API Reference

Expression Change Tracker Manager

Create a tracker for an expression and observe granular change history batches. Pause and continue tracking when needed.

Interface: IExpressionChangeTrackerManager

Open Playground

Description

Tracks expression node updates and emits a list of changed expressions per flush cycle.

Parameters

expressionIExpression

Root expression to track for change history.

pause() and continue() do not take parameters.

Return type

create(expression) returns a keyed-instance-factory result object with instance, id, and referenceCount.

Tracker methods return void; changed returns observable batches of IExpressionChangeHistory[].

Usage notes

Call dispose() on the tracker to release manager references.

pause() suppresses tracking emissions until continue() is called.

API

export interface IExpressionChangeTracker extends IDisposable {
  readonly changed: Observable<IExpressionChangeHistory[]>;
  pause(): void;
  continue(): void;
}

export type IExpressionChangeTrackerManager = IKeyedInstanceFactory<
  IExpression,
  IExpression,
  IExpressionChangeTracker
>;

Usage example

import { InjectionContainer } from '@rs-x/core';
import {
  type IExpressionChangeTrackerManager,
  rsx,
  RsXExpressionParserInjectionTokens,
  RsXExpressionParserModule,
} from '@rs-x/expression-parser';

await InjectionContainer.load(RsXExpressionParserModule);

const trackerManager = InjectionContainer.get<IExpressionChangeTrackerManager>(
  RsXExpressionParserInjectionTokens.IExpressionChangeTrackerManager
);

const model = { a: 10, b: 20 };
const expression = rsx<number>('a + b')(model);

const tracker = trackerManager.create(expression).instance;

tracker.changed.subscribe((history) => {
  // history = list of changed nodes in the last flush
  console.log(history.map((item) => item.expression.expressionString));