I'm attempting to parse an xml file in C++ using a QXmlStreamReader (Qt 5.5.1). I'm using the XML file to map numeric keys to corresponding image files. I've gotten it to work with a simple XML file such as:
<?xml version="1.0" encoding="UTF-8"?>
<images>
<group1>
<image key="1" value="image1_group1.png"/>
<image key="2" value="image2_group1.png"/>
</group1>
<group2>
<image key="1" value="image1_group2.png"/>
<image key="2" value="image2_group2.png"/>
</group2>
</images>
using the following code:
#include <QFile>
xml_image_mapper::xml_image_mapper(QObject* p_parent_ptr)
{
QFile file("myfile.xml");
file.open(QFile::ReadOnly | QFile::Text);
QXmlStreamReader stream_reader(&file);
stream_reader.readNextStartElement();
while (stream_reader.readNextStartElement())
{
auto* inner_map_ptr = new QMap<quint32, QString>();
m_image_map.insert(stream_reader.name().toString(), inner_map_ptr);
parse_xml(stream_reader, *inner_map_ptr);
}
}
void xml_image_mapper::parse_xml(QXmlStreamReader& stream_reader, QMap<quint32, QString>& p_map)
{
while (stream_reader.readNextStartElement())
{
static const QString key_name = "key";
static const QString value_name = "value";
quint32 key;
QString value;
foreach (const QXmlStreamAttribute attribute, stream_reader.attributes())
{
if (key_name == attribute.name())
key = attribute.value().toInt();
else if (value_name == attribute.name())
value = attribute.value().toString();
p_map.insert(key, value);
}
stream_reader.skipCurrentElement();
}
}
This code correctly creates the map from numeric keys to filenames for the simple XML shown above, but fails to work for an XML file that includes references, such as:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE doc [
<!ENTITY group1 SYSTEM "group1.xml">
<!ENTITY group2 SYSTEM "group2.xml">
]>
<images>
<group1>
&group1;
</group1>
<group2>
&group2;
</group2>
</images>
Where group1.xml reads:
<?xml version="1.0" encoding="UTF-8"?>
<image key="1" value="image1_group1.png"/>
<image key="2" value="image2_group1.png"/>
and group2.xml reads:
<?xml version="1.0" encoding="UTF-8"?>
<image key="1" value="image1_group2.png"/>
<image key="2" value="image2_group2.png"/>
Is there a way to parse XML files with references to other XML files using a QXmlStreamReader?
From the Qt documentation:
QXmlStreamReader is a well-formed XML 1.0 parser that does not include external parsed entities.
So you seem to be out of luck here.