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"""This defines a basic set of data for our Star Wars Schema.
This data is hard coded for the sake of the demo, but you could imagine fetching this
data from a backend service rather than from hardcoded JSON objects in a more complex
demo.
"""
from typing import Awaitable, Collection, Dict, Iterator, Optional
__all__ = ["get_droid", "get_friends", "get_hero", "get_human", "get_secret_backstory"]
# These are classes which correspond to the schema.
# They represent the shape of the data visited during field resolution.
class Character:
id: str
name: str
friends: Collection[str]
appearsIn: Collection[str]
# noinspection PyPep8Naming
class Human(Character):
type = "Human"
homePlanet: str
# noinspection PyShadowingBuiltins
def __init__(self, id, name, friends, appearsIn, homePlanet):
self.id, self.name = id, name
self.friends, self.appearsIn = friends, appearsIn
self.homePlanet = homePlanet
# noinspection PyPep8Naming
class Droid(Character):
type = "Droid"
primaryFunction: str
# noinspection PyShadowingBuiltins
def __init__(self, id, name, friends, appearsIn, primaryFunction):
self.id, self.name = id, name
self.friends, self.appearsIn = friends, appearsIn
self.primaryFunction = primaryFunction
luke = Human(
id="1000",
name="Luke Skywalker",
friends=["1002", "1003", "2000", "2001"],
appearsIn=[4, 5, 6],
homePlanet="Tatooine",
)
vader = Human(
id="1001",
name="Darth Vader",
friends=["1004"],
appearsIn=[4, 5, 6],
homePlanet="Tatooine",
)
han = Human(
id="1002",
name="Han Solo",
friends=["1000", "1003", "2001"],
appearsIn=[4, 5, 6],
homePlanet=None,
)
leia = Human(
id="1003",
name="Leia Organa",
friends=["1000", "1002", "2000", "2001"],
appearsIn=[4, 5, 6],
homePlanet="Alderaan",
)
tarkin = Human(
id="1004", name="Wilhuff Tarkin", friends=["1001"], appearsIn=[4], homePlanet=None
)
human_data: Dict[str, Human] = {
"1000": luke,
"1001": vader,
"1002": han,
"1003": leia,
"1004": tarkin,
}
threepio = Droid(
id="2000",
name="C-3PO",
friends=["1000", "1002", "1003", "2001"],
appearsIn=[4, 5, 6],
primaryFunction="Protocol",
)
artoo = Droid(
id="2001",
name="R2-D2",
friends=["1000", "1002", "1003"],
appearsIn=[4, 5, 6],
primaryFunction="Astromech",
)
droid_data: Dict[str, Droid] = {"2000": threepio, "2001": artoo}
# noinspection PyShadowingBuiltins
async def get_character(id: str) -> Optional[Character]:
"""Helper function to get a character by ID."""
# We use an async function just to illustrate that GraphQL-core supports it.
return human_data.get(id) or droid_data.get(id)
def get_friends(character: Character) -> Iterator[Awaitable[Optional[Character]]]:
"""Allows us to query for a character's friends."""
# Notice that GraphQL-core accepts iterators of awaitables.
return map(get_character, character.friends)
def get_hero(episode: int) -> Character:
"""Allows us to fetch the undisputed hero of the trilogy, R2-D2."""
if episode == 5:
# Luke is the hero of Episode V.
return luke
# Artoo is the hero otherwise.
return artoo
# noinspection PyShadowingBuiltins
def get_human(id: str) -> Optional[Human]:
"""Allows us to query for the human with the given id."""
return human_data.get(id)
# noinspection PyShadowingBuiltins
def get_droid(id: str) -> Optional[Droid]:
"""Allows us to query for the droid with the given id."""
return droid_data.get(id)
# noinspection PyUnusedLocal
def get_secret_backstory(character: Character) -> str:
"""Raise an error when attempting to get the secret backstory."""
raise RuntimeError("secretBackstory is secret.")
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