I try to put a button to show/hide some entites.
I'have tried with ToolbatButton and/or Checkboxes, but theses fonctionalities never works. I started with the hello world exemple and I putted JSON dataSources (and i can see them), but the button doesn't appear. I used this (from your exemple "Show or Hide Entities"):
dataSource.show = !dataSource.show;
Firstly Firebug told me he was unable to find Sandcastle, so I putted this in the head of my html page:
Now firebug tell me:
TypeError: document.getElementById(...) is null
document.getElementById(toolbarID || 'toolbar').appendChild(button);
Thanks in advance