Code Igniter Custom Field Validation Not Working

问题:

I created a custom validation in Code Igniter. I have the following code but the is_FieldUnique validation is not working. Even if, I var_dump() the parameters still I am not getting the it was displaying. What am I doing wrong with my code below? I am not getting any return with the is_FieldUnique but the default validation is working fine like the required, min_length.

In application/libraries/Customfieldvalidation.php, I have this line of code below:

class Customfieldvalidation extends CI_Form_validation 
    {
        public function is_FieldUnique($str, $field)
        {
            var_dump($str);
            var_dump($field);
            list($table, $field)=explode('.', $field);
            $q = $this->CI->db->query("SHOW KEYS FROM $table WHERE Key_name = 'PRIMARY'")->row();
            $primary_key = $q->Column_name;
            if($this->CI->input->post($primary_key) > 0):
                $query = $this->CI->db->limit(1)->get_where($table, array($field => $str,$primary_key.' !='=>$this->CI->input->post($primary_key)));
            else:
                $query = $this->CI->db->limit(1)->get_where($table, array($field => $str));
            endif; 
            echo $query;
            exit();
            return $query->num_rows() === 0;
        }
    }

In my controller, I have this code:

class User extends CI_Controller 
{
    function __construct()
    {
        parent::__construct();
        $this->load->library('customfieldvalidation');
    }
    function _setRules()
    {
        $this->form_validation->set_rules('email_address', 'Email Address', 'required|valid_email|min_length[8]|is_FieldUnique[users.email_address]');
        $this->form_validation->set_message('is_FieldUnique', '* must have a unique value');
    }
}

What could be the reason that the custom field is not working? I know this could be pretty simple for everyone but I'm new to Codeigniter and starting to learn.

回答1:

You must correctly prefix your custom library if you are extending a native library. The default prefix is MY_ this can be changed in application/config/config.php, with this config: $config['subclass_prefix'] = 'MY_';.

So this:

class Customfieldvalidation extends CI_Form_validation

Should be:

class MY_Form_validation extends CI_Form_validation

Also ensure that the file name reflects this and is in the appropriate location:

application/libraries/MY_Form_validation.php

You'll also need a constructor to extend the parent class:

function __construct($rules = array())
{
    parent::__construct($rules);
}

Ensure that you're loading the library in your controller or autoload it. You don't need to include the class prefix when you load the library:

$this->load->library('form_validation');

I'm guessing you've added a few of the lines in your is_FieldUnique function for debugging, but you definitely don't want exit() before the return as this will exit the script and won't allow anything to be returned. It's also not clear to me what the function is returning (maybe I'm just being dim!), so a statement like this should help:

if ($query->num_rows() === 0)
{
    return TRUE;
}
else
{
    return FALSE;
}

You could also consider using a callback, which is a common way of adding your own validation rules.