Angular- Material table sorting not working in proper way

Question

I'm creating a table that should sort by file name and date I followed the Angular Material documentation for this purpose but is not working, it's not showing any errors in the compiler or the browser console, the table looks like this:

<mat-table [dataSource]="dataSource" matSort>
      <ng-container matColumnDef="File">
        <mat-header-cell *matHeaderCellDef mat-sort-header> File </mat-header-cell>
        <mat-cell  *matCellDef="let element" data-label="File"> {{element.fileName}} </mat-cell>
      </ng-container>

      <!-- Name Column -->
      <ng-container matColumnDef="Date">
        <mat-header-cell  *matHeaderCellDef mat-sort-header>Date </mat-header-cell>
        <mat-cell  *matCellDef="let element" data-label="Date"> {{element.date}} </mat-cell>
      </ng-container>
      <!-- Weight Column -->
      <ng-container matColumnDef="Extension">
        <mat-header-cell *matHeaderCellDef mat-sort-header>Extension</mat-header-cell>
        <mat-cell  *matCellDef="let element" data-label="Extension"> {{element.extension}} </mat-cell>
      </ng-container>



      <ng-container matColumnDef="View">
        <mat-header-cell *matHeaderCellDef> Actions </mat-header-cell>
        <mat-cell  *matCellDef="let element" data-label="View"> <a href="{{element.url}}" target="_blank" class="green-text"><i class="material-icons">visibility</i></a></mat-cell>
      </ng-container>

      <ng-container matColumnDef="Delete">
        <mat-header-cell *matHeaderCellDef> Delete </mat-header-cell>
        <mat-cell  *matCellDef="let element" data-label="Delete"> <a class="red-text"><i class="material-icons">delete_forever</i></a></mat-cell>
      </ng-container>
      <mat-header-row *matHeaderRowDef="displayedColumns"></mat-header-row>
      <mat-row *matRowDef="let row; columns: displayedColumns;"></mat-row>
    </mat-table>

and this is my ts code

export class FilesComponent implements OnInit {
  displayedColumns: string[] = ['File', 'Extension', 'Date', 'View', 'Delete'];
  dataSource = new MatTableDataSource<Files>(ELEMENT_DATA);
  data = ELEMENT_DATA;
  selects: any;
  @ViewChild(MatPaginator, {static: true}) paginator: MatPaginator;
  @ViewChild(MatSort, {static: true}) sort: MatSort;
  constructor(private addFile: MatDialog) {
  }

  ngOnInit(): void {
    this.Materialize();
    this.dataSource.paginator = this.paginator;
    this.dataSource.sort = this.sort;
  }

  Materialize() {
    this.selects = document.querySelectorAll('select');
    M.FormSelect.init(this.selects);
  }

  changeFiles(value) {
    console.log('option:', value);
    switch (parseInt(value)) {
      case 1:
        this.dataSource = new MatTableDataSource<Files>(ELEMENT_DATA);
        break;
      case 2:
        this.dataSource = new MatTableDataSource<Files>(Charts);
        break;
      case 3:
        this.dataSource = new MatTableDataSource<Files>(Documents);
        break;
      default:
        this.dataSource = new MatTableDataSource<Files>(ELEMENT_DATA);
        break;
    }
    this.dataSource.sort = this.sort;
    this.dataSource.paginator = this.paginator;
  }
}

event the sort header it's applied and the styles (the arrows for the sort) appear in the table the data does not sort.

Answer 1

matColumnDef name and *matCellDef actual value name should be same

In component.html

Change

<ng-container matColumnDef="File"> <mat-header-cell *matHeaderCellDef mat-sort-header> File </mat-header-cell> <mat-cell *matCellDef="let element" data-label="File"> {{element.fileName}} </mat-cell></ng-container>

to

<ng-container matColumnDef="fileName"> <mat-header-cell *matHeaderCellDef mat-sort-header> File </mat-header-cell> <mat-cell *matCellDef="let element" data-label="File"> {{element.fileName}} </mat-cell> </ng-container>

In ts:

change

displayedColumns: string[] = ['File', 'Extension', 'Date', 'View', 'Delete'];

to

displayedColumns: string[] = ['fileName', 'Extension', 'Date', 'View', 'Delete'];

Answer 2

您需要添加MatSortModule在进口阵列app.module.ts

Answer 3

@user12129132's answer will work for normal sorting ( You need to change the field values in the datasource to match the field values in the column definitions and also use the same in matColumn definition) but you have filename with numbers in it, it wont be sorted properly.For that purpose we can use sortingDataAccessor.

See the working version here - Stackblitz: https://stackblitz.com/edit/angular-g4svyj

  ngAfterViewInit() {    
  this.dataSource.sort = this.sort;
  this.dataSource.sortingDataAccessor = (data, attribute) => {
    let formattedData=data[attribute]
    if(attribute=="fileName")
    {  
       formattedData=parseInt(formattedData.match(/(\d)*$/)[0]);
    }
    return formattedData;
  };
   this.dataSource.paginator = this.paginator; 
  }