无法在Material Datatable中使用AngularFirestore获取对象键

Question

I have a Material Datatable that consists of 3 documents. In the columns, I have an edit column which needs to fetch the ids ($key) so I can route to /object:id.

I suspect this is related to async loading but after making a thorough search to the best of my capacity I couldn't really find a solid answer, or admitedly, I don't really know what to search for regarding how to incorporate this into datatable.

<mat-table #table [dataSource]="vehicle1" [trackBy]="trackByUid" matSort>

When I use the collection (observable) as my datatable source as above, I'm able to fetch the keys and display them, however even-though this displays content, it renders the datatable functions useless such as filtering & sorting.

This is my TS & template files:

(I tried assigning the same value to multiple properties [uid, $key] to make sure it's not a keyword issue)

 import { Component, AfterViewInit, ViewChild } from '@angular/core'; import { MatTableDataSource, MatSort, MatDialog } from '@angular/material'; import { AngularFirestore, AngularFirestoreCollection, AngularFirestoreDocument } from '@angular/fire/firestore'; import { StatusDialogComponent } from './status-dialog/status-dialog.component'; import { Vehicle } from '../vehicle'; import { Observable } from 'rxjs'; import { map } from 'rxjs/operators'; @Component({ moduleId: module.id, selector: 'app-list-vehicles', templateUrl: 'list-vehicles.component.html', styleUrls: ['list-vehicles.component.scss'] }) export class ListVehiclesComponent implements AfterViewInit { vehicleKey: {}; vehicles$: AngularFirestoreCollection<Vehicle>; vehicles: Observable<Vehicle[]>; vehicle: AngularFirestoreDocument; displayedColumns = ['vin', 'make', 'model', 'status', '$key', 'details', 'edit']; dataSource: MatTableDataSource<any>; @ViewChild(MatSort) sort: MatSort; constructor( public afs: AngularFirestore, public dialog: MatDialog, ) { this.vehicles = this.afs.collection(`vehicles`).snapshotChanges().pipe( map(actions => { return actions.map(a => { const data = a.payload.doc.data() as Vehicle; const $key = a.payload.doc.id; console.log('payload: ' + a.payload.doc.id); data.$key = a.payload.doc.id; data.uid = a.payload.doc.id; if (data.$key === null || data.$key === undefined) {console.log('null.'); } else {console.log('full' + data.$key); } return {$key, ...data}; }); }) ); } ngAfterViewInit(): void { this.afs.collection<Vehicle>('vehicles').valueChanges().subscribe(data => { this.dataSource = new MatTableDataSource(data); this.dataSource.sort = this.sort; }); } applyFilter(filterValue: string) { filterValue = filterValue.trim(); filterValue = filterValue.toLowerCase(); this.dataSource.filter = filterValue; } openStatusDialog(data): void { const dialogRef = this.dialog.open(StatusDialogComponent, { width: '400px', data: data, }); } trackByUid(index, item) { return item.uid; } } 

 <div *ngFor="let veh of vehicles | async"> {{veh.$key}} <!-- I can fetch the keys here. --> </div> <div *ngIf="vehicles | async as vehicle1"> <button mat-raised-button color="accent"> A Useless Button </button> <div class="example-header"> <mat-form-field> <input matInput (keyup)="applyFilter($event.target.value)" placeholder="Filter"> </mat-form-field> </div> <mat-table #table [dataSource]="dataSource" [trackBy]="trackByUid" matSort> <ng-container matColumnDef="vin"> <mat-header-cell *matHeaderCellDef mat-sort-header>VIN</mat-header-cell> <mat-cell *matCellDef="let vehicle"> {{vehicle.vin}} </mat-cell> </ng-container> <ng-container matColumnDef="make"> <mat-header-cell *matHeaderCellDef mat-sort-header>Make</mat-header-cell> <mat-cell *matCellDef="let vehicle"> {{vehicle.make}} </mat-cell> </ng-container> <ng-container matColumnDef="model"> <mat-header-cell *matHeaderCellDef mat-sort-header>Model</mat-header-cell> <mat-cell *matCellDef="let vehicle"> {{vehicle.model}} </mat-cell> </ng-container> <ng-container matColumnDef="status"> <mat-header-cell *matHeaderCellDef mat-sort-header>Status</mat-header-cell> <mat-cell *matCellDef="let vehicle"> {{vehicle.status}} </mat-cell> </ng-container> <ng-container matColumnDef="$key"> <mat-header-cell *matHeaderCellDef mat-sort-header>Key</mat-header-cell> <mat-cell *matCellDef="let vehicle"> {{vehicle.$key}} </mat-cell> </ng-container> <ng-container matColumnDef="details"> <mat-header-cell *matHeaderCellDef mat-sort-header>Details</mat-header-cell> <mat-cell *matCellDef="let vehicle"> <button mat-raised-button color="primary" [routerLink]="['/vehicles', vehicle.$key]"> Details </button> </mat-cell> </ng-container> <ng-container matColumnDef="edit"> <mat-header-cell *matHeaderCellDef mat-sort-header>Edit</mat-header-cell> <mat-cell *matCellDef="let vehicle"> <button mat-raised-button color="warn" (click)="openStatusDialog(vehicle)"> Edit </button> </mat-cell> </ng-container> <mat-header-row *matHeaderRowDef="displayedColumns"></mat-header-row> <mat-row *matRowDef="let row; columns: displayedColumns;" class="animate"></mat-row> </mat-table> Json: {{(vehicle1 | json)}} <!-- I can also fetch them here. --> </div> 

This is when I'm using the "dataSource" as the data table source:

This is when I'm using the observable as the data table source:

Since I'm able to somehow fetch the keys using the observable asynchronous, how do I incorporate a similar method to the data table so I can get the keys using data table? Is there another way of navigating to the documents within a collection using material data tables that I might have missed?

Answer 1

Subscribing to the observable to build dataSource instead of subscribing to the collection resolved the issue.

so this:

this.afs.collection<Vehicle>('vehicles').valueChanges().subscribe(data => {
        this.dataSource = new MatTableDataSource(data);
        this.dataSource.sort = this.sort;
    });

is replaced with this:

this.vehicles.subscribe((d) => this.dataSource = new MatTableDataSource(d));