Question

I have two objects ingredient & origin.
each ingredient has an origin so in the ingredient I have origin_id
the view displays

<p>
  <b>Name:</b>
  <%= @ingredient.name %>
</p>

<p>
  <b>Origin:</b>
  <%= @ingredient.origin_id %>
</p>

class ingredient is declared as follows

class Ingredient < ActiveRecord::Base
  has_and_belongs_to_many :recipes
  belongs_to :origin

  attr_accessible :name, :origin_id
end

class origin

class Origin < ActiveRecord::Base
  attr_accessible :name
end

in the edit form I write and it works

<% originsArray = Origin.all.map { |origin| [origin.name, origin.id] } %>
  <div class="field">
    <%= f.label :origin_id %><br/>
    <%= f.select(:origin_id, originsArray) %><br/>
</div>

but if I write instead (as in all tutorials)

 <%= collection_select(:origin, :id, @origins, :id, :name, options ={:prompt => "-Select a payment"}, :class =>"origin") %>

i get

undefined method `map' for nil:NilClass

what should I fix ?

Edit
added :

def edit
@ingredient = Ingredient.find(params[:id])
@origins = Origin.all
end

Answer 1

I don’t see here where @origins is declarated. It seems like your @origins is just nil and not collection.