
func matchMapWithRegex(toCheck map[string]*regexp.Regexp, toMatch map[string][]string, canonicalKey bool) bool {
	for k, v := range toCheck {
		// Check if key exists.
		if canonicalKey {
			k = http.CanonicalHeaderKey(k)
		}
		if values := toMatch[k]; values == nil {
			return false
		} else if v != nil {
			// If value was defined as an empty string we only check that the
			// key exists. Otherwise we also check for equality.
			valueExists := false
			for _, value := range values {
				if v.MatchString(value) {
					valueExists = true
					break
				}
			}
			if !valueExists {
				return false
			}
		}
	}
	return true
}

// methodNotAllowed replies to the request with an HTTP status code 405.
func methodNotAllowed(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusMethodNotAllowed)
}

// methodNotAllowedHandler returns a simple request handler
// that replies to each request with a status code 405.
func methodNotAllowedHandler() http.Handler { return http.HandlerFunc(methodNotAllowed) }