echo elgg_list_entities(array(

'type' => 'object',
'subtype' => 'motion_data',

));

This will return a list of your files, not the object.

Use elgg_get_entities. This is how I do it:

First I get all my files:

$featured = elgg_get_entities(array(
	'type' => 'object',
	'subtype' => 'file',
        'category' => 'featured',
        'owner_guid' => $blog->guid,
	//'full_view' => false,
        'limit' => 1,
	'no_results' => elgg_echo("file:none"),
	'preload_owners' => true,
	'preload_containers' => true,
	'distinct' => false,
));

Then I iterate through my array to get the download url:

foreach ($featured as $t) {
                 $file_og = get_entity($t->guid);

                  $image_url = $file_og->getIcon('large');
                  $icon= elgg_get_inline_url($image_url);
                  $image_url = elgg_format_url($image_url);
                  $download_url_image = elgg_get_download_url($file_og);
                  ?>
                 
                 <meta property="og:image" content="<?php echo $icon;?>">
                 <?php
//echo $file_og->getIconURL('large');
                 }

Check the complete code here:

https://github.com/rjcalifornia/softland_theme/blob/master/views/default/resources/posts/view.php

Thanks for your response. I tested out the functionality you suggested and Elgg is still returning a ElggObject instead of a ElggFile.... :/

This throws an error:

Argument 1 passed to elgg_get_download_url() must be an instance of ElggFile, instance of ElggObject given

code:

Yeah, I also had that issue.

Here's the thing, if you are dealing with files, as far as I know, you cannot use another subtype because elgg will not recognized as a file.

If you see at my code, in the elgg_get_entities() I am filtering my files with an specific category. So in my action, I keep the file subtype, but I add a category:

$file = new ElggFile();

$file->title = $file->getFilename();

$file->subtype = "file";

$file->category = "featured";

Then when I want to get the files I need, I just add the category:

elgg_get_entities(array( 'type' => 'object', 'subtype' => 'file', 'category' => 'featured')

You can view how I do my action here:

https://github.com/rjcalifornia/elggpress/blob/master/actions/posts/save.php

@gwcoleman Extend ElggFile using your own Class.

Example:

namespace MyPlugin;

use ElggFile;

class MotionData extends ElggFile {

    const SUBTYPE = 'motion_data';

    public function initializeAttributes() {
      parent::initializeAttributes();
      $this->attributes['subtype'] = self::SUBTYPE;
    }


   public function getDisplayName() {
      $name = parent::getDisplayName();
      
      if (!$name) {
        $name = elgg_echo('untitled');
     }

     return $name;
   }

}