Qt Documentation (Technology Preview) | Qt Network Authorization | Twitter Timeline Example | twittertimelinemodel.cpp Example File

Qt 5.9.3 Reference Documentation

# twittertimelinemodel.cpp Example File

twittertimeline/twittertimelinemodel.cpp

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      #include "twittertimelinemodel.h"

      #include <QtGui>
      #include <QtCore>
      #include <QtWidgets>

      TwitterTimelineModel::TwitterTimelineModel(QObject *parent) : QAbstractTableModel(parent)
      {
          connect(&twitter, &Twitter::authenticated, this, &TwitterTimelineModel::authenticated);
          connect(&twitter, &Twitter::authenticated, this, &TwitterTimelineModel::updateTimeline);
      }

      int TwitterTimelineModel::rowCount(const QModelIndex &parent) const
      {
      #if defined(QT_DEBUG)
          Q_ASSERT(!parent.isValid());
      #else
          Q_UNUSED(parent)
      #endif
          return tweets.size();
      }

      QVariant TwitterTimelineModel::data(const QModelIndex &index, int role) const
      {
          if (role != Qt::DisplayRole)
              return QVariant();

          auto it = tweets.begin();
          std::advance(it, index.row());
          switch (index.column())
          {
          case 0:
              return QString::number(it->id);
          case 1:
              return it->createdAt.toString(Qt::SystemLocaleShortDate);
          case 2:
              return it->user;
          case 3:
              return it->text;
          }
          return QVariant();
      }

      int TwitterTimelineModel::columnCount(const QModelIndex &) const
      {
          return 4;
      }

      QVariant TwitterTimelineModel::headerData(int section, Qt::Orientation orientation, int role) const
      {
          if (role != Qt::DisplayRole)
              return QVariant();

          if (orientation == Qt::Horizontal) {
              switch (section) {
              case 0:
                  return QStringLiteral("Id");
              case 1:
                  return QStringLiteral("Created at");
              case 2:
                  return QStringLiteral("User");
              case 3:
                  return QStringLiteral("Text");
              }
          }
          return section;
      }

      void TwitterTimelineModel::authenticate(const QPair<QString, QString> &clientCredentials)
      {
          twitter.setClientCredentials(clientCredentials);
          twitter.grant();
      }

      QAbstractOAuth::Status TwitterTimelineModel::status() const
      {
          return twitter.status();
      }

      void TwitterTimelineModel::updateTimeline()
      {
          if (twitter.status() != Twitter::Status::Granted)
              QMessageBox::warning(nullptr, qApp->applicationName(), "Not authenticated");

          QUrl url("https://api.twitter.com/1.1/statuses/home_timeline.json");
          QVariantMap parameters;
          if (tweets.size()) {
              // Tweets are time-ordered, newest first.  Pass the most recent
              // ID we have to request everything more recent than it:
              parameters.insert("since_id", QString::number(tweets.first().id));
              // From https://dev.twitter.com/rest/reference/get/search/tweets:
              // Returns results with an ID greater than (that is, more recent than)
              // the specified ID. There are limits to the number of Tweets which can
              // be accessed through the API. If the limit of Tweets has occurred
              // since the since_id, the since_id will be forced to the oldest ID
              // available.
          }
          QNetworkReply *reply = twitter.get(url, parameters);
          connect(reply, &QNetworkReply::finished, this, &TwitterTimelineModel::parseJson);
      }

      void TwitterTimelineModel::parseJson()
      {
          QJsonParseError parseError;
          auto reply = qobject_cast<QNetworkReply*>(sender());
          Q_ASSERT(reply);
          const auto data = reply->readAll();
          const auto document = QJsonDocument::fromJson(data, &parseError);
          if (parseError.error) {
              qCritical() << "TwitterTimelineModel::parseJson. Error at:" << parseError.offset
                          << parseError.errorString();
              return;
          } else if (document.isObject()) {
              // Error received :(
              const auto object = document.object();
              const auto errorArray = object.value("errors").toArray();
              Q_ASSERT_X(errorArray.size(), "parse", data);
              QStringList errors;
              for (const auto error : errorArray) {
                  Q_ASSERT(error.isObject());
                  Q_ASSERT(error.toObject().contains("message"));
                  errors.append(error.toObject().value("message").toString());
              }
              QMessageBox::warning(nullptr, qApp->applicationName(), errors.join("<br />"));
              return;
          }

          Q_ASSERT_X(document.isArray(), "parse", data);
          const auto array = document.array();
          if (array.size()) {
              beginInsertRows(QModelIndex(), 0, array.size() - 1);
              auto before = tweets.begin();
              for (const auto &value : array) {
                  Q_ASSERT(value.isObject());
                  const auto object = value.toObject();
                  const auto createdAt = QDateTime::fromString(object.value("created_at").toString(),
                                                               "ddd MMM dd HH:mm:ss +0000 yyyy");
                  before = tweets.insert(before, Tweet{
                                             object.value("id").toVariant().toULongLong(),
                                             createdAt,
                                             object.value("user").toObject().value("name").toString(),
                                             object.value("text").toString()
                                         });
                  std::advance(before, 1);
              }
              endInsertRows();
          }
      }