io.stargate.graphql.schema.graphqlfirst.fetchers.deployed

Class FederatedEntityFetcher

java.lang.Object

io.stargate.graphql.schema.CassandraFetcher<ResultT>

io.stargate.graphql.schema.graphqlfirst.fetchers.deployed.FederatedEntityFetcher

All Implemented Interfaces:

graphql.schema.DataFetcher<List<FederatedEntity>>

public class FederatedEntityFetcher
extends CassandraFetcher<ResultT>

Executes the _entities query of GraphQL federation.

See Also:

The Apollo Federation spec

Field Summary

Fields inherited from class io.stargate.graphql.schema.CassandraFetcher

DEFAULT_CONSISTENCY, DEFAULT_PAGE_SIZE, DEFAULT_PARAMETERS, DEFAULT_SERIAL_CONSISTENCY

Constructor Summary

Constructors

Constructor and Description
FederatedEntityFetcher(MappingModel mappingModel)

Method Summary

Modifier and Type	Method and Description
protected List<BuiltCondition>	bindIf(List<ConditionModel> conditions, Predicate<String> hasArgument, Function<String,Object> getArgument, Keyspace keyspace)
protected List<BuiltCondition>	bindWhere(List<ConditionModel> conditions, EntityModel entity, Predicate<String> hasArgument, Function<String,Object> getArgument, Keyspace keyspace) Given the WHERE conditions that were inferred from an operation signature, find out which arguments are actually present in an runtime invocation, and bind the corresponding conditions.
protected ResultSet	executeUnchecked(AbstractBound<?> query, Optional<ByteBuffer> pagingState, Optional<Integer> pageSize, DataStore dataStore)
protected List<FederatedEntity>	get(graphql.schema.DataFetchingEnvironment environment, DataStore dataStore, StargateGraphqlContext context)
protected ResultSet	query(EntityModel entity, List<BuiltCondition> whereConditions, Optional<ByteBuffer> pagingState, Optional<Integer> limit, Optional<Integer> pageSize, DataStore dataStore, StargateGraphqlContext context) Queries one or more instances of an entity for the given conditions.
protected Object	toCqlValue(Object graphqlValue, Column.ColumnType cqlType, Keyspace keyspace)
protected List<Map<String,Object>>	toEntities(ResultSet resultSet, EntityModel entity)
protected Object	toGraphqlValue(Object cqlValue, Column.ColumnType cqlType, graphql.language.Type<?> graphqlType)
protected Map<String,Object>	toSingleEntity(ResultSet resultSet, EntityModel entity)

Methods inherited from class io.stargate.graphql.schema.CassandraFetcher

get, getDatastoreParameters

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FederatedEntityFetcher

public FederatedEntityFetcher(MappingModel mappingModel)

Method Detail

get

protected List<FederatedEntity> get(graphql.schema.DataFetchingEnvironment environment,
                                    DataStore dataStore,
                                    StargateGraphqlContext context)
                             throws UnauthorizedException

Specified by:

get in class CassandraFetcher<List<FederatedEntity>>

Throws:

UnauthorizedException

toCqlValue

protected Object toCqlValue(Object graphqlValue,
                            Column.ColumnType cqlType,
                            Keyspace keyspace)

toGraphqlValue

protected Object toGraphqlValue(Object cqlValue,
                                Column.ColumnType cqlType,
                                graphql.language.Type<?> graphqlType)

query

protected ResultSet query(EntityModel entity,
                          List<BuiltCondition> whereConditions,
                          Optional<ByteBuffer> pagingState,
                          Optional<Integer> limit,
                          Optional<Integer> pageSize,
                          DataStore dataStore,
                          StargateGraphqlContext context)
                   throws UnauthorizedException

Queries one or more instances of an entity for the given conditions.

Throws:

UnauthorizedException

toSingleEntity

protected Map<String,Object> toSingleEntity(ResultSet resultSet,
                                            EntityModel entity)

toEntities

protected List<Map<String,Object>> toEntities(ResultSet resultSet,
                                              EntityModel entity)

executeUnchecked

protected ResultSet executeUnchecked(AbstractBound<?> query,
                                     Optional<ByteBuffer> pagingState,
                                     Optional<Integer> pageSize,
                                     DataStore dataStore)

bindWhere

protected List<BuiltCondition> bindWhere(List<ConditionModel> conditions,
                                         EntityModel entity,
                                         Predicate<String> hasArgument,
                                         Function<String,Object> getArgument,
                                         Keyspace keyspace)

Given the WHERE conditions that were inferred from an operation signature, find out which arguments are actually present in an runtime invocation, and bind the corresponding conditions.

Example:

 // Query definition
 type Query { readings(sensorId: ID!, hour: Int, minute: Int): [SensorReading] }

 // Inferred conditions:
 sensorId = ? AND hour = ? AND minute = ?

 // GraphQL call:
 { readings(sensorId: "xyz", hour: 12) { value } }

 // Actual conditions:
 sensorId = 'xyz' AND hour = 12
 

Parameters:

hasArgument - how to know if an argument is present (this is abstracted because in some cases the values are not directly arguments, but instead inner fields of an object argument).

getArgument - how to get the value of an argument (same).

bindIf

protected List<BuiltCondition> bindIf(List<ConditionModel> conditions,
                                      Predicate<String> hasArgument,
                                      Function<String,Object> getArgument,
                                      Keyspace keyspace)