Rails 3 task scopes? - ruby-on-rails

Question

I am working on a simple rails 3 todo application and I am trying to filter the app by completed tasks and none completed task but whenever I try calling a scope I get the error message.
undefined method `completed' for #<Array:0x007fe8420d0e58>
task.rb
scope :completed , where(:completed => true)
scope :incomplete , where(:finished => false)
index.html.erb
<table>
<tr>
<th>Name</th>
<th>Description</th>
<th>Finished</th>
<th>User</th>
</tr>
<% #tasks.each do |task| %>
<tr>
<td><%= task.name %><%= button_to "complete", complete_task_path(task.id)%></td>
<td><%= task.description %></td>
<td><%= task.finished %></td>
<td><%= task.user_id %></td>
<td><%= link_to 'Show', task %></td>
<td><%= link_to 'Edit', edit_task_path(task) %></td>
<td><%= link_to 'Destroy', task, confirm: 'Are you sure?', method: :delete %></td>
</tr>
<% end %>
</table>
<%= content_tag :h2, "Stuff Ive done" %>
<table>
<tr>
<th>Name</th>
</tr>
<% #tasks.completed.each do |task| %>
<tr>
<td><%= task.name %></td>
</tr>
<% end %>
</table>
task_controller.rb
def complete
#task = Task.find(params[:task_id])
#task.completed = true
#task.save
redirect_to task_path
end
routes.rb
match "tasks/:id/complete" => "task#complete", :as => :complete_task
Any reasons why rails is giving me this error?

Answer 1

Just by looking at your view (index.html.erb), in one place, you are treating as a relation.
<% #tasks.each do |task| %>
Later in the code, you are trying to access it as a single object.
<% #tasks.completed.each do |task| %>
Since you are seeing the error on the second instance, you need to access 'completed' as in:
<% #tasks.completed.each do |task| %>
<% completed = task.completed %>
<% completed.each do |com| %>
Does this make sense?