Class MatTableDataSource

src/material/table/table-data-source.ts:43–399

 * own `DataSource`.
 */
export class MatTableDataSource<
  // TODO: Remove `any` type below in a breaking change:
  T extends object | any,
  P extends MatPaginator = MatPaginator,
> extends DataSource<T> {
  /** Stream that emits when a new data array is set on the data source. */
  private readonly _data: BehaviorSubject<T[]>;

  /** Stream emitting render data to the table (depends on ordered data changes). */
  private readonly _renderData = new BehaviorSubject<T[]>([]);

  /** Stream that emits when a new filter string is set on the data source. */
  private readonly _filter = new BehaviorSubject<string>('');

  /** Used to react to internal changes of the paginator that are made by the data source itself. */
  private readonly _internalPageChanges = new Subject<void>();

  /**
   * Subscription to the changes that should trigger an update to the table's rendered rows, such
   * as filtering, sorting, pagination, or base data changes.
   */
  _renderChangesSubscription: Subscription | null = null;

  /**
   * The filtered set of data that has been matched by the filter string, or all the data if there
   * is no filter. Useful for knowing the set of data the table represents.
   * For example, a 'selectAll()' function would likely want to select the set of filtered data
   * shown to the user rather than all the data.
   */
  filteredData!: T[];

  /** Array of data that should be rendered by the table, where each object represents one row. */
  get data() {
    return this._data.value;
  }

  set data(data: T[]) {
    data = Array.isArray(data) ? data : [];
    this._data.next(data);
    // Normally the `filteredData` is updated by the re-render
    // subscription, but that won't happen if it's inactive.
    if (!this._renderChangesSubscription) {
      this._filterData(data);
    }
  }

  /**
   * Filter term that should be used to filter out objects from the data array. To override how
   * data objects match to this filter string, provide a custom function for filterPredicate.
   */
  get filter(): string {
    return this._filter.value;
  }

  set filter(filter: string) {
    this._filter.next(filter);
    // Normally the `filteredData` is updated by the re-render
    // subscription, but that won't happen if it's inactive.