My idea originates from this Collector for ArcGIS tutorial demonstrating how to use relationship classes to establish a link between Hydrants and Inspections within Collector. The upshot of the tutorial is that, once a Hydrant is created, many inspections can be associated with that hydrant in an Inspections table.
Basically I want to replicate this behavior, but instead of using Hydrants and Inspections I want to establish this link between a Project Description layer and a Milestones layer using either a Geo Form or a Web Mapping Application. For instance, say I make a new Project in San Jose, CA using a Geo Form. I want to create the functionality that would essentially let users click a button that says 'Add a Milestone' and then they can update the Milestone table with new information.
Already attempted: I created a relationship class between my Project and Milestone layers but was not able to create this same auto-update functionality that is built into Collector for ArcGIS. Does anyone know of any way to establish these links within a Web Mapping Application?