Form_validation.php

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<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 4.3.2 or newer
 *
 * @package             CodeIgniter
 * @author              ExpressionEngine Dev Team
 * @copyright   Copyright (c) 2008, EllisLab, Inc.
 * @license             http://codeigniter.com/user_guide/license.html
 * @link                http://codeigniter.com
 * @since               Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * Form Validation Class
 *
 * @package             CodeIgniter
 * @subpackage  Libraries
 * @category    Validation
 * @author              ExpressionEngine Dev Team
 * @link                http://codeigniter.com/user_guide/libraries/form_validation.html
 */
class CI_Form_validation {
        
        var $CI;
        var $_field_data                        = array();      
        var $_config_rules                      = array();
        var $_error_array                       = array();
        var $_error_messages            = array();      
        var $_error_prefix                      = '<p>';
        var $_error_suffix                      = '</p>';
        var $error_string                       = '';
        var $_safe_form_data            = FALSE;


        /**
         * Constructor
         *
         */     
        function CI_Form_validation($rules = array())
        {       
                $this->CI =& get_instance();
                
                // Validation rules can be stored in a config file.
                $this->_config_rules = $rules;
                
                // Automatically load the form helper
                $this->CI->load->helper('form');

                // Set the character encoding in MB.
                if (function_exists('mb_internal_encoding'))
                {
                        mb_internal_encoding($this->CI->config->item('charset'));
                }
        
                log_message('debug', "Validation Class Initialized");
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Set Rules
         *
         * This function takes an array of field names and validation
         * rules as input, validates the info, and stores it
         *
         * @access      public
         * @param       mixed
         * @param       string
         * @return      void
         */
        function set_rules($field, $label = '', $rules = '')
        {
                // No reason to set rules if we have no POST data
                if (count($_POST) == 0)
                {
                        return;
                }
        
                // If an array was passed via the first parameter instead of indidual string
                // values we cycle through it and recursively call this function.
                if (is_array($field))
                {
                        foreach ($field as $row)
                        {
                                // Houston, we have a problem...
                                if ( ! isset($row['field']) OR ! isset($row['rules']))
                                {
                                        continue;
                                }

                                // If the field label wasn't passed we use the field name
                                $label = ( ! isset($row['label'])) ? $row['field'] : $row['label'];

                                // Here we go!
                                $this->set_rules($row['field'], $label, $row['rules']);
                        }
                        return;
                }
                
                // No fields? Nothing to do...
                if ( ! is_string($field) OR  ! is_string($rules) OR $field == '')
                {
                        return;
                }

                // If the field label wasn't passed we use the field name
                $label = ($label == '') ? $field : $label;

                // Is the field name an array?  We test for the existence of a bracket "[" in
                // the field name to determine this.  If it is an array, we break it apart
                // into its components so that we can fetch the corresponding POST data later           
                if (strpos($field, '[') !== FALSE AND preg_match_all('/\[(.*?)\]/', $field, $matches))
                {       
                        // Note: Due to a bug in current() that affects some versions
                        // of PHP we can not pass function call directly into it
                        $x = explode('[', $field);
                        $indexes[] = current($x);

                        for ($i = 0; $i < count($matches['0']); $i++)
                        {
                                if ($matches['1'][$i] != '')
                                {
                                        $indexes[] = $matches['1'][$i];
                                }
                        }
                        
                        $is_array = TRUE;
                }
                else
                {
                        $indexes        = array();
                        $is_array       = FALSE;                
                }
                
                // Build our master array               
                $this->_field_data[$field] = array(
                                                                                        'field'                         => $field, 
                                                                                        'label'                         => $label, 
                                                                                        'rules'                         => $rules,
                                                                                        'is_array'                      => $is_array,
                                                                                        'keys'                          => $indexes,
                                                                                        'postdata'                      => NULL,
                                                                                        'error'                         => ''
                                                                                        );
        }

        // --------------------------------------------------------------------
        
        /**
         * Set Error Message
         *
         * Lets users set their own error messages on the fly.  Note:  The key
         * name has to match the  function name that it corresponds to.
         *
         * @access      public
         * @param       string
         * @param       string
         * @return      string
         */
        function set_message($lang, $val = '')
        {
                if ( ! is_array($lang))
                {
                        $lang = array($lang => $val);
                }
        
                $this->_error_messages = array_merge($this->_error_messages, $lang);
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Set The Error Delimiter
         *
         * Permits a prefix/suffix to be added to each error message
         *
         * @access      public
         * @param       string
         * @param       string
         * @return      void
         */     
        function set_error_delimiters($prefix = '<p>', $suffix = '</p>')
        {
                $this->_error_prefix = $prefix;
                $this->_error_suffix = $suffix;
        }

        // --------------------------------------------------------------------
        
        /**
         * Get Error Message
         *
         * Gets the error message associated with a particular field
         *
         * @access      public
         * @param       string  the field name
         * @return      void
         */     
        function error($field = '', $prefix = '', $suffix = '')
        {       
                if ( ! isset($this->_field_data[$field]['error']) OR $this->_field_data[$field]['error'] == '')
                {
                        return '';
                }
                
                if ($prefix == '')
                {
                        $prefix = $this->_error_prefix;
                }

                if ($suffix == '')
                {
                        $suffix = $this->_error_suffix;
                }

                return $prefix.$this->_field_data[$field]['error'].$suffix;
        }

        // --------------------------------------------------------------------
        
        /**
         * Error String
         *
         * Returns the error messages as a string, wrapped in the error delimiters
         *
         * @access      public
         * @param       string
         * @param       string
         * @return      str
         */     
        function error_string($prefix = '', $suffix = '')
        {
                // No errrors, validation passes!
                if (count($this->_error_array) === 0)
                {
                        return '';
                }
                
                if ($prefix == '')
                {
                        $prefix = $this->_error_prefix;
                }

                if ($suffix == '')
                {
                        $suffix = $this->_error_suffix;
                }
                
                // Generate the error string
                $str = '';
                foreach ($this->_error_array as $val)
                {
                        if ($val != '')
                        {
                                $str .= $prefix.$val.$suffix."\n";
                        }
                }
                
                return $str;
        }

        // --------------------------------------------------------------------
        
        /**
         * Run the Validator
         *
         * This function does all the work.
         *
         * @access      public
         * @return      bool
         */             
        function run($group = '')
        {
                // Do we even have any data to process?  Mm?
                if (count($_POST) == 0)
                {
                        return FALSE;
                }
                
                // Does the _field_data array containing the validation rules exist?
                // If not, we look to see if they were assigned via a config file
                if (count($this->_field_data) == 0)
                {
                        // No validation rules?  We're done...
                        if (count($this->_config_rules) == 0)
                        {
                                return FALSE;
                        }
                        
                        // Is there a validation rule for the particular URI being accessed?
                        $uri = ($group == '') ? trim($this->CI->uri->ruri_string(), '/') : $group;
                        
                        if ($uri != '' AND isset($this->_config_rules[$uri]))
                        {
                                $this->set_rules($this->_config_rules[$uri]);
                        }
                        else
                        {
                                $this->set_rules($this->_config_rules);
                        }
        
                        // We're we able to set the rules correctly?
                        if (count($this->_field_data) == 0)
                        {
                                log_message('debug', "Unable to find validation rules");
                                return FALSE;
                        }
                }
        
                // Load the language file containing error messages
                $this->CI->lang->load('form_validation');
                                                        
                // Cycle through the rules for each field, match the 
                // corresponding $_POST item and test for errors
                foreach ($this->_field_data as $field => $row)
                {               
                        // Fetch the data from the corresponding $_POST array and cache it in the _field_data array.
                        // Depending on whether the field name is an array or a string will determine where we get it from.
                        
                        if ($row['is_array'] == TRUE)
                        {
                                $this->_field_data[$field]['postdata'] = $this->_reduce_array($_POST, $row['keys']);
                        }
                        else
                        {
                                if (isset($_POST[$field]) AND $_POST[$field] != "")
                                {
                                        $this->_field_data[$field]['postdata'] = $_POST[$field];
                                }
                        }
                
                        $this->_execute($row, explode('|', $row['rules']), $this->_field_data[$field]['postdata']);             
                }

                // Did we end up with any errors?
                $total_errors = count($this->_error_array);

                if ($total_errors > 0)
                {
                        $this->_safe_form_data = TRUE;
                }

                // Now we need to re-set the POST data with the new, processed data
                $this->_reset_post_array();
                
                // No errors, validation passes!
                if ($total_errors == 0)
                {
                        return TRUE;
                }

                // Validation fails
                return FALSE;
        }

        // --------------------------------------------------------------------
        
        /**
         * Traverse a multidimensional $_POST array index until the data is found
         *
         * @access      private
         * @param       array
         * @param       array
         * @param       integer
         * @return      mixed
         */             
        function _reduce_array($array, $keys, $i = 0)
        {
                if (is_array($array))
                {
                        if (isset($keys[$i]))
                        {
                                if (isset($array[$keys[$i]]))
                                {
                                        $array = $this->_reduce_array($array[$keys[$i]], $keys, ($i+1));
                                }
                                else
                                {
                                        return NULL;
                                }
                        }
                        else
                        {
                                return $array;
                        }
                }
        
                return $array;
        }

        // --------------------------------------------------------------------
        
        /**
         * Re-populate the _POST array with our finalized and processed data
         *
         * @access      private
         * @return      null
         */             
        function _reset_post_array()
        {
                foreach ($this->_field_data as $field => $row)
                {
                        if ( ! is_null($row['postdata']))
                        {
                                if ($row['is_array'] == FALSE)
                                {
                                        if (isset($_POST[$row['field']]))
                                        {
                                                $_POST[$row['field']] = $this->prep_for_form($row['postdata']);
                                        }
                                }
                                else
                                {
                                        $post = '$_POST["';
                                        
                                        if (count($row['keys']) == 1)
                                        {
                                                $post .= current($row['keys']);
                                                $post .= '"]';
                                        }
                                        else
                                        {
                                                $i = 0;
                                                foreach ($row['keys'] as $val)
                                                {
                                                        if ($i == 0)
                                                        {
                                                                $post .= $val.'"]';
                                                                $i++;
                                                                continue;
                                                        }
                                                
                                                        $post .= '["'.$val.'"]';
                                                }
                                        }
                                        
                                        if (is_array($row['postdata']))
                                        {                                       
                                                $array = array();
                                                foreach ($row['postdata'] as $k => $v)
                                                {
                                                        $array[$k] = $this->prep_for_form($v);
                                                }
                                                
                                                $post .= ' = $array;';
                                        }
                                        else
                                        {                                               
                                                $post .= ' = "'.$this->prep_for_form($row['postdata']).'";';
                                        }

                                        eval($post);
                                }
                        }
                }
        }

        // --------------------------------------------------------------------
        
        /**
         * Executes the Validation routines
         *
         * @access      private
         * @param       array
         * @param       array
         * @param       mixed
         * @param       integer
         * @return      mixed
         */     
        function _execute($row, $rules, $postdata = NULL, $cycles = 0)
        {
                // If the $_POST data is an array we will run a recursive call
                if (is_array($postdata))
                { 
                        foreach ($postdata as $key => $val)
                        {
                                $this->_execute($row, $rules, $val, $cycles);
                                $cycles++;
                        }
                        
                        return;
                }
                
                // --------------------------------------------------------------------

                // If the field is blank, but NOT required, no further tests are necessary
                $callback = FALSE;
                if ( ! in_array('required', $rules) AND is_null($postdata))
                {
                        // Before we bail out, does the rule contain a callback?
                        if (preg_match("/(callback_\w+)/", implode(' ', $rules), $match))
                        {
                                $callback = TRUE;
                                $rules = (array('1' => $match[1]));
                        }
                        else
                        {
                                return;
                        }
                }

                // --------------------------------------------------------------------
                
                // Isset Test. Typically this rule will only apply to checkboxes.
                if (is_null($postdata) AND $callback == FALSE)
                {
                        if (in_array('isset', $rules, TRUE) OR in_array('required', $rules))
                        {
                                // Set the message type
                                $type = (in_array('required', $rules)) ? 'required' : 'isset';
                        
                                if ( ! isset($this->_error_messages[$type]))
                                {
                                        if (FALSE === ($line = $this->CI->lang->line($type)))
                                        {
                                                $line = 'The field was not set';
                                        }                                                       
                                }
                                else
                                {
                                        $line = $this->_error_messages[$type];
                                }
                                
                                // Build the error message
                                $message = sprintf($line, $this->_translate_fieldname($row['label']));

                                // Save the error message
                                $this->_field_data[$row['field']]['error'] = $message;
                                
                                if ( ! isset($this->_error_array[$row['field']]))
                                {
                                        $this->_error_array[$row['field']] = $message;
                                }
                        }
                                        
                        return;
                }

                // --------------------------------------------------------------------

                // Cycle through each rule and run it
                foreach ($rules As $rule)
                {
                        $_in_array = FALSE;
                        
                        // We set the $postdata variable with the current data in our master array so that
                        // each cycle of the loop is dealing with the processed data from the last cycle
                        if ($row['is_array'] == TRUE AND is_array($this->_field_data[$row['field']]['postdata']))
                        {
                                // We shouldn't need this safety, but just in case there isn't an array index
                                // associated with this cycle we'll bail out
                                if ( ! isset($this->_field_data[$row['field']]['postdata'][$cycles]))
                                {
                                        continue;
                                }
                        
                                $postdata = $this->_field_data[$row['field']]['postdata'][$cycles];
                                $_in_array = TRUE;
                        }
                        else
                        {
                                $postdata = $this->_field_data[$row['field']]['postdata'];
                        }

                        // --------------------------------------------------------------------
        
                        // Is the rule a callback?                      
                        $callback = FALSE;
                        if (substr($rule, 0, 9) == 'callback_')
                        {
                                $rule = substr($rule, 9);
                                $callback = TRUE;
                        }
                        
                        // Strip the parameter (if exists) from the rule
                        // Rules can contain a parameter: max_length[5]
                        $param = FALSE;
                        if (preg_match("/(.*?)\[(.*?)\]/", $rule, $match))
                        {
                                $rule   = $match[1];
                                $param  = $match[2];
                        }
                        
                        // Call the function that corresponds to the rule
                        if ($callback === TRUE)
                        {
                                if ( ! method_exists($this->CI, $rule))
                                {               
                                        continue;
                                }
                                
                                // Run the function and grab the result
                                $result = $this->CI->$rule($postdata, $param);

                                // Re-assign the result to the master data array
                                if ($_in_array == TRUE)
                                {
                                        $this->_field_data[$row['field']]['postdata'][$cycles] = (is_bool($result)) ? $postdata : $result;
                                }
                                else
                                {
                                        $this->_field_data[$row['field']]['postdata'] = (is_bool($result)) ? $postdata : $result;
                                }
                        
                                // If the field isn't required and we just processed a callback we'll move on...
                                if ( ! in_array('required', $rules, TRUE) AND $result !== FALSE)
                                {
                                        return;
                                }
                        }
                        else
                        {                               
                                if ( ! method_exists($this, $rule))
                                {
                                        // If our own wrapper function doesn't exist we see if a native PHP function does. 
                                        // Users can use any native PHP function call that has one param.
                                        if (function_exists($rule))
                                        {
                                                $result = $rule($postdata);
                                                                                        
                                                if ($_in_array == TRUE)
                                                {
                                                        $this->_field_data[$row['field']]['postdata'][$cycles] = (is_bool($result)) ? $postdata : $result;
                                                }
                                                else
                                                {
                                                        $this->_field_data[$row['field']]['postdata'] = (is_bool($result)) ? $postdata : $result;
                                                }
                                        }
                                                                                
                                        continue;
                                }

                                $result = $this->$rule($postdata, $param);

                                if ($_in_array == TRUE)
                                {
                                        $this->_field_data[$row['field']]['postdata'][$cycles] = (is_bool($result)) ? $postdata : $result;
                                }
                                else
                                {
                                        $this->_field_data[$row['field']]['postdata'] = (is_bool($result)) ? $postdata : $result;
                                }
                        }
                                                        
                        // Did the rule test negatively?  If so, grab the error.
                        if ($result === FALSE)
                        {                       
                                if ( ! isset($this->_error_messages[$rule]))
                                {
                                        if (FALSE === ($line = $this->CI->lang->line($rule)))
                                        {
                                                $line = 'Unable to access an error message corresponding to your field name.';
                                        }                                               
                                }
                                else
                                {
                                        $line = $this->_error_messages[$rule];
                                }

                                // Build the error message
                                $message = sprintf($line, $this->_translate_fieldname($row['label']), $param);

                                // Save the error message
                                $this->_field_data[$row['field']]['error'] = $message;
                                
                                if ( ! isset($this->_error_array[$row['field']]))
                                {
                                        $this->_error_array[$row['field']] = $message;
                                }
                                
                                return;
                        }
                }
        }

        // --------------------------------------------------------------------
        
        /**
         * Translate a field name
         *
         * @access      private
         * @param       string  the field name
         * @return      string
         */     
        function _translate_fieldname($fieldname)
        {
                // Do we need to translate the field name?
                // We look for the prefix lang: to determine this
                if (substr($fieldname, 0, 5) == 'lang:')
                {
                        // Grab the variable
                        $line = substr($fieldname, 5);                  
                        
                        // Were we able to translate the field name?  If not we use $line
                        if (FALSE === ($fieldname = $this->CI->lang->line($line)))
                        {
                                return $line;
                        }
                }

                return $fieldname;
        }

        // --------------------------------------------------------------------
        
        /**
         * Get the value from a form
         *
         * Permits you to repopulate a form field with the value it was submitted
         * with, or, if that value doesn't exist, with the default
         *
         * @access      public
         * @param       string  the field name
         * @param       string
         * @return      void
         */     
        function set_value($field = '', $default = '')
        {
                if ( ! isset($this->_field_data[$field]))
                {
                        return $default;
                }
                
                return $this->_field_data[$field]['postdata'];
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Set Select
         *
         * Enables pull-down lists to be set to the value the user
         * selected in the event of an error
         *
         * @access      public
         * @param       string
         * @param       string
         * @return      string
         */     
        function set_select($field = '', $value = '', $default = FALSE)
        {               
                if ( ! isset($this->_field_data[$field]) OR ! isset($this->_field_data[$field]['postdata']))
                {
                        if ($default === TRUE AND count($this->_field_data) === 0)
                        {
                                return ' selected="selected"';
                        }
                        return '';
                }
        
                $field = $this->_field_data[$field]['postdata'];
                
                if (is_array($field))
                {
                        if ( ! in_array($value, $field))
                        {
                                return '';
                        }
                }
                else
                {
                        if (($field == '' OR $value == '') OR ($field != $value))
                        {
                                return '';
                        }
                }
                        
                return ' selected="selected"';
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Set Radio
         *
         * Enables radio buttons to be set to the value the user
         * selected in the event of an error
         *
         * @access      public
         * @param       string
         * @param       string
         * @return      string
         */     
        function set_radio($field = '', $value = '', $default = FALSE)
        {
                if ( ! isset($this->_field_data[$field]) OR ! isset($this->_field_data[$field]['postdata']))
                {
                        if ($default === TRUE AND count($this->_field_data) === 0)
                        {
                                return ' checked="checked"';
                        }
                        return '';
                }
        
                $field = $this->_field_data[$field]['postdata'];
                
                if (is_array($field))
                {
                        if ( ! in_array($value, $field))
                        {
                                return '';
                        }
                }
                else
                {
                        if (($field == '' OR $value == '') OR ($field != $value))
                        {
                                return '';
                        }
                }
                        
                return ' checked="checked"';
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Set Checkbox
         *
         * Enables checkboxes to be set to the value the user
         * selected in the event of an error
         *
         * @access      public
         * @param       string
         * @param       string
         * @return      string
         */     
        function set_checkbox($field = '', $value = '', $default = FALSE)
        {
                if ( ! isset($this->_field_data[$field]) OR ! isset($this->_field_data[$field]['postdata']))
                {
                        if ($default === TRUE AND count($this->_field_data) === 0)
                        {
                                return ' checked="checked"';
                        }
                        return '';
                }
        
                $field = $this->_field_data[$field]['postdata'];
                
                if (is_array($field))
                {
                        if ( ! in_array($value, $field))
                        {
                                return '';
                        }
                }
                else
                {
                        if (($field == '' OR $value == '') OR ($field != $value))
                        {
                                return '';
                        }
                }
                        
                return ' checked="checked"';
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Required
         *
         * @access      public
         * @param       string
         * @return      bool
         */
        function required($str)
        {
                if ( ! is_array($str))
                {
                        return (trim($str) == '') ? FALSE : TRUE;
                }
                else
                {
                        return ( ! empty($str));
                }
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Match one field to another
         *
         * @access      public
         * @param       string
         * @param       field
         * @return      bool
         */
        function matches($str, $field)
        {
                if ( ! isset($_POST[$field]))
                {
                        return FALSE;                           
                }
                
                $field = $_POST[$field];

                return ($str !== $field) ? FALSE : TRUE;
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Minimum Length
         *
         * @access      public
         * @param       string
         * @param       value
         * @return      bool
         */     
        function min_length($str, $val)
        {
                if (preg_match("/[^0-9]/", $val))
                {
                        return FALSE;
                }

                if (function_exists('mb_strlen'))
                {
                        return (mb_strlen($str) < $val) ? FALSE : TRUE;         
                }
        
                return (strlen($str) < $val) ? FALSE : TRUE;
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Max Length
         *
         * @access      public
         * @param       string
         * @param       value
         * @return      bool
         */     
        function max_length($str, $val)
        {
                if (preg_match("/[^0-9]/", $val))
                {
                        return FALSE;
                }

                if (function_exists('mb_strlen'))
                {
                        return (mb_strlen($str) > $val) ? FALSE : TRUE;         
                }
        
                return (strlen($str) > $val) ? FALSE : TRUE;
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Exact Length
         *
         * @access      public
         * @param       string
         * @param       value
         * @return      bool
         */     
        function exact_length($str, $val)
        {
                if (preg_match("/[^0-9]/", $val))
                {
                        return FALSE;
                }

                if (function_exists('mb_strlen'))
                {
                        return (mb_strlen($str) != $val) ? FALSE : TRUE;                
                }
        
                return (strlen($str) != $val) ? FALSE : TRUE;
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Valid Email
         *
         * @access      public
         * @param       string
         * @return      bool
         */     
        function valid_email($str)
        {
                return ( ! preg_match("/^([a-z0-9\+_\-]+)(\.[a-z0-9\+_\-]+)*@([a-z0-9\-]+\.)+[a-z]{2,6}$/ix", $str)) ? FALSE : TRUE;
        }

        // --------------------------------------------------------------------
        
        /**
         * Valid Emails
         *
         * @access      public
         * @param       string
         * @return      bool
         */     
        function valid_emails($str)
        {
                if (strpos($str, ',') === FALSE)
                {
                        return $this->valid_email(trim($str));
                }
                
                foreach(explode(',', $str) as $email)
                {
                        if (trim($email) != '' && $this->valid_email(trim($email)) === FALSE)
                        {
                                return FALSE;
                        }
                }
                
                return TRUE;
        }

        // --------------------------------------------------------------------
        
        /**
         * Validate IP Address
         *
         * @access      public
         * @param       string
         * @return      string
         */
        function valid_ip($ip)
        {
                return $this->CI->input->valid_ip($ip);
        }

        // --------------------------------------------------------------------
        
        /**
         * Alpha
         *
         * @access      public
         * @param       string
         * @return      bool
         */             
        function alpha($str)
        {
                return ( ! preg_match("/^([a-z])+$/i", $str)) ? FALSE : TRUE;
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Alpha-numeric
         *
         * @access      public
         * @param       string
         * @return      bool
         */     
        function alpha_numeric($str)
        {
                return ( ! preg_match("/^([a-z0-9])+$/i", $str)) ? FALSE : TRUE;
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Alpha-numeric with underscores and dashes
         *
         * @access      public
         * @param       string
         * @return      bool
         */     
        function alpha_dash($str)
        {
                return ( ! preg_match("/^([-a-z0-9_-])+$/i", $str)) ? FALSE : TRUE;
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Numeric
         *
         * @access      public
         * @param       string
         * @return      bool
         */     
        function numeric($str)
        {
                return (bool)preg_match( '/^[\-+]?[0-9]*\.?[0-9]+$/', $str);

        }

        // --------------------------------------------------------------------

    /**
     * Is Numeric
     *
     * @access    public
     * @param    string
     * @return    bool
     */
    function is_numeric($str)
    {
        return ( ! is_numeric($str)) ? FALSE : TRUE;
    } 

        // --------------------------------------------------------------------
        
        /**
         * Integer
         *
         * @access      public
         * @param       string
         * @return      bool
         */     
        function integer($str)
        {
                return (bool)preg_match( '/^[\-+]?[0-9]+$/', $str);
        }
        
        // --------------------------------------------------------------------

    /**
     * Is a Natural number  (0,1,2,3, etc.)
     *
     * @access  public
     * @param   string
     * @return  bool
     */
    function is_natural($str)
    {   
                return (bool)preg_match( '/^[0-9]+$/', $str);
    }

        // --------------------------------------------------------------------

    /**
     * Is a Natural number, but not a zero  (1,2,3, etc.)
     *
     * @access  public
     * @param   string
     * @return  bool
     */
        function is_natural_no_zero($str)
    {
        if ( ! preg_match( '/^[0-9]+$/', $str))
        {
                return FALSE;
        }
        
        if ($str == 0)
        {
                return FALSE;
        }
    
                return TRUE;
    }
        
        // --------------------------------------------------------------------
        
        /**
         * Valid Base64
         *
         * Tests a string for characters outside of the Base64 alphabet
         * as defined by RFC 2045 http://www.faqs.org/rfcs/rfc2045
         *
         * @access      public
         * @param       string
         * @return      bool
         */
        function valid_base64($str)
        {
                return (bool) ! preg_match('/[^a-zA-Z0-9\/\+=]/', $str);
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Prep data for form
         *
         * This function allows HTML to be safely shown in a form.
         * Special characters are converted.
         *
         * @access      public
         * @param       string
         * @return      string
         */
        function prep_for_form($data = '')
        {
                if (is_array($data))
                {
                        foreach ($data as $key => $val)
                        {
                                $data[$key] = $this->prep_for_form($val);
                        }
                        
                        return $data;
                }
                
                if ($this->_safe_form_data == FALSE OR $data === '')
                {
                        return $data;
                }

                return str_replace(array("'", '"', '<', '>'), array("&#39;", "&quot;", '&lt;', '&gt;'), stripslashes($data));
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Prep URL
         *
         * @access      public
         * @param       string
         * @return      string
         */     
        function prep_url($str = '')
        {
                if ($str == 'http://' OR $str == '')
                {
                        return '';
                }
                
                if (substr($str, 0, 7) != 'http://' && substr($str, 0, 8) != 'https://')
                {
                        $str = 'http://'.$str;
                }
                
                return $str;
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Strip Image Tags
         *
         * @access      public
         * @param       string
         * @return      string
         */     
        function strip_image_tags($str)
        {
                return $this->CI->input->strip_image_tags($str);
        }
        
        // --------------------------------------------------------------------
        
        /**
         * XSS Clean
         *
         * @access      public
         * @param       string
         * @return      string
         */     
        function xss_clean($str)
        {
                return $this->CI->input->xss_clean($str);
        }
        
        // --------------------------------------------------------------------
        
        /**
         * Convert PHP tags to entities
         *
         * @access      public
         * @param       string
         * @return      string
         */     
        function encode_php_tags($str)
        {
                return str_replace(array('<?php', '<?PHP', '<?', '?>'),  array('&lt;?php', '&lt;?PHP', '&lt;?', '?&gt;'), $str);
        }

}
// END Form Validation Class

/* End of file Form_validation.php */
/* Location: ./system/libraries/Form_validation.php */