Thread

Hello all,
  I am attempting to pass another argument along with with the form element to the set_rules

set_rules code:

$this->form_validation->set_rules('alias', 'Alias_Exist', 'callback_alias_exist_check[livestock.alias]', 'trim|xss_clean');

call back function:

function alias_exist_check($str, $val)
    {
        
        //echo 'value ' . $str;
        list($table, $column) = explode('.', $val, 2);    
          $query = $this->db->query("SELECT COUNT(*) AS count FROM $table WHERE $column = $str'");
          $row = $query->row();
        return ($row->count > 0) ? FALSE : TRUE;
          
    }

error:
A PHP Error was encountered

Severity: Notice

Message: Undefined offset: 1

Filename: controllers/validate_livestock.php

Line Number: 105

line 105:

list($table, $column) = explode('.', $val, 2);

I slapped that code together after searching google for examples.  I am new to the explode code, but do understand the purpose which is, split livestock.alias to variables.  However, I am receiving the error explained above.  I do not understand what the error means or how to fix this.  Any help is greatly appreciated.

-Thank You,
    Rich

According to me syntax is wrong try this :

$this->form_validation->set_rules(‘alias’, ‘Alias_Exist’, ‘trim|xss_clean|callback_alias_exist_check[livestock.alias]’);

Accordingly change your callback function. Second parameter is not all required in callback function in your case .

According to me syntax is wrong try this :

$this->form_validation->set_rules(‘alias’, ‘Alias_Exist’, ‘trim|xss_clean|callback_alias_exist_check[livestock.alias]’);

I tried your code and still receiving that error.  Also, I had to fix the quotes in your code syntax, but still having no luck.

-Rich

check your callback function now second parameter is not required.

The validation is always returning true so, I am attempting to echo out $table and $column for testing purposes.  The values are not echoing out so I do not know if the code is working as expected.  How do I echo out $table and $column?  Thank You.

-Rich

New code:

$this->form_validation->set_rules('alias','trim|xss_clean|callback_alias_exist_check[livestock.alias]');

        if ($this->form_validation->run() == FALSE)
        {
            //$this->load->view('false'); commented out for testing purposes
        }
        else
        { 
            //$this->load->view('true'); commented out for testing purposes
        }

    function alias_exist_check($str)
    {
        
        list($table, $column) = explode('.', $str, 2);    
          $query = $this->db->query("SELECT COUNT(*) AS count FROM $table WHERE $column = $str'");
          $row = $query->row();
        //return ($row->count > 0) ? FALSE : TRUE;
          echo $table . ' ' . $column;
    }

Go back to basics:

// check if first_item and second_item are equal
$this->form_validation->set_rules('first_item', 'FIRST ITEM', 'trim|xss_clean|callback_some_cb_function[' . $this->input->post('second_item') . ']');

if ($this->form_validation->run() == FALSE)
{
    // bad news
    echo 'FAIL';
}
else
{ 
    // yippee!
    echo 'GOOD';
}

function some_cb_function($str, $str2)
{
    
    // if first_item and second_item are equal
    if($str === $str2)
    {
        // return success
        return $str;
    }
    else
    {
        // set error message
        $this->form_validation->set_message('some_cb_function', 'No match');

        // return fail
        return FALSE;
    }
}

Add this code before you run the form validation:

$this->form_validation->set_rules('alias', 'Alias_Exist', 'trim|xss_clean|callback_alias_exist_check[livestock.alias]');

and add this function to your controller:

function alias_exist_check($value, $str)
{
   var_dump($value);
   var_dump($str);
   exit();
}

What does the output look like after you submit the form?

I’m confused. What is livestock.alias? There is no dollar sign in front of it. Is it defined somewhere?

It’s a string, nothing else, that’s passed as an additional parameter for the callback call. Just like you have additional parameters for other rules, e.g. min_length[5], you can have an additional parameter for callbacks.

In his case he passes a string which contains the table and the field he wants to check.

I don’t think it’s documented in the user guide, but it definetly works.

It’s a string, nothing else, that’s passed as an additional parameter for the callback call. Just like you have additional parameters for other rules, e.g. min_length[5], you can have an additional parameter for callbacks.

In his case he passes a string which contains the table and the field he wants to check.

I don’t think it’s documented in the user guide, but it definetly works.

I thought a string had to be quoted, so that was my confusion. Also, if the string is basically hard coded as an argument to the callback function, then there’s really no point in having it there. Maybe he/she is doing it that way for testing purposes.

Why is there no point?
It’s not hardcoded into the callback function but rather into the list of rules that are being applied to a certain field.

You can still use a different string for a different field:

$this->form_validation->set_rules('alias', 'Alias_Exist', 'trim|xss_clean|callback_alias_exist_check[livestock.alias]');  
$this->form_validation->set_rules('username', 'Username_Exist', 'trim|xss_clean|callback_alias_exist_check[user.name]');  
$this->form_validation->set_rules('foobar', 'Foobar_Exist', 'trim|xss_clean|callback_alias_exist_check[foo.bar]');

and if your callback function looks like this, then 3 different queries will be run:

function alias_exist_check($value, $str)
{
   $parts = explode('.', $str);
   $this->db->from($parts[0]);
   $this->db->where($parts[1], $value);
   $result = $this->db->get();

   echo $this->db->last_query();

   if($result->num_rows() > 0) {
      $this->form_validation->set_message('alias_exist_check', 'Already exists.');
      return FALSE;
   } else {
      return TRUE;
   }
}

Or even if you don’t have multiple fields in one form that you need to run this check on, you could move the callback function into your own controller class (MY_Controller) and use it in multiple controllers for different fields.

Btw: I would move the db related stuff into the model, but that’s up to you.

Yes, I see your point, and I think it’s actually a nice idea for some similar functionality in callback functions of my own. I was initially just confused because of the lack of quotes.

Why is there no point?
It’s not hardcoded into the callback function but rather into the list of rules that are being applied to a certain field.

You can still use a different string for a different field:

$this->form_validation->set_rules('alias', 'Alias_Exist', 'trim|xss_clean|callback_alias_exist_check[livestock.alias]');  
$this->form_validation->set_rules('username', 'Username_Exist', 'trim|xss_clean|callback_alias_exist_check[user.name]');  
$this->form_validation->set_rules('foobar', 'Foobar_Exist', 'trim|xss_clean|callback_alias_exist_check[foo.bar]');

and if your callback function looks like this, then 3 different queries will be run:

function alias_exist_check($value, $str)
{
   $parts = explode('.', $str);
   $this->db->from($parts[0]);
   $this->db->where($parts[1], $value);
   $result = $this->db->get();

   echo $this->db->last_query();

   if($result->num_rows() > 0) {
      $this->form_validation->set_message('alias_exist_check', 'Already exists.');
      return FALSE;
   } else {
      return TRUE;
   }
}

Or even if you don’t have multiple fields in one form that you need to run this check on, you could move the callback function into your own controller class (MY_Controller) and use it in multiple controllers for different fields.

Btw: I would move the db related stuff into the model, but that’s up to you.

As soon as I get the field value to validate with the database I will definitely move it to a model.

All the help and code presented to me does make sense, but the error message I am receiving does not.

line 106 is:

this->db->where($parts[1], $value);

set_rules:

$this->form_validation->set_rules('alias','alias_exist','trim|xss_clean|callback_alias_exist_check[livestock.alias]');

Call back function:

function alias_exist_check($value, $str)
  {

$parts = explode('.', $str);
$this->db->from($parts[0]);
$this->db->where($parts[1], $value);
$result = $this->db->get();

echo $this->db->last_query();
//return ($row->count > 0) ? FALSE : TRUE;
//echo $table . ' ' . $column;
}

error:

A PHP Error was encountered

Severity: Notice

Message: Undefined offset: 1

Filename: controllers/validate_livestock.php

Line Number: 106
A PHP Error was encountered

Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at /home/dickschi/public_html/lsms/system/libraries/Exceptions.php:166)

Filename: codeigniter/Common.php

Line Number: 356

This is a working example, which more or less confirms that your code should work:

<?php

// Test DB

/********************************************

CREATE TABLE IF NOT EXISTS `some_table` (
  `id` int(11) NOT NULL,
  `some_value` int(11) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

INSERT INTO `some_table` (`id`, `some_value`) VALUES
(1, 10),
(2, 20);

*********************************************/

class Test_validation extends CI_Controller {

    public function index()
    {
        $this->load->library('form_validation');
        $this->form_validation->set_rules('field_1', 'Field One', 'required|callback__field_one_checker[some_table.id]');

        if ($this->form_validation->run() == FALSE)
        {
            echo 'either no post submitted, or validation failed';

            if(validation_errors())
            {
                echo validation_errors();
            }
        }
        else
        {
            echo 'success';
        }

        echo '<form action="#" method="post">
                <input type="text" name="field_1" value="" />
                <input type="submit" value="submit" />
            </form>';
    }

    function _field_one_checker($field_one, $table_column)
    {
        /* THIS ALSO WORKS

        list($table_name, $column) = explode('.', $table_column);
        if($query = $this->db
                    ->where($column, $field_one)
                    ->limit(1)
                    ->get($table_name)
        )

        */

        $parts = explode('.', $table_column);
        if($query = $this->db
                    ->where($parts[1], $field_one)
                    ->limit(1)
                    ->get($parts[0])
        )
        {
            if($query->num_rows() > 0)
            {
                return $field_one;
            }
            else
            {
                $this->form_validation->set_message('_field_one_checker', 'Your value was not an ID in some_table');
                return FALSE;
            }
        }
        else
        {
            $this->form_validation->set_message('_field_one_checker', 'Query failed');
            return FALSE;
        }
    }
}