Added 'custom validations' to AR validations and callbacks guide

2 files changed, 67 insertions, 1 deletions

diff --git a/railties/doc/guides/html/activerecord_validations_callbacks.html b/railties/doc/guides/html/activerecord_validations_callbacks.html
index 209722e9e0..45eec6ffa1 100644
--- a/railties/doc/guides/html/activerecord_validations_callbacks.html
+++ b/railties/doc/guides/html/activerecord_validations_callbacks.html
@@ -264,6 +264,9 @@ ul#navMain {
 						</ul>
 					</li>
 					<li>
+					<a href="#_writing_your_own_validation_methods">Writing your own validation methods</a>
+					</li>
+					<li>
 					<a href="#_changelog">Changelog</a>
 					</li>
 			</ol>
@@ -702,7 +705,40 @@ http://www.gnu.org/software/src-highlite -->
 <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>

 </tt></pre></div></div>

 </div>

-<h2 id="_changelog">6. Changelog</h2>

+<h2 id="_writing_your_own_validation_methods">6. Writing your own validation methods</h2>

+<div class="sectionbody">

+<div class="para"><p>When the built-in validation helpers are not enough for your needs, you can write your own validation methods, by implementing one or more of the <tt>validate</tt>, <tt>validate_on_create</tt> or <tt>validate_on_update</tt> methods. As the names of the methods states, the right method to implement depends on when you want the validations to be ran. The meaning of valid is still the same: to make an object invalid you just need to add a message to it's <tt>errors</tt> collection.</p></div>

+<div class="listingblock">

+<div class="content"><!-- Generator: GNU source-highlight 2.9

+by Lorenzo Bettini

+http://www.lorenzobettini.it

+http://www.gnu.org/software/src-highlite -->

+<pre><tt><span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Invoice <span style="color: #990000">&lt;</span> ActiveRecord<span style="color: #990000">::</span>Base

+  <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> validate_on_create

+    errors<span style="color: #990000">.</span>add<span style="color: #990000">(:</span>expiration_date<span style="color: #990000">,</span> <span style="color: #FF0000">"can't be in the past"</span><span style="color: #990000">)</span> <span style="font-weight: bold"><span style="color: #0000FF">if</span></span> <span style="color: #990000">!</span>expiration_date<span style="color: #990000">.</span>blank? <span style="font-weight: bold"><span style="color: #0000FF">and</span></span> expiration_date <span style="color: #990000">&lt;</span> Date<span style="color: #990000">.</span>today

+  <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>

+<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>

+</tt></pre></div></div>

+<div class="para"><p>If your validation rules are too complicated and you want to break it in small methods, you can implement all of them and call one of <tt>validate</tt>, <tt>validate_on_create</tt> or <tt>validate_on_update</tt> methods, passing it the symbols for the methods' names.</p></div>

+<div class="listingblock">

+<div class="content"><!-- Generator: GNU source-highlight 2.9

+by Lorenzo Bettini

+http://www.lorenzobettini.it

+http://www.gnu.org/software/src-highlite -->

+<pre><tt><span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Invoice <span style="color: #990000">&lt;</span> ActiveRecord<span style="color: #990000">::</span>Base

+  validate <span style="color: #990000">:</span>expiration_date_cannot_be_in_the_past<span style="color: #990000">,</span> <span style="color: #990000">:</span>discount_cannot_be_be_more_than_total_value

+

+  <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> expiration_date_cannot_be_in_the_past

+    errors<span style="color: #990000">.</span>add<span style="color: #990000">(:</span>expiration_date<span style="color: #990000">,</span> <span style="color: #FF0000">"can't be in the past"</span><span style="color: #990000">)</span> <span style="font-weight: bold"><span style="color: #0000FF">if</span></span> <span style="color: #990000">!</span>expiration_date<span style="color: #990000">.</span>blank? <span style="font-weight: bold"><span style="color: #0000FF">and</span></span> expiration_date <span style="color: #990000">&lt;</span> Date<span style="color: #990000">.</span>today

+  <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>

+

+  <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> discount_cannot_be_greater_than_total_value

+    errors<span style="color: #990000">.</span>add<span style="color: #990000">(:</span>discount<span style="color: #990000">,</span> <span style="color: #FF0000">"can't be greater than total value"</span><span style="color: #990000">)</span> <span style="font-weight: bold"><span style="color: #0000FF">unless</span></span> discount <span style="color: #990000">&lt;=</span> total_value

+  <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>

+<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>

+</tt></pre></div></div>

+</div>

+<h2 id="_changelog">7. Changelog</h2>

 <div class="sectionbody">

 <div class="para"><p><a href="http://rails.lighthouseapp.com/projects/16213/tickets/26-active-record-validations-and-callbacks">http://rails.lighthouseapp.com/projects/16213/tickets/26-active-record-validations-and-callbacks</a></p></div>

 </div>

diff --git a/railties/doc/guides/source/activerecord_validations_callbacks.txt b/railties/doc/guides/source/activerecord_validations_callbacks.txt
index 29be2182ce..3da4f0361b 100644
--- a/railties/doc/guides/source/activerecord_validations_callbacks.txt
+++ b/railties/doc/guides/source/activerecord_validations_callbacks.txt
@@ -369,6 +369,36 @@ class Account < ActiveRecord::Base
 end
 ------------------------------------------------------------------
 
+== Writing your own validation methods
+
+When the built-in validation helpers are not enough for your needs, you can write your own validation methods, by implementing one or more of the +validate+, +validate_on_create+ or +validate_on_update+ methods. As the names of the methods states, the right method to implement depends on when you want the validations to be ran. The meaning of valid is still the same: to make an object invalid you just need to add a message to it's +errors+ collection.
+
+[source, ruby]
+------------------------------------------------------------------
+class Invoice < ActiveRecord::Base
+  def validate_on_create    
+    errors.add(:expiration_date, "can't be in the past") if !expiration_date.blank? and expiration_date < Date.today
+  end
+end
+------------------------------------------------------------------
+
+If your validation rules are too complicated and you want to break it in small methods, you can implement all of them and call one of +validate+, +validate_on_create+ or +validate_on_update+ methods, passing it the symbols for the methods' names.
+
+[source, ruby]
+------------------------------------------------------------------
+class Invoice < ActiveRecord::Base
+  validate :expiration_date_cannot_be_in_the_past, :discount_cannot_be_be_more_than_total_value
+
+  def expiration_date_cannot_be_in_the_past
+    errors.add(:expiration_date, "can't be in the past") if !expiration_date.blank? and expiration_date < Date.today
+  end  
+  
+  def discount_cannot_be_greater_than_total_value
+    errors.add(:discount, "can't be greater than total value") unless discount <= total_value
+  end
+end
+------------------------------------------------------------------
+
 == Changelog
 
 http://rails.lighthouseapp.com/projects/16213/tickets/26-active-record-validations-and-callbacks