RoR - Select tag with include_blank disable

Answer 1

An application of the above noted solution follows.

create the application helper function

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

then use it in your view:

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