This worked because, in the context of the Users controller, will_paginate assumes the existence of an instance variable called @users (which, as we saw in Section 9.3.3, should be of class ActiveRecord::Relation). In the present case, since we are still in the Users controller but want to paginate microposts instead, we pass an explicit @microposts variable to will_paginate. Of course, this means that we will have to define such a variable in the user show action (Listing 10.22).

     Finally, note that we have taken this opportunity to add a count of the current number of microposts: V

As noted, @user.microposts.count is the analogue of the User.count method, except that it counts the microposts belonging to a given user through the user/micropost association.

We come finally to the micropost list itself:  

This code, which uses the ordered list tag ol, is responsible for generating the list of microposts, but you can see that it just defers the heavy lifting to a micropost partial. We saw in Section 9.3.4 that the code

automatically renders each of the users in the @users variable using the _user .html.erb partial. Similarly, the code

does exactly the same thing for microposts. This means that we must define a _micropost.html.erb partial (along with a micropost views directory), as shown in Listing 10.21.