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: 38 INJECT(RequestDispatcherImpl(const Request& request, Provider<FooHandler> fooHandler, 39 Provider<BarHandler> barHandler)) 40 : request(request), fooHandler(fooHandler), barHandler(barHandler) {} 41 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: 53 static bool stringStartsWith(const string& s, const string& candidatePrefix) { 54 return s.compare(0, candidatePrefix.size(), candidatePrefix) == 0; 55 } 56 }; 57 58 Component<Required<Request, ServerContext>, RequestDispatcher> getRequestDispatcherComponent() { 59 return createComponent() 60 .bind<RequestDispatcher, RequestDispatcherImpl>() 61 .install(getFooHandlerComponent) 62 .install(getBarHandlerComponent); 63 } 64
