Re: [Boost-users] Boost.property_tree help

From: Demetrius Cassidy (dcassidy_at_[hidden])
Date: 2006-06-15 12:51:25

"Johan Nilsson" wrote in message news:...
>
> Well, something along the lines of this should work (caution: not tested):
> ptree technologies; /* load xml */ for (ptree::const_iterator iter = 
> technologies.begin(); iter != technologies.end(); ++iter) { std::cout << 
> "ID: " << (*iter).get<std::string>("<xmlattr>.ID") << '\n'
> }
> HTH // Johan

Unfortunally this does not work, *iter returns ptree::value_type, so even if 
I could do
std::cout << "ID: " << (*iter).second.get<std::string>("<xmlattr>.ID") << 
'\n',
it will throw "ptree_bad_path" because it can't find the key.
It will also throw with get("Technologies.Logistics") and get_child(...).

Even worse is that incrementing my iterator from my root node will cause 
iter.begin == iter.end, and
if I try ptree.find("<xmlattr>.ID") or ptree.find("Technologies.Logistics") 
it will return an invalid iterator.

The only thing that even works is the following code, except it will only 
print out the topmost node.
I need to be able to print out the whole tree and their respective children.

BOOST_FOREACH(ptree::value_type &v, pt.get_child("Technologies.Logistics"))
print(v.second.data());

<Tech>
 <Logistics>
    <somedata>1.0</somedata>
 </Logistics> /* stops here */
 <Logistics>
    ...

Unless someone knows of a similar lightweight XML parser that allows me to 
iterate through the tree, I would greatly appreciate any help with 
property_tree.