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File Uploading Class

CodeIgniter's File Uploading Class permits files to be uploaded. You can set various preferences, restricting the type and size of the files.

The Process

Uploading a file involves the following general process:

  • An upload form is displayed, allowing a user to select a file and upload it.
  • When the form is submitted, the file is uploaded to the destination you specify.
  • Along the way, the file is validated to make sure it is allowed to be uploaded based on the preferences you set.
  • Once uploaded, the user will be shown a success message.

To demonstrate this process here is brief tutorial. Afterward you'll find reference information.

Creating the Upload Form

Using a text editor, create a form called upload_form.php. In it, place this code and save it to your application/views/ folder:

<html>
<head>
<title>Upload Form</title>
</head>
<body>

<?php echo $error;?>

<?php echo form_open_multipart('upload/do_upload');?>

<input type="file" name="userfile" size="20" />

<br /><br />

<input type="submit" value="upload" />

</form>

</body>
</html>

You'll notice we are using a form helper to create the opening form tag. File uploads require a multipart form, so the helper creates the proper syntax for you. You'll also notice we have an $error variable. This is so we can show error messages in the event the user does something wrong.

The Success Page

Using a text editor, create a form called upload_success.php. In it, place this code and save it to your application/views/ folder:

<html>
<head>
<title>Upload Form</title>
</head>
<body>

<h3>Your file was successfully uploaded!</h3>

<ul>
<?php foreach ($upload_data as $item => $value):?>
<li><?php echo $item;?>: <?php echo $value;?></li>
<?php endforeach; ?>
</ul>

<p><?php echo anchor('upload', 'Upload Another File!'); ?></p>

</body>
</html>

The Controller

Using a text editor, create a controller called upload.php. In it, place this code and save it to your application/controllers/ folder:

<?php

class Upload extends CI_Controller {

    public function __construct()
    {
        parent::__construct();
        $this->load->helper(array('form', 'url'));
    }

    public function index()
    {
        $this->load->view('upload_form', array('error' => ' ' ));
    }

    public function do_upload()
    {
        $config['upload_path']      = './uploads/';
        $config['allowed_types']    = 'gif|jpg|png';
        $config['max_size']     = 100;
        $config['max_width']        = 1024;
        $config['max_height']       = 768;

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

        if ( ! $this->upload->do_upload())
        {
            $error = array('error' => $this->upload->display_errors());

            $this->load->view('upload_form', $error);
        }
        else
        {
            $data = array('upload_data' => $this->upload->data());

            $this->load->view('upload_success', $data);
        }
    }
}
?>

The Upload Folder

You'll need a destination folder for your uploaded images. Create a folder at the root of your CodeIgniter installation called uploads and set its file permissions to 777.

Try it!

To try your form, visit your site using a URL similar to this one:

example.com/index.php/upload/

You should see an upload form. Try uploading an image file (either a jpg, gif, or png). If the path in your controller is correct it should work.

Reference Guide

Initializing the Upload Class

Like most other classes in CodeIgniter, the Upload class is initialized in your controller using the $this->load->library function:

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

Once the Upload class is loaded, the object will be available using: $this->upload

Setting Preferences

Similar to other libraries, you'll control what is allowed to be upload based on your preferences. In the controller you built above you set the following preferences:

$config['upload_path'] = './uploads/';
$config['allowed_types'] = 'gif|jpg|png';
$config['max_size'] = '100';
$config['max_width'] = '1024';
$config['max_height'] = '768';

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

// Alternately you can set preferences by calling the initialize function. Useful if you auto-load the class:
$this->upload->initialize($config);

The above preferences should be fairly self-explanatory. Below is a table describing all available preferences.

Preferences

The following preferences are available. The default value indicates what will be used if you do not specify that preference.

Preference Default Value Options Description

upload_path

None

None

The path to the folder where the upload should be placed. The folder must be writable and the path can be absolute or relative.

allowed_types

None

None

The mime types corresponding to the types of files you allow to be uploaded. Usually the file extension can be used as the mime type. Separate multiple types with a pipe.

file_name

None

Desired file name

If set CodeIgniter will rename the uploaded file to this name. The extension provided in the file name must also be an allowed file type. If no extension is provided in the original file_name will be used.

overwrite

FALSE

TRUE/FALSE (boolean)

If set to true, if a file with the same name as the one you are uploading exists, it will be overwritten. If set to false, a number will be appended to the filename if another with the same name exists.

max_size

0

None

The maximum size (in kilobytes) that the file can be. Set to zero for no limit. Note: Most PHP installations have their own limit, as specified in the php.ini file. Usually 2 MB (or 2048 KB) by default.

max_width

0

None

The maximum width (in pixels) that the file can be. Set to zero for no limit.

max_height

0

None

The maximum height (in pixels) that the file can be. Set to zero for no limit.
max_filename 0 None The maximum length that a file name can be. Set to zero for no limit.

max_filename_increment

100

None

When overwrite is set to FALSE, use this to set the maximum filename increment for CodeIgniter to append to the filename.

encrypt_name

FALSE

TRUE/FALSE (boolean)

If set to TRUE the file name will be converted to a random encrypted string. This can be useful if you would like the file saved with a name that can not be discerned by the person uploading it.

remove_spaces

TRUE

TRUE/FALSE (boolean)

If set to TRUE, any spaces in the file name will be converted to underscores. This is recommended.

detect_mime

TRUE

TRUE/FALSE (boolean)

If set to TRUE, a server side detection of the file type will be performed to avoid code injection attacks. DO NOT disable this option unless you have no other option as that would cause a security risk.

Setting preferences in a config file

If you prefer not to set preferences using the above method, you can instead put them into a config file. Simply create a new file called the upload.php, add the $config array in that file. Then save the file in: config/upload.php and it will be used automatically. You will NOT need to use the $this->upload->initialize function if you save your preferences in a config file.

Function Reference

The following functions are available

$this->upload->do_upload()

Performs the upload based on the preferences you've set. Note: By default the upload routine expects the file to come from a form field called userfile, and the form must be a "multipart type:

<form method="post" action="some_action" enctype="multipart/form-data" />

If you would like to set your own field name simply pass its value to the do_upload function:

$field_name = "some_field_name";
$this->upload->do_upload($field_name);

$this->upload->display_errors()

Retrieves any error messages if the do_upload() function returned false. The function does not echo automatically, it returns the data so you can assign it however you need.

Formatting Errors

By default the above function wraps any errors within <p> tags. You can set your own delimiters like this:

$this->upload->display_errors('<p>', '</p>');

$this->upload->data()

This is a helper function that returns an array containing all of the data related to the file you uploaded. Here is the array prototype:

Array
(
    [file_name]    => mypic.jpg
    [file_type]    => image/jpeg
    [file_path]    => /path/to/your/upload/
    [full_path]    => /path/to/your/upload/jpg.jpg
    [raw_name]     => mypic
    [orig_name]    => mypic.jpg
    [client_name]  => mypic.jpg
    [file_ext]     => .jpg
    [file_size]    => 22.2
    [is_image]     => 1
    [image_width]  => 800
    [image_height] => 600
    [image_type]   => jpeg
    [image_size_str] => width="800" height="200"
)

To return one element from the array:

$this->upload->data('file_name');   // Returns: mypic.jpg

Explanation

Here is an explanation of the above array items.

Item Description file_name The name of the file that was uploaded including the file extension. file_type The file's Mime type file_path The absolute server path to the file full_path The absolute server path including the file name raw_name The file name without the extension orig_name The original file name. This is only useful if you use the encrypted name option. client_name The file name as supplied by the client user agent, prior to any file name preparation or incrementing. file_ext The file extension with period file_size The file size in kilobytes is_image Whether the file is an image or not. 1 = image. 0 = not. image_width Image width. image_height Image height image_type Image type. Typically the file extension without the period. image_size_str A string containing the width and height. Useful to put into an image tag.