Matteo Matteo - 7 months ago 26
Ruby Question

Hidden attribute not populating field in form for Rails 3.2

I'm implementing an invitation system and I want the

new user form
to pre-populate the user's email address in the email address field on the form (eventually, I will refactor this so it's not a form_field), so that the user doesn't have to type in all their information, just enter a password.

I have created the getter/setter methods in the
users.rb
model like this:

def invitation_token
invitation.invitation_token if invitation
end
def invitation_token=(invitation_token)
self.invitation = Invitation.find_by_invitation_token(invitation_token)
end


INVITATION MODEL

class Invitation < ActiveRecord::Base

#--== ASSOCIATIONS
belongs_to :sender, :class_name => 'User'
has_one :recipient, :class_name => 'User'
#--== CALLBACKS
before_create :generate_token
before_create :recipient_is_not_registered
before_create :decrement_sender_count, :if => :sender
#--== VALIDATIONS
validates_presence_of :recipient_email
#validate :recipient_is_not_registered
validate :sender_has_invitations, :if => :sender
#--== METHODS
private
def recipient_is_not_registered
if User.find_by_email(recipient_email)
false
else
true
end
end

def sender_has_invitations
unless sender.invitation_limit > 0
redirect_to root_url
end
end

def generate_token #TODO: MOVE to lib/generate_token.rb
self.invitation_token = Digest::SHA1.hexdigest([Time.now, rand].join)
end

def decrement_sender_count
sender.decrement! :invitation_limit
end

end


USER CONTROLLER

class UsersController < ApplicationController
def new
@user = User.new(:invitation_token => params[:invitation_token])
@user.email = @user.invitation.recipient_email if @user.invitation
end

def create
@user = User.new(user_params)
if @user.save
session[:user_id] = @user.id
redirect_to root_url, notice: "Thank you for signing up!"
else
render "new"
end
end

...

def user_params
params.require(:user).permit(:email, :password, :password_confirmation, :admin)
end
end


views/users/_form.html.erb

<%= form_for @user do |f| %>

<%= f.hidden_field :invitation_token %>

<div class="field">
<%= f.label :email %><br />
<%= f.text_field :email %>
</div>
<div class="field">
<%= f.label :password %><br />
<%= f.password_field :password %>
</div>
<div class="field">
<%= f.label :password_confirmation %><br />
<%= f.password_field :password_confirmation %>
</div>
<div class="field">
<%= f.check_box :admin %>
<%= f.label :admin %>
</div>
<div class="actions"><%= f.submit %></div>
<% end %>


I was following Ryan Bates' RC#124 - Beta Invitations, and got stuck here. His code doesn't produce the error, so I should mention that this is a Rails 3.2.18 app.

When I reload the form, the user's email isn't populated in the form. The relevant log shows:

Started GET "/signup.914823d28d07b747213ec3de47f89ad537169e34" for 127.0.0.1
at 2016-04-30 20:24:47 -0600
Processing by UsersController#new as
User Load (1.0ms) SELECT "users".* FROM "users" WHERE "users"."auth_token" = 'rOHiKmDcceytxi_t151YIQ' LIMIT 1
Invitation Load (0.0ms) SELECT "invitations".* FROM "invitations" WHERE "invitations"."invitation_token" IS NULL LIMIT 1
Rendered users/_form.html.erb (5.0ms)
Rendered users/new.html.erb within layouts/application (6.0ms)
Completed 200 OK in 102.0ms (Views: 25.0ms | ActiveRecord: 3.0ms)


So it appears that the invitation_token isn't being passed in, since the log shows it is NULL.

I have gone over the RC code from top to bottom and can't find out why it's not being passed.

Any help would be appreciated. Thanks.

UPDATE: The output from the view source is:

<input id="user_invitation_token" name="user[invitation_token]" type="hidden" />
, so it's not being passed along.

Answer

Set the value on the hidden field by passing the value: key:

<%= f.hidden_field :invitation_token, value: some_value %>