Better XML formatting using Boost? [duplicate] - c++

Question

This question already has answers here:
boost::property_tree XML pretty printing
(4 answers)
Closed 8 years ago.
I'm using Boost Property Trees to export my class-instants as XML nodes.
It works but it just puts everything in 1 line. I would like it to have indents, like:
<?xml version="1.0" encoding="utf-8"?>
<root>
<sensorconfigurations>
<configuration>
<name>SensorConfiguration1</name>
<sensorid>1</sensorid>
<signalindex>1</signalindex>
<mappingscheme>mappingscheme1</mappingscheme>
<soundpack>test1.wav</soundpack>
</configuration>
<configuration>
<name>SensorConfiguration2</name>
<sensorid>2</sensorid>
<signalindex>2</signalindex>
<mappingscheme>mappingscheme1</mappingscheme>
<soundpack>test2.wav</soundpack>
</configuration>
<configuration>
<name>SensorConfiguration3</name>
<sensorid>3</sensorid>
<signalindex>3</signalindex>
<mappingscheme>mappingscheme2</mappingscheme>
<soundpack>test3.wav</soundpack>
</configuration>
</sensorconfigurations>
</root>
Is this possible somehow? Am I missing a parameter in the write_xml method?
Here's my code:
void SensorConfigurationBank::save()
{
using boost::property_tree::ptree;
ptree pt;
for(map<string, SensorConfiguration>:: iterator it = sensorConfigurations_.begin(); it != sensorConfigurations_.end(); ++it)
{
ptree myTree;
myTree.put("name", it->second.getName());
myTree.put("sensorid", it->second.getSensorID());
myTree.put("signalindex", it->second.getsignalIndex());
MappingScheme myScheme = it->second.getMScheme();
myTree.put("mappingscheme", myScheme.getId());
SoundPack mySound = it->second.getSound();
myTree.put("soundpack", mySound.filepath_);
pt.add_child("root.sensorconfigurations.configuration", myTree);
}
write_xml("SensorConfigurationBank2.xml", pt);
}

Answer 1

These days, xml_writer_settings apparently takes a string type as template argument, so:
boost::property_tree::xml_writer_settings<std::string> settings('\t', 1);
write_xml(std::cout, pt, settings);
will do the trick. Full sample:
Live On Coliru
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>
#include <map>
#include <iostream>
struct SoundPack {
std::string filepath_ = "soundpack.wav";
};
struct MappingScheme {
std::string getId() const { return "Id"; }
};
struct SensorConfiguration {
std::string getName() const { return "Name"; }
std::string getSensorID() const { return "SensorID"; }
std::string getsignalIndex() const { return "signalIndex"; }
SoundPack getSound() const { return {}; }
MappingScheme getMScheme() const { return {}; }
};
void save(std::map<std::string, SensorConfiguration> sensorConfigurations_)
{
using boost::property_tree::ptree;
ptree pt;
for(std::map<std::string, SensorConfiguration>:: iterator it = sensorConfigurations_.begin(); it != sensorConfigurations_.end(); ++it)
{
ptree myTree;
MappingScheme myScheme = it->second.getMScheme();
SoundPack mySound = it->second.getSound();
myTree.put("name", it->second.getName());
myTree.put("sensorid", it->second.getSensorID());
myTree.put("signalindex", it->second.getsignalIndex());
myTree.put("mappingscheme", myScheme.getId());
myTree.put("soundpack", mySound.filepath_);
pt.add_child("root.sensorconfigurations.configuration", myTree);
}
boost::property_tree::xml_writer_settings<std::string> settings('\t', 1);
write_xml(std::cout, pt, settings);
}
int main() {
save({
{ "first", SensorConfiguration {} },
{ "second", SensorConfiguration {} },
{ "third", SensorConfiguration {} },
{ "fourth", SensorConfiguration {} }
});
}
Output:
<?xml version="1.0" encoding="utf-8"?>
<root>
<sensorconfigurations>
<configuration>
<name>Name</name>
<sensorid>SensorID</sensorid>
<signalindex>signalIndex</signalindex>
<mappingscheme>Id</mappingscheme>
<soundpack>soundpack.wav</soundpack>
</configuration>
<configuration>
<name>Name</name>
<sensorid>SensorID</sensorid>
<signalindex>signalIndex</signalindex>
<mappingscheme>Id</mappingscheme>
<soundpack>soundpack.wav</soundpack>
</configuration>
<configuration>
<name>Name</name>
<sensorid>SensorID</sensorid>
<signalindex>signalIndex</signalindex>
<mappingscheme>Id</mappingscheme>
<soundpack>soundpack.wav</soundpack>
</configuration>
<configuration>
<name>Name</name>
<sensorid>SensorID</sensorid>
<signalindex>signalIndex</signalindex>
<mappingscheme>Id</mappingscheme>
<soundpack>soundpack.wav</soundpack>
</configuration>
</sensorconfigurations>
</root>