summaryrefslogtreecommitdiffstats
path: root/user_guide/libraries/validation.html
diff options
context:
space:
mode:
authorDerek Allard <derek.allard@ellislab.com>2008-11-13 23:59:24 +0100
committerDerek Allard <derek.allard@ellislab.com>2008-11-13 23:59:24 +0100
commit2067d1a727e7eb5e5ffb40e967f3d1fc4c8a41b2 (patch)
treea95e01024205837e9580757350d04b233e82503f /user_guide/libraries/validation.html
parentdd9f932556d3cd45a1d06cc478f40d06b7649a69 (diff)
Changing EOL style to LF
Diffstat (limited to 'user_guide/libraries/validation.html')
-rw-r--r--user_guide/libraries/validation.html1470
1 files changed, 735 insertions, 735 deletions
diff --git a/user_guide/libraries/validation.html b/user_guide/libraries/validation.html
index 6037a24e8..394be1901 100644
--- a/user_guide/libraries/validation.html
+++ b/user_guide/libraries/validation.html
@@ -1,736 +1,736 @@
-<!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>Form Validation : 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 1.7</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> &nbsp;&#8250;&nbsp;
-<a href="../index.html">User Guide Home</a> &nbsp;&#8250;&nbsp;
-Form Validation
-</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&nbsp; <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" />&nbsp;<input type="submit" class="submit" name="sa" value="Go" /></form></td>
-</tr>
-</table>
-<!-- END BREADCRUMB -->
-
-<br clear="all" />
-
-
-<!-- START CONTENT -->
-<div id="content">
-
-<h1>Form Validation</h1>
-
-<p>Before explaining CodeIgniter's approach to data validation, let's describe the ideal scenario:</p>
-
-<ol>
-<li>A form is displayed.</li>
-<li>You fill it in and submit it.</li>
-<li>If you submitted something invalid, or perhaps missed a required item, the form is redisplayed containing your data along with an error message describing the problem.</li>
-<li>This process continues until you have submitted a valid form.</li>
-</ol>
-
-<p>On the receiving end, the script must:</p>
-
-<ol>
-<li>Check for required data.</li>
-<li>Verify that the data is of the correct type, and meets the correct criteria. (For example, if a username is submitted
-it must be validated to contain only permitted characters. It must be of a minimum length,
-and not exceed a maximum length. The username can't be someone else's existing username, or perhaps even a reserved word. Etc.)</li>
-<li>Sanitize the data for security.</li>
-<li>Pre-format the data if needed (Does the data need to be trimmed? HTML encoded? Etc.)</li>
-<li>Prep the data for insertion in the database.</li>
-</ol>
-
-
-<p>Although there is nothing complex about the above process, it usually requires a significant
-amount of code, and to display error messages, various control structures are usually placed within the form HTML.
-Form validation, while simple to create, is generally very messy and tedious to implement.</p>
-
-<dfn>CodeIgniter provides a comprehensive validation framework that truly minimizes the amount of code you'll write.
-It also removes all control structures from your form HTML, permitting it to be clean and free of code.</dfn>
-
-<h2>Overview</h2>
-
-<p>In order to implement CodeIgniter's form validation you'll need three things:</p>
-
-<ol>
-<li>A <a href="../general/views.html">View</a> file containing the form.</li>
-<li>A View file containing a "success" message to be displayed upon successful submission.</li>
-<li>A <a href="../general/controllers.html">controller</a> function to receive and process the submitted data.</li>
-</ol>
-
-<p>Let's create those three things, using a member sign-up form as the example.</p>
-
-<h2>The Form</h2>
-
-<p>Using a text editor, create a form called <dfn>myform.php</dfn>. In it, place this code and save it to your <samp>applications/views/</samp>
-folder:</p>
-
-
-<textarea class="textarea" style="width:100%" cols="50" rows="30">&lt;html>
-&lt;head>
-&lt;title>My Form&lt;/title>
-&lt;/head>
-&lt;body>
-
-&lt;?php echo $this->validation->error_string; ?>
-
-&lt;?php echo form_open('form'); ?>
-
-&lt;h5>Username&lt;/h5>
-&lt;input type="text" name="username" value="" size="50" />
-
-&lt;h5>Password&lt;/h5>
-&lt;input type="text" name="password" value="" size="50" />
-
-&lt;h5>Password Confirm&lt;/h5>
-&lt;input type="text" name="passconf" value="" size="50" />
-
-&lt;h5>Email Address&lt;/h5>
-&lt;input type="text" name="email" value="" size="50" />
-
-&lt;div>&lt;input type="submit" value="Submit" />&lt;/div>
-
-&lt;/form>
-
-&lt;/body>
-&lt;/html>
-</textarea>
-
-
-<h2>The Success Page</h2>
-
-
-<p>Using a text editor, create a form called <dfn>formsuccess.php</dfn>. In it, place this code and save it to your <samp>applications/views/</samp>
-folder:</p>
-
-
-<textarea class="textarea" style="width:100%" cols="50" rows="14">
-&lt;html>
-&lt;head>
-&lt;title>My Form&lt;/title>
-&lt;/head>
-&lt;body>
-
-&lt;h3>Your form was successfully submitted!&lt;/h3>
-
-&lt;p>&lt;?php echo anchor('form', 'Try it again!'); ?>&lt;/p>
-
-&lt;/body>
-&lt;/html>
-</textarea>
-
-
-<h2>The Controller</h2>
-
-<p>Using a text editor, create a controller called <dfn>form.php</dfn>. In it, place this code and save it to your <samp>applications/controllers/</samp>
-folder:</p>
-
-
-<textarea class="textarea" style="width:100%" cols="50" rows="21">&lt;?php
-
-class Form extends Controller {
-
- function index()
- {
- $this->load->helper(array('form', 'url'));
-
- $this->load->library('validation');
-
- if ($this->validation->run() == FALSE)
- {
- $this->load->view('myform');
- }
- else
- {
- $this->load->view('formsuccess');
- }
- }
-}
-?></textarea>
-
-
-<h2>Try it!</h2>
-
-<p>To try your form, visit your site using a URL similar to this one:</p>
-
-<code>example.com/index.php/<var>form</var>/</code>
-
-<p><strong>If you submit the form you should simply see the form reload. That's because you haven't set up any validation
-rules yet, which we'll get to in a moment.</strong></p>
-
-
-<h2>Explanation</h2>
-
-<p>You'll notice several things about the above pages:</p>
-
-<p>The <dfn>form</dfn> (myform.php) is a standard web form with a couple exceptions:</p>
-
-<ol>
-<li>It uses a <dfn>form helper</dfn> to create the form opening.
-Technically, this isn't necessary. You could create the form using standard HTML. However, the benefit of using the helper
-is that it generates the action URL for you, based on the URL in your config file. This makes your application more portable
-and flexible in the event your URLs change.</li>
-
-<li>At the top of the form you'll notice the following variable:
-<code>&lt;?php echo $this->validation->error_string; ?&gt;</code>
-
-<p>This variable will display any error messages sent back by the validator. If there are no messages it returns nothing.</p>
-</li>
-</ol>
-
-<p>The <dfn>controller</dfn> (form.php) has one function: <dfn>index()</dfn>. This function initializes the validation class and
-loads the <var>form helper</var> and <var>URL helper</var> used by your view files. It also <samp>runs</samp>
-the validation routine. Based on
-whether the validation was successful it either presents the form or the success page.</p>
-
-<p><strong>Since you haven't told the validation class to validate anything yet, it returns "false" (boolean false) by default. The <samp>run()</samp>
-function only returns "true" if it has successfully applied your rules without any of them failing.</strong></p>
-
-
-<h2>Setting Validation Rules</h2>
-
-<p>CodeIgniter lets you set as many validation rules as you need for a given field, cascading them in order, and it even lets you prep and pre-process the field data
-at the same time. Let's see it in action, we'll explain it afterwards.</p>
-
-<p>In your <dfn>controller</dfn> (form.php), add this code just below the validation initialization function:</p>
-
-<code>$rules['username'] = "required";<br />
-$rules['password'] = "required";<br />
-$rules['passconf'] = "required";<br />
-$rules['email'] = "required";<br />
-<br />
-$this->validation->set_rules($rules);</code>
-
-<p>Your controller should now look like this:</p>
-
-<textarea class="textarea" style="width:100%" cols="50" rows="28"><?php
-
-class Form extends Controller {
-
- function index()
- {
- $this->load->helper(array('form', 'url'));
-
- $this->load->library('validation');
-
- $rules['username'] = "required";
- $rules['password'] = "required";
- $rules['passconf'] = "required";
- $rules['email'] = "required";
-
- $this->validation->set_rules($rules);
-
- if ($this->validation->run() == FALSE)
- {
- $this->load->view('myform');
- }
- else
- {
- $this->load->view('formsuccess');
- }
- }
-}
-?></textarea>
-
-<p><dfn>Now submit the form with the fields blank and you should see the error message.
-If you submit the form with all the fields populated you'll see your success page.</dfn></p>
-
-<p class="important"><strong>Note:</strong> The form fields are not yet being re-populated with the data when
-there is an error. We'll get to that shortly, once we're through explaining the validation rules.</p>
-
-
-<h2>Changing the Error Delimiters</h2>
-
-<p>By default, the system adds a paragraph tag (&lt;p&gt;) around each error message shown. You can easily change these delimiters with
-this code, placed in your controller:</p>
-
-<code>$this->validation->set_error_delimiters('<kbd>&lt;div class="error"></kbd>', '<kbd>&lt;/div></kbd>');</code>
-
-<p>In this example, we've switched to using div tags.</p>
-
-<h2>Cascading Rules</h2>
-
-<p>CodeIgniter lets you pipe multiple rules together. Let's try it. Change your rules array like this:</p>
-
-
-<code>$rules['username'] = "required|min_length[5]|max_length[12]";<br />
-$rules['password'] = "required|matches[passconf]";<br />
-$rules['passconf'] = "required";<br />
-$rules['email'] = "required|valid_email";</code>
-
-<p>The above code requires that:</p>
-
-<ol>
-<li>The username field be no shorter than 5 characters and no longer than 12.</li>
-<li>The password field must match the password confirmation field.</li>
-<li>The email field must contain a valid email address.</li>
-</ol>
-
-<p>Give it a try!</p>
-
-<p class="important"><strong>Note:</strong> There are numerous rules available which you can read about in the validation reference.</p>
-
-
-<h2>Prepping Data</h2>
-
-<p>In addition to the validation functions like the ones we used above, you can also prep your data in various ways.
-For example, you can set up rules like this:</p>
-
-<code>$rules['username'] = "<kbd>trim</kbd>|required|min_length[5]|max_length[12]|<kbd>xss_clean</kbd>";<br />
-$rules['password'] = "<kbd>trim</kbd>|required|matches[passconf]|<kbd>md5</kbd>";<br />
-$rules['passconf'] = "<kbd>trim</kbd>|required";<br />
-$rules['email'] = "<kbd>trim</kbd>|required|valid_email";</code>
-
-<p>In the above example, we are "trimming" the fields, converting the password to MD5, and running the username through
-the "xss_clean" function, which removes malicious data.</p>
-
-<p class="important"><strong>Any native PHP function that accepts one parameter can be used as a rule, like <dfn>htmlspecialchars</dfn>,
-<dfn>trim</dfn>, <dfn>MD5</dfn>, etc.</strong></p>
-
-<p><strong>Note:</strong> You will generally want to use the prepping functions <strong>after</strong>
-the validation rules so if there is an error, the original data will be shown in the form.</p>
-
-<h2>Callbacks: Your own Validation Functions</h2>
-
-<p>The validation system supports callbacks to your own validation functions. This permits you to extend the validation class
-to meet your needs. For example, if you need to run a database query to see if the user is choosing a unique username, you can
-create a callback function that does that. Let's create a simple example.</p>
-
-<p>In your controller, change the "username" rule to this:</p>
-
-<code>$rules['username'] = "callback_username_check"; </code>
-
-<p>Then add a new function called <dfn>username_check</dfn> to your controller. Here's how your controller should look:</p>
-
-
-<textarea class="textarea" style="width:100%" cols="50" rows="44"><?php
-
-class Form extends Controller {
-
- function index()
- {
- $this->load->helper(array('form', 'url'));
-
- $this->load->library('validation');
-
- $rules['username'] = "callback_username_check";
- $rules['password'] = "required";
- $rules['passconf'] = "required";
- $rules['email'] = "required";
-
- $this->validation->set_rules($rules);
-
- if ($this->validation->run() == FALSE)
- {
- $this->load->view('myform');
- }
- else
- {
- $this->load->view('formsuccess');
- }
- }
-
- function username_check($str)
- {
- if ($str == 'test')
- {
- $this->validation->set_message('username_check', 'The %s field can not be the word "test"');
- return FALSE;
- }
- else
- {
- return TRUE;
- }
- }
-
-}
-?></textarea>
-
-<p>Reload your form and submit it with the word "test" as the username. You can see that the form field data was passed to your
-callback function for you to process.</p>
-
-<p><strong>To invoke a callback just put the function name in a rule, with "callback_" as the rule prefix.</strong></p>
-
-<p>The error message was set using the <dfn>$this->validation->set_message</dfn> function.
-Just remember that the message key (the first parameter) must match your function name.</p>
-
-<p class="important"><strong>Note:</strong> You can apply your own custom error messages to any rule, just by setting the
-message similarly. For example, to change the message for the "required" rule you will do this:</p>
-
-<code>$this->validation->set_message('required', 'Your custom message here');</code>
-
-<h2>Re-populating the form</h2>
-
-<p>Thus far we have only been dealing with errors. It's time to repopulate the form field with the submitted data.
-This is done similarly to your rules. Add the following code to your controller, just below your rules:</p>
-
-<code>$fields['username'] = 'Username';<br />
-$fields['password'] = 'Password';<br />
-$fields['passconf'] = 'Password Confirmation';<br />
-$fields['email'] = 'Email Address';<br />
-<br />
-$this->validation->set_fields($fields);</code>
-
-<p>The array keys are the actual names of the form fields, the value represents the full name that you want shown in the
-error message.</p>
-
-<p>The index function of your controller should now look like this:</p>
-
-
-<textarea class="textarea" style="width:100%" cols="50" rows="30">function index()
-{
- $this->load->helper(array('form', 'url'));
-
- $this->load->library('validation');
-
- $rules['username'] = "required";
- $rules['password'] = "required";
- $rules['passconf'] = "required";
- $rules['email'] = "required";
-
- $this->validation->set_rules($rules);
-
- $fields['username'] = 'Username';
- $fields['password'] = 'Password';
- $fields['passconf'] = 'Password Confirmation';
- $fields['email'] = 'Email Address';
-
- $this->validation->set_fields($fields);
-
- if ($this->validation->run() == FALSE)
- {
- $this->load->view('myform');
- }
- else
- {
- $this->load->view('formsuccess');
- }
-}</textarea>
-
-
-<p>Now open your <dfn>myform.php</dfn> view file and update the value in each field so that it has an attribute corresponding to its name:</p>
-
-
-<textarea class="textarea" style="width:100%" cols="50" rows="30">
-&lt;html>
-&lt;head>
-&lt;title>My Form&lt;/title>
-&lt;/head>
-&lt;body>
-
-&lt;?php echo $this->validation->error_string; ?>
-
-&lt;?php echo form_open('form'); ?>
-
-&lt;h5>Username&lt;/h5>
-&lt;input type="text" name="username" value="&lt;?php echo $this->validation->username;?>" size="50" />
-
-&lt;h5>Password&lt;/h5>
-&lt;input type="text" name="password" value="&lt;?php echo $this->validation->password;?>" size="50" />
-
-&lt;h5>Password Confirm&lt;/h5>
-&lt;input type="text" name="passconf" value="&lt;?php echo $this->validation->passconf;?>" size="50" />
-
-&lt;h5>Email Address&lt;/h5>
-&lt;input type="text" name="email" value="&lt;?php echo $this->validation->email;?>" size="50" />
-
-&lt;div>&lt;input type="submit" value="Submit" />&lt;/div>
-
-&lt;/form>
-
-&lt;/body>
-&lt;/html>
-</textarea>
-
-
-<p>Now reload your page and submit the form so that it triggers an error. Your form fields should be populated
-and the error messages will contain a more relevant field name.</p>
-
-
-
-<h2>Showing Errors Individually</h2>
-
-<p>If you prefer to show an error message next to each form field, rather than as a list, you can change your form so that it looks like this:</p>
-
-
-<textarea class="textarea" style="width:100%" cols="50" rows="20">
-&lt;h5>Username&lt;/h5>
-&lt;?php echo $this->validation->username_error; ?>
-&lt;input type="text" name="username" value="&lt;?php echo $this->validation->username;?>" size="50" />
-
-&lt;h5>Password&lt;/h5>
-&lt;?php echo $this->validation->password_error; ?>
-&lt;input type="text" name="password" value="&lt;?php echo $this->validation->password;?>" size="50" />
-
-&lt;h5>Password Confirm&lt;/h5>
-&lt;?php echo $this->validation->passconf_error; ?>
-&lt;input type="text" name="passconf" value="&lt;?php echo $this->validation->passconf;?>" size="50" />
-
-&lt;h5>Email Address&lt;/h5>
-&lt;?php echo $this->validation->email_error; ?>
-&lt;input type="text" name="email" value="&lt;?php echo $this->validation->email;?>" size="50" /></textarea>
-
-<p>If there are no errors, nothing will be shown. If there is an error, the message will appear, wrapped in the delimiters you
-have set (&lt;p> tags by default).</p>
-
-<p class="important"><strong>Note: </strong>To display errors this way you must remember to set your fields using the <kbd>$this->validation->set_fields</kbd>
-function described earlier. The errors will be turned into variables that have "_error" after your field name.
-For example, your "username" error will be available at:<br /><dfn>$this->validation->username_error</dfn>.</p>
-
-
-<h2>Rule Reference</h2>
-
-<p>The following is a list of all the native rules that are available to use:</p>
-
-
-
-<table cellpadding="0" cellspacing="1" border="0" style="width:100%" class="tableborder">
-<tr>
-<th>Rule</th>
-<th>Parameter</th>
-<th>Description</th>
-<th>Example</th>
-</tr><tr>
-
-<td class="td"><strong>required</strong></td>
-<td class="td">No</td>
-<td class="td">Returns FALSE if the form element is empty.</td>
-<td class="td">&nbsp;</td>
-</tr><tr>
-
-<td class="td"><strong>matches</strong></td>
-<td class="td">Yes</td>
-<td class="td">Returns FALSE if the form element does not match the one in the parameter.</td>
-<td class="td">matches[form_item]</td>
-</tr><tr>
-
-<td class="td"><strong>min_length</strong></td>
-<td class="td">Yes</td>
-<td class="td">Returns FALSE if the form element is shorter then the parameter value.</td>
-<td class="td">min_length[6]</td>
-</tr><tr>
-
-<td class="td"><strong>max_length</strong></td>
-<td class="td">Yes</td>
-<td class="td">Returns FALSE if the form element is longer then the parameter value.</td>
-<td class="td">max_length[12]</td>
-</tr><tr>
-
-<td class="td"><strong>exact_length</strong></td>
-<td class="td">Yes</td>
-<td class="td">Returns FALSE if the form element is not exactly the parameter value.</td>
-<td class="td">exact_length[8]</td>
-</tr><tr>
-
-<td class="td"><strong>alpha</strong></td>
-<td class="td">No</td>
-<td class="td">Returns FALSE if the form element contains anything other than alphabetical characters.</td>
-<td class="td">&nbsp;</td>
-</tr><tr>
-
-<td class="td"><strong>alpha_numeric</strong></td>
-<td class="td">No</td>
-<td class="td">Returns FALSE if the form element contains anything other than alpha-numeric characters.</td>
-<td class="td">&nbsp;</td>
-</tr><tr>
-
-<td class="td"><strong>alpha_dash</strong></td>
-<td class="td">No</td>
-<td class="td">Returns FALSE if the form element contains anything other than alpha-numeric characters, underscores or dashes.</td>
-<td class="td">&nbsp;</td>
-</tr>
-<tr>
- <td class="td"><strong>numeric</strong></td>
- <td class="td">No</td>
- <td class="td">Returns FALSE if the form element contains anything other than numeric characters.</td>
- <td class="td">&nbsp;</td>
-</tr>
-<tr>
-
-<td class="td"><strong>integer</strong></td>
-<td class="td">No</td>
-<td class="td">Returns FALSE if the form element contains anything other than an integer.</td>
-<td class="td">&nbsp;</td>
-</tr><tr>
-
-<td class="td"><strong>valid_email</strong></td>
-<td class="td">No</td>
-<td class="td">Returns FALSE if the form element does not contain a valid email address.</td>
-<td class="td">&nbsp;</td>
-</tr>
-<tr>
- <td class="td"><strong>valid_emails</strong></td>
- <td class="td">No</td>
- <td class="td">Returns FALSE if any value provided in a comma separated list is not a valid email.</td>
- <td class="td">&nbsp;</td>
-</tr>
-<tr>
-<td class="td"><strong>valid_ip</strong></td>
-<td class="td">No</td>
-<td class="td">Returns FALSE if the supplied IP is not valid.</td>
-<td class="td">&nbsp;</td>
-</tr>
-<tr>
- <td class="td"><strong>valid_base64</strong></td>
- <td class="td">No</td>
- <td class="td">Returns FALSE if the supplied string contains anything other than valid Base64 characters.</td>
- <td class="td">&nbsp;</td>
-</tr>
-</table>
-
-<p><strong>Note:</strong> These rules can also be called as discrete functions. For example:</p>
-
-<code>$this->validation->required($string);</code>
-
-<p class="important"><strong>Note:</strong> You can also use any native PHP functions that permit one parameter.</p>
-
-
-
-<h2>Prepping Reference</h2>
-
-<p>The following is a list of all the prepping functions that are available to use:</p>
-
-
-
-<table cellpadding="0" cellspacing="1" border="0" style="width:100%" class="tableborder">
-<tr>
-<th>Name</th>
-<th>Parameter</th>
-<th>Description</th>
-</tr><tr>
-
-<td class="td"><strong>xss_clean</strong></td>
-<td class="td">No</td>
-<td class="td">Runs the data through the XSS filtering function, described in the <a href="input.html">Input Class</a> page.</td>
-</tr><tr>
-
-<td class="td"><strong>prep_for_form</strong></td>
-<td class="td">No</td>
-<td class="td">Converts special characters so that HTML data can be shown in a form field without breaking it.</td>
-</tr><tr>
-
-<td class="td"><strong>prep_url</strong></td>
-<td class="td">No</td>
-<td class="td">Adds "http://" to URLs if missing.</td>
-</tr><tr>
-
-<td class="td"><strong>strip_image_tags</strong></td>
-<td class="td">No</td>
-<td class="td">Strips the HTML from image tags leaving the raw URL.</td>
-</tr><tr>
-
-<td class="td"><strong>encode_php_tags</strong></td>
-<td class="td">No</td>
-<td class="td">Converts PHP tags to entities.</td>
-</tr>
-
-</table>
-
-<p class="important"><strong>Note:</strong> You can also use any native PHP functions that permit one parameter,
-like <kbd>trim</kbd>, <kbd>htmlspecialchars</kbd>, <kbd>urldecode</kbd>, etc.</p>
-
-
-<h2>Setting Custom Error Messages</h2>
-
-<p>All of the native error messages are located in the following language file: <dfn>language/english/validation_lang.php</dfn></p>
-
-<p>To set your own custom message you can either edit that file, or use the following function:</p>
-
-<code>$this->validation->set_message('<var>rule</var>', '<var>Error Message</var>');</code>
-
-<p>Where <var>rule</var> corresponds to the name of a particular rule, and <var>Error Message</var> is the text you would like displayed.</p>
-
-
-<h2>Dealing with Select Menus, Radio Buttons, and Checkboxes</h2>
-
-<p>If you use select menus, radio buttons or checkboxes, you will want the state of
-these items to be retained in the event of an error. The Validation class has three functions that help you do this:</p>
-
-<h2>set_select()</h2>
-
-<p>Permits you to display the menu item that was selected. The first parameter
-must contain the name of the select menu, the second parameter must contain the value of
-each item. Example:</p>
-
-<code>
-&lt;select name="myselect"><br />
-&lt;option value="one" <dfn>&lt;?php echo $this->validation->set_select('myselect', 'one'); ?></dfn> >One&lt;/option><br />
-&lt;option value="two" <dfn>&lt;?php echo $this->validation->set_select('myselect', 'two'); ?></dfn> >Two&lt;/option><br />
-&lt;option value="three" <dfn>&lt;?php echo $this->validation->set_select('myselect', 'three'); ?></dfn> >Three&lt;/option><br />
-&lt;/select>
-</code>
-
-
-<h2>set_checkbox()</h2>
-
-<p>Permits you to display a checkbox in the state it was submitted. The first parameter
-must contain the name of the checkbox, the second parameter must contain its value. Example:</p>
-
-<code>&lt;input type="checkbox" name="mycheck" value="1" <dfn>&lt;?php echo $this->validation->set_checkbox('mycheck', '1'); ?></dfn> /></code>
-
-
-<h2>set_radio()</h2>
-
-<p>Permits you to display radio buttons in the state they were submitted. The first parameter
-must contain the name of the radio button, the second parameter must contain its value. Example:</p>
-
-<code>&lt;input type="radio" name="myradio" value="1" <dfn>&lt;?php echo $this->validation->set_radio('myradio', '1'); ?></dfn> /></code>
-
-
-
-
-
-</div>
-<!-- END CONTENT -->
-
-
-<div id="footer">
-<p>
-Previous Topic:&nbsp;&nbsp;<a href="user_agent.html">User Agent Class</a>
-&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
-<a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
-<a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
-Next Topic:&nbsp;&nbsp;<a href="xmlrpc.html">XML-RPC Class</a>
-</p>
-<p><a href="http://codeigniter.com">CodeIgniter</a> &nbsp;&middot;&nbsp; Copyright &#169; 2006-2008 &nbsp;&middot;&nbsp; <a href="http://ellislab.com/">Ellislab, Inc.</a></p>
-</div>
-
-</body>
+<!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>Form Validation : 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 1.7</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> &nbsp;&#8250;&nbsp;
+<a href="../index.html">User Guide Home</a> &nbsp;&#8250;&nbsp;
+Form Validation
+</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&nbsp; <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" />&nbsp;<input type="submit" class="submit" name="sa" value="Go" /></form></td>
+</tr>
+</table>
+<!-- END BREADCRUMB -->
+
+<br clear="all" />
+
+
+<!-- START CONTENT -->
+<div id="content">
+
+<h1>Form Validation</h1>
+
+<p>Before explaining CodeIgniter's approach to data validation, let's describe the ideal scenario:</p>
+
+<ol>
+<li>A form is displayed.</li>
+<li>You fill it in and submit it.</li>
+<li>If you submitted something invalid, or perhaps missed a required item, the form is redisplayed containing your data along with an error message describing the problem.</li>
+<li>This process continues until you have submitted a valid form.</li>
+</ol>
+
+<p>On the receiving end, the script must:</p>
+
+<ol>
+<li>Check for required data.</li>
+<li>Verify that the data is of the correct type, and meets the correct criteria. (For example, if a username is submitted
+it must be validated to contain only permitted characters. It must be of a minimum length,
+and not exceed a maximum length. The username can't be someone else's existing username, or perhaps even a reserved word. Etc.)</li>
+<li>Sanitize the data for security.</li>
+<li>Pre-format the data if needed (Does the data need to be trimmed? HTML encoded? Etc.)</li>
+<li>Prep the data for insertion in the database.</li>
+</ol>
+
+
+<p>Although there is nothing complex about the above process, it usually requires a significant
+amount of code, and to display error messages, various control structures are usually placed within the form HTML.
+Form validation, while simple to create, is generally very messy and tedious to implement.</p>
+
+<dfn>CodeIgniter provides a comprehensive validation framework that truly minimizes the amount of code you'll write.
+It also removes all control structures from your form HTML, permitting it to be clean and free of code.</dfn>
+
+<h2>Overview</h2>
+
+<p>In order to implement CodeIgniter's form validation you'll need three things:</p>
+
+<ol>
+<li>A <a href="../general/views.html">View</a> file containing the form.</li>
+<li>A View file containing a "success" message to be displayed upon successful submission.</li>
+<li>A <a href="../general/controllers.html">controller</a> function to receive and process the submitted data.</li>
+</ol>
+
+<p>Let's create those three things, using a member sign-up form as the example.</p>
+
+<h2>The Form</h2>
+
+<p>Using a text editor, create a form called <dfn>myform.php</dfn>. In it, place this code and save it to your <samp>applications/views/</samp>
+folder:</p>
+
+
+<textarea class="textarea" style="width:100%" cols="50" rows="30">&lt;html>
+&lt;head>
+&lt;title>My Form&lt;/title>
+&lt;/head>
+&lt;body>
+
+&lt;?php echo $this->validation->error_string; ?>
+
+&lt;?php echo form_open('form'); ?>
+
+&lt;h5>Username&lt;/h5>
+&lt;input type="text" name="username" value="" size="50" />
+
+&lt;h5>Password&lt;/h5>
+&lt;input type="text" name="password" value="" size="50" />
+
+&lt;h5>Password Confirm&lt;/h5>
+&lt;input type="text" name="passconf" value="" size="50" />
+
+&lt;h5>Email Address&lt;/h5>
+&lt;input type="text" name="email" value="" size="50" />
+
+&lt;div>&lt;input type="submit" value="Submit" />&lt;/div>
+
+&lt;/form>
+
+&lt;/body>
+&lt;/html>
+</textarea>
+
+
+<h2>The Success Page</h2>
+
+
+<p>Using a text editor, create a form called <dfn>formsuccess.php</dfn>. In it, place this code and save it to your <samp>applications/views/</samp>
+folder:</p>
+
+
+<textarea class="textarea" style="width:100%" cols="50" rows="14">
+&lt;html>
+&lt;head>
+&lt;title>My Form&lt;/title>
+&lt;/head>
+&lt;body>
+
+&lt;h3>Your form was successfully submitted!&lt;/h3>
+
+&lt;p>&lt;?php echo anchor('form', 'Try it again!'); ?>&lt;/p>
+
+&lt;/body>
+&lt;/html>
+</textarea>
+
+
+<h2>The Controller</h2>
+
+<p>Using a text editor, create a controller called <dfn>form.php</dfn>. In it, place this code and save it to your <samp>applications/controllers/</samp>
+folder:</p>
+
+
+<textarea class="textarea" style="width:100%" cols="50" rows="21">&lt;?php
+
+class Form extends Controller {
+
+ function index()
+ {
+ $this->load->helper(array('form', 'url'));
+
+ $this->load->library('validation');
+
+ if ($this->validation->run() == FALSE)
+ {
+ $this->load->view('myform');
+ }
+ else
+ {
+ $this->load->view('formsuccess');
+ }
+ }
+}
+?></textarea>
+
+
+<h2>Try it!</h2>
+
+<p>To try your form, visit your site using a URL similar to this one:</p>
+
+<code>example.com/index.php/<var>form</var>/</code>
+
+<p><strong>If you submit the form you should simply see the form reload. That's because you haven't set up any validation
+rules yet, which we'll get to in a moment.</strong></p>
+
+
+<h2>Explanation</h2>
+
+<p>You'll notice several things about the above pages:</p>
+
+<p>The <dfn>form</dfn> (myform.php) is a standard web form with a couple exceptions:</p>
+
+<ol>
+<li>It uses a <dfn>form helper</dfn> to create the form opening.
+Technically, this isn't necessary. You could create the form using standard HTML. However, the benefit of using the helper
+is that it generates the action URL for you, based on the URL in your config file. This makes your application more portable
+and flexible in the event your URLs change.</li>
+
+<li>At the top of the form you'll notice the following variable:
+<code>&lt;?php echo $this->validation->error_string; ?&gt;</code>
+
+<p>This variable will display any error messages sent back by the validator. If there are no messages it returns nothing.</p>
+</li>
+</ol>
+
+<p>The <dfn>controller</dfn> (form.php) has one function: <dfn>index()</dfn>. This function initializes the validation class and
+loads the <var>form helper</var> and <var>URL helper</var> used by your view files. It also <samp>runs</samp>
+the validation routine. Based on
+whether the validation was successful it either presents the form or the success page.</p>
+
+<p><strong>Since you haven't told the validation class to validate anything yet, it returns "false" (boolean false) by default. The <samp>run()</samp>
+function only returns "true" if it has successfully applied your rules without any of them failing.</strong></p>
+
+
+<h2>Setting Validation Rules</h2>
+
+<p>CodeIgniter lets you set as many validation rules as you need for a given field, cascading them in order, and it even lets you prep and pre-process the field data
+at the same time. Let's see it in action, we'll explain it afterwards.</p>
+
+<p>In your <dfn>controller</dfn> (form.php), add this code just below the validation initialization function:</p>
+
+<code>$rules['username'] = "required";<br />
+$rules['password'] = "required";<br />
+$rules['passconf'] = "required";<br />
+$rules['email'] = "required";<br />
+<br />
+$this->validation->set_rules($rules);</code>
+
+<p>Your controller should now look like this:</p>
+
+<textarea class="textarea" style="width:100%" cols="50" rows="28"><?php
+
+class Form extends Controller {
+
+ function index()
+ {
+ $this->load->helper(array('form', 'url'));
+
+ $this->load->library('validation');
+
+ $rules['username'] = "required";
+ $rules['password'] = "required";
+ $rules['passconf'] = "required";
+ $rules['email'] = "required";
+
+ $this->validation->set_rules($rules);
+
+ if ($this->validation->run() == FALSE)
+ {
+ $this->load->view('myform');
+ }
+ else
+ {
+ $this->load->view('formsuccess');
+ }
+ }
+}
+?></textarea>
+
+<p><dfn>Now submit the form with the fields blank and you should see the error message.
+If you submit the form with all the fields populated you'll see your success page.</dfn></p>
+
+<p class="important"><strong>Note:</strong> The form fields are not yet being re-populated with the data when
+there is an error. We'll get to that shortly, once we're through explaining the validation rules.</p>
+
+
+<h2>Changing the Error Delimiters</h2>
+
+<p>By default, the system adds a paragraph tag (&lt;p&gt;) around each error message shown. You can easily change these delimiters with
+this code, placed in your controller:</p>
+
+<code>$this->validation->set_error_delimiters('<kbd>&lt;div class="error"></kbd>', '<kbd>&lt;/div></kbd>');</code>
+
+<p>In this example, we've switched to using div tags.</p>
+
+<h2>Cascading Rules</h2>
+
+<p>CodeIgniter lets you pipe multiple rules together. Let's try it. Change your rules array like this:</p>
+
+
+<code>$rules['username'] = "required|min_length[5]|max_length[12]";<br />
+$rules['password'] = "required|matches[passconf]";<br />
+$rules['passconf'] = "required";<br />
+$rules['email'] = "required|valid_email";</code>
+
+<p>The above code requires that:</p>
+
+<ol>
+<li>The username field be no shorter than 5 characters and no longer than 12.</li>
+<li>The password field must match the password confirmation field.</li>
+<li>The email field must contain a valid email address.</li>
+</ol>
+
+<p>Give it a try!</p>
+
+<p class="important"><strong>Note:</strong> There are numerous rules available which you can read about in the validation reference.</p>
+
+
+<h2>Prepping Data</h2>
+
+<p>In addition to the validation functions like the ones we used above, you can also prep your data in various ways.
+For example, you can set up rules like this:</p>
+
+<code>$rules['username'] = "<kbd>trim</kbd>|required|min_length[5]|max_length[12]|<kbd>xss_clean</kbd>";<br />
+$rules['password'] = "<kbd>trim</kbd>|required|matches[passconf]|<kbd>md5</kbd>";<br />
+$rules['passconf'] = "<kbd>trim</kbd>|required";<br />
+$rules['email'] = "<kbd>trim</kbd>|required|valid_email";</code>
+
+<p>In the above example, we are "trimming" the fields, converting the password to MD5, and running the username through
+the "xss_clean" function, which removes malicious data.</p>
+
+<p class="important"><strong>Any native PHP function that accepts one parameter can be used as a rule, like <dfn>htmlspecialchars</dfn>,
+<dfn>trim</dfn>, <dfn>MD5</dfn>, etc.</strong></p>
+
+<p><strong>Note:</strong> You will generally want to use the prepping functions <strong>after</strong>
+the validation rules so if there is an error, the original data will be shown in the form.</p>
+
+<h2>Callbacks: Your own Validation Functions</h2>
+
+<p>The validation system supports callbacks to your own validation functions. This permits you to extend the validation class
+to meet your needs. For example, if you need to run a database query to see if the user is choosing a unique username, you can
+create a callback function that does that. Let's create a simple example.</p>
+
+<p>In your controller, change the "username" rule to this:</p>
+
+<code>$rules['username'] = "callback_username_check"; </code>
+
+<p>Then add a new function called <dfn>username_check</dfn> to your controller. Here's how your controller should look:</p>
+
+
+<textarea class="textarea" style="width:100%" cols="50" rows="44"><?php
+
+class Form extends Controller {
+
+ function index()
+ {
+ $this->load->helper(array('form', 'url'));
+
+ $this->load->library('validation');
+
+ $rules['username'] = "callback_username_check";
+ $rules['password'] = "required";
+ $rules['passconf'] = "required";
+ $rules['email'] = "required";
+
+ $this->validation->set_rules($rules);
+
+ if ($this->validation->run() == FALSE)
+ {
+ $this->load->view('myform');
+ }
+ else
+ {
+ $this->load->view('formsuccess');
+ }
+ }
+
+ function username_check($str)
+ {
+ if ($str == 'test')
+ {
+ $this->validation->set_message('username_check', 'The %s field can not be the word "test"');
+ return FALSE;
+ }
+ else
+ {
+ return TRUE;
+ }
+ }
+
+}
+?></textarea>
+
+<p>Reload your form and submit it with the word "test" as the username. You can see that the form field data was passed to your
+callback function for you to process.</p>
+
+<p><strong>To invoke a callback just put the function name in a rule, with "callback_" as the rule prefix.</strong></p>
+
+<p>The error message was set using the <dfn>$this->validation->set_message</dfn> function.
+Just remember that the message key (the first parameter) must match your function name.</p>
+
+<p class="important"><strong>Note:</strong> You can apply your own custom error messages to any rule, just by setting the
+message similarly. For example, to change the message for the "required" rule you will do this:</p>
+
+<code>$this->validation->set_message('required', 'Your custom message here');</code>
+
+<h2>Re-populating the form</h2>
+
+<p>Thus far we have only been dealing with errors. It's time to repopulate the form field with the submitted data.
+This is done similarly to your rules. Add the following code to your controller, just below your rules:</p>
+
+<code>$fields['username'] = 'Username';<br />
+$fields['password'] = 'Password';<br />
+$fields['passconf'] = 'Password Confirmation';<br />
+$fields['email'] = 'Email Address';<br />
+<br />
+$this->validation->set_fields($fields);</code>
+
+<p>The array keys are the actual names of the form fields, the value represents the full name that you want shown in the
+error message.</p>
+
+<p>The index function of your controller should now look like this:</p>
+
+
+<textarea class="textarea" style="width:100%" cols="50" rows="30">function index()
+{
+ $this->load->helper(array('form', 'url'));
+
+ $this->load->library('validation');
+
+ $rules['username'] = "required";
+ $rules['password'] = "required";
+ $rules['passconf'] = "required";
+ $rules['email'] = "required";
+
+ $this->validation->set_rules($rules);
+
+ $fields['username'] = 'Username';
+ $fields['password'] = 'Password';
+ $fields['passconf'] = 'Password Confirmation';
+ $fields['email'] = 'Email Address';
+
+ $this->validation->set_fields($fields);
+
+ if ($this->validation->run() == FALSE)
+ {
+ $this->load->view('myform');
+ }
+ else
+ {
+ $this->load->view('formsuccess');
+ }
+}</textarea>
+
+
+<p>Now open your <dfn>myform.php</dfn> view file and update the value in each field so that it has an attribute corresponding to its name:</p>
+
+
+<textarea class="textarea" style="width:100%" cols="50" rows="30">
+&lt;html>
+&lt;head>
+&lt;title>My Form&lt;/title>
+&lt;/head>
+&lt;body>
+
+&lt;?php echo $this->validation->error_string; ?>
+
+&lt;?php echo form_open('form'); ?>
+
+&lt;h5>Username&lt;/h5>
+&lt;input type="text" name="username" value="&lt;?php echo $this->validation->username;?>" size="50" />
+
+&lt;h5>Password&lt;/h5>
+&lt;input type="text" name="password" value="&lt;?php echo $this->validation->password;?>" size="50" />
+
+&lt;h5>Password Confirm&lt;/h5>
+&lt;input type="text" name="passconf" value="&lt;?php echo $this->validation->passconf;?>" size="50" />
+
+&lt;h5>Email Address&lt;/h5>
+&lt;input type="text" name="email" value="&lt;?php echo $this->validation->email;?>" size="50" />
+
+&lt;div>&lt;input type="submit" value="Submit" />&lt;/div>
+
+&lt;/form>
+
+&lt;/body>
+&lt;/html>
+</textarea>
+
+
+<p>Now reload your page and submit the form so that it triggers an error. Your form fields should be populated
+and the error messages will contain a more relevant field name.</p>
+
+
+
+<h2>Showing Errors Individually</h2>
+
+<p>If you prefer to show an error message next to each form field, rather than as a list, you can change your form so that it looks like this:</p>
+
+
+<textarea class="textarea" style="width:100%" cols="50" rows="20">
+&lt;h5>Username&lt;/h5>
+&lt;?php echo $this->validation->username_error; ?>
+&lt;input type="text" name="username" value="&lt;?php echo $this->validation->username;?>" size="50" />
+
+&lt;h5>Password&lt;/h5>
+&lt;?php echo $this->validation->password_error; ?>
+&lt;input type="text" name="password" value="&lt;?php echo $this->validation->password;?>" size="50" />
+
+&lt;h5>Password Confirm&lt;/h5>
+&lt;?php echo $this->validation->passconf_error; ?>
+&lt;input type="text" name="passconf" value="&lt;?php echo $this->validation->passconf;?>" size="50" />
+
+&lt;h5>Email Address&lt;/h5>
+&lt;?php echo $this->validation->email_error; ?>
+&lt;input type="text" name="email" value="&lt;?php echo $this->validation->email;?>" size="50" /></textarea>
+
+<p>If there are no errors, nothing will be shown. If there is an error, the message will appear, wrapped in the delimiters you
+have set (&lt;p> tags by default).</p>
+
+<p class="important"><strong>Note: </strong>To display errors this way you must remember to set your fields using the <kbd>$this->validation->set_fields</kbd>
+function described earlier. The errors will be turned into variables that have "_error" after your field name.
+For example, your "username" error will be available at:<br /><dfn>$this->validation->username_error</dfn>.</p>
+
+
+<h2>Rule Reference</h2>
+
+<p>The following is a list of all the native rules that are available to use:</p>
+
+
+
+<table cellpadding="0" cellspacing="1" border="0" style="width:100%" class="tableborder">
+<tr>
+<th>Rule</th>
+<th>Parameter</th>
+<th>Description</th>
+<th>Example</th>
+</tr><tr>
+
+<td class="td"><strong>required</strong></td>
+<td class="td">No</td>
+<td class="td">Returns FALSE if the form element is empty.</td>
+<td class="td">&nbsp;</td>
+</tr><tr>
+
+<td class="td"><strong>matches</strong></td>
+<td class="td">Yes</td>
+<td class="td">Returns FALSE if the form element does not match the one in the parameter.</td>
+<td class="td">matches[form_item]</td>
+</tr><tr>
+
+<td class="td"><strong>min_length</strong></td>
+<td class="td">Yes</td>
+<td class="td">Returns FALSE if the form element is shorter then the parameter value.</td>
+<td class="td">min_length[6]</td>
+</tr><tr>
+
+<td class="td"><strong>max_length</strong></td>
+<td class="td">Yes</td>
+<td class="td">Returns FALSE if the form element is longer then the parameter value.</td>
+<td class="td">max_length[12]</td>
+</tr><tr>
+
+<td class="td"><strong>exact_length</strong></td>
+<td class="td">Yes</td>
+<td class="td">Returns FALSE if the form element is not exactly the parameter value.</td>
+<td class="td">exact_length[8]</td>
+</tr><tr>
+
+<td class="td"><strong>alpha</strong></td>
+<td class="td">No</td>
+<td class="td">Returns FALSE if the form element contains anything other than alphabetical characters.</td>
+<td class="td">&nbsp;</td>
+</tr><tr>
+
+<td class="td"><strong>alpha_numeric</strong></td>
+<td class="td">No</td>
+<td class="td">Returns FALSE if the form element contains anything other than alpha-numeric characters.</td>
+<td class="td">&nbsp;</td>
+</tr><tr>
+
+<td class="td"><strong>alpha_dash</strong></td>
+<td class="td">No</td>
+<td class="td">Returns FALSE if the form element contains anything other than alpha-numeric characters, underscores or dashes.</td>
+<td class="td">&nbsp;</td>
+</tr>
+<tr>
+ <td class="td"><strong>numeric</strong></td>
+ <td class="td">No</td>
+ <td class="td">Returns FALSE if the form element contains anything other than numeric characters.</td>
+ <td class="td">&nbsp;</td>
+</tr>
+<tr>
+
+<td class="td"><strong>integer</strong></td>
+<td class="td">No</td>
+<td class="td">Returns FALSE if the form element contains anything other than an integer.</td>
+<td class="td">&nbsp;</td>
+</tr><tr>
+
+<td class="td"><strong>valid_email</strong></td>
+<td class="td">No</td>
+<td class="td">Returns FALSE if the form element does not contain a valid email address.</td>
+<td class="td">&nbsp;</td>
+</tr>
+<tr>
+ <td class="td"><strong>valid_emails</strong></td>
+ <td class="td">No</td>
+ <td class="td">Returns FALSE if any value provided in a comma separated list is not a valid email.</td>
+ <td class="td">&nbsp;</td>
+</tr>
+<tr>
+<td class="td"><strong>valid_ip</strong></td>
+<td class="td">No</td>
+<td class="td">Returns FALSE if the supplied IP is not valid.</td>
+<td class="td">&nbsp;</td>
+</tr>
+<tr>
+ <td class="td"><strong>valid_base64</strong></td>
+ <td class="td">No</td>
+ <td class="td">Returns FALSE if the supplied string contains anything other than valid Base64 characters.</td>
+ <td class="td">&nbsp;</td>
+</tr>
+</table>
+
+<p><strong>Note:</strong> These rules can also be called as discrete functions. For example:</p>
+
+<code>$this->validation->required($string);</code>
+
+<p class="important"><strong>Note:</strong> You can also use any native PHP functions that permit one parameter.</p>
+
+
+
+<h2>Prepping Reference</h2>
+
+<p>The following is a list of all the prepping functions that are available to use:</p>
+
+
+
+<table cellpadding="0" cellspacing="1" border="0" style="width:100%" class="tableborder">
+<tr>
+<th>Name</th>
+<th>Parameter</th>
+<th>Description</th>
+</tr><tr>
+
+<td class="td"><strong>xss_clean</strong></td>
+<td class="td">No</td>
+<td class="td">Runs the data through the XSS filtering function, described in the <a href="input.html">Input Class</a> page.</td>
+</tr><tr>
+
+<td class="td"><strong>prep_for_form</strong></td>
+<td class="td">No</td>
+<td class="td">Converts special characters so that HTML data can be shown in a form field without breaking it.</td>
+</tr><tr>
+
+<td class="td"><strong>prep_url</strong></td>
+<td class="td">No</td>
+<td class="td">Adds "http://" to URLs if missing.</td>
+</tr><tr>
+
+<td class="td"><strong>strip_image_tags</strong></td>
+<td class="td">No</td>
+<td class="td">Strips the HTML from image tags leaving the raw URL.</td>
+</tr><tr>
+
+<td class="td"><strong>encode_php_tags</strong></td>
+<td class="td">No</td>
+<td class="td">Converts PHP tags to entities.</td>
+</tr>
+
+</table>
+
+<p class="important"><strong>Note:</strong> You can also use any native PHP functions that permit one parameter,
+like <kbd>trim</kbd>, <kbd>htmlspecialchars</kbd>, <kbd>urldecode</kbd>, etc.</p>
+
+
+<h2>Setting Custom Error Messages</h2>
+
+<p>All of the native error messages are located in the following language file: <dfn>language/english/validation_lang.php</dfn></p>
+
+<p>To set your own custom message you can either edit that file, or use the following function:</p>
+
+<code>$this->validation->set_message('<var>rule</var>', '<var>Error Message</var>');</code>
+
+<p>Where <var>rule</var> corresponds to the name of a particular rule, and <var>Error Message</var> is the text you would like displayed.</p>
+
+
+<h2>Dealing with Select Menus, Radio Buttons, and Checkboxes</h2>
+
+<p>If you use select menus, radio buttons or checkboxes, you will want the state of
+these items to be retained in the event of an error. The Validation class has three functions that help you do this:</p>
+
+<h2>set_select()</h2>
+
+<p>Permits you to display the menu item that was selected. The first parameter
+must contain the name of the select menu, the second parameter must contain the value of
+each item. Example:</p>
+
+<code>
+&lt;select name="myselect"><br />
+&lt;option value="one" <dfn>&lt;?php echo $this->validation->set_select('myselect', 'one'); ?></dfn> >One&lt;/option><br />
+&lt;option value="two" <dfn>&lt;?php echo $this->validation->set_select('myselect', 'two'); ?></dfn> >Two&lt;/option><br />
+&lt;option value="three" <dfn>&lt;?php echo $this->validation->set_select('myselect', 'three'); ?></dfn> >Three&lt;/option><br />
+&lt;/select>
+</code>
+
+
+<h2>set_checkbox()</h2>
+
+<p>Permits you to display a checkbox in the state it was submitted. The first parameter
+must contain the name of the checkbox, the second parameter must contain its value. Example:</p>
+
+<code>&lt;input type="checkbox" name="mycheck" value="1" <dfn>&lt;?php echo $this->validation->set_checkbox('mycheck', '1'); ?></dfn> /></code>
+
+
+<h2>set_radio()</h2>
+
+<p>Permits you to display radio buttons in the state they were submitted. The first parameter
+must contain the name of the radio button, the second parameter must contain its value. Example:</p>
+
+<code>&lt;input type="radio" name="myradio" value="1" <dfn>&lt;?php echo $this->validation->set_radio('myradio', '1'); ?></dfn> /></code>
+
+
+
+
+
+</div>
+<!-- END CONTENT -->
+
+
+<div id="footer">
+<p>
+Previous Topic:&nbsp;&nbsp;<a href="user_agent.html">User Agent Class</a>
+&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
+<a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
+<a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
+Next Topic:&nbsp;&nbsp;<a href="xmlrpc.html">XML-RPC Class</a>
+</p>
+<p><a href="http://codeigniter.com">CodeIgniter</a> &nbsp;&middot;&nbsp; Copyright &#169; 2006-2008 &nbsp;&middot;&nbsp; <a href="http://ellislab.com/">Ellislab, Inc.</a></p>
+</div>
+
+</body>
</html> \ No newline at end of file