creation of a nested_attributes makes before_create not work - ruby-on-rails

Question

I'm tried to create a User in the console doing:
2.2.1 :012 > u.save!
(0.2ms) BEGIN
User Exists (0.7ms) SELECT 1 AS one FROM "users" WHERE LOWER("users"."email") = LOWER('noc#co.co') LIMIT 1
SQL (2.1ms) INSERT INTO "users" ("id", "first_name", "last_name", "email", "title", "time_zone", "company_id", "password_digest", "created_at", "updated_at", "activation_digest") VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11) RETURNING "id" [["id", 200], ["first_name", "Random"], ["last_name", "Dude"], ["email", "noc#co.co"], ["title", "CEO"], ["time_zone", "Stockholm"], ["company_id", 1], ["password_digest", "$2a$10$bHHA/JP5IMrucGUXRWMpsO8sInaouSqn48M.fDHpjGdvedu3Napra"], ["created_at", "2015-10-11 23:09:38.213109"], ["updated_at", "2015-10-11 23:09:38.213109"], ["activation_digest", "$2a$10$WF3bUOtbC1gk4ZnX58cJZO5k7P7YV6wvhmwz7EErTdvIseNuy0oyq"]]
2.2.1 :013 > u.activation_token
=> "vKrs0jtvZRiyU-YVE-aPXw"
now when I try to create a user the before_create doesn't work, I tried changing it to before_validation and that didn't work either.
The user is a nested attribute from companies, and is created in Companies#new.
class User < ActiveRecord::Base
belongs_to :company
attr_accessor :remember_token, :activation_token, :reset_token
before_save :downcase_email
before_create :create_activation_digest
now when I do #user.activation_token it returns nil. Here's the console log from when I try it on the app:
Started POST "/companies" for ::1 at 2015-10-12 01:31:47 +0200
Processing by CompaniesController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"ZTEtGR2Dd1FDDYm9j4/SiqSTP646R8gctFx4aJHM9QDP+RQky8SG6gkomLbf+E+LgMi+aah1YOhCkUsg3uSYoQ==", "company"=>{"time_zone"=>"Stockholm", "users_attributes"=>{"0"=>{"first_name"=>"swaga", "last_name"=>"swaga", "email"=>"swaga#wkoa.com", "password"=>"[FILTERED]"}}, "name"=>"swaga"}, "commit"=>"Create Company"}
(0.2ms) BEGIN
User Exists (1.3ms) SELECT 1 AS one FROM "users" WHERE LOWER("users"."email") = LOWER('swaga#wkoa.com') LIMIT 1
SQL (7.1ms) INSERT INTO "companies" ("name", "time_zone", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id" [["name", "swaga"], ["time_zone", "Stockholm"], ["created_at", "2015-10-11 23:31:47.380530"], ["updated_at", "2015-10-11 23:31:47.380530"]]
SQL (0.5ms) INSERT INTO "users" ("first_name", "last_name", "email", "password_digest", "activation_digest", "company_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5, $6, $7, $8) RETURNING "id" [["first_name", "swaga"], ["last_name", "swaga"], ["email", "swaga#wkoa.com"], ["password_digest", "$2a$10$3GsPACTg5HPodiqdedsCvu52N64BEE3/fA77p.oBHAhM51zCSzUV."], ["activation_digest", "$2a$10$75y9jP.eZxmWI1KjHZrg3.DuB5GSwiS2UsaQdtV25ClBHDi.z4Pte"], ["company_id", 8], ["created_at", "2015-10-11 23:31:47.390462"], ["updated_at", "2015-10-11 23:31:47.390462"]]
(6.7ms) COMMIT
User Load (0.9ms) SELECT "users".* FROM "users" WHERE "users"."company_id" = $1 ORDER BY "users"."id" ASC LIMIT 1 [["company_id", 8]]
Rendered user_mailer/account_activation.html.erb within layouts/mailer (7.8ms)
UserMailer#account_activation: processed outbound mail in 29.2ms
Completed 500 Internal Server Error in 380ms (ActiveRecord: 16.9ms)
ActionController::UrlGenerationError - No route matches {:action=>"edit", :controller=>"account_activations", :email=>"swaga#wkoa.com", :id=>nil} missing required keys: [:id]:
now I see that the activation_digest is returned, so I think the issue is literarily just the before_create not working? Which is weird because then it shouldn't be able to create an activation digest as the two are connected:
# Creates and assigns the activation token and digest.
def create_activation_digest
self.activation_token = User.new_token
self.activation_digest = User.digest(activation_token)
end

Answer 1

Your error says:
ActionController::UrlGenerationError - No route matches {:action=>"edit", :controller=>"account_activations", :email=>"swaga#wkoa.com", :id=>nil} missing required keys: [:id]:
Seems like, in your view, you are calling edit_account_activation_path without the id param and that's creating the problem for you. Try to send the user.id as a parameter in the edit_account_activation_path call.
Something like this:
edit_account_activation_path(user.email, user.id)
That should fix your issue.