Is there a way to have a Codeigniter controller return an image?

Question

I was wondering if there was a way for a controller to, instead of returning a string, or a view, return an image (be it JPG, PNG etc). For example, instead of ending with a $this->load->view('folder/special_view.php), I'd like to do something like $this->load->image('images/gorilla.png'), and have it so if my user were to go to that controller they would see an image as if they'd gone to a normal .png or jpeg. Can I set the headers so it expects a different MIME? Example code of this would be fantastic.

It would take forever for me to explain why I need this, but it involves bringing a premade CMS into codeigniter, and having it need certian things to be true. Thank you so much!

Solution 1

sure you can, use this instead of $this->load->view()

$filename="/path/to/file.jpg"; //<-- specify the image  file
if(file_exists($filename)){ 
  $mime = mime_content_type($filename); //<-- detect file type
  header('Content-Length: '.filesize($filename)); //<-- sends filesize header
  header("Content-Type: $mime"); //<-- send mime-type header
  header('Content-Disposition: inline; filename="'.$filename.'";'); //<-- sends filename header
  readfile($filename); //<--reads and outputs the file onto the output buffer
  exit(); // or die()
}

Solution 2

This is not intended as One-upmanship, but pǝlɐɥʞ's suggestion is a pure PHP implementation that is not all that re-usable. You wanted to use the syntax $this->load->image('images/gorilla.png') so here is how you can.

Create /application/libraries/MY_Loader.php

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**
 * Loader Class
 *
 * Loads views and files
 *
 * @package     CodeIgniter
 * @subpackage  Libraries
 * @author      Phil Sturgeon
 * @category    Loader
 * @link        http://codeigniter.com/user_guide/libraries/loader.html
 */
class MY_Loader extends CI_Loader {

    function image($file_path, $mime_type_or_return = 'image/png')
    {
        $this->helper('file');

        $image_content = read_file($file_path);

        // Image was not found
        if($image_content === FALSE)
        {
            show_error('Image "'.$file_path.'" could not be found.');
            return FALSE;
        }

        // Return the image or output it?
        if($mime_type_or_return === TRUE)
        {
            return $image_content;
        }

        header('Content-Length: '.strlen($image_content)); // sends filesize header
        header('Content-Type: '.$mime_type_or_return); // send mime-type header
        header('Content-Disposition: inline; filename="'.basename($file_path).'";'); // sends filename header
        exit($image_content); // reads and outputs the file onto the output buffer
    }

There are a few ways you can use this:

Basic output (default is jpeg)

$this->load->image('/path/to/images/gorilla.png');

Send mime-type to use other image types

$this->load->image('/path/to/images/gorilla.jpg', 'image/jpeg');

Return the image

$image = $this->load->image('/path/to/images/gorilla.php', TRUE);

Just like $this->load->view, the 3rd parameter being set to TRUE means it will return instead of directly outputting.

Hope this helps :-)

Solution 3

An easier way with automatic mime-type.

$this->load->helper('file');

$image_path = '/path/to/image/file';

$this->output->set_content_type(get_mime_by_extension($image_path));
$this->output->set_output(file_get_contents($image_path));

Solution 4

This method works even if you have $config['compress_output'] set to TRUE

$filename="/path/to/file.jpg"; //<-- specify the image  file
if(file_exists($filename)){ 
  header('Content-Length: '.filesize($filename])); //<-- sends filesize header
  header('Content-Type: image/jpg'); //<-- send mime-type header
  header('Content-Disposition: inline; filename="'.$filename.'";'); //<-- sends filename     header
  $jpg = file_get_contents($filename); 
  $this->output->set_output($jpg);
}

Solution 5

If it fits your use case, simply redirecting to it is just fine. For example, tracking using images would be like:

// Do your logic here

redirect($image_path); // Or PHP's header location function

No need to change headers. Your use case may not fit this, but someone might find this useful ^_^

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Comments

[Admin]

I never noticed the generic file loader. I was going through the code of CodeIgniter... Thanks for pointing this out.. Using the best of codeigniter... :)

[Admin]

Well one more thing which I noted was internally the load function calls the include function... as per the php manual one should use include if its used for processing... instead readfile function should be used... so we can use the readfile function provided in File helper!

[Gaurav Gupta]

The library has to be in application/core/MY_Loader.php

[Phil Sturgeon]

@GauravGupta yes, if you are using 2.0 or later then it needs to be in core/ not libraries/. 2.0 did not exist in 2009. :)

[Ammar Hayder Khan]

I am working on the current version of Codeigniter. this code is not working for me

[Márton Tamás]

I guess the exit command has no purpose, since die terminates the script and they do the same job anyway. Thanks for the code by the way.