Validate XML

General
1

I have an XML string, XMLWebData which may or may not be structured correctly it may or may not be valid XML and need to load it into an XMLDocument. I am using the following:

XMLDoc = new XmlDocument(XMLWebData)

This is all fine unless as I said the XML is invalid and so the parser throws an error. What is the best way to check that XMLWebData is valid XML before creating my XML document?

2

Can you catch the exception (there used to be a problem where you couldn’t)? If so, let the parser validate it for you.

3

Just tried that Tim, its still throwing an exception. Tried:

try XMLDoc = new XmlDocument(XMLWebData) catch StatusChange("There was an error obtaining the categories") end try

but getting the following back from the parser “msg:XML parser error 4: not well-formed (invalid token)”

4

You’ll need to add

#pragma breakonexceptions off

before the try to let the exception be caught in the debugger.

5

[quote=84010:@Wayne Golding]You’ll need to add

#pragma breakonexceptions off

before the try to let the exception be caught in the debugger.[/quote]

That seems to work, thanks wayne

6

XML parsers are required by the spec to completely reject documents that are not at least well-formed. (What isn’t well-formed isn’t XML.) The hope here is to at least be able to get an exception that Xojo can catch.

7

Yes well that is working now. It looks like it is parsing up to the (deliberately) malformed part of the XML. Its a pity it is not validated before it is parsed but I guess that would take 2 passes of the XML so I can see why not.