Rails%203%20In%20Action

442 CHAPTER 16 Basic performance enhancements
SEEING PAGINATION FOR YOURSELF
Here you’ve seen an easy way to add pagination links to resources in your application
by using the Kaminari gem. You could have used the will_paginate gem and that
would have worked just as easily. It’s really up to personal preference. Pagination
allows you to ease the load on the database server by returning only limited amounts
of records per page, and also doesn’t overwhelm the user with choices.
Let’s see how this works in a browser before you continue. First, you’ll need to create
100 tickets for a project so that you can get two pages of pagination. To do that,
launch rails console and put in this code:
project = Project.first
100.times do |i|
project.tickets.create!(
:title => "Fake ticket",
:description => "Fake description",
:user => User.first
)
end
Next, type exit and press Enter to exit out of the console, and then launch your application
with rails server. You can log in using the email and password you’ve set up
in db/seeds.rb, which are admin@ticketee.com and password, respectively. You can
then click the Ticketee Beta page and you should see a page like figure 16.3.
The pagination here shows that you’re on the first page and that there’s a second
page you can go to, by clicking either the 2 link or the Next link. By clicking this link,
the page switches to the second page of tickets and the URL now becomes http://localhost:3000/projects/1?page=2.
This page parameter is passed to the controller as
params[:page] and then passed to the page method provided by Kaminari.
Figure 16.3 Paginated tickets