devise admin user approval setup - ruby-on-rails

Question

Seems like the tutorial located here has a couple omissions:
When creating the admin accessible controller method, they don't specify which custom devise controller to use, or which base controller to inherit from. So I've placed my code in a PagesController:
class PagesController < ApplicationController
def approve_users
if current_user.admin?
if params[:approved] == "false"
#users = User.find_by_approved(false)
else
#users = User.all
end
end
end
end
The view code that allows you to switch between all users and all unapproved users results in a NoMethodError in Pages#approve_users: undefined method 'each' for User whenever you select to show the users for whom :approved => false. I know why noMethodErrors spring up in app development, and would normally be able to wrap my head around why I'm getting this error. It works when #users = User.all, but not when #users = User.find_by_approved(false)
<% if current_user.admin? %>
<h2>Users</h2>
<%= link_to "All Users", :action => "approve_users" %> | <%= link_to "Users awaiting approval", :action => "approve_users", :approved => "false" %>
<div class="ui form">
<table>
<thead>
<tr scope="col">
<th>First name</th>
<th>Last name</th>
<th>E-mail</th>
<th>Approve</th>
</tr>
</thead>
<% #users.each do |user| %>
<tbody>
<tr>
<td><%= user.firstname %></td>
<td><%= user.lastname %></td>
<td><%= user.email %></td>
<td class="ui checkbox">
<input type="checkbox" tabindex="0" class="hidden">
</td>
</tr>
</tbody>
<% end %>
</table>
</div>
<% end %>
The wiki says it that it provides a simple way to approve users, but their view code actually just provides a simple way to list all users. I'm assuming that I need to use a form helper.

Answer 1

I made a custom admin controller specifically for an admin control panel and put all of the tools in an index page. You can probably do it a number of ways, though.
The common consensus on this seems to be that if you switch #users = User.find_by_approved(false) to #users = User.where(approved: false), it works better. That's what I currently have and it works very well.
I had this problem as well, and I ended up scrapping devise and making a custom user sign in method. You should be able to make it work, though. I followed the tutorial here and it helped immensely. Basically, you want to create a method which will approve users in your admin controller. This is the one I used:
`
def approve
User.where(id: params[:user_id]).update_all(approved: true)
redirect_to admin_index_path
end
From there, you add a put method to your routes.
put 'approve_admin', to: "admin#approve", as: :approve_admin
Finally, wrap your list of users in a form tag and add a hash of all of the user IDs you want to update as a hash.
<%= form_tag(approve_admin_path, method: :put) do %>
<% for user in #unapproved_users %>
<tr>
<td class="mdl-data-table__cell--non-numeric"><%= check_box_tag "user_id[]", user.id %></td>
<td><%= user.name %></td>
<td><%= user.email %></td>
</tr>
<% end %>
</tbody>
</table>
<%= submit_tag "Mark as approved", class: 'mdl-button mdl-js-button mdl-button--raised approve' %>
<% end %>
I made a method for approving users and another for unapproving users so I switched up the #users.each iteration in favor of a for iteration. I added #unapproved_users to my index method to make this work properly. Hope this works for you!