group_by two parametrs - ruby-on-rails

Question

In the tasks_controller, I defined:
def index
#tasks = Task.all
respond_to do |format|
format.html # index.html.erb
format.json { render json: #tasks }
end
end
I have three parameters in my table: name, task, done.
now, I want to produce:
<table>
<tr>
<th>Name</th>
<th>num of tasks</th>
<th>num tasks left</th>
</tr>
<% #tasks.group_by(&:name).each do |name, tasks| %>
<tr>
<td><%= name %></td>
<td><%= tasks.size %></td>
<td> here I want to produce the number of tasks left </td>
</tr>
<% end %>
</table>
how can I get the number of tasks left? I think it should be something like:
<% #tasks.group_by(&:name).each do |name, tasks| %>
<tr>
<td><%= name %></td>
<td><%= tasks.size %></td>
<% #tasks.group_by(name, :done => "yes").each do |name, tasks| %>
<td><%= tasks.size %></td>
<% end %>
</tr>
<% end %>

Answer 1

You had a good idea ;)
<% #tasks.group_by(&:name).each do |name, tasks| %>
<tr>
<td><%= name %></td>
<td><%= tasks.size %></td>
<td><%= tasks.select{ |task| task.done != 'yes' }.size %></td>
</tr>
<% end %>
tasks.select{ |task| task.done != 'yes' } : This will select the tasks where done is not yes, put it in an array and calculate its size (number of tasks not done yet).
I strongly recommend you to set your #tasks variable like following (takes much less performances: the DB does the work for you!)
# in the controller
#tasks = Task.count(:group => 'name') #instead of #tasks = Task.all
It has the same output as #tasks.group_by(...) but is much better in execution time.