attach-external-featured-image.php

<?php

// Loose method

public function insert_featured_image($plugin_id, $image_path) {

	// Get the filename from the target.
	$filename = basename($image_path);

	// Get thumbnail id, if any.
	$thumbnail_id = get_post_thumbnail_id($plugin_id);

	// Delete existing image(s).
	if (!empty($thumbnail_id)) {

		$metadata = wp_get_attachment_metadata($thumbnail_id);
		wp_delete_attachment($thumbnail_id, true);
		$files_del = wp_delete_attachment_files($plugin_id, $metadata, false, $image_path);
	}

	// Copy the file into the content directory structure.
	$filesave = wp_upload_bits($filename, null, file_get_contents($image_path));

	// If error copying image over, bail.
	if (!empty($filesave['error'])) {
		return false;
	}

	// Setup properties to insert image as an attachment.
	$attachment = array(
		'post_mime_type' => 'image/jpeg',
		'post_parent'    => 0,
		'post_title'     => preg_replace('/\.[^.]+$/', '', $filename),
		'post_content'   => '',
		'post_status'    => 'inherit'
	);

	$attachment_id = wp_insert_attachment($attachment, $filesave['file'], $thumbnail_id);

	// Error inserting attachment record? Bail.
	if (is_wp_error($attachment_id)) {
		return false;
	}

	// Ensure needed functions are present.
	require_once(PATH_ADMIN.'/includes/image.php');

	// Generate metadata for the attachment.
	$metadata = wp_generate_attachment_metadata($attachment_id, $filesave['file']);

	// Update attachment metadata.
	wp_update_attachment_metadata($attachment_id,  $metadata);

	//
	set_post_thumbnail($plugin_id, $attachment_id);
}