Activity/Data Transform to check if pagelists match then transfer data between them
I have a requirement to build a grid that shows the required attached documents for a case and if they have been uploaded yet or not. The properties in this list of required documents change based on user inputs/attached documents, so I created a page list property named Required Documents that lists the names, categories, deadlines and such for the documents. I also created an Uploaded Documents page list property that references the D_AttachmentList data page (shows what files have been uploaded). I now need to build an activity/data transform that does these things:
1. Iterates through the requirements document list
2. In each iteration, check if that document has been uploaded yet (by iterating through the uploaded documents list).
3. If the document has been uploaded, copy that document data from the uploaded documents list to the requirements document list.
I know that I could do this with a data transform and a bunch of when rules (for each requirements document in the list, check a when rule to see if it has an uploaded document, if the when rule is true then copy the data from the entry on the data page to that page of the requirements document), but I feel like there is a more efficent way to do this. Does anyone have any experience/ideas?