how to modify <select required> to form_dropdown in codeigniter - php

Question

according to the question asked by Outliers here, and according to the answer posted by Adr
echo form_dropdown('salutation', $salutationOptions, '', 'required="required"');
i've tried similar line of code when creating form_dropdown in controller of code igniter, i do it like this
$code = array(
'type' => 'text',
'id' => 'productcode',
'name' => 'productcode',
'class' => 'form-control',
'required'=> 'required'
);
$form['open'] = form_open_multipart('Mould/saveeditproduct');
$form['code'] = form_input($code);
$form['category'] = form_dropdown('category',$category,'','id="category" class="form-control" required="required"');
$form['submit'] = form_input($submit);
$form['close'] = form_close();
i try to run the program, i found that the 'required' property is worked well in form_input, but does not work in form_dropdown. so, how can i fix this? thank you

Answer 1

The problem was that you assigned a value for first option in dropdown (----- Select Category -----) as 0
Try this code:
// $data['category'] = array( array('idcategory' => 4,'categoryname' => 'new'),
// array('idcategory' => 2,'categoryname' => 'old'));
$data['category'] = $this->Mouldmodel->getallcategory();
$category[] = array();
$category[''] = '----- Select Category -----';
foreach($data['category'] as $dm){
$category[$dm['idcategory']] = $dm['categoryname'];
}