In angular 7 , How do I populate a mat-table with

Question

Currently I have the following code to populate a table.

In component.ts:

import { HttpClient } from "@angular/common/http";
import { Component, OnInit } from "@angular/core";
import { FormBuilder, FormGroup, Validators } from "@angular/forms";
import { ActivatedRoute, Router } from "@angular/router";
import { MatTableDataSource } from "@angular/material/table";

@Component({
  styleUrls: ["./styles.scss"],
  templateUrl: "./template.html"
})
export class MyRouteData {
  employeeInfoTable: object;

  constructor(private http: HttpClient) {}

  ngOnInit() {
    this.http
      .get("http://localhost:5000/MyRoute/GetEmployeeInfo")
      .subscribe(response => {
        this.employeeInfoTable = response;
      });
  }
}

My template.html file looks like this:

<mat-card style="height: 98%">
  <div style="height: 95%; overflow: auto;">
      <table class="MyNiceStyle">
        <thead>
          <tr>
            <td>Name</td>
            <td>Age</td>
            <td>Date Of Birth</td>
            <td>Address</td>
            <td>Postcode</td>
            <td>Gender</td>
            <td>Salary</td>
            <td>Job Title</td>
          </tr>
        </thead>

        <tr *ngFor="let data of employeeInfoTable">
          <td>{{data.Name}}</td>
          <td>{{data.Age}}</td>
          <td>{{data.DateOfBirth}}</td>
          <td>{{data.Address}}</td>
          <td>{{data.Postcode}}</td>
          <td>{{data.Gender}}</td>
          <td>{{data.Salary}}</td>
          <td>{{data.JobTitle}}</td>
      </table>
    </div>

</mat-card>

which works but honestly, it looks terrible. What I would like to do is to use a mat-table: https://material.angular.io/components/table/examples

I've updated the template.html to:

<mat-card style="height: 98%">
    <table mat-table [dataSource]="employeeInfoTable" class="mat-elevation-z8">
        <ng-container matColumnDef="Name">
            <th mat-header-cell *matHeaderCellDef>Name </th>
            <td mat-cell *matCellDef="let element"> {{element.Name}} </td>
        </ng-container>
        <ng-container matColumnDef="DateOfBirth">
            <th mat-header-cell *matHeaderCellDef> DateOfBirth </th>
            <td mat-cell *matCellDef="let element"> {{element.DateOfBirth}} </td>
        </ng-container>
        <ng-container matColumnDef="Address">
            <th mat-header-cell *matHeaderCellDef> Address </th>
            <td mat-cell *matCellDef="let element"> {{element.Address}} </td>
        </ng-container>
        <ng-container matColumnDef="Postcode">
            <th mat-header-cell *matHeaderCellDef> Postcode </th>
            <td mat-cell *matCellDef="let element"> {{element.Postcode}} </td>

        <ng-container matColumnDef="Gender">
            <th mat-header-cell *matHeaderCellDef> Gender </th>
            <td mat-cell *matCellDef="let element"> {{element.Gender}} </td>
        </ng-container>
        <ng-container matColumnDef="Salary">
            <th mat-header-cell *matHeaderCellDef> Salary </th>
            <td mat-cell *matCellDef="let element"> {{element.Salary}} </td>
        </ng-container>
        <ng-container matColumnDef="JobTitle">
            <th mat-header-cell *matHeaderCellDef> JobTitle </th>
            <td mat-cell *matCellDef="let element"> {{element.JobTitle}} </td>
        </ng-container>

        <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
        <tr mat-row *matRowDef="let row; columns: displayedColumns;"></tr>
    </table>
</mat-card>

and when I run this I just see a blank screen. There are no console errors or anything like that. What changes do I need to make to template.html and/or component.ts to get the data to show?

Answer 1

You need to make these changes.

In component.ts:

import { HttpClient } from "@angular/common/http";
import { Component, OnInit } from "@angular/core";
import { FormBuilder, FormGroup, Validators } from "@angular/forms";
import { ActivatedRoute, Router } from "@angular/router";
import { MatTableDataSource } from "@angular/material";
import { Object} from "../object.model";

@Component({
   styleUrls: ["./styles.scss"],
   templateUrl: "./template.html"
})
export class MyRouteData implements OnInit {
   employeeInfoTable : Object[] = [];
   employeeInfoTableDataSource = new MatTableDataSource(this.employeeInfoTable);
   displayedColumns: string[] = [
     "Name",
     "DateOfBirth",
     "Address",
     "Postcode",
     "Gender",
     "Salary"
     "JobTitle"
  ];

   constructor(private http: HttpClient) {}

   ngOnInit() {
      this.http.get("http://localhost:5000/MyRoute/GetEmployeeInfo")
          .subscribe(response => {
             this.employeeInfoTable = response;
             this.employeeInfoTableDataSource.data = this.employeeInfoTable;
      });
   }
}

In object.model.ts

export interface Object{
   id: number;
   Name: string;
   DateOfBirth: Date;
   Address: string;
   Postcode: string;
   Gender: string;
   Salary : number;
   JobTitle : string;
}

In your .html

<mat-card style="height: 98%">
  <table mat-table [dataSource]="employeeInfoTableDataSource" class="mat-elevation-z8">
    <ng-container matColumnDef="Name">
        <th mat-header-cell *matHeaderCellDef>Name </th>
        <td mat-cell *matCellDef="let element"> {{element.Name}} </td>
    </ng-container>
    <ng-container matColumnDef="DateOfBirth">
        <th mat-header-cell *matHeaderCellDef> DateOfBirth </th>
        <td mat-cell *matCellDef="let element"> {{element.DateOfBirth}} </td>
    </ng-container>
    <ng-container matColumnDef="Address">
        <th mat-header-cell *matHeaderCellDef> Address </th>
        <td mat-cell *matCellDef="let element"> {{element.Address}} </td>
    </ng-container>
    <ng-container matColumnDef="Postcode">
        <th mat-header-cell *matHeaderCellDef> Postcode </th>
        <td mat-cell *matCellDef="let element"> {{element.Postcode}} </td>

    <ng-container matColumnDef="Gender">
        <th mat-header-cell *matHeaderCellDef> Gender </th>
        <td mat-cell *matCellDef="let element"> {{element.Gender}} </td>
    </ng-container>
    <ng-container matColumnDef="Salary">
        <th mat-header-cell *matHeaderCellDef> Salary </th>
        <td mat-cell *matCellDef="let element"> {{element.Salary}} </td>
    </ng-container>
    <ng-container matColumnDef="JobTitle">
        <th mat-header-cell *matHeaderCellDef> JobTitle </th>
        <td mat-cell *matCellDef="let element"> {{element.JobTitle}} </td>
    </ng-container>

    <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
    <tr mat-row *matRowDef="let row; columns: displayedColumns;"></tr>
  </table>
</mat-card>

Answer 2

You need to make 2 changes into your Component.ts file:

1) Add defination for 'displayedColumns'. (Please note that your table have 2 'Postcode' columns which is not allowed and i removed one of the columns from displayedColumns defination. Please remove it from your html table also).

public displayedColumns = ['Name', 'DateOfBirth', 'address', 'Postcode', 'Gender', 'Salary', 'JobTitle', 'inbound', 'ping_time'];

2) Assign response to employeeInfoTable as MatTableDataSource. It will be required while working on rows separatly.

public employeeInfoTable: any;
this.employeeInfoTable = new MatTableDataSource<any>([...response]);;