Saturday, April 28, 2012

Upload photo on facebook using Qt

Some time back I wrote blog post about how to Post message on facebook wall, Here is link.

This post I will show how to upload a photo from local machine to facebook. On facebook photo can be uploaded to application's album or existing album created by user or application.

Where photo will be uploaded is decided by URL used during http requst.

https://graph.facebook.com/USER_ID/photos will upload photo to application's album, https://graph.facebook.com/ALBUM_ID/photos will upload photo to specific album indicated by ALBUM_ID.

My code describe method to upload photo to application's album. You can visit this post to know how to login and how to post message on facebook wall.

This post describe process how to upload photo using php, I tried to convert that code to Qt code. As code shows that photo is uploaded using multipart/form-data method, we need to create post request with multipart/form-data method.

Following code describe the process.

void FacebookHelper::uploadPicture(const QString& picLocation, 
    const QString& comment) {
    if( !isAuthorized() ) {
        qDebug() << "Please login first...";
        emit messageStatus(1,"Please login first...");
        return;
    }

   // Show photo upload form to user and post to the Graph URL
    QString uploadUrl = "https://graph.facebook.com/me/photos?access_token="
       + mAccessToken;

    QFileInfo fileInfo(picLocation);
    QFile file(picLocation);
    if (!file.open(QIODevice::ReadWrite)) {
        qDebug() << "Can not open file:" << picLocation;
        emit messageStatus(2,"Could not open file" + picLocation);
        return;
    }

    QString bound="---------------------------723690991551375881941828858";
    QByteArray data(QString("--"+bound+"\r\n").toAscii());
    data += "Content-Disposition: form-data; name=\"action\"\r\n\r\n";
    data += "\r\n";
    data += QString("--" + bound + "\r\n").toAscii();
    data += "Content-Disposition: form-data; name=\"source\"; filename=\""
             +file.fileName()+"\"\r\n";
    data += "Content-Type: image/"+fileInfo.suffix().toLower()+"\r\n\r\n";
    data += file.readAll();
    data += "\r\n";
    data += QString("--" + bound + "\r\n").toAscii();
    data += QString("--" + bound + "\r\n").toAscii();
    data += "Content-Disposition: form-data; name=\"message\"\r\n\r\n";
    data += comment.toAscii();
    data += "\r\n";
    data += "\r\n";

    QNetworkRequest request(uploadUrl);
    request.setRawHeader(QByteArray("Content-Type"),
           QString("multipart/form-data; boundary=" + bound).toAscii());
    request.setRawHeader(QByteArray("Content-Length"),
          QString::number(data.length()).toAscii());
    mCurrentRequest = mNetManager.post(request,data);
    connect(mCurrentRequest,SIGNAL(finished()),this,SLOT(messageResponse()));
}

2 comments:

  1. hi, i used tis code but it doesn't work. why?

    ReplyDelete
  2. can you please provide some more information ? any debug log , how it does not work ? any error ?

    ReplyDelete