Rails 4: render controller/action again when validation fails - ruby-on-rails

Question

There are already a couple of questions addressing this issue:
render/redirect to new action when validation fails (rails)
Keeping validation errors after redirect from partial back to the same page that has the partial
I tried to implement some of the solutions recommended but did not manage fixing my issue.
So here we go.
In my Rails 4 app, there are four models:
class User < ActiveRecord::Base
has_many :administrations
has_many :calendars, through: :administrations
has_many :invitations, :class_name => "Invite", :foreign_key => 'recipient_id'
has_many :sent_invites, :class_name => "Invite", :foreign_key => 'sender_id'
end
class Calendar < ActiveRecord::Base
has_many :administrations
has_many :users, through: :administrations
has_many :invites
end
class Administration < ActiveRecord::Base
belongs_to :user
belongs_to :calendar
end
class Invite < ActiveRecord::Base
belongs_to :calendar
belongs_to :sender, :class_name => 'User'
belongs_to :recipient, :class_name => 'User'
end
Here, we are going to focus on the Invite and the Calendar models.
In the calendar edit view, I have a form to create a new invite:
<h2>Edit <%= #calendar.name %> calendar</h2>
<%= render 'form' %>
<h2>Invite new users to <%= #calendar.name %> calendar</h2>
<%= form_for #invite , :url => invites_path do |f| %>
<%= f.hidden_field :calendar_id, :value => #invite.calendar_id %>
<%= f.label :email %>
<%= f.email_field :email %>
<%= f.label "Role" %>
<%= f.radio_button(:recipient_role, "Editor") %>
<%= f.label "Editor" %>
<%= f.radio_button(:recipient_role, "Viewer") %>
<%= f.label "Viewer" %>
<%= f.submit 'Send' %>
<% end %>
<%= link_to 'Show', calendar_path %> |
<%= link_to 'Back', calendars_path %>
–––––
UPDATE: please note that I have defined a calendars.html.erb layout for my calendar views, including the following code to display alerts:
<% flash.each do |key, value| %>
<div class="alert alert-<%= key %>">
<%= value %>
</div>
<% end %>
–––––
In the Invite model, I want to validate the presence of :email and :recipient_role (both values submitted by the user through the form), so I added this to the Invite model:
validates :email, :recipient_role, presence: true
And I would like users to be redirected to the form with an error message if they forgot to fill one of these two fields, which I implemented with the following code in the InvitesController:
class InvitesController < ApplicationController
def create
# some code
if #invite.save
# some code
else
format.html { render :template => "calendars/edit", notice: 'Invitation could not be sent.' }
end
redirect_to calendar_path(#calendar), notice: 'Invitation was successfully sent.'
end
private
def invite_params
params.require(:invite).permit(:email, :calendar_id, :recipient_role)
end
end
In particular, I thought that the line format.html { render :template => "calendars/edit", notice: 'Invitation could not be sent.' } would allow me to do what I wanted, as recommended here.
However, when I try to submit the form with at least an empty field, I get the following error:
ArgumentError in InvitesController#create
too few arguments
end
else
format.html { render :template => "calendars/edit", notice: 'Invitation could not be sent.' }
end
redirect_to calendar_path(#calendar), notice: 'Invitation was successfully sent.'
end
And this is the server log:
Processing by InvitesController#create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"p+yxM9Tw3JiNw/6Chv9//N8uvWhMy0TqrudTu0y9D9zXCl6kK2LtCqPu1rvTGv5gOMBuv2RK/IX2MBpWUTelZw==", "invite"=>{"calendar_id"=>"3", "email"=>"test#example.com"}, "commit"=>"Send"}
User Load (0.2ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT 1 [["id", 1]]
Calendar Load (0.1ms) SELECT "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1 [["id", 3]]
(0.0ms) begin transaction
(0.0ms) rollback transaction
Completed 500 Internal Server Error in 27ms (ActiveRecord: 1.3ms)
ArgumentError (too few arguments):
app/controllers/invites_controller.rb:16:in `format'
app/controllers/invites_controller.rb:16:in `create'
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1#global/gems/actionpack-4.2.2/lib/action_dispatch/middleware/templates/rescues/_source.erb (3.7ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1#global/gems/actionpack-4.2.2/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (1.5ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1#global/gems/actionpack-4.2.2/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (0.9ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1#global/gems/actionpack-4.2.2/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout (54.0ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/_markup.html.erb (0.3ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/_inner_console_markup.html.erb within layouts/inlined_string (0.3ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/_prompt_box_markup.html.erb within layouts/inlined_string (0.4ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/style.css.erb within layouts/inlined_string (0.3ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/console.js.erb within layouts/javascript (36.5ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/main.js.erb within layouts/javascript (0.2ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/error_page.js.erb within layouts/javascript (0.5ms)
Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/index.html.erb (83.2ms)
What am I doing wrong?

Answer 1

Do the following things please
def create
# some code
if #invite.save
redirect_to calendar_path(#calendar), notice: 'Invitation was successfully sent.'
else
render template: "calendars/edit", notice: 'Invitation could not be sent.'
end
end