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An in_array() solution for form validation - El Forum - 06-30-2009

[eluser]Unknown[/eluser]
Hey,

I've been using CodeIgniter for a couple of days now as framework of a rather large application interacting with a couple of VoIP servers. So far it's been great.

However, I found one limitation in the form validation class. I like to filter a value of a selectbox against a whitelist array.

In its simplest form:

Code:
<?php
$white_list = array(1, 2, 3);

$post_result = $_POST['my_selectbox'];

if(!in_array($post_result, $white_list) die('No access here!');
?>

I discovered the Form_validation library has no such feature, so I decided to create one myself, which I would like to share with you all. Perhaps there's a better solution which one of you would want to share with me, instead?

First of all, I created a file in system/application/libraries called My_Form_validation.php:

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

/**
* My Validation class
*
* Adds a couple of validation rules, such as an in_array() check
*/
class My_Form_validation extends CI_Form_validation
{
    /**
     * Constructor
     *
     * @return    void
     */
    function My_Form_validation()
    {
        parent::CI_Form_validation();
    }
    
    /**
     * Apparantly, when writing a validation rule, it won't accept an array as param
     *
     * i.e.     $this->form_validation->set_rules('servers', 'servers', 'is_in_array['.$array.']');
     *
     * $array can't be an array... that's why we convert our array to a string first, using implode
     *
     * The 2nd parameter allows you to choose between array keys or just values
     *
     * @param     array
     * @param     bool
     * @return     string
     */
    function prepare_array($array, $keys = true)
    {
        // We need to create a string out of this array
        if(is_array($array) && count($array))
        {
            if($keys)
            {
                $array = array_keys($array);
            }
            
            $string = implode(',', $array);
        }
        
        return $string;
    }
    
    /**
     * Basically the in_array() php function, but then wrapped in the CI_Validation class
     *
     * We receive a comma seperated string (imploded), which we will need to explode again
     *
     * @param     mixed
     * @param     string
     * @return    bool
     */
    function is_in_array($val = '', $array = '')
    {
        $array = explode(',', $array);
        return in_array($val, $array);
    }
}

/* End of file Isaeus_Form_validation.php */
/* Location: ./system/application/libraries/Isaeus_Form_validation.php */

Basically, the comments should say it all. When using:

Code:
$this->form_validation->set_rules('servers', 'servers', 'is_in_array['.$white_list.']');

$white_list can't be an array. That's why I created a function that will turn it into a comma seperated string, which should be called like this:

Code:
$white_list = $this->form_validation->prepare_array($servers);

Setting the 2nd parameter to false (default is true), $white_list will contain the array of just the values, so you don't need two seperate functions (in_array() and array_key_exists()).

Now I'll just need to think of a workaround for whenever a value might contain a comma, cause that will obviously mess things up. Ideally, I should make the delimiter configurable. Feel free to add to this.

An in_array() solution for form validation - El Forum - 06-30-2009

[eluser]Phil Sturgeon[/eluser]
Use something other than a comma then. ;-) The validation library is taking care of the join and the split so you could use the following.

Code:
$string = implode('[!!!--SUPERDOOPERFRICKINUNLIKLY--!!!]', $array);

Or possibly something a little shorter :-P

An in_array() solution for form validation - El Forum - 06-30-2009

[eluser]Unknown[/eluser]
Heh, yeah, I could actually just use something like that I guess Smile.