Basic inspectors for editing. Changing from block to inline, or
adding "hidden" or "describe" flags not supported.
The UI layout for two-way and one-way rules could certainly be improved.
Bug: T49411
Change-Id: I5ce29e4bf47abf509afde0a57f64b5d1189f5185
For magical HTML reasons, a `<tbody>` node is automatically inserted
inside the `<table>` node. Therefore the table always had exactly one
direct child, this check always failed and table was never shown.
Instead, count the rows.
Change-Id: Ia8a5387c3f605689ab1053c923952ec955b83253
