Ruby on Rails — multiple selection in f.select

Question

I have the following select box in my form:

Related Type:   <%= f.select(:TYPE, [[\'Type A\', \'Type A\'],
                                  [\'T         


        

Answer 1

HTML

<%= form.select(:product_ids, Product.all.collect {|p| [ p.name, p.id ] }, 
                                                   { :prompt => "Please select"}, 
                                                   { :multiple => true, :size => 5  }) %>

Controller

@category = Category.new(category_params) 

def category_params
    params.require(:category).permit(:name, product_ids: [])
end