def generate_resolvers(self, graphql_api, type_name, data_source):
"""
Creates AppSync resolvers for the given GraphQL type. Resolvers are created by
iterating through the `resolvers` directory in the API's build folder and
parsing the resolver template filenames to find the operation name and type.
:param type_name The name of the GraphQL type. This is the identifier which
appears after the `type` keyword in the schema.
:param data_source The AppSync data source Pulumi resource for the type.
"""
resolvers_dir = self.amplify_api_build_dir.joinpath("resolvers")
resolvers = []
for req_file in resolvers_dir.iterdir():
regex_match = match(
f"^([a-zA-Z]+)\\.([a-zA-Z]+{type_name}s?)\\.req\\.vtl$",
str(req_file.name),
)
if regex_match:
operation_type = regex_match.group(1)
operation_name = regex_match.group(2)
res_file = resolvers_dir.joinpath(
f"{operation_type}.{operation_name}.res.vtl"
)
resolver = appsync.Resolver(
f"{self.stack_name}_{operation_name}_resolver",
api_id=graphql_api.id,
data_source=data_source.name,
field=operation_name,
type=operation_type,
request_template=req_file.read_text(),
response_template=res_file.read_text(),
)
resolvers.append(resolver)
return resolvers
## Link a data source to the Dynamo DB Table
data_source = appsync.DataSource("tenants-ds",
name="TenantsDataSource",
api_id=api.id,
type="AMAZON_DYNAMODB",
dynamodb_config={"table_name": table.name},
service_role_arn=role.arn)
## A resolver for the [getTenantById] query
get_resolver = appsync.Resolver("get-resolver",
api_id=api.id,
data_source=data_source.name,
type="Query",
field="getTenantById",
request_template="""{
"version": "2017-02-28",
"operation": "GetItem",
"key": {
"id": $util.dynamodb.toDynamoDBJson($ctx.args.id),
}
}
""",
response_template="$util.toJson($ctx.result)")
## A resolver for the [addTenant] mutation
add_resolver = appsync.Resolver("add-resolver",
api_id=api.id,
data_source=data_source.name,
type="Mutation",
field="addTenant",
request_template="""{
"version" : "2017-02-28",