Asymmetrik/ngx-starter

import { SelectionModel } from '@angular/cdk/collections';
import { CdkTableModule } from '@angular/cdk/table';
import { ChangeDetectionStrategy, Component, OnInit, booleanAttribute, input } from '@angular/core';

import { AsyAbstractColumnComponent } from '../asy-abstract-column.component';

type IsExpandableFn<T> = (index: number, rowData: T) => boolean;
type TrackByFn<T, TB> = (index: number, rowData: T) => TB;

@Component({
    selector: 'asy-expander-column',
    templateUrl: './asy-expander-column.component.html',
    styleUrls: ['./asy-expander-column.component.scss'],
    changeDetection: ChangeDetectionStrategy.Default,
    standalone: true,
    imports: [CdkTableModule]
})
export class AsyExpanderColumnComponent<T, TB>
    extends AsyAbstractColumnComponent<T>
    implements OnInit
{
    #selectionModel: SelectionModel<TB>;

    readonly multi = input(true, { transform: booleanAttribute });
    readonly isExpandable = input<IsExpandableFn<T>>(() => true);
    readonly trackBy = input<TrackByFn<T, TB>>((index, rowData) => rowData as unknown as TB);

    constructor() {
        super();
        this.name = 'expander';
    }

    override ngOnInit(): void {
        super.ngOnInit();

        this.#selectionModel = new SelectionModel<TB>(this.multi());
    }

    expand(...trackByValues: TB[]) {
        this.#selectionModel.select(...trackByValues);
    }

    toggle(index: number, result: T) {
        this.#selectionModel.toggle(this.trackBy()(index, result));
    }

    isExpanded(index: number, result: T) {
        return this.#selectionModel.isSelected(this.trackBy()(index, result));
    }

    get expanded() {
        return this.#selectionModel.selected;
    }

    // eslint-disable-next-line rxjs/finnish
    get changed() {
        return this.#selectionModel.changed;
    }

    hasExpanded() {
        return this.#selectionModel.hasValue();
    }
}