grouped_options_for_select(grouped_options, selected_key = nil, options = {})
Instance Public methods
Returns a string of <option> tags, like
options_for_select, but wraps them with
<optgroup> tags:
grouped_options = [
['North America',
[['United States','US'],'Canada']],
['Europe',
['Denmark','Germany','France']]
]
grouped_options_for_select(grouped_options)
grouped_options = {
'North America' => [['United States','US'], 'Canada'],
'Europe' => ['Denm