I am invoking a workflow file that takes in a DataTable, adds an item to it, and outputs the collated DataTable. I think this requires an In/Out argument, but I am not sure how this works. Do I place the “In” variable I want to store it in the “Value” field and when I call it again it is updated with the “Out” value?
While invoking work flow assign datatable to In/Out arguments
In the same way while you are in the child workflow which has been invoked you can assign out_datatable variable to this argument and you will have its value in parent workflow.
See this also
Here you can get clear idea about the arguments
But it is not a best practice to pass data table as a argument Since it will take really long time to execute.
Yes you are right. But some unavoidable situation we can not omit it dependence upon the project.