RESTful server Address Book Example

This example shows how to set up a RESTful API server using the QHttpServer class. The Address Book API allows create, read, update and delete operations of name and address entries.

 httpServer.route("/v2/contact", QHttpServerRequest::Method::Get,
                  [&contacts](const QHttpServerRequest &) {
                      QJsonArray array;
                      std::transform(contacts.cbegin(), contacts.cend(),
                                     std::inserter(array, array.begin()),
                                     [](const auto &it) { return it.toJson(); });

                      return QHttpServerResponse(array);
                  });

In the example above, the route is specified for the GET method, which returns the JSON array with all address entries stored. To achieve that, the QHttpServer::route() method is used with the QHttpServerRequest::Method::Get enumeration.

 httpServer.route(
         "/v2/contact", QHttpServerRequest::Method::Post,
         [&contacts](const QHttpServerRequest &request) {
             if (!checkApiKeyHeader(request.headers())) {
                 return QHttpServerResponse(QHttpServerResponder::StatusCode::Unauthorized);
             }
             const auto json = byteArrayToJsonObject(request.body());
             if (!json || !json->contains("address") || !json->contains("name"))
                 return QHttpServerResponse(QHttpServerResponder::StatusCode::BadRequest);
             const auto entry = insertAddress(contacts, json->value("name").toString(),
                                              json->value("address").toString());
             return QHttpServerResponse(entry, QHttpServerResponder::StatusCode::Created);
         });

In this example, the route is specified for the POST method, which adds a new entry to the address book and returns a JSON object that represents the added entry. This JSON object also contains an HTTP status code: Created for new entries, or AlreadyReported for pre-existing entries. This example makes use of an overload of QHttpServerResponse::QHttpServerResponse to send a JSON object and corresponding HTTP status code.

To create an entry the request body must be a JSON object with address and name fields. For example:

 {
     "address": "Example Street 1, Big City"
     "name": "John Smith"
 }

Files:

• addressbook/CMakeLists.txt
• addressbook/main.cpp