RecordProxyProvider

Manages the metadata required for constructing RecordProxy objects.

A view that has joins will have one RecordProxyProvider instance that deals RecordProxy instances for each row of the view. This allows for metadata and state about the joins to be shared at the view level rather than being recreated for each individual row.

Constructors

new RecordProxyProvider<T extends Model<string, T>>(context: Context, query: Query, metadata: QueryReflectionMetadata): RecordProxyProvidersource

Properties

readonlyjoinExecutors: Map<string | number | symbol, JoinExecutor<T, Model<any>>>source

Each join has an 'executor' which resolves a LHS record to a RHS record by applying the conditions of the join.

readonlyjoinExecutorsByModel: SetMap<ModelType<Model<string>>, JoinExecutor<T, Model<any>>>source

The same as joinExecutors, but grouped by foreign model.

readonlykeys: string[]source

Cached field names, used for the proxy's ownKeys handler.

readonlymetadata: QueryReflectionMetadatasource

readonlyquery: Querysource

readonlyresolvers: Map<string | number | symbol, Function>source

Each field of the composite record has a 'resolver', which is a function that takes a single record proxy argument and applies the logic needed to look up the value either directly on the base record or via a foreign join.

Methods

Instance methods

dispose(): voidsource

When the parent view is disposed, we need to release any materialised subquery views so that they can be disposed of as well.

getTransform(): Functionsource

Returns a function that receives a base record and returns a Proxy that wraps that record with the interceptors that execute the joins.

makeEquijoinExecutor(context: Context, join: JoinSpec): voidsource

Builds the executor for an equijoin. This is a PK lookup against the root view for the foreign model in this context.

makeJoinExecutors(context: Context): voidsource

Builds the executors for each join.

makeJoinResolvers(): voidsource

Builds the resolvers for each join.

makeSubqueryJoinExecutor<Right extends Model<string, Right>>(context: Context, leftHandField: string | number | symbol, query: Query, predicates: JoinPredicate[]): voidsource

Builds the executor for a subquery join. This is a scan of a view for the subquery.

makeSubqueryNonPkJoinExecutor<Right extends Model<string, Right>>(subqueryView: Handle, predicates: JoinPredicate[]): JoinExecutor<T, Model<string>>source

Slow path: for the general join case, use a table scan to get the RHS record.

makeSubqueryPkJoinExecutorMaybe<Right extends Model<string, Right>>(subqueryView: Handle, predicates: JoinPredicate[]): undefined | JoinExecutor<T, Model<string>>source

Fast path: if the join clause consists of a single "eq" predicate where the field of the RHS is its primary key, use a hashtable lookup to get the RHS record.