question Nifi ReplaceText, escapeCsv does not return anything in Support Questions

Nifi ReplaceText, escapeCsv does not return anything

AndreyDE — Wed, 23 Oct 2024 12:46:38 GMT

Hello!

The general task is to transform xml to csv

For this aim I created following pipeline:

Source xml content is:

Parameters of EvaluateXPath are:

ReplaceText parameters:

Attribute grn successfully produced with expected value:

But value "3214600023849" is not translated to csv. Only ; delimiter.

Encoding is UTF-8

What am I doing wrong?

Re: Nifi ReplaceText, escapeCsv does not return anything

MattWho — Wed, 23 Oct 2024 13:33:05 GMT

@AndreyDE

Post your EvaluateXPath processor you have a FlowFile that now has a FlowFile Attribute "/grn" with a value of "3214600023849".

In ReplaceText, it appears you intent is to replace the entire content of the FlowFile with the value returned by the NiFi Expression Language (NEL) statement:

${grn:escapeCsv()};

Your expression language statement grabs the value from FlowFile Attribute "grn", passes it the escapeCsv NEL function and then appends a ";" to the returned result.

Problem 1 is your FlowFile has no attribute "grn", it has an attribute "/grn"
Since "/grn" contains special character "/", it will need to be quoted in the NEL statement as follows:

${"/grn":escapeCsv()};

reference: Structure of a NiFi Expression

Above would output content with:

3214600023849;

This content would not require being surrounded by quotes under RFC 4180

reference: escapeCSV function

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Thank you,
Matt

Re: Nifi ReplaceText, escapeCsv does not return anything

AndreyDE — Wed, 23 Oct 2024 16:55:55 GMT

Thank you, the matter was in "/", indeed ))