Images are not uploading - php

Question

i am trying to upload an image in codigniter but unable to do so when I try it shows me an error array to string conversion
<?php
public function do_upload() {
$config['upload_path'] = base_url().'assets/uploads/';
$config['allowed_types'] = 'gif|jpg|png';
$config['max_size'] = '100';
$config['max_width'] = '1024';
$config['max_height'] = '768';
$this->load->library('upload', $config);
$this->upload->do_upload();
if (!$this->upload->do_upload()) {
$error = array('error' => $this->upload->display_errors());
$this->session->set_flashdata('success_msg', $error);
redirect('admin/theme');
} else {
$data = array('upload_data' => $this->upload->data());
$this->load->view('upload_success', $data);
}
}
?>

Answer 1

base_url() is return HTTP path not directory path, you should use directory path for upload content.
change
$config['upload_path'] = base_url().'assets/uploads/';
to
$config['upload_path'] = getcwd().'assets/uploads/';
you can use getcwd() native PHP function to get project root directory, and CI is also provides constant variable FCPATH for root directory.

Answer 2

Array to string conversion usually shows up, when you try to echo an Array.
so it seems, that the problem lies on this line:
echo validation_errors();
To avoid this error but still print out the values in the array use Foreach().
This Code should solve your problem:
foreach (validation_errors() as $error) {
//I assume you get an array as a return value
echo $error;
}
EDIT
This answer doesn't help anymore, as the author edited his question

Answer 3

You are uploding your files two time. After first uploding every thing is vanished and you have nothing to upload
$this->upload->do_upload();// first time
if (!$this->upload->do_upload()) {// second time
$error = array('error' => $this->upload->display_errors());
$this->session->set_flashdata('success_msg', $error);
redirect('admin/theme');
}
Just comment it
// $this->upload->do_upload();// comment this line
EDIT
You can send your message into set_flashdata() as
if (!$this->upload->do_upload('file_name')) {// add file name here
$error = $this->upload->display_errors();// remove array from here
$this->session->set_flashdata('success_msg', $error);
redirect('admin/theme');
}
To read a flashdata variable:
$this->session->flashdata('success_msg');