def list(cls, substance):
kit_list = []
author_id = substance.get("author_id")
category_id = substance.get("category_id")
tags = substance.get("tags")
if author_id:
author_key = Author.get_key_by_id(author_id)
if author_key:
kit_list = [kit.to_hash_short() for kit in Kit.query(Kit.author == author_key)]
elif category_id:
category_key = Category.get_key_by_id(category_id)
if category_key:
kit_list = [kit.to_hash_short() for kit in Kit.query(Kit.category == category_key, True == Kit.valid)]
elif tags:
kit_list = [
kit.to_hash_short() for kit in Kit.query(Kit.tags.IN(Kit.sanitize_tags(tags)), True == Kit.valid)
]
else:
kit_list = [kit.to_hash_short() for kit in Kit.query(True == Kit.valid)]
return dict(items=kit_list)
