C++/Qt/QDomDocument

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Get XML element by tag name

  
Foundations of Qt Development\Chapter08\xmldommodify\main.cpp
/*
 * Copyright (c) 2006-2007, Johan Thelin
 * 
 * All rights reserved.
 * 
 * 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 APress 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.
 *
 */
#include <QFile>
#include <QTextStream>
#include <QDomDocument>
#include <QDomElement>
#include <QDomText>
int main( int argc, char **argv )
{
  QFile inFile( "simple.xml" );
  if( !inFile.open( QIODevice::ReadOnly | QIODevice::Text ) )
  {
    qDebug( "Failed to open file for reading." );
    return 0;
  }
  QDomDocument document;
  if( !document.setContent( &inFile ) )
  {
    qDebug( "Failed to parse the file into a DOM tree." );
    inFile.close();
    return 0;
  }
  
  inFile.close();
  QDomElement documentElement = document.documentElement();
  QDomNodeList elements = documentElement.elementsByTagName( "bar" );
  if( elements.size() == 0 )
  {
    QDomElement bar = document.createElement( "bar" );
    documentElement.insertBefore( bar, QDomNode() );
  }
  else if( elements.size() == 1 )
  {
    QDomElement bar = elements.at(0).toElement();
    
    QDomElement baz = document.createElement( "baz" );
    baz.setAttribute( "count", QString::number( bar.elementsByTagName( "baz" ).size() + 1 ) );
      
    bar.appendChild( baz );
  }
  QFile outFile( "simple-modified.xml" );
  if( !outFile.open( QIODevice::WriteOnly | QIODevice::Text ) )
  {
    qDebug( "Failed to open file for writing." );
    return 0;
  }
  
  QTextStream stream( &outFile );
  stream << document.toString();
  
  outFile.close();
  
  return 0;
}


Put table to text document

  
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef XMLWRITER_H
#define XMLWRITER_H
#include <QDomDocument>
class QTextDocument;
class XmlWriter
{
public:
    XmlWriter(QTextDocument *document) : textDocument(document) {}
    QDomDocument *toXml();
private:
    void processBlock(QDomElement &parent, const QTextBlock &block);
    void processFrame(QDomElement &parent, QTextFrame *frame);
    void processTable(QDomElement &parent, QTextTable *table);
    void processTableCell(QDomElement &parent, const QTextTableCell &cell);
    QDomDocument *document;
    QTextDocument *textDocument;
};
#endif



#include <QtGui>
#include "xmlwriter.h"
QDomDocument *XmlWriter::toXml()
{
    QDomImplementation implementation;
    QDomDocumentType docType = implementation.createDocumentType(
        "scribe-document", "scribe", "qt,nokia.com/scribe");
    document = new QDomDocument(docType);
    // ### This processing instruction is required to ensure that any kind
    // of encoding is given when the document is written.
    QDomProcessingInstruction process = document->createProcessingInstruction(
        "xml", "version=\"1.0\" encoding=\"utf-8\"");
    document->appendChild(process);
    QDomElement documentElement = document->createElement("document");
    document->appendChild(documentElement);
    QTextFrame *root = textDocument->rootFrame();
    
    if (root)
        processFrame(documentElement, root);
    return document;
}
void XmlWriter::processBlock(QDomElement &parent, const QTextBlock &block)
{
    QDomElement blockElement = document->createElement("block");
    blockElement.setAttribute("position", block.position());
    blockElement.setAttribute("length", block.length());
    parent.appendChild(blockElement);
    QTextBlock::iterator it;
    for (it = block.begin(); !(it.atEnd()); ++it) {
        QTextFragment fragment = it.fragment();
        if (fragment.isValid()) {
            QDomElement fragmentElement = document->createElement("fragment");
            blockElement.appendChild(fragmentElement);
            fragmentElement.setAttribute("length", fragment.length());
            QDomText fragmentText = document->createTextNode(fragment.text());
            fragmentElement.appendChild(fragmentText);
        }
    }
}
void XmlWriter::processFrame(QDomElement &parent, QTextFrame *frame)
{
    QDomElement frameElement = document->createElement("frame");
    frameElement.setAttribute("begin", frame->firstPosition());
    frameElement.setAttribute("end", frame->lastPosition());
    parent.appendChild(frameElement);

    QTextFrame::iterator it;
    for (it = frame->begin(); !(it.atEnd()); ++it) {
        QTextFrame *childFrame = it.currentFrame();
        QTextBlock childBlock = it.currentBlock();
        if (childFrame) {
            QTextTable *childTable = qobject_cast<QTextTable*>(childFrame);
            if (childTable)
                processTable(frameElement, childTable);
            else
                processFrame(frameElement, childFrame);
        } else if (childBlock.isValid())
 
            processBlock(frameElement, childBlock);
    }
}
void XmlWriter::processTable(QDomElement &parent, QTextTable *table)
{
    QDomElement element = document->createElement("table");
    for (int row = 0; row < table->rows(); ++row) {
        for (int column = 0; column < table->columns(); ++column) {
            QTextTableCell cell = table->cellAt(row, column);
            processTableCell(element, cell);
        }
    }
    parent.appendChild(element);
}
void XmlWriter::processTableCell(QDomElement &parent, const QTextTableCell &cell)
{
    QDomElement element = document->createElement("cell");
    element.setAttribute("row", cell.row());
    element.setAttribute("column", cell.column());
    
    QTextFrame::iterator it;
    for (it = cell.begin(); !(it.atEnd()); ++it) {
        QTextFrame *childFrame = it.currentFrame();
        QTextBlock childBlock = it.currentBlock();
        if (childFrame)
            processFrame(element, childFrame);
        else if (childBlock.isValid())
            processBlock(element, childBlock);
    }
    parent.appendChild(element);
}



#ifndef WINDOW_H
#define WINDOW_H
#include <QMainWindow>
class QTextEdit;
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow();
public slots:
    void saveFile();
    void showTable();
private:
    bool writeXml(const QString &fileName);
    QTextEdit *editor;
};
#endif


#include <QtGui>
#include "mainwindow.h"
#include "xmlwriter.h"
MainWindow::MainWindow()
{
    QMenu *fileMenu = new QMenu(tr("&File"));
    QAction *saveAction = fileMenu->addAction(tr("&Save..."));
    saveAction->setShortcut(tr("Ctrl+S"));
    QAction *quitAction = fileMenu->addAction(tr("E&xit"));
    quitAction->setShortcut(tr("Ctrl+Q"));
    QMenu *showMenu = new QMenu(tr("&Show"));
    QAction *showTableAction = showMenu->addAction(tr("&Table"));
    menuBar()->addMenu(fileMenu);
    menuBar()->addMenu(showMenu);
    editor = new QTextEdit();
 
    QTextCursor cursor(editor->textCursor());
    cursor.movePosition(QTextCursor::Start);

    int rows = 11;
    int columns = 4;

    QTextTableFormat tableFormat;
    tableFormat.setBackground(QColor("#e0e0e0"));
    QVector<QTextLength> constraints;
    constraints << QTextLength(QTextLength::PercentageLength, 16);
    constraints << QTextLength(QTextLength::PercentageLength, 28);
    constraints << QTextLength(QTextLength::PercentageLength, 28);
    constraints << QTextLength(QTextLength::PercentageLength, 28);
    tableFormat.setColumnWidthConstraints(constraints);
    QTextTable *table = cursor.insertTable(rows, columns, tableFormat);
 
    int column;
    int row;
    QTextTableCell cell;
    QTextCursor cellCursor;
    
    QTextCharFormat charFormat;
    charFormat.setForeground(Qt::black);

    cell = table->cellAt(0, 0);
    cellCursor = cell.firstCursorPosition();
    cellCursor.insertText(tr("Week"), charFormat);

    for (column = 1; column < columns; ++column) {
        cell = table->cellAt(0, column);
        cellCursor = cell.firstCursorPosition();
        cellCursor.insertText(tr("Team %1").arg(column), charFormat);
    }
    for (row = 1; row < rows; ++row) {
        cell = table->cellAt(row, 0);
        cellCursor = cell.firstCursorPosition();
        cellCursor.insertText(tr("%1").arg(row), charFormat);
        for (column = 1; column < columns; ++column) {
            if ((row-1) % 3 == column-1) {
 
                cell = table->cellAt(row, column);
                QTextCursor cellCursor = cell.firstCursorPosition();
                cellCursor.insertText(tr("On duty"), charFormat);
            }
 
        }
 
    }

    connect(saveAction, SIGNAL(triggered()), this, SLOT(saveFile()));
    connect(quitAction, SIGNAL(triggered()), this, SLOT(close()));
    connect(showTableAction, SIGNAL(triggered()), this, SLOT(showTable()));
    setCentralWidget(editor);
    setWindowTitle(tr("Text Document Tables"));
}
void MainWindow::saveFile()
{
    QString fileName = QFileDialog::getSaveFileName(this,
        tr("Save document as:"), "", tr("XML (*.xml)"));
    if (!fileName.isEmpty()) {
        if (writeXml(fileName))
            setWindowTitle(fileName);
        else
            QMessageBox::warning(this, tr("Warning"),
                tr("Failed to save the document."), QMessageBox::Cancel,
                QMessageBox::NoButton);
    }
}
void MainWindow::showTable()
{
    QTextCursor cursor = editor->textCursor();
    QTextTable *table = cursor.currentTable();
    if (!table)
        return;
    QTableWidget *tableWidget = new QTableWidget(table->rows(), table->columns());

    for (int row = 0; row < table->rows(); ++row) {
        for (int column = 0; column < table->columns(); ++column) {
            QTextTableCell tableCell = table->cellAt(row, column);
            QTextFrame::iterator it;
            QString text;
            for (it = tableCell.begin(); !(it.atEnd()); ++it) {
                QTextBlock childBlock = it.currentBlock();
                if (childBlock.isValid())
                    text += childBlock.text();
            }
            QTableWidgetItem *newItem = new QTableWidgetItem(text);
            tableWidget->setItem(row, column, newItem);
            /*
            processTableCell(tableCell);
            */
        }
 
    }

    tableWidget->setWindowTitle(tr("Table Contents"));
    tableWidget->show();
}
bool MainWindow::writeXml(const QString &fileName)
{
    XmlWriter documentWriter(editor->document());
    QDomDocument *domDocument = documentWriter.toXml();
    QFile file(fileName);
    if (file.open(QFile::WriteOnly)) {
        QTextStream textStream(&file);
        textStream.setCodec(QTextCodec::codecForName("UTF-8"));
        textStream << domDocument->toString(1).toUtf8();
        file.close();
        return true;
    }
    else
        return false;
}


#include <QtGui>
#include "mainwindow.h"
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow *window = new MainWindow;
    window->resize(480, 480);
    window->show();
    return app.exec();
}


Save created xml document to a file

  
Foundations of Qt Development\Chapter08\xmldommodify\main.cpp
/*
 * Copyright (c) 2006-2007, Johan Thelin
 * 
 * All rights reserved.
 * 
 * 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 APress 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.
 *
 */
#include <QFile>
#include <QTextStream>
#include <QDomDocument>
#include <QDomElement>
#include <QDomText>
int main( int argc, char **argv )
{
  QFile inFile( "simple.xml" );
  if( !inFile.open( QIODevice::ReadOnly | QIODevice::Text ) )
  {
    qDebug( "Failed to open file for reading." );
    return 0;
  }
  QDomDocument document;
  if( !document.setContent( &inFile ) )
  {
    qDebug( "Failed to parse the file into a DOM tree." );
    inFile.close();
    return 0;
  }
  
  inFile.close();
  QDomElement documentElement = document.documentElement();
  QDomNodeList elements = documentElement.elementsByTagName( "bar" );
  if( elements.size() == 0 )
  {
    QDomElement bar = document.createElement( "bar" );
    documentElement.insertBefore( bar, QDomNode() );
  }
  else if( elements.size() == 1 )
  {
    QDomElement bar = elements.at(0).toElement();
    
    QDomElement baz = document.createElement( "baz" );
    baz.setAttribute( "count", QString::number( bar.elementsByTagName( "baz" ).size() + 1 ) );
      
    bar.appendChild( baz );
  }
  QFile outFile( "simple-modified.xml" );
  if( !outFile.open( QIODevice::WriteOnly | QIODevice::Text ) )
  {
    qDebug( "Failed to open file for writing." );
    return 0;
  }
  
  QTextStream stream( &outFile );
  stream << document.toString();
  
  outFile.close();
  
  return 0;
}