javascript - How to add data dynamically to mat-table dataSource?

Question

I have data streaming from backend and i see it printing in console now i am trying to push event to dataSource its throwing error dataSource is not defined. Can someone help how to dynamically add data to materialize table ?

stream.component.html

<mat-table #table [dataSource]="dataSource"></mat-table>

stream.component.ts

import {
    Component,
    OnInit
} from '@angular/core';
import {
    StreamService
} from '../stream.service';
import {
    MatTableDataSource
} from '@angular/material';
import * as io from 'socket.io-client';

@Component({
    selector: 'app-stream',
    templateUrl: './stream.component.html',
    styleUrls: ['./stream.component.css']
})
export class StreamComponent implements OnInit {
    displayedColumns = ['ticketNum', "assetID", "severity", "riskIndex", "riskValue", "ticketOpened", "lastModifiedDate", "eventType"];
    dataSource: MatTableDataSource < Element[] > ;
    socket = io();

    constructor(private streamService: StreamService) {};

    ngOnInit() {
        this.streamService.getAllStream().subscribe(stream => {
            this.dataSource = new MatTableDataSource(stream);
        });
        this.socket.on('newMessage', function(event) {
            console.log('Datasource', event);
            this.dataSource.MatTableDataSource.filteredData.push(event);
        });
    }
}


export interface Element {
    ticketNum: number;
    ticketOpened: number;
    eventType: string;
    riskIndex: string;
    riskValue: number;
    severity: string;
    lastModifiedDate: number;
    assetID: string;
}

Answer 1

I have found a solution for this problem, basically if you do:

this.dataSource.data.push(newElement); //Doesn't work

But if you replace the complete array then it works fine. So your final code must be :

this.socket.on('newMessage', function(event) {
    const data = this.dataSource.data;
    data.push(event);
    this.dataSource.data = data;
});

You can see the issue here -> https://github.com/angular/material2/issues/8381