Method checkCommonLevel

src/backend/datasources/MQTTClient.cpp:597–643

! *\brief Returns the '+' wildcard containing topic name, which includes the given topic names * * \param first the name of a topic * \param second the name of a topic * \return The name of the common topic, if it exists, otherwise an empty string */

 * \return The name of the common topic, if it exists, otherwise an empty string
 */
QString MQTTClient::checkCommonLevel(const QString& first, const QString& second) {
	QStringList firstList = first.split(QLatin1Char('/'), Qt::SkipEmptyParts);
	QStringList secondtList = second.split(QLatin1Char('/'), Qt::SkipEmptyParts);
	QString commonTopic;

	if (!firstList.isEmpty()) {
		// the two topics have to be the same size and can't be identic
		if ((firstList.size() == secondtList.size()) && (first != second)) {
			// the index where they differ
			int differIndex = -1;
			for (int i = 0; i < firstList.size(); ++i) {
				if (firstList.at(i) != secondtList.at(i)) {
					differIndex = i;
					break;
				}
			}

			// they can differ at only one level and that can't be the first
			bool differ = false;
			if (differIndex > 0) {
				for (int j = differIndex + 1; j < firstList.size(); ++j) {
					if (firstList.at(j) != secondtList.at(j)) {
						differ = true;
						break;
					}
				}
			} else
				differ = true;

			if (!differ) {
				for (int i = 0; i < firstList.size(); ++i) {
					if (i != differIndex) {
						commonTopic.append(firstList.at(i));
					} else {
						// we put '+' wildcard at the level where they differ
						commonTopic.append(QStringLiteral("+"));
					}

					if (i != firstList.size() - 1)
						commonTopic.append(QStringLiteral("/"));
				}
			}
		}
	}
	// qDebug() << first << " " << second << " common topic: "<<commonTopic;
	return commonTopic;
}

void MQTTClient::setWillSettings(const MQTTWill& settings) {
	m_MQTTWill = settings;