I'm really enjoying all the extra functionality that has come with custom post types but I'm still struggling to find a good solution/function for creating an image uploader that adds the images to the media library and resizes them to the 'thumbnail', 'medium' and 'large' sizes.
The default media uploader is far to cumbersome and I need to work in the image upload process into my own UI.
I'm currently using the 'wp_handle_upload' function followed by 'wp_insert_attachment' and then 'wp_update_attachment_metadata'. It works to an extent, my images get uploaded, but I'd expect any function that uploads an image to the media library should automatically handle the resizing. I'm trying to avoid plug-ins for this because I feel like they should be avoided when creating a custom post type.