你将如何从 boost xml 属性树中删除一个节点?
我有这样的文件:
<folders>
<folder>some/folder</folder>
<folder>some/folder</folder>
<folder>some/folder</folder>
</folders>
我知道如何迭代和打印所有文件夹,但是我将如何删除其中一项并将 xml 保存回来?
你将如何从 boost xml 属性树中删除一个节点?
我有这样的文件:
<folders>
<folder>some/folder</folder>
<folder>some/folder</folder>
<folder>some/folder</folder>
</folders>
我知道如何迭代和打印所有文件夹,但是我将如何删除其中一项并将 xml 保存回来?
我可能会尝试:
boost::property_tree::ptree pt;
pt.erase(key);
void Backups::removeGeneric(const std::string key, const std::string value)
{
typedef boost::property_tree::ptree Tree;
Tree pt;
boost::property_tree::xml_parser::read_xml(Backups::getBackupFile(), pt);
std::pair< Tree::assoc_iterator, Tree::assoc_iterator> range = pt.equal_range(key);
if(range.first == pt.not_found())
{
std::cout << "There is nothing to remove." << std::endl;
}
else
{
bool removed = false;
do
{
if(assoc_i->second.data() == value) {
Tree::iterator i = pt.to_iterator(assoc_i);
pt.erase(i);
removed = true;
// not sure if this is completely necessary - trying
// to guard against invalidating the iterator
// via erase - if removed, remember to ++i!
range = pt.equal_range(key);
i = range.first;
}
else
++i;
} while(i != pt.not_found());
if(removed)
{
boost::property_tree::xml_parser::write_xml(Backups::getBackupFile(), pt);
std::cout << value << " was removed." << std::endl;
}
else
std::cout << value << " is not added." << std::endl;
}
}
好吧,我是这样做的:
void Backups::removeGeneric(const std::string key, const std::string value)
{
boost::property_tree::ptree pt;
boost::property_tree::xml_parser::read_xml(Backups::getBackupFile(), pt);
bool remove = true;
try {
pt.get_child(key);
}
catch(boost::exception &ex)
{
std::cout << "There is nothing to remove." << std::endl;
remove = false;
}
if(remove)
{
bool exists = false;
boost::property_tree::ptree newPt;
BOOST_FOREACH(boost::property_tree::ptree::value_type &v, pt.get_child(key))
{
if(v.second.data() != value)
newPt.add("scheme", v.second.data());
if(v.second.data() == value)
exists = true;
}
if(exists)
{
pt.put_child(key, newPt);
boost::property_tree::xml_parser::write_xml(Backups::getBackupFile(), pt);
std::cout << value << " was removed." << std::endl;
}
else
std::cout << value << " is not added." << std::endl;
}
}
// Recursively erase nodes
void prune_nodes(ptree& Prop_tree, const char* Node_name)
{
ptree::iterator Root = Prop_tree.begin(); // Node iterator
ptree::iterator End = Prop_tree.end(); // Stop sentinel
// Loop through current 'Root-Level'
for(Root; Root != End; Root++)
{
Root->second.erase(Node_name); // Erase nodes in current 'Root-Level' sub-tree
prune_nodes(Root->second, Node_name); // Recurse using current sub-tree as next call's ptree
}
}