sqlconversationmodel.cpp Example File

  /****************************************************************************
  **
  ** Copyright (C) 2015 The Qt Company Ltd.
  ** Contact: http://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** You may use this file under the terms of the BSD license as follows:
  **
  ** "Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
  **
  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  #include "sqlconversationmodel.h"

  #include <QDateTime>
  #include <QDebug>
  #include <QSqlError>
  #include <QSqlRecord>
  #include <QSqlQuery>

  static const char *conversationsTableName = "Conversations";

  static void createTable()
  {
      if (QSqlDatabase::database().tables().contains(conversationsTableName)) {
          // The table already exists; we don't need to do anything.
          return;
      }

      QSqlQuery query;
      if (!query.exec(
          "CREATE TABLE IF NOT EXISTS 'Conversations' ("
          "'author' TEXT NOT NULL,"
          "'recipient' TEXT NOT NULL,"
          "'timestamp' TEXT NOT NULL,"
          "'message' TEXT NOT NULL,"
          "FOREIGN KEY('author') REFERENCES Contacts ( name ),"
          "FOREIGN KEY('recipient') REFERENCES Contacts ( name )"
          ")")) {
          qFatal("Failed to query database: %s", qPrintable(query.lastError().text()));
      }

      query.exec("INSERT INTO Conversations VALUES('Me', 'Ernest Hemingway', '2016-01-07T14:36:06', 'Hello!')");
      query.exec("INSERT INTO Conversations VALUES('Ernest Hemingway', 'Me', '2016-01-07T14:36:16', 'Good afternoon.')");
      query.exec("INSERT INTO Conversations VALUES('Me', 'Albert Einstein', '2016-01-01T11:24:53', 'Hi!')");
      query.exec("INSERT INTO Conversations VALUES('Albert Einstein', 'Me', '2016-01-07T14:36:16', 'Good morning.')");
      query.exec("INSERT INTO Conversations VALUES('Hans Gude', 'Me', '2015-11-20T06:30:02', 'God morgen. Har du fått mitt maleri?')");
      query.exec("INSERT INTO Conversations VALUES('Me', 'Hans Gude', '2015-11-20T08:21:03', 'God morgen, Hans. Ja, det er veldig fint. Tusen takk! "
                 "Hvor mange timer har du brukt på den?')");
  }

  SqlConversationModel::SqlConversationModel(QObject *parent) :
      QSqlTableModel(parent)
  {
      createTable();
      setTable(conversationsTableName);
      setSort(2, Qt::DescendingOrder);
      // Ensures that the model is sorted correctly after submitting a new row.
      setEditStrategy(QSqlTableModel::OnManualSubmit);
  }

  QString SqlConversationModel::recipient() const
  {
      return m_recipient;
  }

  void SqlConversationModel::setRecipient(const QString &recipient)
  {
      if (recipient == m_recipient)
          return;

      m_recipient = recipient;

      const QString filterString = QString::fromLatin1(
          "(recipient = '%1' AND author = 'Me') OR (recipient = 'Me' AND author='%1')").arg(m_recipient);
      setFilter(filterString);
      select();

      emit recipientChanged();
  }

  QVariant SqlConversationModel::data(const QModelIndex &index, int role) const
  {
      if (role < Qt::UserRole)
          return QSqlTableModel::data(index, role);

      const QSqlRecord sqlRecord = record(index.row());
      return sqlRecord.value(role - Qt::UserRole);
  }

  QHash<int, QByteArray> SqlConversationModel::roleNames() const
  {
      QHash<int, QByteArray> names;
      names[Qt::UserRole] = "author";
      names[Qt::UserRole + 1] = "recipient";
      names[Qt::UserRole + 2] = "timestamp";
      names[Qt::UserRole + 3] = "message";
      return names;
  }

  void SqlConversationModel::sendMessage(const QString &recipient, const QString &message)
  {
      const QString timestamp = QDateTime::currentDateTime().toString(Qt::ISODate);

      QSqlRecord newRecord = record();
      newRecord.setValue("author", "Me");
      newRecord.setValue("recipient", recipient);
      newRecord.setValue("timestamp", timestamp);
      newRecord.setValue("message", message);
      if (!insertRecord(rowCount(), newRecord)) {
          qWarning() << "Failed to send message:" << lastError().text();
          return;
      }

      submitAll();
  }