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<div class="section" id="trackback-class">
<h1>Trackback Class<a class="headerlink" href="#trackback-class" title="Permalink to this headline">¶</a></h1>
<p>The Trackback Class provides functions that enable you to send and
receive Trackback data.</p>
<p>If you are not familiar with Trackbacks you’ll find more information
<a class="reference external" href="http://en.wikipedia.org/wiki/Trackback">here</a>.</p>
<div class="contents local topic" id="contents">
<ul class="simple">
<li><a class="reference internal" href="#using-the-trackback-class" id="id1">Using the Trackback Class</a><ul>
<li><a class="reference internal" href="#initializing-the-class" id="id2">Initializing the Class</a></li>
<li><a class="reference internal" href="#sending-trackbacks" id="id3">Sending Trackbacks</a></li>
<li><a class="reference internal" href="#receiving-trackbacks" id="id4">Receiving Trackbacks</a></li>
<li><a class="reference internal" href="#your-ping-url" id="id5">Your Ping URL</a></li>
<li><a class="reference internal" href="#creating-a-trackback-table" id="id6">Creating a Trackback Table</a></li>
<li><a class="reference internal" href="#processing-a-trackback" id="id7">Processing a Trackback</a><ul>
<li><a class="reference internal" href="#notes" id="id8">Notes:</a></li>
</ul>
</li>
</ul>
</li>
<li><a class="reference internal" href="#class-reference" id="id9">Class Reference</a></li>
</ul>
</div>
<div class="custom-index container"></div><div class="section" id="using-the-trackback-class">
<h2><a class="toc-backref" href="#id1">Using the Trackback Class</a><a class="headerlink" href="#using-the-trackback-class" title="Permalink to this headline">¶</a></h2>
<div class="section" id="initializing-the-class">
<h3><a class="toc-backref" href="#id2">Initializing the Class</a><a class="headerlink" href="#initializing-the-class" title="Permalink to this headline">¶</a></h3>
<p>Like most other classes in CodeIgniter, the Trackback class is
initialized in your controller using the <code class="docutils literal"><span class="pre">$this->load->library()</span></code> method:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-></span><span class="na">load</span><span class="o">-></span><span class="na">library</span><span class="p">(</span><span class="s1">'trackback'</span><span class="p">);</span>
</pre></div>
</div>
<p>Once loaded, the Trackback library object will be available using:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span>
</pre></div>
</div>
</div>
<div class="section" id="sending-trackbacks">
<h3><a class="toc-backref" href="#id3">Sending Trackbacks</a><a class="headerlink" href="#sending-trackbacks" title="Permalink to this headline">¶</a></h3>
<p>A Trackback can be sent from any of your controller functions using code
similar to this example:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-></span><span class="na">load</span><span class="o">-></span><span class="na">library</span><span class="p">(</span><span class="s1">'trackback'</span><span class="p">);</span>
<span class="nv">$tb_data</span> <span class="o">=</span> <span class="k">array</span><span class="p">(</span>
<span class="s1">'ping_url'</span> <span class="o">=></span> <span class="s1">'http://example.com/trackback/456'</span><span class="p">,</span>
<span class="s1">'url'</span> <span class="o">=></span> <span class="s1">'http://www.my-example.com/blog/entry/123'</span><span class="p">,</span>
<span class="s1">'title'</span> <span class="o">=></span> <span class="s1">'The Title of My Entry'</span><span class="p">,</span>
<span class="s1">'excerpt'</span> <span class="o">=></span> <span class="s1">'The entry content.'</span><span class="p">,</span>
<span class="s1">'blog_name'</span> <span class="o">=></span> <span class="s1">'My Blog Name'</span><span class="p">,</span>
<span class="s1">'charset'</span> <span class="o">=></span> <span class="s1">'utf-8'</span>
<span class="p">);</span>
<span class="k">if</span> <span class="p">(</span> <span class="o">!</span> <span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">send</span><span class="p">(</span><span class="nv">$tb_data</span><span class="p">))</span>
<span class="p">{</span>
<span class="k">echo</span> <span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">display_errors</span><span class="p">();</span>
<span class="p">}</span>
<span class="k">else</span>
<span class="p">{</span>
<span class="k">echo</span> <span class="s1">'Trackback was sent!'</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
<p>Description of array data:</p>
<ul class="simple">
<li><strong>ping_url</strong> - The URL of the site you are sending the Trackback to.
You can send Trackbacks to multiple URLs by separating each URL with a comma.</li>
<li><strong>url</strong> - The URL to YOUR site where the weblog entry can be seen.</li>
<li><strong>title</strong> - The title of your weblog entry.</li>
<li><strong>excerpt</strong> - The content of your weblog entry.</li>
<li><strong>blog_name</strong> - The name of your weblog.</li>
<li><strong>charset</strong> - The character encoding your weblog is written in. If omitted, UTF-8 will be used.</li>
</ul>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The Trackback class will automatically send only the first 500 characters of your
entry. It will also strip all HTML.</p>
</div>
<p>The Trackback sending method returns TRUE/FALSE (boolean) on success
or failure. If it fails, you can retrieve the error message using:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">display_errors</span><span class="p">();</span>
</pre></div>
</div>
</div>
<div class="section" id="receiving-trackbacks">
<h3><a class="toc-backref" href="#id4">Receiving Trackbacks</a><a class="headerlink" href="#receiving-trackbacks" title="Permalink to this headline">¶</a></h3>
<p>Before you can receive Trackbacks you must create a weblog. If you don’t
have a blog yet there’s no point in continuing.</p>
<p>Receiving Trackbacks is a little more complex than sending them, only
because you will need a database table in which to store them, and you
will need to validate the incoming trackback data. You are encouraged to
implement a thorough validation process to guard against spam and
duplicate data. You may also want to limit the number of Trackbacks you
allow from a particular IP within a given span of time to further
curtail spam. The process of receiving a Trackback is quite simple; the
validation is what takes most of the effort.</p>
</div>
<div class="section" id="your-ping-url">
<h3><a class="toc-backref" href="#id5">Your Ping URL</a><a class="headerlink" href="#your-ping-url" title="Permalink to this headline">¶</a></h3>
<p>In order to accept Trackbacks you must display a Trackback URL next to
each one of your weblog entries. This will be the URL that people will
use to send you Trackbacks (we will refer to this as your “Ping URL”).</p>
<p>Your Ping URL must point to a controller function where your Trackback
receiving code is located, and the URL must contain the ID number for
each particular entry, so that when the Trackback is received you’ll be
able to associate it with a particular entry.</p>
<p>For example, if your controller class is called Trackback, and the
receiving function is called receive, your Ping URLs will look something
like this:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">http</span><span class="o">://</span><span class="nx">example</span><span class="o">.</span><span class="nx">com</span><span class="o">/</span><span class="nx">index</span><span class="o">.</span><span class="nx">php</span><span class="o">/</span><span class="nx">trackback</span><span class="o">/</span><span class="nx">receive</span><span class="o">/</span><span class="nx">entry_id</span>
</pre></div>
</div>
<p>Where entry_id represents the individual ID number for each of your
entries.</p>
</div>
<div class="section" id="creating-a-trackback-table">
<h3><a class="toc-backref" href="#id6">Creating a Trackback Table</a><a class="headerlink" href="#creating-a-trackback-table" title="Permalink to this headline">¶</a></h3>
<p>Before you can receive Trackbacks you must create a table in which to
store them. Here is a basic prototype for such a table:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">CREATE</span> <span class="nx">TABLE</span> <span class="nx">trackbacks</span> <span class="p">(</span>
<span class="nx">tb_id</span> <span class="nx">int</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span> <span class="nx">unsigned</span> <span class="k">NOT</span> <span class="k">NULL</span> <span class="nx">auto_increment</span><span class="p">,</span>
<span class="nx">entry_id</span> <span class="nx">int</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span> <span class="nx">unsigned</span> <span class="k">NOT</span> <span class="k">NULL</span> <span class="k">default</span> <span class="mi">0</span><span class="p">,</span>
<span class="nx">url</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">200</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
<span class="nx">title</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">100</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
<span class="nx">excerpt</span> <span class="nx">text</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
<span class="nx">blog_name</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">100</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
<span class="nx">tb_date</span> <span class="nx">int</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
<span class="nx">ip_address</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">45</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
<span class="nx">PRIMARY</span> <span class="nx">KEY</span> <span class="sb">`tb_id`</span> <span class="p">(</span><span class="sb">`tb_id`</span><span class="p">),</span>
<span class="nx">KEY</span> <span class="sb">`entry_id`</span> <span class="p">(</span><span class="sb">`entry_id`</span><span class="p">)</span>
<span class="p">);</span>
</pre></div>
</div>
<p>The Trackback specification only requires four pieces of information to
be sent in a Trackback (url, title, excerpt, blog_name), but to make
the data more useful we’ve added a few more fields in the above table
schema (date, IP address, etc.).</p>
</div>
<div class="section" id="processing-a-trackback">
<h3><a class="toc-backref" href="#id7">Processing a Trackback</a><a class="headerlink" href="#processing-a-trackback" title="Permalink to this headline">¶</a></h3>
<p>Here is an example showing how you will receive and process a Trackback.
The following code is intended for use within the controller function
where you expect to receive Trackbacks.:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-></span><span class="na">load</span><span class="o">-></span><span class="na">library</span><span class="p">(</span><span class="s1">'trackback'</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-></span><span class="na">load</span><span class="o">-></span><span class="na">database</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nv">$this</span><span class="o">-></span><span class="na">uri</span><span class="o">-></span><span class="na">segment</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span> <span class="o">==</span> <span class="k">FALSE</span><span class="p">)</span>
<span class="p">{</span>
<span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">send_error</span><span class="p">(</span><span class="s1">'Unable to determine the entry ID'</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span> <span class="o">!</span> <span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">receive</span><span class="p">())</span>
<span class="p">{</span>
<span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">send_error</span><span class="p">(</span><span class="s1">'The Trackback did not contain valid data'</span><span class="p">);</span>
<span class="p">}</span>
<span class="nv">$data</span> <span class="o">=</span> <span class="k">array</span><span class="p">(</span>
<span class="s1">'tb_id'</span> <span class="o">=></span> <span class="s1">''</span><span class="p">,</span>
<span class="s1">'entry_id'</span> <span class="o">=></span> <span class="nv">$this</span><span class="o">-></span><span class="na">uri</span><span class="o">-></span><span class="na">segment</span><span class="p">(</span><span class="mi">3</span><span class="p">),</span>
<span class="s1">'url'</span> <span class="o">=></span> <span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">data</span><span class="p">(</span><span class="s1">'url'</span><span class="p">),</span>
<span class="s1">'title'</span> <span class="o">=></span> <span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">data</span><span class="p">(</span><span class="s1">'title'</span><span class="p">),</span>
<span class="s1">'excerpt'</span> <span class="o">=></span> <span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">data</span><span class="p">(</span><span class="s1">'excerpt'</span><span class="p">),</span>
<span class="s1">'blog_name'</span> <span class="o">=></span> <span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">data</span><span class="p">(</span><span class="s1">'blog_name'</span><span class="p">),</span>
<span class="s1">'tb_date'</span> <span class="o">=></span> <span class="nb">time</span><span class="p">(),</span>
<span class="s1">'ip_address'</span> <span class="o">=></span> <span class="nv">$this</span><span class="o">-></span><span class="na">input</span><span class="o">-></span><span class="na">ip_address</span><span class="p">()</span>
<span class="p">);</span>
<span class="nv">$sql</span> <span class="o">=</span> <span class="nv">$this</span><span class="o">-></span><span class="na">db</span><span class="o">-></span><span class="na">insert_string</span><span class="p">(</span><span class="s1">'trackbacks'</span><span class="p">,</span> <span class="nv">$data</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-></span><span class="na">db</span><span class="o">-></span><span class="na">query</span><span class="p">(</span><span class="nv">$sql</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">send_success</span><span class="p">();</span>
</pre></div>
</div>
<div class="section" id="notes">
<h4><a class="toc-backref" href="#id8">Notes:</a><a class="headerlink" href="#notes" title="Permalink to this headline">¶</a></h4>
<p>The entry ID number is expected in the third segment of your URL. This
is based on the URI example we gave earlier:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">http</span><span class="o">://</span><span class="nx">example</span><span class="o">.</span><span class="nx">com</span><span class="o">/</span><span class="nx">index</span><span class="o">.</span><span class="nx">php</span><span class="o">/</span><span class="nx">trackback</span><span class="o">/</span><span class="nx">receive</span><span class="o">/</span><span class="nx">entry_id</span>
</pre></div>
</div>
<p>Notice the entry_id is in the third URI segment, which you can retrieve
using:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-></span><span class="na">uri</span><span class="o">-></span><span class="na">segment</span><span class="p">(</span><span class="mi">3</span><span class="p">);</span>
</pre></div>
</div>
<p>In our Trackback receiving code above, if the third segment is missing,
we will issue an error. Without a valid entry ID, there’s no reason to
continue.</p>
<p>The $this->trackback->receive() function is simply a validation function
that looks at the incoming data and makes sure it contains the four
pieces of data that are required (url, title, excerpt, blog_name). It
returns TRUE on success and FALSE on failure. If it fails you will issue
an error message.</p>
<p>The incoming Trackback data can be retrieved using this function:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">data</span><span class="p">(</span><span class="s1">'item'</span><span class="p">)</span>
</pre></div>
</div>
<p>Where item represents one of these four pieces of info: url, title,
excerpt, or blog_name</p>
<p>If the Trackback data is successfully received, you will issue a success
message using:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-></span><span class="na">trackback</span><span class="o">-></span><span class="na">send_success</span><span class="p">();</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The above code contains no data validation, which you are
encouraged to add.</p>
</div>
</div>
</div>
</div>
<div class="section" id="class-reference">
<h2><a class="toc-backref" href="#id9">Class Reference</a><a class="headerlink" href="#class-reference" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="CI_Trackback">
<em class="property">class </em><code class="descname">CI_Trackback</code><a class="headerlink" href="#CI_Trackback" title="Permalink to this definition">¶</a></dt>
<dd><dl class="attribute">
<dt>
<code class="descname">$data = array('url' => '', 'title' => '', 'excerpt' => '', 'blog_name' => '', 'charset' => '')</code></dt>
<dd><p>Trackback data array.</p>
</dd></dl>
<dl class="attribute">
<dt>
<code class="descname">$convert_ascii = TRUE</code></dt>
<dd><p>Whether to convert high ASCII and MS Word characters to HTML entities.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::send">
<code class="descname">send</code><span class="sig-paren">(</span><em>$tb_data</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::send" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$tb_data</strong> (<em>array</em>) – Trackback data</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE on success, FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">bool</p>
</td>
</tr>
</tbody>
</table>
<p>Send trackback.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::receive">
<code class="descname">receive</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::receive" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">TRUE on success, FALSE on failure</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">bool</td>
</tr>
</tbody>
</table>
<p>This method simply validates the incoming TB data, returning TRUE on success and FALSE on failure.
If the data is valid it is set to the <code class="docutils literal"><span class="pre">$this->data</span></code> array so that it can be inserted into a database.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::send_error">
<code class="descname">send_error</code><span class="sig-paren">(</span><span class="optional">[</span><em>$message = 'Incomplete information'</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::send_error" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$message</strong> (<em>string</em>) – Error message</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">void</p>
</td>
</tr>
</tbody>
</table>
<p>Responses to a trackback request with an error message.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">This method will terminate script execution.</p>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::send_success">
<code class="descname">send_success</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::send_success" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">void</td>
</tr>
</tbody>
</table>
<p>Responses to a trackback request with a success message.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">This method will terminate script execution.</p>
</div>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::data">
<code class="descname">data</code><span class="sig-paren">(</span><em>$item</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::data" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$item</strong> (<em>string</em>) – Data key</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Data value or empty string if not found</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Returns a single item from the response data array.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::process">
<code class="descname">process</code><span class="sig-paren">(</span><em>$url</em>, <em>$data</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::process" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$url</strong> (<em>string</em>) – Target url</li>
<li><strong>$data</strong> (<em>string</em>) – Raw POST data</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE on success, FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">bool</p>
</td>
</tr>
</tbody>
</table>
<p>Opens a socket connection and passes the data to the server, returning TRUE on success and FALSE on failure.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::extract_urls">
<code class="descname">extract_urls</code><span class="sig-paren">(</span><em>$urls</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::extract_urls" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$urls</strong> (<em>string</em>) – Comma-separated URL list</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Array of URLs</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">array</p>
</td>
</tr>
</tbody>
</table>
<p>This method lets multiple trackbacks to be sent. It takes a string of URLs (separated by comma or space) and puts each URL into an array.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::validate_url">
<code class="descname">validate_url</code><span class="sig-paren">(</span><em>&$url</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::validate_url" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$url</strong> (<em>string</em>) – Trackback URL</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">void</p>
</td>
</tr>
</tbody>
</table>
<p>Simply adds the <em>http://</em> prefix it it’s not already present in the URL.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::get_id">
<code class="descname">get_id</code><span class="sig-paren">(</span><em>$url</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::get_id" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$url</strong> (<em>string</em>) – Trackback URL</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">URL ID or FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Find and return a trackback URL’s ID or FALSE on failure.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::convert_xml">
<code class="descname">convert_xml</code><span class="sig-paren">(</span><em>$str</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::convert_xml" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$str</strong> (<em>string</em>) – Input string</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Converted string</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Converts reserved XML characters to entities.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::limit_characters">
<code class="descname">limit_characters</code><span class="sig-paren">(</span><em>$str</em><span class="optional">[</span>, <em>$n = 500</em><span class="optional">[</span>, <em>$end_char = '&#8230;'</em><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::limit_characters" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$str</strong> (<em>string</em>) – Input string</li>
<li><strong>$n</strong> (<em>int</em>) – Max characters number</li>
<li><strong>$end_char</strong> (<em>string</em>) – Character to put at end of string</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Shortened string</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Limits the string based on the character count. Will preserve complete words.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::convert_ascii">
<code class="descname">convert_ascii</code><span class="sig-paren">(</span><em>$str</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::convert_ascii" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$str</strong> (<em>string</em>) – Input string</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Converted string</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Converts high ASCII text and MS Word special characterss to HTML entities.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::set_error">
<code class="descname">set_error</code><span class="sig-paren">(</span><em>$msg</em><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::set_error" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$msg</strong> (<em>string</em>) – Error message</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">void</p>
</td>
</tr>
</tbody>
</table>
<p>Set an log an error message.</p>
</dd></dl>
<dl class="method">
<dt id="CI_Trackback::display_errors">
<code class="descname">display_errors</code><span class="sig-paren">(</span><span class="optional">[</span><em>$open = '<p>'</em><span class="optional">[</span>, <em>$close = '</p>'</em><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#CI_Trackback::display_errors" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$open</strong> (<em>string</em>) – Open tag</li>
<li><strong>$close</strong> (<em>string</em>) – Close tag</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">HTML formatted error messages</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Returns error messages formatted in HTML or an empty string if there are no errors.</p>
</dd></dl>
</dd></dl>
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