ACF file query returning null or a number

• Darcey

• February 18, 2020 at 4:04 am

Hi I just purchased ACF pro and am having an issue with an ACF file type associated to a custom post type called “link”, it either returns null or a number which I assume is the ID but not what id in the documentation of usage for $file[“url”] as get_field(“link”); is always null. Full details below.

I’ve setup a custom post type called “links”, singular “link” via:

	function setup_links_post_type()
	{

		$args = array(
			"labels" => array(
				"name" => "Links",
				"singular_name" => "Link",
			),
			"menu_position" => 2,
			"hirarchical" => true, // page vs posts mode
			"public" => true,
			"has_archive" => true,
			"supports" => array(
				"title",
				"editor",
				"thumbnail",
			),
			"menu_icon" => "dashicons-admin-links",
			// "rewrite" => array("slug" => "downloads")
		);

		register_post_type("links", $args);
	}

	add_action("init", "setup_links_post_type");

Then I used ACF Pro to setup a field group called ACF1, then in this group I created a custom field called “link” which is an ACF type of “file” and attached it to the custom post type of “link”.

I use the following code to do a query:

	$args = array(
		'numberposts' => 3,
		'post_type' => 'links',
	);
	$my_posts = get_posts($args);

	if (!empty($my_posts)) {
		$output = '<ul>';
		foreach ($my_posts as $p) {
            $file = get_field('link');
			var_dump( get_field('file') ); // dumps NULL
			// print_r( get_post_meta($p->ID,"link",true) ); // This will print out a number

			$output .= '<li>
				<a>ID) . '">' . $p->post_title . '</a><br>
				test = ' . get_post_meta($p->ID,"link",true) . '<br>
			';

			if( $file ) {
				// NEVER RUNS
				$output .= '
					' . $file['url'] . '<br>
					' . $file['filename'] . '<br>
				';
			}
		}
		$output .= '</ul>';
		echo($output);
	}

I always get

$file = get_field('link'); // NULL

and a number from

get_post_meta($p->ID,"link",true);

Anyone know why or got a working script to get the file name of the file link from ACF (Advanced Custom Fields)?

Thanks

• videohead

• March 17, 2023 at 4:00 pm

I had the same problem. I used var_dump to see what ACF was returning and it was just a numerical string. So then I used a WordPress function wp_get_attachment_url($my_variable) and that returned the correct URL.

• John Huebner

• May 7, 2023 at 11:40 am

In your loop you must supply the post ID to get fields from the specific post

foreach ($my_posts as $p) {
  $file = get_field('link', $p->ID);
  ...

get_post_meta() returns an number because ACF only stores the ID of the file attachment.