def METHOD_NAME(blog_id):
    data = request.get_json(silent=True) or {}
    start_date = data.get('start_date')
    auto_retrieve = data.get('auto_retrieve', True)
    if start_date:
        try:
            start_date = str_to_date(start_date)
        except ValueError:
            return api_error('start_date is not valid.', 400)
    consumer_blog_id = data.get('consumer_blog_id')
    if not consumer_blog_id:
        return api_error('Missing "consumer_blog_id" in form data.', 422)
    if request.method == 'DELETE':
        return _delete_blogs_syndicate(blog_id, consumer_blog_id)
    elif request.method == 'PATCH':
        return _update_blogs_syndicate(blog_id, consumer_blog_id, auto_retrieve, start_date)
    else:
        return _create_blogs_syndicate(blog_id, consumer_blog_id, auto_retrieve, start_date)