Revision control
++ // Copyright (C) 2016 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include "rsslisting.h"
++
++ #include <QtCore>
++ #include <QtWidgets>
++ #include <QtNetwork>
++
++ //! [setup]
++ RSSListing::RSSListing(const QString &url, QWidget *parent)
++ : QWidget(parent), currentReply(0)
++ {
++ connect(&manager, &QNetworkAccessManager::finished, this, &RSSListing::finished);
++
++ lineEdit = new QLineEdit(this);
++ lineEdit->setText(url);
++ connect(lineEdit, &QLineEdit::returnPressed, this, &RSSListing::fetch);
++
++ fetchButton = new QPushButton(tr("Fetch"), this);
++ connect(fetchButton, &QPushButton::clicked, this, &RSSListing::fetch);
++
++ treeWidget = new QTreeWidget(this);
++ connect(treeWidget, &QTreeWidget::itemActivated,
++ // Open the link in the browser:
++ this, [](QTreeWidgetItem *item) { QDesktopServices::openUrl(QUrl(item->text(1))); });
++ treeWidget->setHeaderLabels(QStringList { tr("Title"), tr("Link") });
++ treeWidget->header()->setSectionResizeMode(QHeaderView::ResizeToContents);
++
++ QHBoxLayout *hboxLayout = new QHBoxLayout;
++ hboxLayout->addWidget(lineEdit);
++ hboxLayout->addWidget(fetchButton);
++
++ QVBoxLayout *layout = new QVBoxLayout(this);
++ layout->addLayout(hboxLayout);
++ layout->addWidget(treeWidget);
++
++ setWindowTitle(tr("RSS listing example"));
++ resize(640, 480);
++ }
++ //! [setup]
++
++ //! [slots]
++ void RSSListing::fetch()
++ {
++ lineEdit->setReadOnly(true);
++ fetchButton->setEnabled(false);
++ treeWidget->clear();
++
++ get(QUrl(lineEdit->text()));
++ }
++
++ void RSSListing::consumeData()
++ {
++ int statusCode = currentReply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
++ if (statusCode >= 200 && statusCode < 300)
++ parseXml();
++ }
++
++ void RSSListing::error(QNetworkReply::NetworkError)
++ {
++ qWarning("error retrieving RSS feed");
++ xml.clear();
++ currentReply->disconnect(this);
++ currentReply->deleteLater();
++ currentReply = nullptr;
++ }
++
++ void RSSListing::finished(QNetworkReply *reply)
++ {
++ Q_UNUSED(reply);
++ lineEdit->setReadOnly(false);
++ fetchButton->setEnabled(true);
++ }
++ //! [slots]
++
++ // Private methods
++
++ //! [get]
++ void RSSListing::get(const QUrl &url)
++ {
++ if (currentReply) {
++ currentReply->disconnect(this);
++ currentReply->deleteLater();
++ }
++ currentReply = url.isValid() ? manager.get(QNetworkRequest(url)) : nullptr;
++ if (currentReply) {
++ connect(currentReply, &QNetworkReply::readyRead, this, &RSSListing::consumeData);
++ connect(currentReply, &QNetworkReply::errorOccurred, this, &RSSListing::error);
++
++ }
++ xml.setDevice(currentReply); // Equivalent to clear() if currentReply is null.
++ }
++ //! [get]
++
++ // TODO: this is a candidate for showing how to use coroutines, once available.
++ //! [parse]
++ void RSSListing::parseXml()
++ {
++ while (!xml.atEnd()) {
++ xml.readNext();
++ if (xml.isStartElement()) {
++ if (xml.name() == u"item") {
++ linkString = xml.attributes().value("rss:about").toString();
++ titleString.clear();
++ }
++ currentTag = xml.name().toString();
++ } else if (xml.isEndElement()) {
++ if (xml.name() == u"item") {
++
++ QTreeWidgetItem *item = new QTreeWidgetItem;
++ item->setText(0, titleString);
++ item->setText(1, linkString);
++ treeWidget->addTopLevelItem(item);
++ }
++ } else if (xml.isCharacters() && !xml.isWhitespace()) {
++ if (currentTag == "title")
++ titleString += xml.text();
++ else if (currentTag == "link")
++ linkString += xml.text();
++ }
++ }
++ if (xml.error() && xml.error() != QXmlStreamReader::PrematureEndOfDocumentError)
++ qWarning() << "XML ERROR:" << xml.lineNumber() << ": " << xml.errorString();
++ }
++ //! [parse]