RoR - select the tag with include_blank disabled

Question

I want to get this result:

<select dir="rtl">
  <option selected disabled>Choose a car</option>
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select>

With the following code, I can only:

<%= f.select(:car, xxxxxx, {:include_blank => 'Choose a car', :disabled => 'Choose a car'}) %>

=>

<select id="xxx" name="xxx">
  <option value="">Choose a car</option>
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select>

The first option is not disabled ...

Answer 1

I consider what you are looking for as below:

<%= f.select(:car, xxxxxx, {:include_blank => 'Choose a car', :disabled => 1}) %>

Answer 2

Ito Answer will not work in Rails 4.2 (not sure about earlier versions). From the documentation ...

: disabled - there can be one value or an array of values ​​that will be disabled in the final result.

:disabled , . , :disabled => 'volvo' value='volvo'. include_blank, , select.

Rails . , .

, .

car_names = %w(volvo saab mercedes audi)
car_names_with_blank = car_names.map{|c| [c, c]}.prepend(['Choose a car', nil])

:

<%= f.select(:name, car_names_with_blank, {disabled: '', selected: ''}) %>

Github . , SO .

: .

Answer 3

.

def build_selections(prompt: "Select One", selections: {})
    selections.reverse!.push([prompt, nil]).reverse! 
end

:

<%= f.select :category_id, build_selections(prompt: 'Select Category',
                           selections: @category.collect{|x| [x.name, x.id]}),
                           disabled: '' %>