Question: I have a problem with validation on form actually sub-form.

In my website I have some kind of table and "Add row" button (BlockingAjaxSubmitLink).
When I try add let say 2 rows, I get validation error (because row in this table has Required=True parameter) and I can't add another row. I tried use simple AjaxLink but it doesn't have reference to form in onClick method and when I complete some rows and click "Add row" this data get lost.

I want to enable validation only after "save" button click.

Any idea how to deal with this problem?

Answer: 
Another alternative is to create a set of custom map tiles that replace or overlay the standard map tiles for your development area, see 
<https://developers.google.com/maps/documentation/javascript/maptypes#CustomMapTypes>

You might even be able to create custom streetview images to create a virtual drive though of the development and the inside of the buildings, see <https://developers.google.com/maps/documentation/javascript/streetview#CustomStreetView>
Is Google Map Maker <https://www.google.co.uk/mapmaker> enabled for your area?
This would allow you to add all the roads, buildings parks in your development.

Note: You would need to check the terms of use to ensure that adding planned but not yet built developments was permitted, but I do see that you can set the construction status of a road to Planned so I assume it is OK.

You can also do similar editing with Open Street map <https://www.openstreetmap.org>