Getting the actual XPATH of an xml_node (xml_node::path() doesn't seem to do it...)

[tstack]

Hi,

I'm working on a SQLite extension that provides an xpath() table-valued function and wanted to return the "actual" path of a node in the xpath_node_set. I was hoping to use xml_node::path(), but that doesn't seem to return what I was expecting. For example, given this document:

<abc>
    <def>
        Hi
    </def>
    <def>
        Bye
    </def>
</abc>

The xpath expression /abc/def returns the expected nodes, however, the path() method returns /abc/def for both nodes. I kind of expect the following paths to be returned: /abc/def[1] and /abc/def[2]. Basically, I think you should be able to use the result of path() in an XPATH expression to get back to that very node.

So, is this the expected behavior of path() or would you consider it a bug?

Thanks,

Tim

[zeux]

path() predates XPath, and uses a simpler syntax that is compatible with first_element_by_path - but it indeed doesn't work when the sibling name is not unique. It's not a bug, just a limitation of the format that path() works with; maybe it's worth highlighting in the documentation / header comment, but otherwise it's by design.

Note that the general construction of the path may need to be somewhat domain-specific, for example if the path needs to survive document changes but elements have unique ids then it may be better to construct smth like /abc/def[@id = 'hi'].

[tstack]

Sounds good. Would you be open to a PR that does return the "actual" XPATH for an xml_node?