CODEWITHSUNDEEP
c++xmlboostboost-propertytree
Hummingbird
Hummingbird

Reputation: 645

Accessing multi-valued keys in Property Tree

I am trying to query multi-valued keys in Property Tree.

I have taken the reference from this SO link.

Here is a piece of my Xml:

<Element type="MyType">
<Name type="Number">
<KeyFrame time="0">1920</KeyFrame>
<KeyFrame time="3000">1080</KeyFrame>
<KeyFrame time="4000">720</KeyFrame>
</Name>
</Element>

Following is the code :

#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>
#include <sstream>
#include <iostream>

using boost::property_tree::ptree;

int main() {
    std::stringstream ss("<Element type=\"MyType\">" 
    "<Name type=\"Number\">"
    "<KeyFrame time=\"0\">1920</KeyFrame>"
    "<KeyFrame time=\"3000\">1080</KeyFrame>" 
    "<KeyFrame time=\"4000\">720</KeyFrame></Name>" 
    "</Element>");

    ptree pt;
    boost::property_tree::read_xml(ss, pt);
   
    auto& root =  pt.get_child("Element");
    for (auto& child : root.get_child("Name"))
    {
        if(child.first == "KeyFrame")
        {
            std::cout<<child.second.get<int>("<xmlattr>.time", 0)<<" : "<<child.second.data()<<std::endl;
        }
    }
 }

Here I am able to access the <xmlattr>.time by specifying the type int but the value is retrieved in a string using child.second.data().

Can I specify the type for value as well? something like child.second.get<int>, So that I get the value in its type for ex int, double etc. and not as a string.

Upvotes: 1

Views: 1374

Answers (1)

sehe
sehe

Reputation: 393164

I'd suggest get_value<>:

Live On Coliru

#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>
#include <iostream>
#include <sstream>

std::string const sample = R"(<Element type="MyType">
    <Name type="Number">
        <KeyFrame time="0">1920</KeyFrame>
        <KeyFrame time="3000">1080</KeyFrame>
        <KeyFrame time="4000">720</KeyFrame>
    </Name>
</Element>)";

using boost::property_tree::ptree;

int main() {
  std::stringstream ss(sample);

  ptree pt;
  boost::property_tree::read_xml(ss, pt);

  auto &root = pt.get_child("Element");
  for (auto &child : root.get_child("Name")) {
    if (child.first == "KeyFrame") {
        auto node = child.second;
        std::cout << node.get<int>("<xmlattr>.time", 0) << " : "
                  << node.get_value<int>() << std::endl;
    }
  }
}

Prints

0 : 1920
3000 : 1080
4000 : 720

Upvotes: 1

Related Questions