diff options
| author | Joël Cox <joel@joelcox.nl> | 2011-10-09 18:39:39 +0200 |
|---|---|---|
| committer | Joël Cox <joel@joelcox.nl> | 2011-10-09 18:39:39 +0200 |
| commit | f4fb1db458fab52d0493ead52c9ea7e01206eaa7 (patch) | |
| tree | c549600f342f4d3f0df75a2f2f7c265be0f1cc72 /user_guide/helpers/captcha_helper.html | |
| parent | c4dd200c1155a118afa32cd91d9bd67bc243f83a (diff) | |
Moved tutorial to new user guide directory.
Diffstat (limited to 'user_guide/helpers/captcha_helper.html')
| -rw-r--r-- | user_guide/helpers/captcha_helper.html | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/user_guide/helpers/captcha_helper.html b/user_guide/helpers/captcha_helper.html deleted file mode 100644 index 991c2d3f1..000000000 --- a/user_guide/helpers/captcha_helper.html +++ /dev/null @@ -1,195 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> -<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> -<head> - -<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> -<title>CAPTCHA Helper : CodeIgniter User Guide</title> - -<style type='text/css' media='all'>@import url('../userguide.css');</style> -<link rel='stylesheet' type='text/css' media='all' href='../userguide.css' /> - -<script type="text/javascript" src="../nav/nav.js"></script> -<script type="text/javascript" src="../nav/prototype.lite.js"></script> -<script type="text/javascript" src="../nav/moo.fx.js"></script> -<script type="text/javascript" src="../nav/user_guide_menu.js"></script> - -<meta http-equiv='expires' content='-1' /> -<meta http-equiv= 'pragma' content='no-cache' /> -<meta name='robots' content='all' /> -<meta name='author' content='ExpressionEngine Dev Team' /> -<meta name='description' content='CodeIgniter User Guide' /> - -</head> -<body> - -<!-- START NAVIGATION --> -<div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div> -<div id="nav2"><a name="top"></a><a href="javascript:void(0);" onclick="myHeight.toggle();"><img src="../images/nav_toggle_darker.jpg" width="154" height="43" border="0" title="Toggle Table of Contents" alt="Toggle Table of Contents" /></a></div> -<div id="masthead"> -<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> -<tr> -<td><h1>CodeIgniter User Guide Version 2.0.3</h1></td> -<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td> -</tr> -</table> -</div> -<!-- END NAVIGATION --> - - -<!-- START BREADCRUMB --> -<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> -<tr> -<td id="breadcrumb"> -<a href="http://codeigniter.com/">CodeIgniter Home</a> › -<a href="../index.html">User Guide Home</a> › -CAPTCHA Helper -</td> -<td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="codeigniter.com/user_guide/" />Search User Guide <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" /> <input type="submit" class="submit" name="sa" value="Go" /></form></td> -</tr> -</table> -<!-- END BREADCRUMB --> - -<br clear="all" /> - - -<!-- START CONTENT --> -<div id="content"> - - -<h1>CAPTCHA Helper</h1> - -<p>The CAPTCHA Helper file contains functions that assist in creating CAPTCHA images.</p> - - -<h2>Loading this Helper</h2> - -<p>This helper is loaded using the following code:</p> -<code>$this->load->helper('captcha');</code> - -<p>The following functions are available:</p> - -<h2>create_captcha(<var>$data</var>)</h2> - -<p>Takes an array of information to generate the CAPTCHA as input and creates the image to your specifications, returning an array of associative data about the image.</p> - -<code>[array]<br /> -(<br /> - 'image' => IMAGE TAG<br /> - 'time' => TIMESTAMP (in microtime)<br /> - 'word' => CAPTCHA WORD<br /> -)</code> - - <p>The "image" is the actual image tag: -<code><img src="http://example.com/captcha/12345.jpg" width="140" height="50" /></code></p> - - <p>The "time" is the micro timestamp used as the image name without the file - extension. It will be a number like this: 1139612155.3422</p> - - <p>The "word" is the word that appears in the captcha image, which if not - supplied to the function, will be a random string.</p> - - <h3>Using the CAPTCHA helper</h3> - - <p>Once loaded you can generate a captcha like this:</p> - -<code>$vals = array(<br /> - 'word' => 'Random word',<br /> - 'img_path' => './captcha/',<br /> - 'img_url' => 'http://example.com/captcha/',<br /> - 'font_path' => './path/to/fonts/texb.ttf',<br /> - 'img_width' => '150',<br /> - 'img_height' => 30,<br /> - 'expiration' => 7200<br /> - );<br /> -<br /> -$cap = create_captcha($vals);<br /> -echo $cap['image'];</code> - - <ul> - <li>The captcha function requires the GD image library.</li> - <li>Only the img_path and img_url are required.</li> - <li>If a "word" is not supplied, the function will generate a random - ASCII string. You might put together your own word library that - you can draw randomly from.</li> - <li>If you do not specify a path to a TRUE TYPE font, the native ugly GD - font will be used.</li> - <li>The "captcha" folder must be writable (666, or 777)</li> - <li>The "expiration" (in seconds) signifies how long an image will - remain in the captcha folder before it will be deleted. The default - is two hours.</li> - </ul> - - <h3>Adding a Database</h3> - - <p>In order for the captcha function to prevent someone from submitting, you will need - to add the information returned from <kbd>create_captcha()</kbd> function to your database. - Then, when the data from the form is submitted by the user you will need to verify - that the data exists in the database and has not expired.</p> - - <p>Here is a table prototype:</p> - -<code>CREATE TABLE captcha (<br /> - captcha_id bigint(13) unsigned NOT NULL auto_increment,<br /> - captcha_time int(10) unsigned NOT NULL,<br /> - ip_address varchar(16) default '0' NOT NULL,<br /> - word varchar(20) NOT NULL,<br /> - PRIMARY KEY `captcha_id` (`captcha_id`),<br /> - KEY `word` (`word`)<br /> -);</code> - - <p>Here is an example of usage with a database. On the page where the CAPTCHA will be shown you'll have something like this:</p> - -<code>$this->load->helper('captcha');<br /> -$vals = array(<br /> - 'img_path' => './captcha/',<br /> - 'img_url' => 'http://example.com/captcha/'<br /> - );<br /> -<br /> -$cap = create_captcha($vals);<br /> -<br /> -$data = array(<br /> - 'captcha_time' => $cap['time'],<br /> - 'ip_address' => $this->input->ip_address(),<br /> - 'word' => $cap['word']<br /> - );<br /> -<br /> -$query = $this->db->insert_string('captcha', $data);<br /> -$this->db->query($query);<br /> -<br /> -echo 'Submit the word you see below:';<br /> -echo $cap['image'];<br /> -echo '<input type="text" name="captcha" value="" />';</code> - - <p>Then, on the page that accepts the submission you'll have something like this:</p> - -<code>// First, delete old captchas<br /> -$expiration = time()-7200; // Two hour limit<br /> -$this->db->query("DELETE FROM captcha WHERE captcha_time < ".$expiration); <br /> -<br /> -// Then see if a captcha exists:<br /> -$sql = "SELECT COUNT(*) AS count FROM captcha WHERE word = ? AND ip_address = ? AND captcha_time > ?";<br /> -$binds = array($_POST['captcha'], $this->input->ip_address(), $expiration);<br /> -$query = $this->db->query($sql, $binds);<br /> -$row = $query->row();<br /> -<br /> -if ($row->count == 0)<br /> -{<br /> - echo "You must submit the word that appears in the image";<br /> -}</code> - -</div> -<!-- END CONTENT --> - - -<div id="footer"> -<p> -Previous Topic: <a href="array_helper.html">Array Helper</a> - · -<a href="#top">Top of Page</a> · -<a href="../index.html">User Guide Home</a> · -Next Topic: <a href="cookie_helper.html">Cookie Helper</a></p> -<p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2006 - 2011 · <a href="http://ellislab.com/">EllisLab, Inc.</a></p> -</div> - -</body> -</html> |