diff options
| author | Jeff Dean <jeff@zilkey.com> | 2008-11-13 01:44:34 -0500 |
|---|---|---|
| committer | Jeff Dean <jeff@zilkey.com> | 2008-11-13 01:44:34 -0500 |
| commit | 41d0dbcb8661a866ddf4b3534b8b1efd724ecba1 (patch) | |
| tree | aa59d83197ea83ded0067241f010baf8e47b3130 /railties | |
| parent | bc75de8e4f60a774423290872aeb25d09561531b (diff) | |
| download | rails-41d0dbcb8661a866ddf4b3534b8b1efd724ecba1.tar.gz rails-41d0dbcb8661a866ddf4b3534b8b1efd724ecba1.tar.bz2 rails-41d0dbcb8661a866ddf4b3534b8b1efd724ecba1.zip | |
Plugin guide: update acts_as section
Diffstat (limited to 'railties')
4 files changed, 197 insertions, 215 deletions
diff --git a/railties/doc/guides/html/creating_plugins.html b/railties/doc/guides/html/creating_plugins.html index bbb4719b0f..793cd2b7a7 100644 --- a/railties/doc/guides/html/creating_plugins.html +++ b/railties/doc/guides/html/creating_plugins.html @@ -216,16 +216,23 @@ ul#navMain { <a href="#_extending_core_classes">Extending core classes</a> <ul> - <li><a href="#_working_with_init_rb">Working with init.rb</a></li> - <li><a href="#_creating_the_test">Creating the test</a></li> <li><a href="#_organize_your_files">Organize your files</a></li> + <li><a href="#_working_with_init_rb">Working with init.rb</a></li> + </ul> </li> <li> - <a href="#_add_an_tt_acts_as_yaffle_tt_method_to_activerecord">Add an <tt>acts_as_yaffle</tt> method to ActiveRecord</a> + <a href="#_add_an_tt_acts_as_yaffle_tt_method_to_active_record">Add an <tt>acts_as_yaffle</tt> method to Active Record</a> + <ul> + + <li><a href="#_add_a_class_method">Add a class method</a></li> + + <li><a href="#_add_an_instance_method">Add an instance method</a></li> + + </ul> </li> <li> <a href="#_create_a_tt_squawk_info_for_tt_view_helper">Create a <tt>squawk_info_for</tt> view helper</a> @@ -529,12 +536,6 @@ ActiveRecord<span style="color: #990000">::</span>Base<span style="color: #99000 <span style="font-weight: bold"><span style="color: #0000FF">load</span></span><span style="color: #990000">(</span>File<span style="color: #990000">.</span>dirname<span style="color: #990000">(</span><span style="font-weight: bold"><span style="color: #0000FF">__FILE__</span></span><span style="color: #990000">)</span> <span style="color: #990000">+</span> <span style="color: #FF0000">"/schema.rb"</span><span style="color: #990000">)</span>
<span style="font-weight: bold"><span style="color: #000080">require</span></span> File<span style="color: #990000">.</span>dirname<span style="color: #990000">(</span><span style="font-weight: bold"><span style="color: #0000FF">__FILE__</span></span><span style="color: #990000">)</span> <span style="color: #990000">+</span> <span style="color: #FF0000">'/../init.rb'</span>
-
-<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Hickwall <span style="color: #990000"><</span> ActiveRecord<span style="color: #990000">::</span>Base
-<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
-
-<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Wickwall <span style="color: #990000"><</span> ActiveRecord<span style="color: #990000">::</span>Base
-<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
</tt></pre></div></div>
<h3 id="_run_the_plugin_tests">1.4. Run the plugin tests</h3>
<div class="para"><p>Once you have these files in place, you can write your first test to ensure that your plugin-testing setup is correct. By default rails generates a file in <em>vendor/plugins/yaffle/test/yaffle_test.rb</em> with a sample test. Replace the contents of that file with:</p></div>
@@ -548,9 +549,15 @@ http://www.gnu.org/software/src-highlite --> <span style="font-weight: bold"><span style="color: #0000FF">class</span></span> YaffleTest <span style="color: #990000"><</span> Test<span style="color: #990000">::</span>Unit<span style="color: #990000">::</span>TestCase
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_active_record_classes_from_test_helper
- assert_kind_of Hickwall<span style="color: #990000">,</span> Hickwall<span style="color: #990000">.</span>new
- assert_kind_of Wickwall<span style="color: #990000">,</span> Wickwall<span style="color: #990000">.</span>new
+ <span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Hickwall <span style="color: #990000"><</span> ActiveRecord<span style="color: #990000">::</span>Base
+ <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
+
+ <span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Wickwall <span style="color: #990000"><</span> ActiveRecord<span style="color: #990000">::</span>Base
+ <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
+
+ <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_schema_has_loaded_correctly
+ assert_equal <span style="color: #990000">[],</span> Hickwall<span style="color: #990000">.</span>all
+ assert_equal <span style="color: #990000">[],</span> Wickwall<span style="color: #990000">.</span>all
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
@@ -605,36 +612,7 @@ Creating and requiring the correct files </p>
</li>
</ul></div>
-<h3 id="_working_with_init_rb">2.1. Working with init.rb</h3>
-<div class="para"><p>When rails loads plugins it looks for the file named init.rb. However, the plugin initializer script <em>init.rb</em> is invoked via <tt>eval</tt> (not <tt>require</tt>) so it has slightly different behavior.</p></div>
-<div class="para"><p>Under certain circumstances if you reopen classes or modules in <em>init.rb</em> itself, you may inadvertently create a new class, rather than reopening an existing class. A better alternative is to reopen the class in a different file, and require that file from <tt>init.rb</tt>.</p></div>
-<div class="para"><p>If you must reopen a class in <tt>init.rb</tt> you can use <tt>module_eval</tt> or <tt>class_eval</tt>:</p></div>
-<div class="para"><p><strong>vendor/plugins/yaffle/init.rb</strong></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>Hash<span style="color: #990000">.</span>class_eval <span style="font-weight: bold"><span style="color: #0000FF">do</span></span>
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> is_a_special_hash?
- <span style="font-weight: bold"><span style="color: #0000FF">true</span></span>
- <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>Another way is to explicitly define the top-level module space for all modules and classes, like <tt>::Hash</tt>:</p></div>
-<div class="para"><p><strong>vendor/plugins/yaffle/init.rb</strong></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> <span style="color: #990000">::</span>Hash
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> is_a_special_hash?
- <span style="font-weight: bold"><span style="color: #0000FF">true</span></span>
- <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>
-<h3 id="_creating_the_test">2.2. Creating the test</h3>
+<h3 id="_creating_the_test">2.1. Creating the test</h3>
<div class="para"><p>In this example you will add a method to String named <tt>to_squawk</tt>. To begin, create a new test file with a few assertions:</p></div>
<div class="para"><p><strong>vendor/plugins/yaffle/test/core_ext_test.rb</strong></p></div>
<div class="listingblock">
@@ -665,8 +643,8 @@ NoMethodError: undefined method `to_squawk' for "Hello World":String ./test/core_ext_test.rb:5:in `test_to_squawk_prepends_the_word_squawk'</tt></pre>
</div></div>
<div class="para"><p>Great - now you are ready to start development.</p></div>
-<h3 id="_organize_your_files">2.3. Organize your files</h3>
-<div class="para"><p>A common pattern in rails plugins is to set up the file structure something like this:</p></div>
+<h3 id="_organize_your_files">2.2. Organize your files</h3>
+<div class="para"><p>A common pattern in rails plugins is to set up the file structure like this:</p></div>
<div class="listingblock">
<div class="content">
<pre><tt>|-- init.rb
@@ -713,11 +691,40 @@ http://www.gnu.org/software/src-highlite --> >> "Hello World".to_squawk
=> "squawk! Hello World"</tt></pre>
</div></div>
+<h3 id="_working_with_init_rb">2.3. Working with init.rb</h3>
+<div class="para"><p>When rails loads plugins it looks for the file named init.rb. However, when the plugin is initialized, <em>init.rb</em> is invoked via <tt>eval</tt> (not <tt>require</tt>) so it has slightly different behavior.</p></div>
+<div class="para"><p>Under certain circumstances if you reopen classes or modules in <em>init.rb</em> you may inadvertently create a new class, rather than reopening an existing class. A better alternative is to reopen the class in a different file, and require that file from <tt>init.rb</tt>, as shown above.</p></div>
+<div class="para"><p>If you must reopen a class in <tt>init.rb</tt> you can use <tt>module_eval</tt> or <tt>class_eval</tt> to avoid any issues:</p></div>
+<div class="para"><p><strong>vendor/plugins/yaffle/init.rb</strong></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>Hash<span style="color: #990000">.</span>class_eval <span style="font-weight: bold"><span style="color: #0000FF">do</span></span>
+ <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> is_a_special_hash?
+ <span style="font-weight: bold"><span style="color: #0000FF">true</span></span>
+ <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>Another way is to explicitly define the top-level module space for all modules and classes, like <tt>::Hash</tt>:</p></div>
+<div class="para"><p><strong>vendor/plugins/yaffle/init.rb</strong></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> <span style="color: #990000">::</span>Hash
+ <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> is_a_special_hash?
+ <span style="font-weight: bold"><span style="color: #0000FF">true</span></span>
+ <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="_add_an_tt_acts_as_yaffle_tt_method_to_activerecord">3. Add an <tt>acts_as_yaffle</tt> method to ActiveRecord</h2>
+<h2 id="_add_an_tt_acts_as_yaffle_tt_method_to_active_record">3. Add an <tt>acts_as_yaffle</tt> method to Active Record</h2>
<div class="sectionbody">
-<div class="para"><p>A common pattern in plugins is to add a method called <tt>acts_as_something</tt> to models. In this case, you want to write a method called <tt>acts_as_yaffle</tt> that adds a <tt>squawk</tt> method to your models.</p></div>
-<div class="para"><p>To keep things clean, create a new test file called <em>acts_as_yaffle_test.rb</em> in your plugin's test directory and require your test helper.</p></div>
+<div class="para"><p>A common pattern in plugins is to add a method called <em>acts_as_something</em> to models. In this case, you want to write a method called <em>acts_as_yaffle</em> that adds a <em>squawk</em> method to your models.</p></div>
+<div class="para"><p>To begin, set up your files so that you have:</p></div>
<div class="para"><p><strong>vendor/plugins/yaffle/test/acts_as_yaffle_test.rb</strong></p></div>
<div class="listingblock">
<div class="content"><!-- Generator: GNU source-highlight 2.9
@@ -726,24 +733,30 @@ http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite -->
<pre><tt><span style="font-weight: bold"><span style="color: #000080">require</span></span> File<span style="color: #990000">.</span>dirname<span style="color: #990000">(</span><span style="font-weight: bold"><span style="color: #0000FF">__FILE__</span></span><span style="color: #990000">)</span> <span style="color: #990000">+</span> <span style="color: #FF0000">'/test_helper.rb'</span>
-<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Hickwall <span style="color: #990000"><</span> ActiveRecord<span style="color: #990000">::</span>Base
- acts_as_yaffle
-<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
-
<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> ActsAsYaffleTest <span style="color: #990000"><</span> Test<span style="color: #990000">::</span>Unit<span style="color: #990000">::</span>TestCase
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
</tt></pre></div></div>
-<div class="para"><p><strong>vendor/plugins/lib/acts_as_yaffle.rb</strong></p></div>
+<div class="para"><p><strong>vendor/plugins/yaffle/lib/yaffle.rb</strong></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: #000080">require</span></span> <span style="color: #FF0000">'yaffle/acts_as_yaffle'</span>
+</tt></pre></div></div>
+<div class="para"><p><strong>vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb</strong></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">module</span></span> Yaffle
+ <span style="font-style: italic"><span style="color: #9A1900"># your code will go here</span></span>
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
</tt></pre></div></div>
-<div class="para"><p>One of the most common plugin patterns for <tt>acts_as_yaffle</tt> plugins is to structure your file like so:</p></div>
-<div class="para"><p><strong>vendor/plugins/lib/acts_as_yaffle.rb</strong></p></div>
+<div class="para"><p>Note that after requiring <em>acts_as_yaffle</em> you also have to include it into ActiveRecord::Base so that your plugin methods will be available to the rails models.</p></div>
+<div class="para"><p>One of the most common plugin patterns for <em>acts_as_yaffle</em> plugins is to structure your file like so:</p></div>
+<div class="para"><p><strong>vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb</strong></p></div>
<div class="listingblock">
<div class="content"><!-- Generator: GNU source-highlight 2.9
by Lorenzo Bettini
@@ -767,20 +780,9 @@ http://www.gnu.org/software/src-highlite --> <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
</tt></pre></div></div>
<div class="para"><p>With structure you can easily separate the methods that will be used for the class (like <tt>Hickwall.some_method</tt>) and the instance (like <tt>@hickwell.some_method</tt>).</p></div>
-<div class="para"><p>Let's add class method named <tt>acts_as_yaffle</tt> - testing it out first. You already defined the ActiveRecord models in your test helper, so if you run tests now they will fail.</p></div>
-<div class="para"><p>Back in your <tt>acts_as_yaffle</tt> file, update ClassMethods like so:</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">module</span></span> ClassMethods
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> acts_as_yaffle<span style="color: #990000">(</span>options <span style="color: #990000">=</span> <span style="color: #FF0000">{}</span><span style="color: #990000">)</span>
- send <span style="color: #990000">:</span><span style="font-weight: bold"><span style="color: #0000FF">include</span></span><span style="color: #990000">,</span> InstanceMethods
- <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>Now that test should pass. Since your plugin is going to work with field names, you need to allow people to define the field names, in case there is a naming conflict. You can write a few simple tests for this:</p></div>
+<h3 id="_add_a_class_method">3.1. Add a class method</h3>
+<div class="para"><p>This plugin will expect that you've added a method to your model named <em>last_squawk</em>. However, the plugin users might have already defined a method on their model named <em>last_squawk</em> that they use for something else. This plugin will allow the name to be changed by adding a class method called <em>yaffle_text_field</em>.</p></div>
+<div class="para"><p>To start out, write a failing test that shows the behavior you'd like:</p></div>
<div class="para"><p><strong>vendor/plugins/yaffle/test/acts_as_yaffle_test.rb</strong></p></div>
<div class="listingblock">
<div class="content"><!-- Generator: GNU source-highlight 2.9
@@ -789,26 +791,26 @@ http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite -->
<pre><tt><span style="font-weight: bold"><span style="color: #000080">require</span></span> File<span style="color: #990000">.</span>dirname<span style="color: #990000">(</span><span style="font-weight: bold"><span style="color: #0000FF">__FILE__</span></span><span style="color: #990000">)</span> <span style="color: #990000">+</span> <span style="color: #FF0000">'/test_helper.rb'</span>
+<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Hickwall <span style="color: #990000"><</span> ActiveRecord<span style="color: #990000">::</span>Base
+ acts_as_yaffle
+<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
+
+<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Wickwall <span style="color: #990000"><</span> ActiveRecord<span style="color: #990000">::</span>Base
+ acts_as_yaffle <span style="color: #990000">:</span>yaffle_text_field <span style="color: #990000">=></span> <span style="color: #990000">:</span>last_tweet
+<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
+
<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> ActsAsYaffleTest <span style="color: #990000"><</span> Test<span style="color: #990000">::</span>Unit<span style="color: #990000">::</span>TestCase
<span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_a_hickwalls_yaffle_text_field_should_be_last_squawk
assert_equal <span style="color: #FF0000">"last_squawk"</span><span style="color: #990000">,</span> Hickwall<span style="color: #990000">.</span>yaffle_text_field
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_a_hickwalls_yaffle_date_field_should_be_last_squawked_at
- assert_equal <span style="color: #FF0000">"last_squawked_at"</span><span style="color: #990000">,</span> Hickwall<span style="color: #990000">.</span>yaffle_date_field
- <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
-
<span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_a_wickwalls_yaffle_text_field_should_be_last_tweet
assert_equal <span style="color: #FF0000">"last_tweet"</span><span style="color: #990000">,</span> Wickwall<span style="color: #990000">.</span>yaffle_text_field
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
-
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_a_wickwalls_yaffle_date_field_should_be_last_tweeted_at
- assert_equal <span style="color: #FF0000">"last_tweeted_at"</span><span style="color: #990000">,</span> Wickwall<span style="color: #990000">.</span>yaffle_date_field
- <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>To make these tests pass, you could modify your <tt>acts_as_yaffle</tt> file like so:</p></div>
-<div class="para"><p><strong>vendor/plugins/yaffle/lib/acts_as_yaffle.rb</strong></p></div>
+<div class="para"><p><strong>vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb</strong></p></div>
<div class="listingblock">
<div class="content"><!-- Generator: GNU source-highlight 2.9
by Lorenzo Bettini
@@ -821,18 +823,17 @@ http://www.gnu.org/software/src-highlite --> <span style="font-weight: bold"><span style="color: #0000FF">module</span></span> ClassMethods
<span style="font-weight: bold"><span style="color: #0000FF">def</span></span> acts_as_yaffle<span style="color: #990000">(</span>options <span style="color: #990000">=</span> <span style="color: #FF0000">{}</span><span style="color: #990000">)</span>
- cattr_accessor <span style="color: #990000">:</span>yaffle_text_field<span style="color: #990000">,</span> <span style="color: #990000">:</span>yaffle_date_field
+ cattr_accessor <span style="color: #990000">:</span>yaffle_text_field
<span style="font-weight: bold"><span style="color: #0000FF">self</span></span><span style="color: #990000">.</span>yaffle_text_field <span style="color: #990000">=</span> <span style="color: #990000">(</span>options<span style="color: #990000">[:</span>yaffle_text_field<span style="color: #990000">]</span> <span style="color: #990000">||</span> <span style="color: #990000">:</span>last_squawk<span style="color: #990000">).</span>to_s
- <span style="font-weight: bold"><span style="color: #0000FF">self</span></span><span style="color: #990000">.</span>yaffle_date_field <span style="color: #990000">=</span> <span style="color: #990000">(</span>options<span style="color: #990000">[:</span>yaffle_date_field<span style="color: #990000">]</span> <span style="color: #990000">||</span> <span style="color: #990000">:</span>last_squawked_at<span style="color: #990000">).</span>to_s
- send <span style="color: #990000">:</span><span style="font-weight: bold"><span style="color: #0000FF">include</span></span><span style="color: #990000">,</span> InstanceMethods
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
-
- <span style="font-weight: bold"><span style="color: #0000FF">module</span></span> InstanceMethods
- <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
+
+ActiveRecord<span style="color: #990000">::</span>Base<span style="color: #990000">.</span>send <span style="color: #990000">:</span><span style="font-weight: bold"><span style="color: #0000FF">include</span></span><span style="color: #990000">,</span> Yaffle
</tt></pre></div></div>
-<div class="para"><p>Now you can add tests for the instance methods, and the instance method itself:</p></div>
+<h3 id="_add_an_instance_method">3.2. Add an instance method</h3>
+<div class="para"><p>This plugin will add a method named <em>squawk</em> to any Active Record objects that call <em>acts_as_yaffle</em>. The <em>squawk</em> method will simply set the value of one of the fields in the database.</p></div>
+<div class="para"><p>To start out, write a failing test that shows the behavior you'd like:</p></div>
<div class="para"><p><strong>vendor/plugins/yaffle/test/acts_as_yaffle_test.rb</strong></p></div>
<div class="listingblock">
<div class="content"><!-- Generator: GNU source-highlight 2.9
@@ -841,46 +842,38 @@ http://www.lorenzobettini.it http://www.gnu.org/software/src-highlite -->
<pre><tt><span style="font-weight: bold"><span style="color: #000080">require</span></span> File<span style="color: #990000">.</span>dirname<span style="color: #990000">(</span><span style="font-weight: bold"><span style="color: #0000FF">__FILE__</span></span><span style="color: #990000">)</span> <span style="color: #990000">+</span> <span style="color: #FF0000">'/test_helper.rb'</span>
-<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> ActsAsYaffleTest <span style="color: #990000"><</span> Test<span style="color: #990000">::</span>Unit<span style="color: #990000">::</span>TestCase
+<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Hickwall <span style="color: #990000"><</span> ActiveRecord<span style="color: #990000">::</span>Base
+ acts_as_yaffle
+<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
+<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> Wickwall <span style="color: #990000"><</span> ActiveRecord<span style="color: #990000">::</span>Base
+ acts_as_yaffle <span style="color: #990000">:</span>yaffle_text_field <span style="color: #990000">=></span> <span style="color: #990000">:</span>last_tweet
+<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
+
+<span style="font-weight: bold"><span style="color: #0000FF">class</span></span> ActsAsYaffleTest <span style="color: #990000"><</span> Test<span style="color: #990000">::</span>Unit<span style="color: #990000">::</span>TestCase
<span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_a_hickwalls_yaffle_text_field_should_be_last_squawk
assert_equal <span style="color: #FF0000">"last_squawk"</span><span style="color: #990000">,</span> Hickwall<span style="color: #990000">.</span>yaffle_text_field
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_a_hickwalls_yaffle_date_field_should_be_last_squawked_at
- assert_equal <span style="color: #FF0000">"last_squawked_at"</span><span style="color: #990000">,</span> Hickwall<span style="color: #990000">.</span>yaffle_date_field
- <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_a_wickwalls_yaffle_text_field_should_be_last_squawk
+ <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_a_wickwalls_yaffle_text_field_should_be_last_tweet
assert_equal <span style="color: #FF0000">"last_tweet"</span><span style="color: #990000">,</span> Wickwall<span style="color: #990000">.</span>yaffle_text_field
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_a_wickwalls_yaffle_date_field_should_be_last_squawked_at
- assert_equal <span style="color: #FF0000">"last_tweeted_at"</span><span style="color: #990000">,</span> Wickwall<span style="color: #990000">.</span>yaffle_date_field
- <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
<span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_hickwalls_squawk_should_populate_last_squawk
hickwall <span style="color: #990000">=</span> Hickwall<span style="color: #990000">.</span>new
hickwall<span style="color: #990000">.</span>squawk<span style="color: #990000">(</span><span style="color: #FF0000">"Hello World"</span><span style="color: #990000">)</span>
assert_equal <span style="color: #FF0000">"squawk! Hello World"</span><span style="color: #990000">,</span> hickwall<span style="color: #990000">.</span>last_squawk
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_hickwalls_squawk_should_populate_last_squawked_at
- hickwall <span style="color: #990000">=</span> Hickwall<span style="color: #990000">.</span>new
- hickwall<span style="color: #990000">.</span>squawk<span style="color: #990000">(</span><span style="color: #FF0000">"Hello World"</span><span style="color: #990000">)</span>
- assert_equal Date<span style="color: #990000">.</span>today<span style="color: #990000">,</span> hickwall<span style="color: #990000">.</span>last_squawked_at
- <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
- <span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_wickwalls_squawk_should_populate_last_tweet
- wickwall <span style="color: #990000">=</span> Wickwall<span style="color: #990000">.</span>new
- wickwall<span style="color: #990000">.</span>squawk<span style="color: #990000">(</span><span style="color: #FF0000">"Hello World"</span><span style="color: #990000">)</span>
- assert_equal <span style="color: #FF0000">"squawk! Hello World"</span><span style="color: #990000">,</span> wickwall<span style="color: #990000">.</span>last_tweet
- <span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
<span style="font-weight: bold"><span style="color: #0000FF">def</span></span> test_wickwalls_squawk_should_populate_last_tweeted_at
wickwall <span style="color: #990000">=</span> Wickwall<span style="color: #990000">.</span>new
wickwall<span style="color: #990000">.</span>squawk<span style="color: #990000">(</span><span style="color: #FF0000">"Hello World"</span><span style="color: #990000">)</span>
- assert_equal Date<span style="color: #990000">.</span>today<span style="color: #990000">,</span> wickwall<span style="color: #990000">.</span>last_tweeted_at
+ assert_equal <span style="color: #FF0000">"squawk! Hello World"</span><span style="color: #990000">,</span> wickwall<span style="color: #990000">.</span>last_tweet
<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><strong>vendor/plugins/yaffle/lib/acts_as_yaffle.rb</strong></p></div>
+<div class="para"><p>Run this test to make sure the last two tests fail, then update <em>acts_as_yaffle.rb</em> to look like this:</p></div>
+<div class="para"><p><strong>vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb</strong></p></div>
<div class="listingblock">
<div class="content"><!-- Generator: GNU source-highlight 2.9
by Lorenzo Bettini
@@ -893,9 +886,8 @@ http://www.gnu.org/software/src-highlite --> <span style="font-weight: bold"><span style="color: #0000FF">module</span></span> ClassMethods
<span style="font-weight: bold"><span style="color: #0000FF">def</span></span> acts_as_yaffle<span style="color: #990000">(</span>options <span style="color: #990000">=</span> <span style="color: #FF0000">{}</span><span style="color: #990000">)</span>
- cattr_accessor <span style="color: #990000">:</span>yaffle_text_field<span style="color: #990000">,</span> <span style="color: #990000">:</span>yaffle_date_field
+ cattr_accessor <span style="color: #990000">:</span>yaffle_text_field
<span style="font-weight: bold"><span style="color: #0000FF">self</span></span><span style="color: #990000">.</span>yaffle_text_field <span style="color: #990000">=</span> <span style="color: #990000">(</span>options<span style="color: #990000">[:</span>yaffle_text_field<span style="color: #990000">]</span> <span style="color: #990000">||</span> <span style="color: #990000">:</span>last_squawk<span style="color: #990000">).</span>to_s
- <span style="font-weight: bold"><span style="color: #0000FF">self</span></span><span style="color: #990000">.</span>yaffle_date_field <span style="color: #990000">=</span> <span style="color: #990000">(</span>options<span style="color: #990000">[:</span>yaffle_date_field<span style="color: #990000">]</span> <span style="color: #990000">||</span> <span style="color: #990000">:</span>last_squawked_at<span style="color: #990000">).</span>to_s
send <span style="color: #990000">:</span><span style="font-weight: bold"><span style="color: #0000FF">include</span></span><span style="color: #990000">,</span> InstanceMethods
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
@@ -903,10 +895,11 @@ http://www.gnu.org/software/src-highlite --> <span style="font-weight: bold"><span style="color: #0000FF">module</span></span> InstanceMethods
<span style="font-weight: bold"><span style="color: #0000FF">def</span></span> squawk<span style="color: #990000">(</span>string<span style="color: #990000">)</span>
write_attribute<span style="color: #990000">(</span><span style="font-weight: bold"><span style="color: #0000FF">self</span></span><span style="color: #990000">.</span><span style="font-weight: bold"><span style="color: #0000FF">class</span></span><span style="color: #990000">.</span>yaffle_text_field<span style="color: #990000">,</span> string<span style="color: #990000">.</span>to_squawk<span style="color: #990000">)</span>
- write_attribute<span style="color: #990000">(</span><span style="font-weight: bold"><span style="color: #0000FF">self</span></span><span style="color: #990000">.</span><span style="font-weight: bold"><span style="color: #0000FF">class</span></span><span style="color: #990000">.</span>yaffle_date_field<span style="color: #990000">,</span> Date<span style="color: #990000">.</span>today<span style="color: #990000">)</span>
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span>
+
+ActiveRecord<span style="color: #990000">::</span>Base<span style="color: #990000">.</span>send <span style="color: #990000">:</span><span style="font-weight: bold"><span style="color: #0000FF">include</span></span><span style="color: #990000">,</span> Yaffle
</tt></pre></div></div>
<div class="admonitionblock">
<table><tr>
diff --git a/railties/doc/guides/source/creating_plugins/acts_as_yaffle.txt b/railties/doc/guides/source/creating_plugins/acts_as_yaffle.txt index 06878543e4..41ffa61537 100644 --- a/railties/doc/guides/source/creating_plugins/acts_as_yaffle.txt +++ b/railties/doc/guides/source/creating_plugins/acts_as_yaffle.txt @@ -1,8 +1,8 @@ -== Add an `acts_as_yaffle` method to ActiveRecord == +== Add an `acts_as_yaffle` method to Active Record == -A common pattern in plugins is to add a method called `acts_as_something` to models. In this case, you want to write a method called `acts_as_yaffle` that adds a `squawk` method to your models. +A common pattern in plugins is to add a method called 'acts_as_something' to models. In this case, you want to write a method called 'acts_as_yaffle' that adds a 'squawk' method to your models. -To keep things clean, create a new test file called 'acts_as_yaffle_test.rb' in your plugin's test directory and require your test helper. +To begin, set up your files so that you have: *vendor/plugins/yaffle/test/acts_as_yaffle_test.rb* @@ -10,25 +10,31 @@ To keep things clean, create a new test file called 'acts_as_yaffle_test.rb' in ------------------------------------------------------ require File.dirname(__FILE__) + '/test_helper.rb' -class Hickwall < ActiveRecord::Base - acts_as_yaffle -end - class ActsAsYaffleTest < Test::Unit::TestCase end ------------------------------------------------------ -*vendor/plugins/lib/acts_as_yaffle.rb* +*vendor/plugins/yaffle/lib/yaffle.rb* + +[source, ruby] +------------------------------------------------------ +require 'yaffle/acts_as_yaffle' +------------------------------------------------------ + +*vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb* [source, ruby] ------------------------------------------------------ module Yaffle + # your code will go here end ------------------------------------------------------ -One of the most common plugin patterns for `acts_as_yaffle` plugins is to structure your file like so: +Note that after requiring 'acts_as_yaffle' you also have to include it into ActiveRecord::Base so that your plugin methods will be available to the rails models. + +One of the most common plugin patterns for 'acts_as_yaffle' plugins is to structure your file like so: -*vendor/plugins/lib/acts_as_yaffle.rb* +*vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb* [source, ruby] ------------------------------------------------------ @@ -52,20 +58,11 @@ end With structure you can easily separate the methods that will be used for the class (like `Hickwall.some_method`) and the instance (like `@hickwell.some_method`). -Let's add class method named `acts_as_yaffle` - testing it out first. You already defined the ActiveRecord models in your test helper, so if you run tests now they will fail. +=== Add a class method === -Back in your `acts_as_yaffle` file, update ClassMethods like so: +This plugin will expect that you've added a method to your model named 'last_squawk'. However, the plugin users might have already defined a method on their model named 'last_squawk' that they use for something else. This plugin will allow the name to be changed by adding a class method called 'yaffle_text_field'. -[source, ruby] ------------------------------------------------------- -module ClassMethods - def acts_as_yaffle(options = {}) - send :include, InstanceMethods - end -end ------------------------------------------------------- - -Now that test should pass. Since your plugin is going to work with field names, you need to allow people to define the field names, in case there is a naming conflict. You can write a few simple tests for this: +To start out, write a failing test that shows the behavior you'd like: *vendor/plugins/yaffle/test/acts_as_yaffle_test.rb* @@ -73,28 +70,28 @@ Now that test should pass. Since your plugin is going to work with field names, ------------------------------------------------------ require File.dirname(__FILE__) + '/test_helper.rb' +class Hickwall < ActiveRecord::Base + acts_as_yaffle +end + +class Wickwall < ActiveRecord::Base + acts_as_yaffle :yaffle_text_field => :last_tweet +end + class ActsAsYaffleTest < Test::Unit::TestCase def test_a_hickwalls_yaffle_text_field_should_be_last_squawk assert_equal "last_squawk", Hickwall.yaffle_text_field end - def test_a_hickwalls_yaffle_date_field_should_be_last_squawked_at - assert_equal "last_squawked_at", Hickwall.yaffle_date_field - end - def test_a_wickwalls_yaffle_text_field_should_be_last_tweet assert_equal "last_tweet", Wickwall.yaffle_text_field end - - def test_a_wickwalls_yaffle_date_field_should_be_last_tweeted_at - assert_equal "last_tweeted_at", Wickwall.yaffle_date_field - end end ------------------------------------------------------ To make these tests pass, you could modify your `acts_as_yaffle` file like so: -*vendor/plugins/yaffle/lib/acts_as_yaffle.rb* +*vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb* [source, ruby] ------------------------------------------------------ @@ -105,19 +102,20 @@ module Yaffle module ClassMethods def acts_as_yaffle(options = {}) - cattr_accessor :yaffle_text_field, :yaffle_date_field + cattr_accessor :yaffle_text_field self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s - self.yaffle_date_field = (options[:yaffle_date_field] || :last_squawked_at).to_s - send :include, InstanceMethods end end - - module InstanceMethods - end end + +ActiveRecord::Base.send :include, Yaffle ------------------------------------------------------ -Now you can add tests for the instance methods, and the instance method itself: +=== Add an instance method === + +This plugin will add a method named 'squawk' to any Active Record objects that call 'acts_as_yaffle'. The 'squawk' method will simply set the value of one of the fields in the database. + +To start out, write a failing test that shows the behavior you'd like: *vendor/plugins/yaffle/test/acts_as_yaffle_test.rb* @@ -125,47 +123,40 @@ Now you can add tests for the instance methods, and the instance method itself: ------------------------------------------------------ require File.dirname(__FILE__) + '/test_helper.rb' -class ActsAsYaffleTest < Test::Unit::TestCase +class Hickwall < ActiveRecord::Base + acts_as_yaffle +end + +class Wickwall < ActiveRecord::Base + acts_as_yaffle :yaffle_text_field => :last_tweet +end +class ActsAsYaffleTest < Test::Unit::TestCase def test_a_hickwalls_yaffle_text_field_should_be_last_squawk assert_equal "last_squawk", Hickwall.yaffle_text_field end - def test_a_hickwalls_yaffle_date_field_should_be_last_squawked_at - assert_equal "last_squawked_at", Hickwall.yaffle_date_field - end - def test_a_wickwalls_yaffle_text_field_should_be_last_squawk + def test_a_wickwalls_yaffle_text_field_should_be_last_tweet assert_equal "last_tweet", Wickwall.yaffle_text_field end - def test_a_wickwalls_yaffle_date_field_should_be_last_squawked_at - assert_equal "last_tweeted_at", Wickwall.yaffle_date_field - end - + def test_hickwalls_squawk_should_populate_last_squawk hickwall = Hickwall.new hickwall.squawk("Hello World") assert_equal "squawk! Hello World", hickwall.last_squawk - end - def test_hickwalls_squawk_should_populate_last_squawked_at - hickwall = Hickwall.new - hickwall.squawk("Hello World") - assert_equal Date.today, hickwall.last_squawked_at - end - - def test_wickwalls_squawk_should_populate_last_tweet - wickwall = Wickwall.new - wickwall.squawk("Hello World") - assert_equal "squawk! Hello World", wickwall.last_tweet - end + end + def test_wickwalls_squawk_should_populate_last_tweeted_at wickwall = Wickwall.new wickwall.squawk("Hello World") - assert_equal Date.today, wickwall.last_tweeted_at - end + assert_equal "squawk! Hello World", wickwall.last_tweet + end end ------------------------------------------------------ -*vendor/plugins/yaffle/lib/acts_as_yaffle.rb* +Run this test to make sure the last two tests fail, then update 'acts_as_yaffle.rb' to look like this: + +*vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb* [source, ruby] ------------------------------------------------------ @@ -176,9 +167,8 @@ module Yaffle module ClassMethods def acts_as_yaffle(options = {}) - cattr_accessor :yaffle_text_field, :yaffle_date_field + cattr_accessor :yaffle_text_field self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s - self.yaffle_date_field = (options[:yaffle_date_field] || :last_squawked_at).to_s send :include, InstanceMethods end end @@ -186,10 +176,11 @@ module Yaffle module InstanceMethods def squawk(string) write_attribute(self.class.yaffle_text_field, string.to_squawk) - write_attribute(self.class.yaffle_date_field, Date.today) end end end + +ActiveRecord::Base.send :include, Yaffle ------------------------------------------------------ .Editor's note: diff --git a/railties/doc/guides/source/creating_plugins/core_ext.txt b/railties/doc/guides/source/creating_plugins/core_ext.txt index 33d3dc8ce7..9bb7691b83 100644 --- a/railties/doc/guides/source/creating_plugins/core_ext.txt +++ b/railties/doc/guides/source/creating_plugins/core_ext.txt @@ -5,39 +5,6 @@ This section will explain how to add a method to String that will be available a * Writing tests for the desired behavior * Creating and requiring the correct files - -=== Working with init.rb === - -When rails loads plugins it looks for the file named init.rb. However, the plugin initializer script 'init.rb' is invoked via `eval` (not `require`) so it has slightly different behavior. - -Under certain circumstances if you reopen classes or modules in 'init.rb' itself, you may inadvertently create a new class, rather than reopening an existing class. A better alternative is to reopen the class in a different file, and require that file from `init.rb`. - -If you must reopen a class in `init.rb` you can use `module_eval` or `class_eval`: - -*vendor/plugins/yaffle/init.rb* - -[source, ruby] ---------------------------------------------------- -Hash.class_eval do - def is_a_special_hash? - true - end -end ---------------------------------------------------- - -Another way is to explicitly define the top-level module space for all modules and classes, like `::Hash`: - -*vendor/plugins/yaffle/init.rb* - -[source, ruby] ---------------------------------------------------- -class ::Hash - def is_a_special_hash? - true - end -end ---------------------------------------------------- - === Creating the test === In this example you will add a method to String named `to_squawk`. To begin, create a new test file with a few assertions: @@ -75,7 +42,7 @@ Great - now you are ready to start development. === Organize your files === -A common pattern in rails plugins is to set up the file structure something like this: +A common pattern in rails plugins is to set up the file structure like this: -------------------------------------------------------- |-- init.rb @@ -124,3 +91,34 @@ $ ./script/console => "squawk! Hello World" -------------------------------------------------------- +=== Working with init.rb === + +When rails loads plugins it looks for the file named init.rb. However, when the plugin is initialized, 'init.rb' is invoked via `eval` (not `require`) so it has slightly different behavior. + +Under certain circumstances if you reopen classes or modules in 'init.rb' you may inadvertently create a new class, rather than reopening an existing class. A better alternative is to reopen the class in a different file, and require that file from `init.rb`, as shown above. + +If you must reopen a class in `init.rb` you can use `module_eval` or `class_eval` to avoid any issues: + +*vendor/plugins/yaffle/init.rb* + +[source, ruby] +--------------------------------------------------- +Hash.class_eval do + def is_a_special_hash? + true + end +end +--------------------------------------------------- + +Another way is to explicitly define the top-level module space for all modules and classes, like `::Hash`: + +*vendor/plugins/yaffle/init.rb* + +[source, ruby] +--------------------------------------------------- +class ::Hash + def is_a_special_hash? + true + end +end +--------------------------------------------------- diff --git a/railties/doc/guides/source/creating_plugins/test_setup.txt b/railties/doc/guides/source/creating_plugins/test_setup.txt index dc9ef6bc29..583d058494 100644 --- a/railties/doc/guides/source/creating_plugins/test_setup.txt +++ b/railties/doc/guides/source/creating_plugins/test_setup.txt @@ -155,12 +155,6 @@ ActiveRecord::Base.establish_connection(config[db_adapter]) load(File.dirname(__FILE__) + "/schema.rb") require File.dirname(__FILE__) + '/../init.rb' - -class Hickwall < ActiveRecord::Base -end - -class Wickwall < ActiveRecord::Base -end ---------------------------------------------- === Run the plugin tests === @@ -175,9 +169,15 @@ require File.dirname(__FILE__) + '/test_helper.rb' class YaffleTest < Test::Unit::TestCase - def test_active_record_classes_from_test_helper - assert_kind_of Hickwall, Hickwall.new - assert_kind_of Wickwall, Wickwall.new + class Hickwall < ActiveRecord::Base + end + + class Wickwall < ActiveRecord::Base + end + + def test_schema_has_loaded_correctly + assert_equal [], Hickwall.all + assert_equal [], Wickwall.all end end |