How to output uploading errors as flashdata - CodeIgniter - codeigniter

Question

I'm wanting to display any errors produced while uploading a file by redirecting the user back to the same page they used to upload the file. The thing is that I pre-populate some inputs on that page, so I can't use redirect(controller/method_to_load_page) as that wouldn't carry out the data population.
Using $this->load->view('add_page',$error); won't work either (the way that I'm using it), because although that will show the errors, it won't show the input fields with the pre-populated data.
This is the method in my controller which loads the form to upload a file and other fields:
public function add_products_page()
{
//get each categories subcategory and place them in their own variable
$data['categories1'] = $this->admin_model->getSubcategories('1');
$data['error'] = '';
$this->load->view('add_page',$data);
}
And from that page, the user can fill in the form and choose an image. The form will then be submitted to this method in the same controller:
public function add_book()
{
$id = $this->admin_model->add_book();
$config['file_name'] = $id;
$config['upload_path'] = './images/';
$config['allowed_types'] = 'jpg';
$this->load->library('upload', $config);
if ( ! $this->upload->do_upload())
{
$error = array('error' => $this->upload->display_errors());
$this->load->view('add_page', $error);
}
else
{
redirect('admin/add_products_page', 'refresh');
}
}
If there are no errors, the redirect to add_products_page() method is okay, however when there's an error, the view 'add_page' is loaded and the errors are shown, but my pre-populated field isn't populated anymore because the method to do that isn't being called.
So I really would like to know how I can both load my view by calling the method add_products_page to populate my input fields, and also show errors when they occur. Please if someone could help I would appreciate it greatly.

Answer 1

Why post to a different method and then redirect? You can handle it all in the same method.
public function add_products_page()
{
if ($this->input->server('REQUEST_METHOD') == 'POST')
{
$result = $this->_add_book();
if ($result['is_error'])
{
// TODO: whatever it takes to show an error message
$data['error'] = $result['message'];
}
else
{
// TODO: whatever it takes to show a success message
$data['error'] = '';
}
}
//get each categories subcategory and place them in their own variable
$data['categories1'] = $this->admin_model->getSubcategories('1');
$this->load->view('add_page',$data);
}
public function _add_book() // add underscore so it's not directly accessible
{
$result = array(
'is_error' => TRUE,
'message' => '',
);
$id = $this->admin_model->add_book();
$config['file_name'] = $id;
$config['upload_path'] = './images/';
$config['allowed_types'] = 'jpg';
$this->load->library('upload', $config);
if ( ! $this->upload->do_upload())
{
$error = array('error' => $this->upload->display_errors());
// set an error message
$result['message'] = $error;
}
else
{
// set a success message
$result['is_error'] = FALSE;
$result['message'] = 'SOME SUCCESS MSG';
}
return $result;
}