1 /*
2 * Copyright 2014 Google Inc. All rights reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "request_dispatcher.h"
18
19 #include "bar_handler.h"
20 #include "foo_handler.h"
21
22 #include <iostream>
23
24 using namespace std;
25 using namespace fruit;
26
27 class RequestDispatcherImpl : public RequestDispatcher {
28 private:
29 const Request& request;
30 // We hold providers here for lazy injection; we only want to inject the handler that is actually used for the
31 // request.
32 // In a large system, there will be many handlers, and many will have lots of dependencies that also have to be
33 // injected.
34 Provider<FooHandler> fooHandler;
35 Provider<BarHandler> barHandler;
36
37 public:
INJECT(RequestDispatcherImpl (const Request & request,Provider<FooHandler> fooHandler,Provider<BarHandler> barHandler))38 INJECT(RequestDispatcherImpl(const Request& request, Provider<FooHandler> fooHandler,
39 Provider<BarHandler> barHandler))
40 : request(request), fooHandler(fooHandler), barHandler(barHandler) {}
41
handleRequest()42 void handleRequest() override {
43 if (stringStartsWith(request.path, "/foo/")) {
44 fooHandler.get()->handleRequest();
45 } else if (stringStartsWith(request.path, "/bar/")) {
46 barHandler.get()->handleRequest();
47 } else {
48 cerr << "Error: no handler found for request path: '" << request.path << "' , ignoring request." << endl;
49 }
50 }
51
52 private:
stringStartsWith(const string & s,const string & candidatePrefix)53 static bool stringStartsWith(const string& s, const string& candidatePrefix) {
54 return s.compare(0, candidatePrefix.size(), candidatePrefix) == 0;
55 }
56 };
57
getRequestDispatcherComponent()58 Component<Required<Request, ServerContext>, RequestDispatcher> getRequestDispatcherComponent() {
59 return createComponent()
60 .bind<RequestDispatcher, RequestDispatcherImpl>()
61 .install(getFooHandlerComponent)
62 .install(getBarHandlerComponent);
63 }
64