Hi,
I am just getting started with Design Studio 1.2 and the development of Design Studio components and my team and I are currently trying to develop our own data-bound table component. We want to add some customized functionality to the table, but also add some functionality that is currently missing in the Design Studio table component, like selecting a parent/aggregation row of a hierarchy (not possible in current Crosstab component).
In my current approach I am translating the ResultSet from the connected Data Source into a special JSON object and then binding the result to my SAP UI5 TreeTable using the sap.ui.model.json.JSONModel-Binder. So far I get a simple table with headers and rows and I can see when a row has a hierarchy (see screenshot). At this point the ResultSet only has the data of the initial view (all hierarchy nodes are collapsed).
Hence the problem is that I need to tell the Data Source that I need a new or updated ResultSet when a user filters or sorts various table columns or toggles a hierarchy node. As far as my understanding goes this is not possible with the current SDK version because I cannot modify a data source and I am restricted to the available property types (ResultSet, …). Is this correct? Is there any workaround to modify the data source?
I thought about getting all the data in advance and handle filtering, sorting and hierarchy toggling with the available SAP UI5 functionality. But I doubt this workaround will work in production mode, since we are talking about pre-loading hundreds of thousands of data sets (including all hierarchy and child elements) and the development guide mentions a limitation of 10.000 data sets.
Is there maybe a way to establish an oData connection where the filtering, sorting, hierarchy toggling etc. is handled by the server? (this way I would at least avoid pre-loading all the child nodes of a hierarchy)
Current version of my table component
(cell data is hidden in this screenshot)
I am grateful for any thoughts and ideas 
Thanks in advance!
Jonas