Parse XML response with xpathsnippet

RE: Parse XML response with xpathsnippet

Robert Shankin — Wed, 02 Oct 2019 17:44:31 GMT

Yup. As I noted, xpath seems super easy right up until namespaces are involved.

RE: Parse XML response with xpathsnippet

Mike Schmitt — Tue, 01 Oct 2019 23:39:06 GMT

Thanks, I see what you mean now - I altered my original sample code to include a fake prefix definition and it seems to work now.

RE: Parse XML response with xpathsnippet

Robert Shankin — Tue, 01 Oct 2019 22:17:13 GMT

The namespace prefix is not defined in the original post.

RE: Parse XML response with xpathsnippet

Mike Schmitt — Tue, 01 Oct 2019 21:07:55 GMT

[quote userid="3416" url="~/discussions/f/general/17695/parse-xml-response-with-xpathsnippet/69679"]Appian does handle this.[/quote]

Can you confirm this? Because when I tried calling xpathsnippet() on the original poster's code, I got the following pink error even when just using the xpath "select all" command:

Additionally, playing with it in the expression editor, I can't get any combination of syntax for the xpath expression to not return this error message when the input string has the "a:" delimiters. Am I still just doing something wrong?

RE: Parse XML response with xpathsnippet

Robert Shankin — Tue, 01 Oct 2019 20:47:44 GMT

Mike -

Appian does handle this.
Performing xpath on xml with namespaces is just a bit more complicated than parsing xml without namespaces.

This is well documented on the web; it's a common problem people have with xpath, and discussed repeatedly on sites like stackoverflow.
sayalip I expect if you do a bit more research on the topic of XML with namespaces and xpath, you'll have your solution.

RE: Parse XML response with xpathsnippet

Mike Schmitt — Tue, 01 Oct 2019 15:45:50 GMT

Fair enough - though it looks like the current version of xpathsnippet() doesn't handle this, so my suggested workaround might still be necessary.

RE: Parse XML response with xpathsnippet

Robert Shankin — Tue, 01 Oct 2019 15:44:10 GMT

I think the syntax checks out. It has to do with namespaces.
https://www.w3schools.com/xml/xml_namespaces.asp

RE: Parse XML response with xpathsnippet

Mike Schmitt — Tue, 01 Oct 2019 14:27:41 GMT

As far as I can tell, having a colon in the tag name ("a:") is either against XML best practices, or maybe even plainly not allowed. Refer to the "Best Naming Practices" found here: https://www.w3schools.com/xml/xml_elements.asp

If you have no control over the XML response you're needing to deal with, I suggest perhaps developing local-side sanitization rules to pass all the XML through first to get the tag names into a format that won't break xpathsnippet. Maybe something along the lines of:

xpathsnippet(
  substitute(
    "<a:isSuccessful>true</a:isSuccessful>",
    ":",
    "_COLON_"
  ),
  "//a_COLON_isSuccessful/text()"
)