tsbase/Patterns/EventStore/IEventStore.d.ts

Base class libraries for TypeScript

import { Observable } from '../Observable/Observable';
import { Result } from '../Result/Result';
import { Transaction } from './Transaction';
export type MemberLambda<Store, Member> = (func: Store) => Member;
/**
 * A light state management pattern allowing storage, retrieval, and
 * monitoring of state.
 */
export interface IEventStore<T extends object> {
    /**
     * Returns a copy of the current state
     */
    GetState(): T;
    /**
     * Returns a portion of the state based on the given path
     * @param path object path to the desired state
     */
    GetState<V>(member: MemberLambda<T, V> | string): V;
    /**
     * Update the current state of the entire store
     * @param state state to set at a root level
     */
    SetState<T>(state: T): Result<T>;
    /**
     * Sets the state at a given path, returning a result indicating
     * success and a copy of the state set
     * @param state state to set
     * @param path object path to be set
     */
    SetState<V>(member: MemberLambda<T, V> | string, state: V): Result<V>;
    /**
     * Returns an observable which can be subscribed to in order
     * to act on ANY state changes within the store
     */
    ObservableAt(): Observable<T>;
    /**
     * Returns an observable which can be subscribed to in order
     * to act on state changes
     * @param path object path to the desired state
     */
    ObservableAt<V>(member: MemberLambda<T, V> | string): Observable<V>;
    /**
     * Returns a collection of all the transactions which resulted
     * in the current state
     */
    GetLedger(): Array<Transaction<T>>;
    /**
     * Voids the most recent (non-voided) transaction, returning the
     * stores value to the previous 'from' state
     */
    Undo(): Result<T | undefined>;
    /**
     * Reverses the void on the newest voided transaction excluding any
     * voided transaction that follows a non-voided one
     * (Once state is set, prior voided transactions cannot be reversed)
     */
    Redo(): Result<T | undefined>;
}