114 lines
3.2 KiB
TypeScript
114 lines
3.2 KiB
TypeScript
import * as plugins from './smartstate.plugins.js';
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import { StateAction, IActionDef } from './smartstate.classes.stateaction.js';
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export class StatePart<TStatePartName, TStatePayload> {
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public name: TStatePartName;
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public state = new plugins.smartrx.rxjs.Subject<TStatePayload>();
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public stateStore: TStatePayload;
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private cumulativeDeferred = plugins.smartpromise.cumulativeDefer();
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constructor(nameArg: TStatePartName) {
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this.name = nameArg;
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}
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/**
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* gets the state from the state store
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*/
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public getState(): TStatePayload {
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return this.stateStore;
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}
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/**
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* sets the stateStore to the new state
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* @param newStateArg
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*/
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public setState(newStateArg: TStatePayload) {
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this.stateStore = newStateArg;
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this.notifyChange();
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}
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/**
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* notifies of a change on the state
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*/
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public notifyChange() {
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const createStateHash = (stateArg: any) => {
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return plugins.isohash.sha256FromString(plugins.smartjson.stringify(stateArg));
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};
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if (this.stateStore && this.lastStateNotificationPayloadHash && createStateHash(this.stateStore) === createStateHash(this.lastStateNotificationPayloadHash)) {
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return;
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} else {
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this.lastStateNotificationPayloadHash = this.stateStore;
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}
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this.state.next(this.stateStore);
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}
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private lastStateNotificationPayloadHash: any;
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/**
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* selects a state or a substate
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*/
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public select<T = TStatePayload>(
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selectorFn?: (state: TStatePayload) => T
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): plugins.smartrx.rxjs.Observable<T> {
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if (!selectorFn) {
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selectorFn = (state: TStatePayload) => <T>(<any>state);
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}
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const mapped = this.state.pipe(
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plugins.smartrx.rxjs.ops.startWith(this.getState()),
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plugins.smartrx.rxjs.ops.map((stateArg) => {
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try {
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return selectorFn(stateArg);
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} catch (e) {
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// Nothing here
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}
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})
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);
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return mapped;
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}
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/**
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* creates an action capable of modifying the state
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*/
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public createAction<TActionPayload>(
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actionDef: IActionDef<TStatePayload, TActionPayload>
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): StateAction<TStatePayload, TActionPayload> {
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return new StateAction(this, actionDef);
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}
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/**
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* dispatches an action on the statepart level
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*/
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public async dispatchAction<T>(stateAction: StateAction<TStatePayload, T>, actionPayload: T) {
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await this.cumulativeDeferred.promise;
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const newState = await stateAction.actionDef(this, actionPayload);
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this.setState(newState);
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}
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/**
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* waits until a certain part of the state becomes available
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* @param selectorFn
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*/
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public async waitUntilPresent<T = TStatePayload>(
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selectorFn?: (state: TStatePayload) => T
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): Promise<T> {
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const done = plugins.smartpromise.defer<T>();
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const selectedObservable = this.select(selectorFn);
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const subscription = selectedObservable.subscribe(async (value) => {
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if (value) {
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done.resolve(value);
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}
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});
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const result = await done.promise;
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subscription.unsubscribe();
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return result;
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}
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/**
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* is executed
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*/
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public stateSetup(funcArg: (statePartArg?: StatePart<any, TStatePayload>) => Promise<TStatePayload | void>) {
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this.cumulativeDeferred.addPromise(funcArg(this));
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}
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}
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