js__typescript__pluralsight2/course/src/app/reports.component.ts

import {Component, Inject} from '@angular/core';
import {DataSource} from '@angular/cdk/collections';
import {Observable} from 'rxjs/Observable';
import 'rxjs/add/observable/merge';
import 'rxjs/add/observable/of';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/take';
import {Report, ReportDataService} from './services/reportData.service';
import {ActivatedRoute, ParamMap} from '@angular/router';
import {WindowService} from "./services/window.service";

export class ReportsDataSource extends DataSource<any> {

    constructor(private dataSource: ReportDataService) {
        super();
    }

    connect(): Observable<Report[]> {
        return this
            .dataSource
            .dataChange
            .map(data => data);
    }

    disconnect() { }
}

function mapUser(params: ParamMap): boolean {
    const userName = params.get('user') || '';
    return userName.indexOf('admin') > -1;
}

/**
 *  Special syntax: using "this" as first argument does NOT add a first
 * parameter, but specifies the type of "this" within the function.
 */
function toggleApprovedStyle(this: HTMLElement, approved: boolean) {
    if (approved && this.className.indexOf('approved') === -1) {
        this.className += ' approved';
    } else {
        this.className = this.className.replace('approved', '');
    }
}

@Component({
    selector: 'ps-reports',
    templateUrl: './reports.component.html',
    styleUrls: ['./reports.component.css']
})
export class ReportsComponent {
    reports: ReportsDataSource;
    isAdmin = Observable.of(false);
    displayedColumns = ['id', 'description', 'date', 'amount', 'approved', 'actions'];

  constructor(private route: ActivatedRoute,
        private reportDataService: ReportDataService,
        @Inject(WindowService) private _window: Window) {
    this.reports = new ReportsDataSource(reportDataService);
        this.isAdmin = this.route.queryParamMap.map(mapUser);
    }

    approve(report: Report) {
        this.toggleApproval(report, true);
        this.toggleApprovedStyle(report.id, true);
    }

    reject(report: Report) {
        this.toggleApproval(report, false);
        this.toggleApprovedStyle(report.id, false);
    }


    private toggleApprovedStyle(reportId: number, approved: boolean) {
      setTimeout(() => {
            const row = this._window.document.getElementById(`report$${reportId}`).closest("mat-row");
            toggleApprovedStyle.call(row, approved);
        }, 50);
    }

    private toggleApproval(report: Report, approved: boolean) {
        report.approved = approved;
        this.route
            .queryParamMap
            .take(1)
            .subscribe(params => this.reportDataService.toggleApproval(report, params.get('user')));

    }
}