Moving Query from View to Model - ruby

Question

I have two non-attached models - milestones and users. (My milestones actually belong to companies and companies have many milestones.)
Each milestone has a user who'd responsible for it - in my milestone form, I'm using the following to find and select users:
<%= f.input :milestone_user, :as => :select, :collection => User.find(:all, :order => "name ASC") %>
This gives me a user_id which I've converted in one view to a name as follows:
<%= User.find(milestone.milestone_user).name %>
This works fine but I want to use this in a few views now and don't like having the query in my views.
I have tried to move it into my User model but I don't know how to go about it. I've tried this in the model:
scope :username, lambda { where("id = milestone_user")}
And this in my view:
<%= User.username.first_name %>
But it complains about an undefined method for first_name..
Thanks in advance

Answer 1

Add this to your Milestone model:
def username
User.find(milestone_user).try :name
end
and use it like this in your view:
<%= milestone.username %>
But this isn't efficient, the better way would be to stick belongs_to :user, :foreign_key => "milestone_user", :class_name => "User" in your Milestone model. You won't have to fill the association, you still could create milestones without an assigned user.
The belongs_to would also allow you to use code like this in your views:
<%= milestone.user.name %>
without having to create additional methods for every user property that you'd like to access.

Answer 2

Move the query in the action of the related controller:
#milestone_user=User.find(milestone.milestone_user)
And then use try in the view
<%= #milestone_user.try(:name) %>

Answer 3

set the model to have a default_scope => :order('name asc')
In your controllers do #users = User.all
In your views use collection_select with #users
e.g. collection_select(:milestone, :user_id, #users, :id, :name )
See http://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html#method-i-collection_select for more info about
collection_select, grouped_collection_select, grouped_options_for_select and other helpers which have options like
'grouped_collection_select(object, method, collection, group_method, group_label_method, option_key_method, option_value_method, options = {}, html_options = {})'

Answer 4

I think associations should be like this:
class Milestone < ActiveRecord::Base
belongs_to :company
has_one :user
end
class Company < ActiveRecord::Base
has_many :milestones
end
class User < ActiveRecord::Base
has_one :milestone
end
if you make association like above one then on the view side you can simply write
<%= #milestone.user.firstname%>
otherwise you can just modify your scope:
scope :milestone_user, lambda { |user_id|
where("id = ?",user_id)
}
Here I have just modify the name of scope.
and call from view through passing the parameter.
<%= User.milestone_user(milestone.milestone_user).first_name %>
Also you can use delegate methods.