atom.xml

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<feed xmlns="http://www.w3.org/2005/Atom">

  <title><![CDATA[Railstic]]></title>
  <link href="http://emrekutlu.github.com/atom.xml" rel="self"/>
  <link href="http://emrekutlu.github.com/"/>
  <updated>2012-08-21T14:26:11+03:00</updated>
  <id>http://emrekutlu.github.com/</id>
  <author>
    <name><![CDATA[İ. Emre Kutlu]]></name>
    
  </author>
  <generator uri="http://octopress.org/">Octopress</generator>

  
  <entry>
    <title type="html"><![CDATA[Check Existence of DelayedJob Records]]></title>
    <link href="http://emrekutlu.github.com/2011/08/check-existence-of-delayedjob-records/"/>
    <updated>2011-08-29T03:23:19+03:00</updated>
    <id>http://emrekutlu.github.com/2011/08/check-existence-of-delayedjob-records</id>
    <content type="html"><![CDATA[<p>I&#8217;m using the collectiveidea fork of <a href="http://github.com/collectiveidea/delayed_job" target="_blank">DelayedJob</a>. There are two ways to create a DelayedJob record. First you can use the <code>delay</code> method.</p>

<script src="https://gist.github.com/1177431.js?file=dj_delay.rb"></script>


<p>Second way to create DelayedJob records is custom jobs.</p>

<script src="https://gist.github.com/1177431.js?file=dj_custom_job.rb"></script>

]]></content>
  </entry>
  
  <entry>
    <title type="html"><![CDATA[Dynamically Defining Methods with define_method]]></title>
    <link href="http://emrekutlu.github.com/2011/06/dynamically-defining-methods-with-define_method/"/>
    <updated>2011-06-11T02:08:08+03:00</updated>
    <id>http://emrekutlu.github.com/2011/06/dynamically-defining-methods-with-define_method</id>
    <content type="html"><![CDATA[<p>If you have been hacking ruby for a while you should have heard that &#8220;Everything is an object&#8221;. To understand this concept knowing what a <strong>singleton class</strong> is important. <a href="http://yehudakatz.com/2009/11/15/metaprogramming-in-ruby-its-all-about-the-self/" target="_blank">Yehuda Katz&#8217;s post</a> is a good source for it.</p>

<p>My ruby version 1.9.2.</p>

<script src="https://gist.github.com/1009449.js?file=ruby_version.bash"></script>


<p>First I&#8217;m going to show you how to add methods to instances by using <code><strong>define_method</strong></code>.</p>

<script src="https://gist.github.com/1009449.js?file=add_instance_methods.rb"></script>


<p>You can also write an instance method to create instance methods. <code><strong>send</strong></code> must be used because <code><strong>define_method</strong></code> is private.</p>

<script src="https://gist.github.com/1009449.js?file=add_instance_methods_by_instance_method.rb"></script>


<p>Write a singleton method to create instance methods.</p>

<script src="https://gist.github.com/1009449.js?file=add_instance_methods_by_singleton_method.rb"></script>


<p>Now it is time to add singleton methods. When we call <code><strong>define_method</strong></code>, it creates an instance method. What we have to do is call <code><strong>define_method</strong></code> on class&#8217; singleton class.</p>

<p>Getting singleton class of a class:</p>

<script src="https://gist.github.com/1009449.js?file=get_singleton_class.rb"></script>


<p>First defining singleton method to create singleton methods.</p>

<script src="https://gist.github.com/1009449.js?file=add_singleton_methods_by_singleton_method.rb"></script>


<p>Then defining instance method to create singleton methods.</p>

<script src="https://gist.github.com/1009449.js?file=add_singleton_methods_by_instance_method.rb"></script>

]]></content>
  </entry>
  
  <entry>
    <title type="html"><![CDATA[Nested Object Forms with has_one Relation]]></title>
    <link href="http://emrekutlu.github.com/2009/06/nested-object-forms-with-has_one-relation/"/>
    <updated>2009-06-15T15:40:30+03:00</updated>
    <id>http://emrekutlu.github.com/2009/06/nested-object-forms-with-has_one-relation</id>
    <content type="html"><![CDATA[<p>Rails 2.3 has a good solution for multi model forms. But there is not much examples of  how to use<code> <strong>accepts_nested_attributes_for</strong></code> with <code><strong>has_one</strong></code> relation.</p>

<p>Assume that we have a Book model which has one Author.</p>

<script src="http://snipt.net/embed/821f03288846297c2cf43c34766a38f7" type="text/javascript"><!--mce:0--></script>


<br />


<script src="http://snipt.net/embed/02bd92faa38aaa6cc0ea75e59937a1ef" type="text/javascript"><!--mce:1--></script>


<br />


<p>Controller :<script src="http://snipt.net/embed/f0ef6bf2d1b0bc59796999ff717bf149" type="text/javascript"><!--mce:2--></script></p>

<br />


<p>View:</p>

<script src="http://snipt.net/embed/2b2d98bcfa219f53623aa6c1f1301a01" type="text/javascript"><!--mce:3--></script>


<br />


<p>No special action is needed for <strong><code>create</code></strong> method of BooksController,  <strong>attr_accessible</strong> is not necessary for Book model. Just don&#8217;t forget to add the second parameter (<strong><code>@book</code></strong>) of <strong><code>form_for</code></strong> and build your nested object (@book.build_author).</p>
]]></content>
  </entry>
  
  <entry>
    <title type="html"><![CDATA[Tidbit: Converting Strings with Line Feed to Array]]></title>
    <link href="http://emrekutlu.github.com/2009/01/tidbit-converting-strings-with-line-feed-to-array/"/>
    <updated>2009-01-21T10:08:02+02:00</updated>
    <id>http://emrekutlu.github.com/2009/01/tidbit-converting-strings-with-line-feed-to-array</id>
    <content type="html"><![CDATA[<p>If you have trouble when converting string to array, check if your string includes any line feed (\n). Check how <code>Array("string")</code> behaves:</p>

<pre lang="bash">irb(main):001:0> Array("izzet emre \nkutlu")
=> ["izzet emre \n", "kutlu"]
</pre>


<p>This output is not what most of the people expected. Be careful!</p>
]]></content>
  </entry>
  
  <entry>
    <title type="html"><![CDATA[Rails 2.2 &amp; Inflector]]></title>
    <link href="http://emrekutlu.github.com/2008/12/rails-22-inflector/"/>
    <updated>2008-12-14T22:14:52+02:00</updated>
    <id>http://emrekutlu.github.com/2008/12/rails-22-inflector</id>
    <content type="html"><![CDATA[<p>If you have recently updated to Rails 2.2.2, you may encounter this error when you want to start your application:</p>

<pre lang="bash">/.gem/ruby/1.8/gems/activesupport-2.2.2/lib/active_support/dependencies.rb:445:in
`load_missing_constant': uninitialized constant Inflector (NameError)</pre>


<p>As I learned from <a href="http://paulsturgess.co.uk/articles/show/76-load_missing_constant-uninitialized-constant-inflector-when-upgrading-to-ruby-on-rails-222" target="_blank">Paul&#8217;s post</a> usage of <code>Inflector</code> class is changed a bit. You can see the difference when you compare the inflections.rb files. Path of the file is <em>yourApp/config/initializers/inflections.rb</em></p>

<p>inflections.rb (Rails 2.1.0)</p>

<pre lang="ruby"> Inflector.inflections do |inflect|
  .
  .
  .
 end</pre>


<p>inflections.rb (Rails 2.2.2)</p>

<pre lang="ruby"> ActiveSupport::Inflector.inflections do |inflect|
  .
  .
  .
 end</pre>


<p>In my situation changing <code>Inflector</code> to <code>ActiveSupport::Inflector</code> was enough to solve the problem.</p>
]]></content>
  </entry>
  
  <entry>
    <title type="html"><![CDATA[Updating RubyGems to 1.2 (Manually)]]></title>
    <link href="http://emrekutlu.github.com/2008/08/updating-rubygems-to-12-manually/"/>
    <updated>2008-08-27T12:34:50+03:00</updated>
    <id>http://emrekutlu.github.com/2008/08/updating-rubygems-to-12-manually</id>
    <content type="html"><![CDATA[<br />


<p>This is what happened when I want to install rmagick gem.</p>

<br />


<pre lang="bash" colla="+">
username@username-desktop:~$ sudo gem install rmagick
Bulk updating Gem source index for: http://gems.rubyforge.org/
ERROR:  could not find rmagick locally or in a repository
</pre>


<br />


<p>What the hell&#8230;
After some googling I found that RubGems 1.1.x is buggy and and update to RubyGems 1.2 is necessary.
To learn your RubyGems version:</p>

<br />


<pre lang="bash" colla="+">
username@username-desktop:~$ gem -v
1.1.0
</pre>


<!--more-->


<p> I try to update RubyGems :</p>

<br />


<pre lang="bash" colla="+">
username@username-desktop:~$ sudo gem update --system
Updating RubyGems
Bulk updating Gem source index for: http://gems.rubyforge.org/
Nothing to update
</pre>


<br />


<p>After this failed attempt, I realized that RubyGems 1.1.x is really buggy. So I must go on manually to update RubyGems.</p>

<br />


<p><strong>Now the solution:</strong></p>

<br />


<ol>
<li>
Download <a href="http://rubyforge.org/frs/download.php/38844/rubygems-update-1.2.0.gem">rubygems-update-1.2.0.gem</a>
</li>
<li>
Change your directory where your downloaded gem is. In these example my gem is at Desktop.
Now you must install <em>rubygems-update-1.2.0.gem</em>.
<pre lang="bash" colla="+">
username@username-desktop:~$ cd Desktop/
username@username-desktop:~/Desktop$ sudo gem install rubygems-update-1.2.0.gem
</pre>
</li>
<li>
<pre lang="bash" colla="+">
username@username-desktop:~$sudo update_rubygems
</pre>
</li>
</ol>


<br />


<p>To check if our process is successful :</p>

<br />


<pre lang="bash" colla="+">
username@username-desktop:~$gem -v
1.2.0
</pre>


<br />


<p>If you see <em>1.2.0</em>, you did it.</p>
]]></content>
  </entry>
  
  <entry>
    <title type="html"><![CDATA[Recursive methods with block in Ruby]]></title>
    <link href="http://emrekutlu.github.com/2008/08/recursive-methods-with-block/"/>
    <updated>2008-08-26T10:46:17+03:00</updated>
    <id>http://emrekutlu.github.com/2008/08/recursive-methods-with-block</id>
    <content type="html"><![CDATA[<br />


<pre lang="ruby" colla="+">
def comic(cast)
   cast.each do |character|
      unless character.is_a?(Array)
         yield(character)
      else
     comic(character) {|x| yield x}
      end
   end
end
</pre>


<br />


<p>This method takes an array as argument and checks each element if it is an <em>Array</em>.
If the element is not an <em>Array</em> then the block is called.
If the element is an <em>Array</em> then the same method is called with that element as an argument and with the same block.</p>

<br />


<p>Now let&#8217;s look how we can call this method.</p>

<pre lang="ruby" colla="+">
names = ['lucky luke', 'jolly jumper', 'rin tin tin', ['joe', 'william','jack', 'averell']]
comic(names) {|c| puts c}
</pre>


<br />


<p><strong>Output :</strong></p>

<pre lang="bash">
lucky luke
jolly jumper
rin tin tin
joe
william
jack
averell
</pre>

]]></content>
  </entry>
  
  <entry>
    <title type="html"><![CDATA[How to check if a div exists in rjs?]]></title>
    <link href="http://emrekutlu.github.com/2008/08/how-to-check-if-a-div-exists-in-rjs/"/>
    <updated>2008-08-24T17:52:36+03:00</updated>
    <id>http://emrekutlu.github.com/2008/08/how-to-check-if-a-div-exists-in-rjs</id>
    <content type="html"><![CDATA[<br />


<pre lang="html4strict" colla="+">
&lt;body&gt;
   &lt;div id='main'&gt;
      Main Div
   &lt;/div&gt;
&lt;/body&gt;
</pre>


<br />


<pre lang="ruby" colla="+">
render :update do |page|
   page << "if ($('main')){"
   page.replace_html 'main', :inline => 'Here it is'
   page << "}"
end
</pre>


<p>This ruby code checks if there is a DOM object that its id = &#8220;main&#8221;.
If there is then changes its content to &#8220;Here it is&#8221;, if there is not do nothing.</p>
]]></content>
  </entry>
  
</feed>