Content projection inside angular-material table

Question

Instead of a regular way of displaying data to table. I'm trying to create my custom-table component and project the data in the material table via .

like this:

<table mat-table [dataSource]="dataSource">
 <!-- I want to Render the header and cell data here -->
 <ng-content></ng-content>
 
 <mat-header-row *matHeaderRowDef="headers; sticky: true"></mat-header-row>
 <mat-row *matRowDef="let row; columns: headers;"></mat-row>
</table>

So I can call this customized component like this:

<app-customized-table>
 <ng-container matColumnDef="id">
  <mat-header-cell *matHeaderCellDef> Id </mat-header-cell>
  <mat-cell *matCellDef="let element"> {{element.Id}} </mat-cell>
 </ng-container>
 ...etc
</app-customized-table>

However, it won't detect the content. Here's a stackblitz example that i'm trying to do.

https://stackblitz.com/edit/angular-qwvcln?file=src%2Fapp%2Fcustom-table.component.ts

Is there a way to do this?

Thanks.

Answer 1

Bit late to the party, but I had the same challenge and was able to solve it as follows:

You can solve it by adding the column definitions to the table programmatically, by using the @ContentChildren and @ViewChild functionality:

your template file (e.g. customized-table.component.html):

<table mat-table [dataSource]="dataSource">
    <ng-content></ng-content>

    <mat-header-row *matHeaderRowDef="headers; sticky: true"></mat-header-row>
    <mat-row *matRowDef="let row; columns: headers;"></mat-row>
</table>

your codebehind (e.g. customized-table.component.ts):

@Component({
    selector: 'app-customized-table',
    templateUrl: './customized-table.component.html'
})
export class CustomizedTableComponent<T> implements AfterContentInit {
    constructor() { }

    @Input() dataSource: T[]; // or whatever type of datasource you have
    @Input() headers: string[];

    // this is where the magic happens: 
    @ViewChild(MatTable, { static: true }) table: MatTable<T>;
    @ContentChildren(MatColumnDef) columnDefs: QueryList<MatColumnDef>;

    // after the <ng-content> has been initialized, the column definitions are available.
    // All that's left is to add them to the table ourselves:
    ngAfterContentInit() {
        this.columnDefs.forEach(columnDef => this.table.addColumnDef(columnDef));
    }
}

Now, you're able to use:

<app-customized-table [headers]="headers">
    <ng-container matColumnDef="id">
        <mat-header-cell *matHeaderCellDef> Id </mat-header-cell>
        <mat-cell *matCellDef="let element"> {{element.Id}} </mat-cell>
    </ng-container>
    ...etc
</app-customized-table>

Stackblitz working demo with lazy loaded modules

Answer 2

You would have to take a very different approach to get this to work. As you have noticed, mat-table can't have it's content wrapped in something else. A possibility is to provide just the data to your custom component rather than the the DOM as content. For example:

Component:

import { Component, OnInit, Input } from '@angular/core';

@Component({
  selector: 'app-custom-table',
  template: `
    <div>
      {{name}}

      <div class="example-container mat-elevation-z8">
        <table mat-table [dataSource]="dataSource">

          <mat-header-row *matHeaderRowDef="displayedColumns; sticky: true"></mat-header-row>
          <mat-row *matRowDef="let row; columns: displayedColumns;"></mat-row>

          <ng-container *ngFor="let column of displayedColumns; index as i" >

            <ng-container [matColumnDef]="column">
              <mat-header-cell *matHeaderCellDef>{{ columnLabels[i] }}</mat-header-cell>
              <mat-cell mat-cell *matCellDef="let element"> {{element[valueKeys[i]]}} </mat-cell>
            </ng-container>

          </ng-container>

        </table>
      </div>

      asd
    </div>
  `
})
export class CustomTable implements OnInit {
  @Input() public columnLabels: any[];
  @Input() public displayedColumns;
  @Input() public dataSource;
  @Input() public name: any;
  @Input() public valueKeys: any[];

  constructor() { }

  ngOnInit() {
  }

}

Usage:

<app-custom-table name="sdf" 
    [dataSource]="dataSource" 
    [displayedColumns]="displayedColumns"
    [columnLabels]="columnLabels" 
    [valueKeys]="displayedColumns">

</app-custom-table>

Where:

displayedColumns = ['position', 'name', 'weight', 'symbol'];
dataSource = ELEMENT_DATA;
columnLabels = ['No.', 'Name', 'Weight', 'Symbol'];

But even this way there might be some more challenges.

Answer 3

You can project content like this:

<ng-container *ngFor=”let column of displayedColumns” matColumnDef=”{{column.id}}”>
   <th mat-header-cell *matHeaderCellDef mat-sort-header>{{column.name}}</th>
   <td mat-cell *matCellDef=”let row”>
      {{row[column.id]}}
   </td>
</ng-container>

Then you pass the template for content projection:

<my-component …
[itemTemplate]=”itemTemplate”>
   <ng-template let-item #itemTemplate>
      column id: {{item.column.id}}
      value: {{item.value}}
   </ng-template>
</my-component>

source