Marco Song Marco Song - 3 months ago 11
Ruby Question

Rails4 : How to assign a nested resource id to another resource

Model:

order & material

order has_many materials

material belongs_to order


material & user

material has_may users

user belongs_to material


Assume I create a material with id = 20 , order_id = 1


In materials_controller update action, I want to assign material id to specific users.In materials_controller update action I did it like this


if @material.update_attributes(material_params)
if @material.ready == true
@users = User.where("is_manager = 't'")
@users.each do |user|
user.material_id = @material.id
end
end
end


But attribute material_id in user did not get changed after the action.
Anybody could tell me what cause the failure to pass material id to user ?

Answer

You also need to do user.save after you change user.material_id.

      user.material_id = @material.id
      user.save #Saves the changes

That changed the attribute of user object, but the change has not been persisted yet. It's now a stale object which has some attributes changed. To persist those attributes, user.save is required.

Or you can use update_attribute like below:

if @material.update_attributes(material_params)
  if @material.ready
    @users = User.where("is_manager = 't'")
    @users.each do |user|
      user.update_attribute(:material_id, @material.id)
    end
  end

end

Comments