You can't. You would need to extend CI's Form Helper and modify
form_dropdown to accept other attributes like ID's
you will have to extend the helper .
to extend the native Form Helper you'll create a file named
application/helpers/MY_form_helper.php, and add or override
functions:
if you want to override function form_dropdown
simply write the function the way you want in MY_form_helper.php
here is the base function
if ( ! function_exists('form_dropdown'))
{
function form_dropdown($name = '', $options = array(), $selected = array(), $extra = '')
{
if ( ! is_array($selected))
{
$selected = array($selected);
}
// If no selected state was submitted we will attempt to set it automatically
if (count($selected) === 0)
{
// If the form name appears in the $_POST array we have a winner!
if (isset($_POST[$name]))
{
$selected = array($_POST[$name]);
}
}
if ($extra != '') $extra = ' '.$extra;
$multiple = (count($selected) > 1 && strpos($extra, 'multiple') === FALSE) ? ' multiple="multiple"' : '';
$form = '<select name="'.$name.'"'.$extra.$multiple.">\n";
foreach ($options as $key => $val)
{
$key = (string) $key;
if (is_array($val) && ! empty($val))
{
$form .= '<optgroup label="'.$key.'">'."\n";
foreach ($val as $optgroup_key => $optgroup_val)
{
$sel = (in_array($optgroup_key, $selected)) ? ' selected="selected"' : '';
$form .= '<option value="'.$optgroup_key.'"'.$sel.'>'.(string) $optgroup_val."</option>\n";
}
$form .= '</optgroup>'."\n";
}
else
{
$sel = (in_array($key, $selected)) ? ' selected="selected"' : '';
$form .= '<option value="'.$key.'"'.$sel.'>'.(string) $val."</option>\n";
}
}
$form .= '</select>';
return $form;
}
}
you have to edit this part ,
foreach ($options as $key => $val)
{
$key = (string) $key;
if (is_array($val) && ! empty($val))
{
$form .= '<optgroup label="'.$key.'">'."\n";
foreach ($val as $optgroup_key => $optgroup_val)
{
$sel = (in_array($optgroup_key, $selected)) ? ' selected="selected"' : '';
$form .= '<option value="'.$optgroup_key.'"'.$sel.'>'.(string) $optgroup_val."</option>\n";
}
$form .= '</optgroup>'."\n";
}
else
{
$sel = (in_array($key, $selected)) ? ' selected="selected"' : '';
$form .= '<option value="'.$key.'"'.$sel.'>'.(string) $val."</option>\n";
}
}
as you can see , only the option's value attribute is set by the function , you can edit this code and
do the thing you want ,
try it , if you could not do it , tell me i ll help you , but first give it a try :)