error in uploading image file - php

Question

i am trying to make a user profile and add a profile picture functionality to it in codeigniter,i simpy copy pasted the file upload code given in the documentation but it is showing error.my view file is
<?php echo form_open_multipart('upload/do_upload');?>
<input type="file" name="userfile" size="20" />
<br /><br />
<input type="submit" value="upload" />
my controller is
<?php
class Upload extends CI_Controller {
public function __construct()
{
parent::__construct();
$this->load->helper(array('form', 'url'));
$this->load->library('upload');
}
public function do_upload()
{
$config['upload_path'] = './images/';
$config['allowed_types'] = 'gif|jpg|jpeg|png';
$config['max_size'] = 100;
$config['max_width'] = 1024;
$config['max_height'] = 768;
$this->load->library('upload', $config);
if ( ! $this->upload->do_upload('userfile'))
{
$error = array('error' => $this->upload->display_errors());
echo'not happening';
}
else
{
$data = array('upload_data' => $this->upload->data());
$this->load->view('upload_success', $data);
}
}
}
?>
it is showing error over here i mean it is echoing 'not happening',which means it is not uploading.if someone can please help me,it will be great.

Answer 1

Why not you check what is the exact error? I have just updated the code to track exact error what codeigniter is returning.
if ( ! $this->upload->do_upload('userfile'))
{
$error = array('error' => $this->upload->display_errors());
echo '<pre>';
print_r($this->upload->display_errors());
}

Answer 2

You have loaded the library twice sometimes I found causes issues you have placed one in the constructor and one in the function
Try like below and use $this->upload->initialize($config); in the function and load library in the __constructor.
https://www.codeigniter.com/user_guide/libraries/file_uploading.html#preferences
<?php
class Upload extends CI_Controller {
public function __construct()
{
parent::__construct();
$this->load->helper(array('form', 'url'));
$this->load->library('upload');
}
public function do_upload()
{
$config['upload_path'] = './images/';
$config['allowed_types'] = 'gif|jpg|jpeg|png';
$config['max_size'] = 5000;
$config['max_width'] = 0;
$config['max_height'] = 0;
$this->upload->initialize($config);
if ( ! $this->upload->do_upload('userfile'))
{
$error = array('error' => $this->upload->display_errors());
echo'not happening';
}
else
{
$data = array('upload_data' => $this->upload->data());
$this->load->view('upload_success', $data);
}
}
}
Note no need to close codeigniter controllers and models with ?> as
says in user guide
application
// Where you upload images to
images
system
index.php