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Diffstat (limited to 'src/xml/doc/src/qt6-changes.qdoc')
| -rw-r--r-- | src/xml/doc/src/qt6-changes.qdoc | 118 |
1 files changed, 88 insertions, 30 deletions
diff --git a/src/xml/doc/src/qt6-changes.qdoc b/src/xml/doc/src/qt6-changes.qdoc index d4cba3c596..f3ff82130a 100644 --- a/src/xml/doc/src/qt6-changes.qdoc +++ b/src/xml/doc/src/qt6-changes.qdoc @@ -1,35 +1,11 @@ -/**************************************************************************** -** -** Copyright (C) 2020 The Qt Company Ltd. -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the documentation of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:FDL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** GNU Free Documentation License Usage -** Alternatively, this file may be used under the terms of the GNU Free -** Documentation License version 1.3 as published by the Free Software -** Foundation and appearing in the file included in the packaging of -** this file. Please review the following information to ensure -** the GNU Free Documentation License version 1.3 requirements -** will be met: https://www.gnu.org/licenses/fdl-1.3.html. -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2020 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only /*! \page xml-changes-qt6.html - \title Porting to Qt 6 - Qt XML - \ingroup porting-guides-5-to-6 - \brief Migrate Qt XML to Qt 6. + \title Changes to Qt XML + \ingroup changes-qt-5-to-6 + \brief Use QXmlStreamReader for reading XML files. Qt 6 is a result of the conscious effort to make the framework more efficient and easy to use. @@ -41,6 +17,88 @@ In this topic we summarize those changes in Qt XML, and provide guidance to handle them. - \section1 ADD STUFF HERE + \section1 Simple API for XML (SAX) parser + All \b SAX classes have been removed from Qt XML. Use + QXmlStreamReader for reading XML files. Here are some simple steps to + port your current code to QXmlStreamReader: + For example, if you have code like + + \code + QFile *file = new QFile(...); + QXmlInputSource *source = new QXmlInputSource(file); + + Handler *handler = new Handler; + + QXmlSimpleReader xmlReader; + xmlReader.setErrorHandler(handler); + xmlReader.setContentHandler(handler); + + if (xmlReader.parse(source)) { + ... // do processing + } else { + ... // do error handling + } + \endcode + + you can rewrite it as + + \code + QFile file = ...; + QXmlStreamReader reader(&file); + + while (!reader.atEnd()) { + reader.readNext(); + ... // do processing + } + if (reader.hasError()) { + ... // do error handling + } + \endcode + + \section2 QDom and QDomDocument + + As \b SAX classes have been removed from Qt XML, QDomDocument + has been re-implemented using QXmlStreamReader. + This causes a few behavioral changes: + + \list + \li Attribute values will be normalized. For example, + \c{<tag attr=" a \n b " />} is equivalent to \c{<tag attr="a b"/>}. + \li Identical qualified attribute names are no longer allowed. This + means attributes of an element must have unique names. + \li Undeclared namespace prefixes are no longer allowed. + \endlist + + If you use QDomDocument and rely on any of these, you must update + your code and XML documents accordingly. + + \section3 Spacing-only text nodes + + By default, text nodes containing only spacing characters are stripped + and won't appear in the QDomDocument. The Qt 5 way of changing this behavior + was using the QDomDocument::setContent() overload that allowed a \c QXmlReader + to be supplied. That overload was removed in Qt 6.0, but since Qt 6.5, + you can pass QDomDocument::ParseOption::PreserveSpacingOnlyNodes as a parse + option, to specify that spacing-only text nodes must be preserved. + + \section2 Qt Core5 compatibility library + + If your application or library cannot be ported right now, the \l + QXmlSimpleReader and related classes still exist in Qt5Compat to keep + old code-bases working. If you want to use those SAX classes further, you + need to link against the new Qt5Compat module and add this line to your \l + qmake \c .pro file: + + \code + QT += core5compat + \endcode + + In case you already ported your application or library to the + \l {Build with CMake}{cmake} build system, add the following to your + \c CMakeList.txt: + \code + PUBLIC_LIBRARIES + Qt::Core5Compat + \endcode */ |