How can I implement grouped_collection_select for my model which is use closure_tree gem?
I have Location model, which is have name and parent_id attribute. I want to do something like this.
<select name="locations">
<optgroup label="Office">
<option value="3">Office Table 1</option>
<option value="4">Office Table 2</option>
</optgroup>
<optgroup label="Lab">
<option value="5">Another Door 1</option>
<option value="6">Another Door 2</option>
<option value="7">Another Door 3</option>
<option value="8">Another Door 4</option>
<option value="11">Another Door 5</option>
</optgroup>
⋮
</select>