codeigniter file upload - optional?

I'm sure this is sim开发者_如何学Gople but I can't see how to make uploading a file with CI optional.

If you leave the file input box empty, the error "You didn't choose an upload file" appears.

The reason I want it to be optional is that my form edits a directory type listing, and I don't need to upload the image each time I edit the listing.

Is there a way to remove the "required" error handling on the file class

---

Use the following:

<?php if ( $_FILES AND $_FILES['field_name']['name'] ) 
{
    // Upload the file
}

---

codeigniter file upload optionally ...works perfect..... :)

---------- controller ---------

function file()
{
 $this->load->view('includes/template', $data);
}

function valid_file()
{
 $this->form_validation->set_rules('userfile', 'File', 'trim|xss_clean');

 if ($this->form_validation->run()==FALSE) 
 {
    $this->file();
 }
 else
 {
  $config['upload_path']   = './documents/';
  $config['allowed_types'] = 'gif|jpg|png|docx|doc|txt|rtf';
  $config['max_size']      = '1000';
  $config['max_width']     = '1024';
  $config['max_height']    = '768';

  $this->load->library('upload', $config);

  if ( !$this->upload->do_upload('userfile',FALSE))
  {
    $this->form_validation->set_message('checkdoc', $data['error'] = $this->upload->display_errors());

    if($_FILES['userfile']['error'] != 4)
    {
        return false;
    }

  }
  else
  {
    return true;
  }
}

i just use this lines which makes it optionally,

if($_FILES['userfile']['error'] != 4)
{
 return false;
}

$_FILES['userfile']['error'] != 4 is for file required to upload.

you can u make it unneccessory by using $_FILES['userfile']['error'] != 4 , then it will pass this error for file required and works great with other types of errors if any by using return false , hope it works for u ....

---

Use this code in the controller before calling do_upload()

if (is_uploaded_file($_FILES['field_name']['tmp_name'])) {
    // your code here
}

---

Use This Code :-

$config['upload_path'] = 'assets/img/';
        $config['allowed_types'] = 'gif|jpg|png|jpeg';
        $this->load->library('upload', $config);
    // Upload the file
        if ($this->upload->do_upload('Image')){
            $dataimage = $this->upload->data();
                $data = array(
                   'image' => $dataimage['file_name'],
                   'UserName' => $this->input->post('UserName'),
                   'Password' => $this->input->post('Password'),
                   'xid' => $this->input->post('xid')
                );
        }
        else{
               /*$out['msg'] = show_err_msg($this->upload->display_errors());
               echo json_encode($out);
               exit();*/
                $data = array(
                   'image' => NULL,
                   'UserName' => $this->input->post('UserName'),
                   'Password' => $this->input->post('Password'),
                   'xid' => $this->input->post('xid')
                );
        }