Is it possible to add id for each xml_node?

[little-brother]

Currently each node has unique hash_value. But this value changes between runs.
Is it possible to add id that will be unique for each node and persistent for every runs (same input XMLs produce same ids)?
Or at least to add a user-data field?

I work on SQLite XML extension. ids will allow to connect results between different sql-XML-statements for the same XML and recreate a XML-tree in a database.

[PhantomzBack]

Yes, I think that's possible. You can use XPath and get the corresponding result xpath_node_set for //*. Then use the iterator, and create a variable to keep the count which you increment everytime. And that's the value, so you can do use the set_value function.

[little-brother]

set_value changes a node, isn't? I don't want to change XML-tree. I need a special place in the xml-node to store the counter e.g. id or userdata field. Also your suggestion requires additional parsing. I think it should be way to set the counter-value in a xml_node-constructor.

[zeux]

I'd recommend to use something like std::unordered_map<pugi::xml_node, int> to store external data, and fill it using a depth-first traversal after loading the document (which guarantees stability). Or use a better (faster) unordered container like Google's DenseHash or equivalent.

The reason why pugixml doesn't provide a way to store user data in the node is simple: it's a significant memory overhead which 95% of use cases don't need.

[little-brother]

Thanks.