I'm trying to extend the CodeIgniter Form Validation library

Question

This is my custom validation function. It uses geocoding from a Google Maps CodeIgniter library to check if a location exists.

public function address_check($str)
{
    $this->load->library('GMap');
    $this->gmap->GoogleMapAPI();

    // this method checks the cache and returns the cached response if available
    $geocodes = $this->gmap->getGeoCode("{$str}, United States");
    
    $this->form_validation->set_message('address_check', 'The %s field contains an invalid address');

    if (empty($geocodes))
    {
        return FALSE;
    }
    else
    {
        return TRUE;
    }
}

If I place the function above inside my Controller along with the following rule, it works perfectly well.

$this->load->library('form_validation');
$this->form_validation->set_rules('location', 'Location', 'callback_address_check');

---

Now I simply want to move it out of my Controller. So I'm trying to extend my CodeIgniter Form Validation library as per this SO answer and the CI documentation.

I created a file here: /codeigniter/application/libraries/MY_Form_validation.php:

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class MY_Form_validation extends CI_Form_validation {

    public function __construct()
    {
        parent::__construct();
    }

    public function address_check($str)
    {
        $this->load->library('GMap');
        $this->gmap->GoogleMapAPI();

        // this method checks the cache and returns the cached response if available
        $geocodes = $this->gmap->getGeoCode("{$str}, United States");

        $this->form_validation->set_message('address_check', 'The %s field contains an invalid address');
        
        if (empty($geocodes))
        {
            return FALSE;
        }
        else
        {
            return TRUE;
        }
    }

}

And from within my controller, I am setting the rule like this...

$this->load->library('form_validation');
$this->form_validation->set_rules('location', 'Location', 'address_check');

The first problem I found and solved myself was that nothing was happening because that SO answer incorrectly specified the file name to be My_Form_validation.php where it should have been MY_Form_validation.php

Now that the function is being called, the new problem is that I am getting the following error:

Message: Undefined property: MY_Form_validation::$load

Filename: libraries/MY_Form_validation.php

Line Number: 12

This is line 12:

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

I can't access a library from within a library? What's the proper way to fix this? I'd prefer not to auto-load the GMap library since I won't be using it all the time. Any other problems within my method?

Answer 1

Use this:

$CI =& get_instance();
$CI->load->library('GMap');

And then use it like:

$CI->gmap->GoogleMapAPI();

You have to do it that way, because Form Validation is not like CI Model or Controller class, it's only library.