@fraktalio/fmodel-ts/build/main/lib/application/materialized-view.d.ts

Functional domain modeling with TypeScript. Optimized for event sourcing and CQRS

import { IView } from '../domain/view';
/**
 * View State repository interface
 *
 * @typeParam E - Event
 * @typeParam S - State
 * @typeParam V - Version of the state
 * @typeParam EM - Event Metadata
 *
 * @author Иван Дугалић / Ivan Dugalic / @idugalic
 */
export interface IViewStateRepository<E, S, V, EM> {
    /**
     * Fetch state
     *
     * @param event - Event of type `E` with metadata of type `EM`
     *
     * @return current state / `S` with version / `V`, or NULL
     */
    readonly fetch: (event: E & EM) => Promise<(S & V) | null>;
    /**
     * Save state
     *
     * @param state - State and Event Metadata of type `S & EM`
     * @param eventMetadata - Event Metadata of type `EM`
     * @param version - State version of type `V | null`
     * @return newly saved State and Version of type `S` & `V`
     */
    readonly save: (state: S, eventMetadata: EM, version: V | null) => Promise<S & V>;
}
/**
 * Materialized view interface is using/delegating a `IView` to handle events of type `E` and to maintain a state of projection(s) via `IViewStateRepository` as a result.
 * Essentially, it represents the query/view side of the CQRS pattern.
 *
 * @typeParam S - Materialized View state of type `S`
 * @typeParam E - Events of type `E` that are handled by this Materialized View
 * @typeParam V - Version of the state
 * @typeParam EM - Event Metadata
 *
 * @author Иван Дугалић / Ivan Dugalic / @idugalic
 */
export interface IMaterializedView<S, E, V, EM> extends IView<S, E>, IViewStateRepository<E, S, V, EM> {
    /**
     * Handles the event of type `E`, and returns new persisted state of type `S`
     *
     * @param event Event of type `E & EM` to be handled / event with event metadata
     * @return State of type `S` & `V`
     */
    readonly handle: (event: E & EM) => Promise<S & V>;
}
/**
 * Materialized view is using/delegating a `View` to handle events of type `E` and to maintain a state of projection(s) via `IViewStateRepository` as a result.
 * Essentially, it represents the query/view side of the CQRS pattern.
 *
 * @typeParam S - Materialized View state of type `S`
 * @typeParam E - Events of type `E` that are handled by this Materialized View
 * @typeParam V - Version of the state
 * @typeParam EM - Event Metadata
 *
 * @author Иван Дугалић / Ivan Dugalic / @idugalic
 */
export declare class MaterializedView<S, E, V, EM> implements IMaterializedView<S, E, V, EM> {
    protected readonly view: IView<S, E>;
    protected readonly viewStateRepository: IViewStateRepository<E, S, V, EM>;
    constructor(view: IView<S, E>, viewStateRepository: IViewStateRepository<E, S, V, EM>);
    readonly initialState: S;
    evolve(state: S, event: E): S;
    fetch(event: E & EM): Promise<(S & V) | null>;
    save(state: S, eventMetadata: EM, version: V | null): Promise<S & V>;
    handle(event: E & EM): Promise<S & V>;
}