Yes
this is a good starting point, I think the turning point can be the possibility to dynamically create objects.
John Rossati
I was taking a look on your idea and I liked it a lot.
For me it is very interesting to use it. I create apps that need many screens (forms) and besides the designer approach is interesting it is confusing for em. With many form it will be needed to declare a lot of variables to be used. Not everytime I need, for example, a layout for cellphone and for tablet, sometimes is very different at point that cellphone have less data or fields (a resumed version)
Then keeping a lot of layouts is ugly and mess with the code.
However with a form generator I can create a class that knows its needs: handle its data and its forms with no variables created on main.
The Form Generator could be OO oriented, to interact better, however the idea of reading a string and parse is the difference, since it is much less code, easier to have a library of forms in memory, even can send an receive over internet updates of the form.
I am doing a form editor and liked your idea. I have created a windows app to edit the form, like the b4a editor, however I save it as Json string. It will solve more complex situations, but your solution is very handy. It should be continued and expanded...