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Added 'custom validations' to AR validations and callbacks guide

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commit fdd1ef5ca26de29eee3e5246e609c883ea3d9319 1 parent af320ef
@cassiomarques cassiomarques authored
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38 railties/doc/guides/html/activerecord_validations_callbacks.html
@@ -264,6 +264,9 @@ <h2 id="site_title_tagline">Sustainable productivity for web-application develop
</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 @@ <h3 id="_using_a_proc_object_with_the_tt_if_tt_and_tt_unless_tt_options">5.3. Us
<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>
View
30 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
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