PHP WordPress Generate Thumbnail By Url Without Extension

PHP WordPress Generate Thumbnail By Url Without Extension

I recently faced this issue where the normal way of downloading images from a url, and then attaching it as a thumbnail, didn’t work out. This was because the link of the image was generated by a .php script, hence it didn’t have any image extension at the end, such as ‘.jpeg’.

The normal way didn’t work, because the call on media_handle_sideload, would eventually lead to _wp_handle_upload, which does a sanity check by calling is_uploaded_file, a php function, producing the error WP_Error that says ‘Specified file failed upload test.’

After much trial and error, I finally came up with a way to accomplish this (albeit with some small hacks). That is, to simply prepend our extension (.jpeg/.png/.whatever image type) to the filename that we want, while avoiding the use of the function media_handle_sideload.

The code is as shown below. Currently, what it does is to ensure firstly that the filename has an extension, then manually download the image file through file_get_contents, before uploading it to WordPress via wp_upload_bits, before inserting and performing other attachment related stuff.

public function generate_featured_image_1( $file_url, $post_id, $desc ) 
{
    /*
     * $file is the path to your uploaded file (for example as set in the $_FILE posted file array)
     * $filename is the name of the file
     * first we need to upload the file into the wp upload folder.
    */			

    $filename = basename($file_url);
    if( stristr($filename, '.jpeg') ) {   // you might want to make it so that it supports more extension, etc..
    
    } else {
        $filename .= ".jpeg";
    }
    $upload_file = wp_upload_bits( $filename, null, @file_get_contents( $file_url ) );
    Debug::pretty_dump($upload_file);
    if ( ! $upload_file['error'] ) {
        // if succesfull insert the new file into the media library (create a new attachment post type).
        $wp_filetype = wp_check_filetype($filename, null );
     
        $attachment = array(
            'post_mime_type' => $wp_filetype['type'],
            'post_parent'    => $post_id,
            'post_title'     => preg_replace( '/\.[^.]+$/', '', $filename ),
            'post_content'   => '',
            'post_status'    => 'inherit'
        );
     			

        $attachment_id = wp_insert_attachment( $attachment, $upload_file['file'], $post_id );
     			

        if ( ! is_wp_error( $attachment_id ) ) {
        
            // if attachment post was successfully created, insert it as a thumbnail to the post $post_id.
            require_once(ABSPATH . "wp-admin" . '/includes/image.php');
         
            $attachment_data = wp_generate_attachment_metadata( $attachment_id, $upload_file['file'] );
         
            wp_update_attachment_metadata( $attachment_id,  $attachment_data );
            $alt_meta_id = update_post_meta($attachment_id, '_wp_attachment_image_alt', $desc); //https://developer.wordpress.org/reference/functions/update_post_meta/

            return set_post_thumbnail( $post_id, $attachment_id );
        } else {
            $error_string = $attachment_id->get_error_message();
            echo '<div id="message" class="error"><p>' . $error_string . '</p></div>';
        }
    } else {
        echo "error: " . $upload_file['error'];
    }
    return false;
}