summaryrefslogtreecommitdiffstats
path: root/src/xmlpatterns/api/qxmlformatter.cpp
blob: 7e1c1f569c8cfe8ee8a9483382c4e7d6f457de01 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (qt-info@nokia.com)
**
** This file is part of the QtXmlPatterns module 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 either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** 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 1.0, 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 are unsure which license is appropriate for your use, please
** contact the sales department at qt-sales@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/

#include <QtDebug>

#include "qxmlformatter.h"
#include "qxpathhelper_p.h"
#include "qxmlserializer_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

class QXmlFormatterPrivate : public QXmlSerializerPrivate
{
public:
    inline QXmlFormatterPrivate(const QXmlQuery &q,
                                QIODevice *const outputDevice);

    int             indentationDepth;
    int             currentDepth;
    QString         characterBuffer;
    QString         indentString;

    /**
     * Whether we /have/ sent nodes like processing instructions and comments
     * to QXmlSerializer.
     */
    QStack<bool>    canIndent;
};

QXmlFormatterPrivate::QXmlFormatterPrivate(const QXmlQuery &query,
                                           QIODevice *const outputDevice) : QXmlSerializerPrivate(query, outputDevice)
                                                                          , indentationDepth(4)
                                                                          , currentDepth(0)
{
    indentString.reserve(30);
    indentString.resize(1);
    indentString[0] = QLatin1Char('\n');
    canIndent.push(false);
}

/*!
   \class QXmlFormatter
   \brief The QXmlFormatter class is an implementation of QXmlSerializer for transforming XQuery output into formatted XML.
   \reentrant
   \since 4.4
   \ingroup xml-tools

   QXmlFormatter is a subclass of QXmlSerializer that formats the XML
   output to make it easier for humans to read.

   QXmlSerializer outputs XML without adding unnecessary whitespace.
   In particular, it does not add \e {newlines} and indentation.
   To make the XML output easier to read, QXmlFormatter adds \e{newlines}
   and indentation by adding, removing, and modifying
   \l{XQuery Sequence}{sequence nodes} that only consist of whitespace.
   It also modifies whitespace in other places where it is not
   significant; e.g., between attributes and in the document prologue.

   For example, where the base class QXmlSerializer would
   output this:

   \quotefile doc/src/snippets/patternist/notIndented.xml

   QXmlFormatter outputs this:

   \quotefile doc/src/snippets/patternist/indented.xml

   If you just want to serialize your XML in a human-readable
   format, use QXmlFormatter as it is. The default indentation
   level is 4 spaces, but you can set your own indentation value
   setIndentationDepth().

   The \e{newlines} and indentation added by QXmlFormatter are
   suitable for common formats, such as XHTML, SVG, or Docbook,
   where whitespace is not significant. However, if your XML will
   be used as input where whitespace is significant, then you must
   write your own subclass of QXmlSerializer or QAbstractXmlReceiver.

   Note that using QXmlFormatter instead of QXmlSerializer will
   increase computational overhead and document storage size due
   to the insertion of whitespace.

   Note also that the indentation style used by QXmlFormatter
   remains loosely defined and may change in future versions of
   Qt. If a specific indentation style is required then either
   use the base class QXmlSerializer directly, or write your own
   subclass of QXmlSerializer or QAbstractXmlReceiver.
   Alternatively, you can subclass QXmlFormatter and reimplement
   the callbacks there.

   \snippet doc/src/snippets/code/src_xmlpatterns_api_qxmlformatter.cpp 0
*/

/*!
  Constructs a formatter that uses the name pool and message
  handler in \a query, and writes the result to \a outputDevice
  as formatted XML.

  \a outputDevice is passed directly to QXmlSerializer's constructor.

  \sa QXmlSerializer
 */
QXmlFormatter::QXmlFormatter(const QXmlQuery &query,
                             QIODevice *outputDevice) : QXmlSerializer(new QXmlFormatterPrivate(query, outputDevice))
{
}

/*!
  \internal
 */
void QXmlFormatter::startFormattingContent()
{
    Q_D(QXmlFormatter);

    if(QPatternist::XPathHelper::isWhitespaceOnly(d->characterBuffer))
    {
        if(d->canIndent.top())
            QXmlSerializer::characters(QStringRef(&d->indentString));
    }
    else
    {
        if(!d->characterBuffer.isEmpty()) /* Significant data, we don't touch it. */
            QXmlSerializer::characters(QStringRef(&d->characterBuffer));
    }

    d->characterBuffer.clear();
}

/*!
  \reimp
 */
void QXmlFormatter::startElement(const QXmlName &name)
{
    Q_D(QXmlFormatter);
    startFormattingContent();
    ++d->currentDepth;
    d->indentString.append(QString(d->indentationDepth, QLatin1Char(' ')));
    d->canIndent.push(true);

    QXmlSerializer::startElement(name);
}

/*!
  \reimp
 */
void QXmlFormatter::endElement()
{
    Q_D(QXmlFormatter);
    --d->currentDepth;
    d->indentString.chop(d->indentationDepth);

    if(!d->hasClosedElement.top().second)
        d->canIndent.top() = false;

    startFormattingContent();

    d->canIndent.pop();
    d->canIndent.top() = true;
    QXmlSerializer::endElement();
}

/*!
  \reimp
 */
void QXmlFormatter::attribute(const QXmlName &name,
                              const QStringRef &value)
{
    QXmlSerializer::attribute(name, value);
}

/*!
 \reimp
 */
void QXmlFormatter::comment(const QString &value)
{
    Q_D(QXmlFormatter);
    startFormattingContent();
    QXmlSerializer::comment(value);
    d->canIndent.top() = true;
}

/*!
 \reimp
 */
void QXmlFormatter::characters(const QStringRef &value)
{
    Q_D(QXmlFormatter);
    d->isPreviousAtomic = false;
    d->characterBuffer += value.toString();
}

/*!
 \reimp
 */
void QXmlFormatter::processingInstruction(const QXmlName &name,
                                          const QString &value)
{
    Q_D(QXmlFormatter);
    startFormattingContent();
    QXmlSerializer::processingInstruction(name, value);
    d->canIndent.top() = true;
}

/*!
 \reimp
 */
void QXmlFormatter::atomicValue(const QVariant &value)
{
    Q_D(QXmlFormatter);
    d->canIndent.top() = false;
    QXmlSerializer::atomicValue(value);
}

/*!
 \reimp
 */
void QXmlFormatter::startDocument()
{
    QXmlSerializer::startDocument();
}

/*!
 \reimp
 */
void QXmlFormatter::endDocument()
{
    QXmlSerializer::endDocument();
}

/*!
 \reimp
 */
void QXmlFormatter::startOfSequence()
{
    QXmlSerializer::startOfSequence();
}

/*!
 \reimp
 */
void QXmlFormatter::endOfSequence()
{
    Q_D(QXmlFormatter);

    /* Flush any buffered content. */
    if(!d->characterBuffer.isEmpty())
        QXmlSerializer::characters(QStringRef(&d->characterBuffer));

    d->write('\n');
    QXmlSerializer::endOfSequence();
}

/*!
 \internal
 */
void QXmlFormatter::item(const QPatternist::Item &item)
{
    Q_D(QXmlFormatter);

    if(item.isAtomicValue())
    {
        if(QPatternist::XPathHelper::isWhitespaceOnly(item.stringValue()))
           return;
        else
        {
            d->canIndent.top() = false;
            startFormattingContent();
        }
    }

    QXmlSerializer::item(item);
}

/*!
  Returns the number of spaces QXmlFormatter will output for each
  indentation level. The default is four.

 \sa setIndentationDepth()
 */
int QXmlFormatter::indentationDepth() const
{
    Q_D(const QXmlFormatter);
    return d->indentationDepth;
}

/*!
  Sets \a depth to be the number of spaces QXmlFormatter will
  output for level of indentation. The default is four.

 \sa indentationDepth()
 */
void QXmlFormatter::setIndentationDepth(int depth)
{
    Q_D(QXmlFormatter);
    d->indentationDepth = depth;
}

QT_END_NAMESPACE