[Bug]: Can't inject "Group field" field in "Row denormaliser" transform

[enricomariam42]

Apache Hop version?

SNAPSHOT-20221221

Java version?

openjdk version "11.0.9.1" 2020-11-04 OpenJDK Runtime Environment (build 11.0.9.1+1-post-Uos-1deb10u2) OpenJDK 64-Bit Server VM (build 11.0.9.1+1-post-Uos-1deb10u2, mixed mode, sharing)

Operating system

Linux

What happened?

Injecting "Group field" with a constant value in "Row denormaliser" transform has no effect and the group is missing in the injected transform.

Workaround: define the group in a field (e.g. in a "Add constants" transform) and select that in the metadata injection transform.

(Migrated from https://issues.apache.org/jira/browse/HOP-3860)

injection.zip

The attached pipeline denormalizer_template.hpl containing a "Row denormaliser" is injected in the two ways:

• with a constant value inject_denormalizer_not_working.hpl produce injected_denormalizer_no_group.hpl
• with the group in a field inject_denormalizer_working.hpl produce injected_denormalizer_with_group.hpl

Obtained (output of injected_denormalizer_no_group.hpl):

group	SNS	SERVIZI SAN	RicaviSan
3A120	-13576,2	-322,8	3,5

Espected (output of injected_denormalizer_with_group.hpl):

group	SNS	SERVIZI SAN	RicaviSan
3A120			3,5
2G112	-13576,2	-322,8

Issue Priority

Priority: 3

Issue Component

Component: Metadata

[hansva]

.take-issue

[hansva]

Bit of an annoying issue, for lists it expects data rows as it does not really know how many fields to add when using a constant. I'm leaning towards "works as intended". Though I understand the edge case when you only need 1 value

[enricomariam42]

I understand. Letting input a constant value lead to an unexpected behavior, though.
So, block the use of a constant filed if lists expected, or map a constant to a single value list, or split it to a list of fields based on special char can be possible?
I don't think document it is enough, even if there is a way around.