Hello,

In glancing at the processor I believe the reason that the Expression Language 
is not supported is due to efficiency purposes.
The processor grabs up to 50 FlowFiles, then compiles the XPath Expressions and 
runs them over all 50 FlowFiles. If we
did support Expression Language and EL were used, we would have to re-compile 
the XPath Expression for every FlowFile.
That said, there's no reason we can't do that. However, in order to avoid 
hurting performance when not necessary it would need
to contain a bit of logic to pre-compile the expressions that aren't configured 
with Expression Language, so it's not a trivial change.
If you're interested in updating the Processor, though, I'd be happy to review 
it.

Thanks
-Mark



> On Jul 14, 2017, at 6:51 AM, claudiu-stanciu <[email protected]> 
> wrote:
> 
> Hello,
> 
> I saw that  EvaluateXPath declares that expression language is not supported
> <https://github.com/apache/nifi/blob/master/nifi-nar-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/EvaluateXPath.java#L209>
>   
> 
> My question is: can we have support for expression language with XPath ?
> (I'm not an expression language or xpath expert :) ).
> 
> This would be nice when you want to pass the xpath from a content or an
> attribute.
> 
> Thank you
> 
> 
> 
> --
> View this message in context: 
> http://apache-nifi-developer-list.39713.n7.nabble.com/Expression-language-support-in-EvaluateXPath-tp16441.html
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