Description of problem:

Currently user need to enter the value for CollectionExpression in the simple text field. This is quite error pron and in contradiction with other data editors which are present designer.


Documentation states the following:
The variable must be an array or be of the java.util.Collection type.

What I suggest is to implement some sort of drop down menu or other editor which will lists all the process variables which fulfils this condition.

Let's have following process variables defined:

myString: java.lang.String
myInteger: java.lang.Integer
myArray: java.lang.String[]
myList: java.util.List

In the multi-instance sub process component, following values would be available for selection for the CollectionExpression attribute:

myArray
myList


Version-Release number of selected component (if applicable):

bpm 6.0.x
How reproducible:

always
Steps to Reproduce:
1. crate multi-instance sub process component in the designer
2. try to fill CollectionExpression value - no suggestions available

Actual results:
Editor for CollectionExpression is a text input.

Expected results:
Editor for CollectionExpression is a drop down menu or any sort of editor which will hold the list of appropriate values so user can choose without having to type it manually.