Lesson Using Hydra Access Controls and CanCan to conditionally render part of a page

This Tutorial is known to work with hydra-head version 6.4.0.
Please update this wiki to reflect any other versions that have been tested.

Goals

Explanation

Steps

Step: Use can? to conditionally render html on a page

In app/views/books/show.html.erb find the code that's displaying the "Edit" and "Back" links at the bottom of the page.

<%= link_to 'Edit', edit_book_path(@book) %> |
<%= link_to 'Back', books_path %>

Use an if ... end clause to only show the "Edit" link if the current user has permission to edit the current book.

<%- if can?(:edit, @book) %>
  <%= link_to 'Edit', edit_book_path(@book) %> |
<%- end %>
<%= link_to 'Back', books_path %>

Now go into the rails console and give yourself edit access to one book but only read access for another. Look at the show views for the two books. You should see the "Edit" link on the book that you have permission to edit and you should not see the "Edit" link for the book that you do not have permission to edit.

Next Step

Return to the Access Controls with Hydra tutorial.