Ability to pull in user defined functions

[nlewis05]

Users will sometimes create their own functions and may want to use them, determine if there would be a way to access the lsit of these functions and include them as suggestions
Edited 01-29-2026
According to Steve's comment of August 15, 2023 this would require a Daffodil enhancement to be able to handle user defined functions. Also there are dozens of built in DFDL functions described in the Apache DFDL specification https://daffodil.apache.org/docs/dfdl/ that the intellisense logic currently doesn't suggest. I'm not sure how those function suggests should be implemented.

[stevedlawrence]

Documentation about the UDF proposal an implementation is on the wiki here: https://cwiki.apache.org/confluence/display/DAFFODIL/Proposal%3A+Feature+to+Support+User+Defined+Functions

The UserDefinedFunctionService.lookupUserDefinedFunctionCallingInfo provides a way to query information about a user defined function, given a namespace and name:

https://github.com/apache/daffodil/blob/main/daffodil-runtime1/src/main/scala/org/apache/daffodil/runtime1/udf/UserDefinedFunctionService.scala#L249-L252

Daffodil doesn't currently have a way to query all the available UDFs, so if you need that we may need an enhancement to daffodil.

Also note that UDF's come from jars on the classpath, so the extension would also need a way to add these jars to the classpath.