Zend_Service_Akismet provides a client for the Akismet API. The Akismet service is used to determine if incoming data is potentially spam; it also exposes methods for submitting data as known spam or as false positives (ham). Originally intended to help categorize and identify spam for Wordpress, it can be used for any type of data.

Akismet requires an API key for usage. You may get one for signing up for a WordPress.com account. You do not need to activate a blog; simply acquiring the account will provide you with the API key.

Additionally, Akismet requires that all requests contain a URL to the resource for which data is being filtered, and, because of Akismet's origins in WordPress, this resource is called the blog url. This value should be passed as the second argument to the constructor, but may be reset at any time using the setBlogUrl() accessor, or overridden by specifying a 'blog' key in the various method calls.

Zend_Service_Akismet::verifyKey($key) is used to verify that an Akismet API key is valid. In most cases, you will not need to check, but if you need a sanity check, or to determine if a newly acquired key is active, you may do so with this method.

<?php
require_once 'Zend/Service/Akismet.php';

// Instantiate with the API key and a URL to the application or resource being
// used
$akismet = new Zend_Service_Akismet($apiKey, 'http://framework.zend.com/wiki/');
if ($akismet->verifyKey($apiKey) {
echo "Key is valid.\n";
} else {
echo "Key is not valid\n";
}
?>

If called with no arguments, verifyKey() uses the API key provided to the constructor.

verifyKey() implements Akismet's verify-key REST method.

Zend_Service_Akismet::isSpam($data) is used to determine if the data provided is considered spam by Akismet. It accepts an associative array as the sole argument. That array requires the following keys be set:

The following keys are also recognized specifically by the API:

You may also submit any other environmental variables you feel might be a factor in determining if data is spam. Akismet suggests the contents of the entire $_SERVER array.

The isSpam() method will return either true or false, and throw an exception if the API key is invalid.

<?php
$data = array(
    'user_ip'              => '111.222.111.222',
    'user_agent'           => 'Mozilla/5.0 (Windows; U; Windows NT 5.2; en-GB; rv:1.8.1) Gecko/20061010 Firefox/2.0',
    'comment_type'         => 'contact',
    'comment_author'       => 'John Doe',
    'comment_author_email' => 'nospam@myhaus.net',
    'comment_content'      => "I'm not a spammer, honest!"
);
if ($akismet->isSpam($data)) {
    echo "Sorry, but we think you're a spammer.";
} else {
    echo "Welcome to our site!";
}
?>

isSpam() implements the comment-check Akismet API method.

Occasionally spam data will get through the filter. If in your review of incoming data you discover spam that you feel should have been caught, you can submit it to Akismet to help improve their filter.

Zend_Service_Akismet::submitSpam() takes the same data array as passed to isSpam(), but does not return a value. An exception will be raised if the API key used is invalid.

<?php
$data = array(
    'user_ip'              => '111.222.111.222',
    'user_agent'           => 'Mozilla/5.0 (Windows; U; Windows NT 5.2; en-GB; rv:1.8.1) Gecko/20061010 Firefox/2.0',
    'comment_type'         => 'contact',
    'comment_author'       => 'John Doe',
    'comment_author_email' => 'nospam@myhaus.net',
    'comment_content'      => "I'm not a spammer, honest!"
);
$akismet->submitSpam($data));
?>

submitSpam() implements the submit-spam Akismet API method.

Occasionally data will be trapped erroneously as spam by Akismet. For this reason, you should probably keep a log of all data trapped as spam by Akismet and review it periodically. If you find such occurrences, you can submit the data to Akismet as "ham", or a false positive (ham is good, spam is not).

Zend_Service_Akismet::submitHam() takes the same data array as passed to isSpam() or submitSpam(), and, like submitSpam(), does not return a value. An exception will be raised if the API key used is invalid.

<?php
$data = array(
    'user_ip'              => '111.222.111.222',
    'user_agent'           => 'Mozilla/5.0 (Windows; U; Windows NT 5.2; en-GB; rv:1.8.1) Gecko/20061010 Firefox/2.0',
    'comment_type'         => 'contact',
    'comment_author'       => 'John Doe',
    'comment_author_email' => 'nospam@myhaus.net',
    'comment_content'      => "I'm not a spammer, honest!"
);
$akismet->submitHam($data));
?>

submitHam() implements the submit-ham Akismet API method.

While the Akismet API only specifies four methods, Zend_Service_Akismet has several additional accessors that may be used for modifying internal properties.