/****************************************************************************+
−
**+
−
** Copyright (C) 2010 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.+
−
**+
−
** $QT_BEGIN_LICENSE:LGPL$+
−
** No Commercial Usage+
−
** This file contains pre-release code and may not be distributed.+
−
** You may use this file in accordance with the terms and conditions+
−
** contained in the Technology Preview License Agreement accompanying+
−
** this package.+
−
**+
−
** 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.+
−
**+
−
** If you have questions regarding the use of this file, please contact+
−
** Nokia at qt-info@nokia.com.+
−
**+
−
**+
−
**+
−
**+
−
**+
−
**+
−
**+
−
**+
−
** $QT_END_LICENSE$+
−
**+
−
****************************************************************************/+
−
+
−
/*!+
−
  \example xmlpatterns/schema+
−
  \title XML Schema Validation Example+
−
+
−
  This example shows how to use QtXmlPatterns to validate XML with+
−
  a W3C XML Schema.+
−
+
−
  \tableofcontents+
−
+
−
  \section1 Introduction+
−
+
−
  The example application shows different XML schema definitions and+
−
  for every definition two XML instance documents, one that is valid+
−
  according to the schema and one that is not.+
−
  The user can select the valid or invalid instance document, change+
−
  it and validate it again.+
−
+
−
  \section2 The User Interface+
−
+
−
  The UI for this example was created using \l{Qt Designer Manual} {Qt+
−
  Designer}:+
−
+
−
  \image schema-example.png+
−
+
−
  The UI consists of three parts, at the top the XML schema \l{QComboBox} {selection}+
−
  and the schema \l{QTextBrowser} {viewer}, below the XML instance \l{QComboBox} {selection}+
−
  and the instance \l{QTextEdit} {editor} and at the bottom the validation status \l{QLabel} {label}+
−
  next to the validation \l{QPushButton} {button}.+
−
+
−
  \section2 Validating XML Instance Documents+
−
+
−
  You can select one of the three predefined XML schemas and for each schema+
−
  an valid or invalid instance document. A click on the 'Validate' button will+
−
  validate the content of the XML instance editor against the schema from the+
−
  XML schema viewer. As you can modify the content of the instance editor, different+
−
  instances can be tested and validation error messages analysed.+
−
+
−
  \section1 Code Walk-Through+
−
+
−
  The example's main() function creates the standard instance of+
−
  QApplication. Then it creates an instance of the mainwindow class, shows it,+
−
  and starts the Qt event loop:+
−
+
−
  \snippet examples/xmlpatterns/schema/main.cpp 0+
−
+
−
  \section2 The UI Class: MainWindow+
−
+
−
  The example's UI is a conventional Qt GUI application inheriting+
−
  QMainWindow and the class generated by \l{Qt Designer Manual} {Qt+
−
  Designer}:+
−
+
−
  \snippet examples/xmlpatterns/schema/mainwindow.h 0+
−
+
−
  The constructor fills the schema and instance \l{QComboBox} selections with the predefined+
−
  schemas and instances and connects their \l{QComboBox::currentIndexChanged()} {currentIndexChanged()}+
−
  signals to the window's \c{schemaSelected()} resp. \c{instanceSelected()} slot.+
−
  Furthermore the signal-slot connections for the validation \l{QPushButton} {button}+
−
  and the instance \l{QTextEdit} {editor} are set up.+
−
+
−
  The call to \c{schemaSelected(0)} and \c{instanceSelected(0)} will trigger the validation+
−
  of the initial Contact Schema example.+
−
+
−
  \snippet examples/xmlpatterns/schema/mainwindow.cpp 0+
−
+
−
  In the \c{schemaSelected()} slot the content of the instance \l{QComboBox} {selection}+
−
  is adapted to the selected schema and the corresponding schema is loaded from the+
−
  \l{The Qt Resource System} {resource file} and displayed in the schema \l{QTextBrowser} {viewer}.+
−
  At the end of the method a revalidation is triggered.+
−
+
−
  \snippet examples/xmlpatterns/schema/mainwindow.cpp 1+
−
+
−
  In the \c{instanceSelected()} slot the selected instance is loaded from the+
−
  \l{The Qt Resource System} {resource file} and loaded into the instance \l{QTextEdit} {editor}+
−
  an the revalidation is triggered again.+
−
+
−
  \snippet examples/xmlpatterns/schema/mainwindow.cpp 2+
−
+
−
  The \c{validate()} slot does the actual work in this example.+
−
  At first it stores the content of the schema \l{QTextBrowser} {viewer} and the+
−
  \l{QTextEdit} {editor} into temporary \l{QByteArray} {variables}.+
−
  Then it instanciates a \c{MessageHandler} object which inherits from+
−
  \l{QAbstractMessageHandler} {QAbstractMessageHandler} and is a convenience+
−
  class to store error messages from the XmlPatterns system.+
−
+
−
  \snippet examples/xmlpatterns/schema/mainwindow.cpp 4+
−
+
−
  After the \l{QXmlSchema} {QXmlSchema} is instanciated and the message handler set+
−
  on it, the \l{QXmlSchema::load()} {load()} method is called with the schema data as argument.+
−
  If the schema is invalid or a parsing error has occured, \l{QXmlSchema::isValid()} {isValid()}+
−
  returns \c{false} and the error is flagged in \c{errorOccurred}.+
−
  If the loading was successful, a \l{QXmlSchemaValidator} {QXmlSchemaValidator} is+
−
  instanciated and the schema passed in the constructor.+
−
  A call to \l{QXmlSchemaValidator::validate()} {validate()} will validate the passed+
−
  XML instance data against the XML schema. The return value of that method signals+
−
  whether the validation was successful.+
−
  Depending on the success the status \l{QLabel} {label} is set to 'validation successful'+
−
  or the error message stored in the \c{MessageHandler}+
−
+
−
  The rest of the code does only some fancy coloring and eyecandy.+
−
+
−
  \snippet examples/xmlpatterns/schema/mainwindow.cpp 3+
−
*/+
−