Hi There, I am working on a functionality that converts events table into feature classes. I have large number of tables that need to processed. In order to keep the process clean, I created custom transformer that I could call for all these layers, details below:
Issue: Once I call the custom transformer, for List Attribute option, it doesn’t let me put a value. I wanted to know the best way to resolve this issue.
Appreciate any feedback
Thanks
Jay
Hi Jay (@jayd3vl), Thanks for your question. I did some testing, and realized you might have uncovered a bug. But, I have an idea to help work around the issue.
I suspect, when you created the custom transformer, you didn't explicitly set the List Attribute in the ListExploder transformer as a User Parameter. Because in my testing, this parameter gets linked to a User Parameter, by default. I think this is not necessary, and likely a bug. I will look into it with the team.
However, in your scenario, I don't see a reason for exposing this List Attribute parameter in the main workflow. The list attribute is created by the FeatureMerger inside the custom transformer, with a static name "MergedList", and this is the list you will always want to explode in the ListExploder. Am I correctly understanding your scenario?
If my understanding is correct above, you can resolve this issue, by manually setting the List Attribute Parameter in the ListExploder to the list attribute "MergedList{}", this will unlink and remove the user parameter and remove the List Attribute as a parameter for your custom transformer "PointGenerator". 
Hope that makes sense. Let me know, if you have any more questions.
Hi Jay (@jayd3vl), Thanks for your question. I did some testing, and realized you might have uncovered a bug. But, I have an idea to help work around the issue.
I suspect, when you created the custom transformer, you didn't explicitly set the List Attribute in the ListExploder transformer as a User Parameter. Because in my testing, this parameter gets linked to a User Parameter, by default. I think this is not necessary, and likely a bug. I will look into it with the team.
However, in your scenario, I don't see a reason for exposing this List Attribute parameter in the main workflow. The list attribute is created by the FeatureMerger inside the custom transformer, with a static name "MergedList", and this is the list you will always want to explode in the ListExploder. Am I correctly understanding your scenario?
If my understanding is correct above, you can resolve this issue, by manually setting the List Attribute Parameter in the ListExploder to the list attribute "MergedList{}", this will unlink and remove the user parameter and remove the List Attribute as a parameter for your custom transformer "PointGenerator".
Hope that makes sense. Let me know, if you have any more questions.
Thanks for your comment, the step you described allowed me to get it working.