From b41032d2df1e63566f1183533b388372538c46d0 Mon Sep 17 00:00:00 2001 From: Derek Jones Date: Fri, 5 Mar 2010 11:22:45 -0600 Subject: moved CAPTCHA plugin to a helper --- user_guide/helpers/captcha_helper.html | 195 +++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 user_guide/helpers/captcha_helper.html (limited to 'user_guide') diff --git a/user_guide/helpers/captcha_helper.html b/user_guide/helpers/captcha_helper.html new file mode 100644 index 000000000..297e47e2a --- /dev/null +++ b/user_guide/helpers/captcha_helper.html @@ -0,0 +1,195 @@ + + + + + +CAPTCHA Helper : CodeIgniter User Guide + + + + + + + + + + + + + + + + + + + + + +
+ + + + + +

CodeIgniter User Guide Version 1.7.2

+
+ + + + + + + + + +
+ + +
+ + + +
+ + +

CAPTCHA Helper

+ +

The CAPTCHA Helper file contains functions that assist in creating CAPTCHA images.

+ + +

Loading this Helper

+ +

This helper is loaded using the following code:

+$this->load->helper('captcha'); + +

The following functions are available:

+ +

captcha_create($data)

+ +

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.

+ +[array]
+(
+  'image' => IMAGE TAG
+  'time' => TIMESTAMP (in microtime)
+  'word' => CAPTCHA WORD
+) + +

The "image" is the actual image tag: +<img src="http://example.com/captcha/12345.jpg" width="140" height="50" />

+ +

The "time" is the micro timestamp used as the image name without the file + extension. It will be a number like this: 1139612155.3422

+ +

The "word" is the word that appears in the captcha image, which if not + supplied to the function, will be a random string.

+ +

Using the CAPTCHA plugin

+ +

Once loaded you can generate a captcha like this:

+ +$vals = array(
+    'word' => 'Random word',
+    'img_path' => './captcha/',
+    'img_url' => 'http://example.com/captcha/',
+    'font_path' => './path/to/fonts/texb.ttf',
+    'img_width' => '150',
+    'img_height' => 30,
+    'expiration' => 7200
+    );
+
+$cap = create_captcha($vals);
+echo $cap['image']; + + + +

Adding a Database

+ +

In order for the captcha function to prevent someone from submitting, you will need + to add the information returned from create_captcha() 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.

+ +

Here is a table prototype:

+ +CREATE TABLE captcha (
+ captcha_id bigint(13) unsigned NOT NULL auto_increment,
+ captcha_time int(10) unsigned NOT NULL,
+ ip_address varchar(16) default '0' NOT NULL,
+ word varchar(20) NOT NULL,
+ PRIMARY KEY `captcha_id` (`captcha_id`),
+ KEY `word` (`word`)
+) + +

Here is an example of usage with a database. On the page where the CAPTCHA will be shown you'll have something like this:

+ +$this->load->plugin('captcha');
+$vals = array(
+    'img_path' => './captcha/',
+    'img_url' => 'http://example.com/captcha/'
+    );
+
+$cap = create_captcha($vals);
+
+$data = array(
+    'captcha_time' => $cap['time'],
+    'ip_address' => $this->input->ip_address(),
+    'word' => $cap['word']
+    );
+
+$query = $this->db->insert_string('captcha', $data);
+$this->db->query($query);
+
+echo 'Submit the word you see below:';
+echo $cap['image'];
+echo '<input type="text" name="captcha" value="" />'; + +

Then, on the page that accepts the submission you'll have something like this:

+ +// First, delete old captchas
+$expiration = time()-7200; // Two hour limit
+$this->db->query("DELETE FROM captcha WHERE captcha_time < ".$expiration);
+
+// Then see if a captcha exists:
+$sql = "SELECT COUNT(*) AS count FROM captcha WHERE word = ? AND ip_address = ? AND date > ?";
+$binds = array($_POST['captcha'], $this->input->ip_address(), $expiration);
+$query = $this->db->query($sql, $binds);
+$row = $query->row();
+
+if ($row->count == 0)
+{
+    echo "You must submit the word that appears in the image";
+} + +
+ + + + + + + \ No newline at end of file -- cgit v1.2.3-24-g4f1b