Question

We have the following code working for a complex rails form with checkboxes. I’m not really happy with the solution we have in place and I was wondering if anyone knows of a more proper way to do this in rails. All the code below is working I just want to know if there is a cleaner approach.

In my Admins controller I want to remove the need to call the following code on each update.

@user.admin.school_admin_roles.destroy_all
params[:roles].each do |school_role|
    ids = school_role.split('_')
    @user.admin.school_admin_roles.find_or_create_by_school_id_and_school_role_id(ids[0], ids[1])
end if !params[:roles].nil?

So I basically want to be able to call @user.update_attributes(params[:user]) and have rails take care of creating the needed relationships for me. I have that working with AccountRole in the form below. I want to know if there is a way to do the same thing with SchoolRole given I have an extra variable school_id in the join table.

We have the following form for editing a user and assigning roles

Screenshot of form ->
https://i.stack.imgur.com/PJwbf.png

I have the following form where an admin can edit other users and assign account based roles and school based roles via checkboxes. The account based roles were easy to implement. The school based rules are a bit complicated since the join table school_admin_roles has school_id, user_id, role_id fields. We had to implement the school roles part of the form in a rather hackish way. We have the form implemented like this – notice how we hacked together school.id.to_s+’_’+role.id.to_s into the same checkbox on school roles.

In the Admins controller’s update function we manually destroy all school_admin roles on each update then loop through the school roles params do a split on the ids on ‘-‘ then manually re-create each school based role. I really hate the way we’ve had to go about this. Could anyone shed some light on a cleaner more rails centric approach to solving this scenario?

The form –

<%= form_for @user, :url => {:controller => 'admins', :action => 'update'} do |f| %>
    <%= f.label :username %>
    <%= f.text_field :username %>

    <%= f.fields_for :admin do |uf| %>
    <div class="field">
        <%= uf.label :first_name %>
        <%= uf.text_field :first_name %>
    </div>

<label>Admin Permissions</label>  
    #account level permissions works fine
    <%= hidden_field_tag "#{uf.object_name}[account_role_ids][]"   %>
    <% AccountRole.find(:all).each do |role| %>
    <div class="account_role">
        <%= check_box_tag "#{uf.object_name}[account_role_ids][]", role.id,  @user.admin.account_roles.include?(role)%>
    <%= role.name %>
    </div>
    <% end %>

   #school level permissions a bit of a hack    
    <%= hidden_field_tag "#{uf.object_name}[school_role_ids][]"   %>
        <% SchoolRole.find(:all).each_with_index do |role, index| %>
        <div class="school_role">
        <%= check_box_tag "#{uf.object_name}[school_role_ids][]",role.id, @user.admin.school_roles.include?(role) %>
        <%= role.name %>
        <span class="advanced_box admin_permissions" <% if @user.admin.school_roles.include?(role) %>style="display:inline"<% end %>>
        <div class="content" id="perm_<%= index %>">
        <h4><%= role.name %></h4>
    <% uf.object.account.schools.each do |school|%>
    <div>
    <%= check_box_tag "roles[]", school.id.to_s+'_'+role.id.to_s, role.school_admin_roles.where(:admin_id => uf.object.id).collect(&:school_id).include?(school.id)%>
    <%= school.name %>
</div>
<% end %>
<%= link_to 'Done', '#', :class => "done" %>
</div>
<a href="#" class="open"> Advanced</a>
</span>
</div>
<% end %>
</div>
<% end %>

The controller

class AdminsController < ApplicationController
def update
    @user = User.find(params[:id])
    if  @user.update_attributes(params[:user])

      # TODO find a way to refactor this 
      @user.admin.school_admin_roles.destroy_all
      params[:roles].each do |school_role|
        ids = school_role.split('_')
        @user.admin.school_admin_roles.find_or_create_by_school_id_and_school_role_id(ids[0], ids[1])
      end if !params[:roles].nil?
      #

      flash[:notice] = "Successfully updated Admin."
      redirect_to admins_path
    else
      render "edit"
    end
  end
end

Given the following models

class User < ActiveRecord::Base
  has_one :parent
  has_one :admin
  has_many :scool_admin_roles
  has_many :account_admin_roles
end

class AccountAdminRole < ActiveRecord::Base
  before_save :set_account_id

  belongs_to :admin
  belongs_to :account_role
end

class SchoolAdminRole < ActiveRecord::Base
  belongs_to :admin
  belongs_to :school_role
  belongs_to :school
end

class SchoolRole < ActiveRecord::Base
  has_many :school_admin_roles
end


class AccountRole < ActiveRecord::Base
  has_many :account_admin_role
end

Answer 1

We refactored the code above as follows

In the model we added accepts_nested_attributes_for :school_admin_roles, :reject_if => proc { |attr| attr[‘school_role_id’].blank? }

and added school_admin_roles_attributes to attr_accessible

class Admin < ActiveRecord::Base
  belongs_to :account
  belongs_to :user

  has_many :school_admin_roles
  has_many :school_roles, :through => :school_admin_roles
  has_many :account_admin_roles
  has_many :account_roles, :through => :account_admin_roles

  accepts_nested_attributes_for :account

  accepts_nested_attributes_for :school_admin_roles, :reject_if => proc { |attr|  attr['school_role_id'].blank? }

  attr_accessible :account_role_ids, :email, :first_name, :last_name, :account_id, :user_id, :account_attributes, :school_admin_roles_attributes
  default_scope where(:deleted => false)
end

We then built the form as follows

<% index2 = 0 %>
<% SchoolRole.find(:all).each_with_index do |role, index| %>
<div class="school_role">
<%= check_box_tag "school_roles[]",role.id, @user.admin.school_roles.include?(role) %>
<%= role.name %>
<span class="advanced_box admin_permissions" <% if @user.admin.school_roles.include?(role) %>style="display:inline"<% end %>>
div class="content" id="perm_<%= index %>">
<h4><%= role.name %></h4>
                                <%  uf.object.account.schools.each do |school|%>
<div>
<%=    check_box_tag "#{uf.object_name}[school_admin_roles_attributes][#{index2}][school_role_id]", role.id, role.school_admin_roles.where(:admin_id => uf.object.id).collect(&:school_id).include?(school.id)%>
                                            <%= school.name %>
                                        <%= hidden_field_tag "#{uf.object_name}[school_admin_roles_attributes][#{index2}][school_id]", school.id %>
                                    </div>
                                    <% index2 += 1 %>
                            <% end %>
                            <%= link_to 'Done', '#', :class => "done" %>
                    </div>
                    <a href="#" class="open"> Advanced</a>
                </span>
            </div>
            <% end %>
        </div>
    <% end %>

Which then enabled us to refactor the controller without splitting the ids but we still have to call destroy all each time which I can live with.

def update
    @user = User.find(params[:id])
    @user.admin.school_admin_roles.destroy_all
    if  @user.update_attributes(params[:user])
      flash[:notice] = "Successfully updated Admin."
      redirect_to admins_path
    else
      render "edit"
    end
  end