Qt desktop app

The casdoor-cpp-qt-example shows Casdoor sign-in in a Qt desktop app, using casdoor-cpp-sdk.

Run the example

Prerequisites

• Qt 6 with the Qt WebEngine module (on Windows, use the MSVC build of Qt)
• CMake 3.16+ and a C++17 compiler
• OpenSSL 1.1.1 or 3.x

CMake downloads casdoor-cpp-sdk when it configures the project, so the SDK doesn't need to be installed.

Initialization

In Casdoor, add http://localhost:8080/callback to the application's Redirect URLs. Nothing needs to listen on that port: the example catches the redirect inside its embedded browser.

Set these 7 parameters:

Name	Description	File
kCasdoorEndpoint	Your Casdoor server URL, like http://localhost:8000	config.h
kClientId	The Client ID of your Casdoor application	config.h
kClientSecret	The Client Secret of your Casdoor application	config.h
kCertificate	The public certificate of the cert your application uses	config.h
kOrganizationName	The name of your Casdoor organization	config.h
kApplicationName	The name of your Casdoor application	config.h
kRedirectUri	The redirect URL, http://localhost:8080/callback	config.h

Running

Qt Creator

1. Open CMakeLists.txt
2. Press Ctrl + R to start

Command line

cmake -S . -B build -DCMAKE_PREFIX_PATH=/path/to/Qt/6.x/<compiler>
cmake --build build
./build/casdoor-cpp-qt-example

On Windows, if CMake can't find OpenSSL, add -DOPENSSL_ROOT_DIR="C:/Program Files/OpenSSL-Win64".

Preview

Click Sign In to open the login window. After sign-in, the user profile is shown.

Integration

Create the client

#include <casdoor/casdoor.h>

casdoor::Config config;
config.endpoint = kCasdoorEndpoint;
config.client_id = kClientId;
config.client_secret = kClientSecret;
config.certificate = kCertificate;
config.organization_name = kOrganizationName;
config.application_name = kApplicationName;

casdoor::Client casdoor(config);

Open the login window

// A random state ties the callback to this sign-in attempt
m_state = QUuid::createUuid().toString(QUuid::WithoutBraces);
std::string signinUrl = m_casdoor.GetSigninUrl(kRedirectUri, m_state.toStdString());

m_webview->load(QUrl(QString::fromStdString(signinUrl)));
m_webview->show();

Catch the callback

After sign-in, Casdoor redirects to the redirect URL with code and state. A QWebEnginePage subclass stops the embedded browser from loading that URL and hands it to the app:

bool CallbackPage::acceptNavigationRequest(const QUrl& url, NavigationType type, bool isMainFrame)
{
    if (isMainFrame && url.adjusted(QUrl::RemoveQuery | QUrl::RemoveFragment) == m_redirectUri) {
        emit callbackReceived(url);
        return false;
    }
    return QWebEnginePage::acceptNavigationRequest(url, type, isMainFrame);
}

Get the user info with the code

Check state, exchange the code for a token, then verify the token with the certificate:

QUrlQuery query(url);
QString code = query.queryItemValue("code", QUrl::FullyDecoded);
QString state = query.queryItemValue("state", QUrl::FullyDecoded);
if (code.isEmpty() || state != m_state) {
    return;
}

try {
    casdoor::Token token = m_casdoor.GetOAuthToken(code.toStdString());
    casdoor::Claims claims = m_casdoor.ParseJwtToken(token.access_token);
    // claims.name, claims.display_name, claims.email, claims.owner, claims.payload ...
} catch (const casdoor::Error& e) {
    QMessageBox::warning(this, "Sign in failed", e.what());
}

ParseJwtToken throws casdoor::Error if the signature, expiry or audience of the token is invalid. See casdoor-cpp-sdk for the other APIs, such as refreshing tokens and managing users.