Re: [xml] libxml2 equivalents for expat's XML_GetCurrentByteIndex and XML_GetCurrentByteCount

[Daniel Veillard <veillard redhat com>]

On Thu, Oct 18, 2012 at 04:35:25PM +0200, Graham Leggett wrote:
> Hi all,
>
> I am currently tasked with replacing the expat parser within an application with the more lenient html 
> parser found in libxml2.
>
> I am using the parser to work out the location within the document of certain elements (tags), and once I 
> have found the element I am looking for, I need to know the offset of the element from the start of the 
> document, and the length of the element. These two bits of information are provided by expat in 
> XML_GetCurrentByteIndex() and XML_GetCurrentByteCount() respectively.
>
> I am struggling to find equivalents of these functions inside libxml2.
>
> I can see inside the parser structures, but I cannot find a clear explanation as to what the fields in 
> those structures represent, and what kind of maths I would need to do on them to derive the two bits of 
> information I am looking for.
>
> Is there an API call that I should be using for this? Failing that, which fields of the parser should I be 
> looking at to calculate this information?

  See xmlByteConsumed() but it's more complex for us than for expat
as we convert the initial byte stream to UTF-8 if it was in a different
encoding. See the xmlByteConsumed() code. I don't understand what
"the length of the element" is supposed to mean.

Daniel

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