ruby group collection via first letter in view in foreach - ruby-on-rails

Question

I have for example collection with such data:
80 (0)
90 (0)
100 (0)
200 (0)
A2 (0)
A3 (0)
A4 (0)
A5 (0)
A6 (0)
A8 (0)
Allroad (0)
Cabriolet (0)
Coupe (0)
Q7 (0)
Quattro (0)
R8 (0)
RS4 (0)
RS6 (0)
S2 (0)
S3 (0)
S4 (0)
S5 (0)
S6 (0)
S8 (0)
TT (0)
V8 (D11) (0)
and such view:
.vip-offers#manufacturers-list
.man-area
%ul
- #models.each do |car|
%li
= link_to "#{car.name} (#{car.get_cars_model_count(car.id)})", advanced_search_show_path(by_model: car.id), id: "link-blue", data: { no_turbolink: true }
so as you can see - i display whole data as list, but i need to group it by first letter in name, for example:
8
80 (0)
9
90 (0)
1
100 (0)
2
200 (0)
A
A2 (0)
A3 (0)
A4 (0)
A5 (0)
A6 (0)
A8 (0)
Allroad (0)
etc...
i didn't imagine how to select first letter and group by it in view... Maybe somebody have ideas?

Answer 1

.group_by is your friend:
#grouped_cars = cars.group_by { |one_record| one_record.name[0].to_s # returns the first letter of the name }
This code should create a hash structured as following:
{
'0' => [<Car id:12, name: '007'>],
'A' => [<Car id:13, name: 'Audi'>, <Car id:14, name: 'Audi RS5'>],
# etc.
}
Then in you can do:
%ul
- #grouped_cars.each do |first_letter, cars|
%li.first_letter= first_letter
%ul
- cars.each do |car|
%li.one_car= car.name
You might want to add some stuff in the group_by block:
#grouped_cars = cars.group_by do |car|
car.name[0].to_s.upcase # transforms 'a' into 'A'
end
I also noticed that you will probably loose the alphabetical order, because Hashes are not ordered. To solve this, you can do as following:
%ul
- #grouped_cars.keys.sort.each do |letter|
%li.first_letter= first_letter
%ul
- #grouped_cars[letter].each do |car|
%li.one_car= car.name
Or check #DaniëlKnippers comment on my answer