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  <div class="section" id="codeigniter-at-a-glance">
<h1>CodeIgniter at a Glance<a class="headerlink" href="#codeigniter-at-a-glance" title="Permalink to this headline">¶</a></h1>
<div class="section" id="codeigniter-is-an-application-framework">
<h2>CodeIgniter is an Application Framework<a class="headerlink" href="#codeigniter-is-an-application-framework" title="Permalink to this headline">¶</a></h2>
<p>CodeIgniter is a toolkit for people who build web applications using
PHP. Its goal is to enable you to develop projects much faster than you
could if you were writing code from scratch, by providing a rich set of
libraries for commonly needed tasks, as well as a simple interface and
logical structure to access these libraries. CodeIgniter lets you
creatively focus on your project by minimizing the amount of code needed
for a given task.</p>
</div>
<div class="section" id="codeigniter-is-free">
<h2>CodeIgniter is Free<a class="headerlink" href="#codeigniter-is-free" title="Permalink to this headline">¶</a></h2>
<p>CodeIgniter is licensed under the MIT license so you can use it however
you please. For more information please read the
<a class="reference internal" href="../license.html"><span class="doc">license agreement</span></a>.</p>
</div>
<div class="section" id="codeigniter-is-light-weight">
<h2>CodeIgniter is Light Weight<a class="headerlink" href="#codeigniter-is-light-weight" title="Permalink to this headline">¶</a></h2>
<p>Truly light weight. The core system requires only a few very small
libraries. This is in stark contrast to many frameworks that require
significantly more resources. Additional libraries are loaded
dynamically upon request, based on your needs for a given process, so
the base system is very lean and quite fast.</p>
</div>
<div class="section" id="codeigniter-is-fast">
<h2>CodeIgniter is Fast<a class="headerlink" href="#codeigniter-is-fast" title="Permalink to this headline">¶</a></h2>
<p>Really fast. We challenge you to find a framework that has better
performance than CodeIgniter.</p>
</div>
<div class="section" id="codeigniter-uses-m-v-c">
<h2>CodeIgniter Uses M-V-C<a class="headerlink" href="#codeigniter-uses-m-v-c" title="Permalink to this headline">¶</a></h2>
<p>CodeIgniter uses the Model-View-Controller approach, which allows great
separation between logic and presentation. This is particularly good for
projects in which designers are working with your template files, as the
code these files contain will be minimized. We describe MVC in more
detail on its own page.</p>
</div>
<div class="section" id="codeigniter-generates-clean-urls">
<h2>CodeIgniter Generates Clean URLs<a class="headerlink" href="#codeigniter-generates-clean-urls" title="Permalink to this headline">¶</a></h2>
<p>The URLs generated by CodeIgniter are clean and search-engine friendly.
Rather than using the standard “query string” approach to URLs that is
synonymous with dynamic systems, CodeIgniter uses a segment-based
approach:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">example</span><span class="o">.</span><span class="nx">com</span><span class="o">/</span><span class="nx">news</span><span class="o">/</span><span class="nx">article</span><span class="o">/</span><span class="mi">345</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">By default the <em>index.php</em> file is included in the URL but it can
be removed using a simple <em>.htaccess</em> file.</p>
</div>
</div>
<div class="section" id="codeigniter-packs-a-punch">
<h2>CodeIgniter Packs a Punch<a class="headerlink" href="#codeigniter-packs-a-punch" title="Permalink to this headline">¶</a></h2>
<p>CodeIgniter comes with full-range of libraries that enable the most
commonly needed web development tasks, like accessing a database,
sending email, validating form data, maintaining sessions, manipulating
images, working with XML-RPC data and much more.</p>
</div>
<div class="section" id="codeigniter-is-extensible">
<h2>CodeIgniter is Extensible<a class="headerlink" href="#codeigniter-is-extensible" title="Permalink to this headline">¶</a></h2>
<p>The system can be easily extended through the use of your own libraries,
helpers, or through class extensions or system hooks.</p>
</div>
<div class="section" id="codeigniter-does-not-require-a-template-engine">
<h2>CodeIgniter Does Not Require a Template Engine<a class="headerlink" href="#codeigniter-does-not-require-a-template-engine" title="Permalink to this headline">¶</a></h2>
<p>Although CodeIgniter <em>does</em> come with a simple template parser that can
be optionally used, it does not force you to use one. Template engines
simply can not match the performance of native PHP, and the syntax that
must be learned to use a template engine is usually only marginally
easier than learning the basics of PHP. Consider this block of PHP code:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="o">&lt;</span><span class="nx">ul</span><span class="o">&gt;</span>
<span class="o">&lt;?</span><span class="nx">php</span> <span class="k">foreach</span> <span class="p">(</span><span class="nv">$addressbook</span> <span class="k">as</span> <span class="nv">$name</span><span class="p">)</span><span class="o">:</span><span class="cp">?&gt;</span>
        <span class="p">&lt;</span><span class="nt">li</span><span class="p">&gt;</span><span class="cp">&lt;?</span><span class="o">=</span><span class="nv">$name</span><span class="cp">?&gt;</span><span class="p">&lt;/</span><span class="nt">li</span><span class="p">&gt;</span>
<span class="cp">&lt;?php</span> <span class="k">endforeach</span><span class="p">;</span> <span class="cp">?&gt;</span>
<span class="p">&lt;/</span><span class="nt">ul</span><span class="p">&gt;</span>
</pre></div>
</div>
<p>Contrast this with the pseudo-code used by a template engine:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="o">&lt;</span><span class="nx">ul</span><span class="o">&gt;</span>
<span class="p">{</span><span class="k">foreach</span> <span class="nx">from</span><span class="o">=</span><span class="nv">$addressbook</span> <span class="nx">item</span><span class="o">=</span><span class="s2">&quot;name&quot;</span><span class="p">}</span>
        <span class="o">&lt;</span><span class="nx">li</span><span class="o">&gt;</span><span class="p">{</span><span class="nv">$name</span><span class="p">}</span><span class="o">&lt;/</span><span class="nx">li</span><span class="o">&gt;</span>
<span class="p">{</span><span class="o">/</span><span class="k">foreach</span><span class="p">}</span>
<span class="o">&lt;/</span><span class="nx">ul</span><span class="o">&gt;</span>
</pre></div>
</div>
<p>Yes, the template engine example is a bit cleaner, but it comes at the
price of performance, as the pseudo-code must be converted back into PHP
to run. Since one of our goals is <em>maximum performance</em>, we opted to not
require the use of a template engine.</p>
</div>
<div class="section" id="codeigniter-is-thoroughly-documented">
<h2>CodeIgniter is Thoroughly Documented<a class="headerlink" href="#codeigniter-is-thoroughly-documented" title="Permalink to this headline">¶</a></h2>
<p>Programmers love to code and hate to write documentation. We’re no
different, of course, but since documentation is <strong>as important</strong> as the
code itself, we are committed to doing it. Our source code is extremely
clean and well commented as well.</p>
</div>
<div class="section" id="codeigniter-has-a-friendly-community-of-users">
<h2>CodeIgniter has a Friendly Community of Users<a class="headerlink" href="#codeigniter-has-a-friendly-community-of-users" title="Permalink to this headline">¶</a></h2>
<p>Our growing community of users can be seen actively participating in our
<a class="reference external" href="http://forum.codeigniter.com/">Community Forums</a>.</p>
</div>
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