I am know approaching to boost property tree and saw that it is a good feature of boost libs for c++ programming.
Well, I have one doubt? how to iterate a property tree using iterators or similar?
In reference there is just an example of browsing the tree through:
BOOST_FOREACH
But is there nothing more? Something like an stl-like container? It would be a better solution, speaking about code quality....
Here is what I came up with after much experimentation. I wanted to share it in the community because I couldn't find what I wanted. Everybody seemed to just post the answer from the boost docs, which I found to be insufficient. Anyhow:
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/json_parser.hpp>
#include <string>
#include <iostream>
using namespace std;
using boost::property_tree::ptree;
string indent(int level) {
string s;
for (int i=0; i<level; i++) s += " ";
return s;
}
void printTree (ptree &pt, int level) {
if (pt.empty()) {
cerr << "\""<< pt.data()<< "\"";
}
else {
if (level) cerr << endl;
cerr << indent(level) << "{" << endl;
for (ptree::iterator pos = pt.begin(); pos != pt.end();) {
cerr << indent(level+1) << "\"" << pos->first << "\": ";
printTree(pos->second, level + 1);
++pos;
if (pos != pt.end()) {
cerr << ",";
}
cerr << endl;
}
cerr << indent(level) << " }";
}
return;
}
int main(int, char*[]) {
// first, make a json file:
string tagfile = "testing2.pt";
ptree pt1;
pt1.put("object1.type","ASCII");
pt1.put("object2.type","INT64");
pt1.put("object3.type","DOUBLE");
pt1.put("object1.value","one");
pt1.put("object2.value","2");
pt1.put("object3.value","3.0");
write_json(tagfile, pt1);
ptree pt;
bool success = true;
try {
read_json(tagfile, pt);
printTree(pt, 0);
cerr << endl;
}catch(const json_parser_error &jpe){
//do error handling
success = false
}
return success;
}
Here is the output:
rcook@rzbeast (blockbuster): a.out
{
"object1":
{
"type": "ASCII",
"value": "one"
},
"object2":
{
"type": "INT64",
"value": "2"
},
"object3":
{
"type": "DOUBLE",
"value": "3.0"
}
}
rcook@rzbeast (blockbuster): cat testing2.pt
{
"object1":
{
"type": "ASCII",
"value": "one"
},
"object2":
{
"type": "INT64",
"value": "2"
},
"object3":
{
"type": "DOUBLE",
"value": "3.0"
}
}