Support FEEL Scala Engine as integrated Script Engine

[ThorbenLindhauer]

This issue was imported from JIRA:

Field	Value
JIRA Link	CAM-11288
Reporter	@tasso94
Has restricted visibility comments	true

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Description

• this is a hidden feature when using the Scala FEEL Engine
• before we add the FEEL support to the documentation, we should add integration tests

AT

• add tests (unit and integration)
• add documentation

Hints: Until this is part of the codebase, this can be made to work by adding the below in a text file called org.camunda.feel.valuemapper.CustomValueMapper under META-INF/services/:

org.camunda.feel.impl.JavaValueMapper
org.camunda.spin.plugin.impl.feel.integration.SpinValueMapper

This adds two additional SPIs:

• the JavaValueMapper, which allows transforming FEEL types into Java objects
• the SpinValueMapper, which allows transforming Spin objects into FEEL types

For example:

• for a Spring Boot application, the META-INF folder sits under resources
• for a Tomcat distribution, a small maven project such as the attached feel-value-mapper.zip can be built to generate a JAR file, which should be dropped into the Tomcat folder $TOMCAT_HOME/lib. If using our docker image, this can be accomplished using a bind mount (docker volume).

Links:

• depends on https://jira.camunda.com/browse/CAM-11184
• is depended on by https://jira.camunda.com/browse/SUPPORT-8802
• is depended on by https://jira.camunda.com/browse/SUPPORT-8803
• is related to https://jira.camunda.com/browse/SUPPORT-14166
• is related to https://jira.camunda.com/browse/SUPPORT-14129
• is related to https://jira.camunda.com/browse/SUPPORT-19516
• https://jira.camunda.com/browse/SUPPORT-16228

[ThorbenLindhauer]

This comment was imported from JIRA and written by user @tasso94

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Pull request: https://github.com/camunda/camunda-bpm-platform/pull/810

[ThorbenLindhauer]

This comment was imported from JIRA and written by user OK77Jow

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Hello  @Tassilo and/or @Thorben,

what is the current status ? Is there a chance to get this feature officially supported in 7.14 ?

[ThorbenLindhauer]

This comment was imported from JIRA and written by user @tasso94

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Hi OK77Jow,

This feature is currently not scheduled for implementation.

As an enterprise customer, feel free to create a support case of type feature request so our product management can have a look.

Best, Tassilo

[ThorbenLindhauer]

This comment was imported from JIRA and written by user OK77Jow

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Hi @Tassilo,

you already got my point :).

 

The thing is, I need this feature support for Camunda 7.13)

Please give me some advice how we can proceed? Is there a realistic chance to get this feature for 7.13 ?

[ThorbenLindhauer]

This comment was imported from JIRA and written by user @tasso94

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Hi OK77Jow,

Usually, we only backport bug fixes.

Best, Tassilo

[ThorbenLindhauer]

This comment was imported from JIRA and written by user OK77Jow

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Hi Tassilo,

I created corresponding tickets SUPPORT-8802 (Backport to 7.13) and SUPPORT-8803 (finalize for 7.14)  

[ThorbenLindhauer]

This comment was imported from JIRA and written by user NYBzR2x

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Hey @garima-camunda, could you take a moment to show the customer how to set up the usage of the feel scripting engine following this article?

You can read about it here: https://camunda.com/blog/2020/05/camunda-bpm-user-task-assignment-based-on-a-dmn-decision-table/

Specifically, the part at the end of the article explains how to enable the usage of the feel scripting engine.

"For this approach to work, as of version 7.13.0-alpha4, Camunda still requires the registration of a customer value mapper. The mapper is registered by placing a text file called org.camunda.feel.valuemapper.CustomValueMapper with the content: org.camunda.feel.impl.JavaValueMapper into the folder: META_INF/services.

This step will likely no longer be required in newer versions."

Thank you! :) In case you have any questions, feel free to approach me or Tasso for clarifications.

[ThorbenLindhauer]

This comment was imported from JIRA and written by user OK77Jow

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Hello @Andre,

thanks for your help. We have already set this up.

 

Still: there are some problems with FEEL <-> SPIN integration that worked perviously in 7.12 (community feel engine plugin) but not in 7.13 (new feel engine). 

[jonathanlukas]

There is a possible relation to Camunda 8.2 supporting embedded feel scripts.

Context: https://camunda.slack.com/archives/C6M6X3EKZ/p1674651738425669