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With a final release of Rails 3 edging closer every day it seems like a good time to revisit some of my old articles from the last few years and bring them up to date.

Back in the summer of 2008 I wrote about custom link renderers using will_paginate and, as it is still one of the most popular posts on the blog, it’s the one I’ve decided to refresh first. Don’t worry if you haven’t read the original article as I’ll be covering the same things here. So without further ado, let’s get stuck in!

Mislav’s will_paginate plugin (and Gem) has become the de facto standard for pagination in Rails, replacing the often derided classic pagination from the dark days before Rails 2.0. If you haven’t used will_paginate before then Ryan Bates’ RailsCast is a good introduction, although be warned that it is just over a year old and there have been a number of changes to the plugin in that time (the current version is 2.3.2 2.3.6).

The default Rails behaviour for highlighting form fields with errors is to wrap them in a div, so:

<div>
  <%= f.label(:email) %>
  <%= f.text_field(:email, :size => '30') %>
</div>

Becomes:

<div>
  <div class="fieldWithErrors"><label for="user_email">Email</label></div>
  <div class="fieldWithErrors"><input id="user_email" name="user[email]" size="30" type="text" value="" /></div>
</div>

This is great when knocking together a quick prototype but as your site evolves you’ll probably want to customise it. This can be done very easily by using ActionView::Base.field_error_proc, assign a Proc to it either in your environment.rb or, if you’re a modern thinker, in an initializer and you’re good to go.