Question

I am developing an app on BB 10 based on C++ where I need to send HTTP post requests to the server and retrieve some JSON data. Are there some framework classes that help you send HTTP post requests to the server? Any links to code etc.? Thanks.

Answer 1

I can’t remember which sample app I found this code in, but this worked for what I needed in my app.

Add the following in c++

header file (.hpp)

public:
    Q_INVOKABLE void doNetworkRequest(QString url);

signals:
void networkReply(const QVariantMap &data);
void networkError();

private Q_SLOTS:
    void handleNetworkData(QNetworkReply *reply);

private:
    QNetworkAccessManager networkManager;

Then in add this in your main file (.cpp)

this goes inside the main app function

// Hook this signal so we can respond to network replies
connect(&networkManager, SIGNAL(finished(QNetworkReply *)), this,
        SLOT(handleNetworkData(QNetworkReply *)));

add these functions:

void Top12Wines::doNetworkRequest(QString url)
{
qDebug() << "Request URL " << url;
QUrl qurl = url;
networkManager.get(QNetworkRequest(qurl));
}

void Top12Wines::handleNetworkData(QNetworkReply *reply)
{

if (!reply->error()) {
    qDebug() << "Got network data";
    // Let's get ALL the data
    const QByteArray response(reply->readAll());

    JsonDataAccess jda;
    QVariantMap results = jda.loadFromBuffer(response).toMap();

    emit networkReply(results);

} else {
    qDebug() << "Got network error";
    emit networkError();
}

// Cleanup
reply->deleteLater();
}

Then in your QML you can access it like so:

    _App.networkReply.connect(checkVersion); //
    _App.networkError.connect(checkVersionError);
    _App.doNetworkRequest("http://myserver/version.json");

function checkVersion(data)
{
    _App.networkReply.disconnect(checkVersion); //disconnect links after retrieving data
    _App.networkError.disconnect(checkVersionError);
    var newVersion = data.version;
}

function checkVersionError()
{
    _App.networkReply.disconnect(checkVersion); //disconnect links after retrieving data
    _App.networkError.disconnect(checkVersionError);        
    //do something to alert user that an error occurred.
}