Angular Material 2 DataTable Sorting with nested objects

Question

I have a normal Angular Material 2 DataTable with sort headers. All sort are headers work fine. Except for the one with an object as value. These doesn\'t sort at all.

Answer 1

Another alternative, that no one threw out here, flatten the column first...

yourData.map((d) => 
   d.flattenedName = d.project && d.project.name ? 
                     d.project.name : 
                     'Not Specified');

this.dataSource = new MatTableDataSource(yourData);

Just another alternative, pros and cons for each!

Answer 2

I customized for multiple nested object level.

this.dataSource.sortingDataAccessor =
  (data: any, sortHeaderId: string): string | number => {
    let value = null;
    if (sortHeaderId.includes('.')) {
      const ids = sortHeaderId.split('.');
      value = data;
      ids.forEach(function (x) {
        value = value? value[x]: null;
      });
    } else {
      value = data[sortHeaderId];
    }
    return _isNumberValue(value) ? Number(value) : value;
  };

Answer 3

You can write a function in component to get deeply property from object. Then use it in dataSource.sortingDataAccessor like below

getProperty = (obj, path) => (
  path.split('.').reduce((o, p) => o && o[p], obj)
)

ngOnInit() {
  this.dataSource = new MatTableDataSource(yourData);
  this.dataSource.sortingDataAccessor = (obj, property) => this.getProperty(obj, property);
  this.dataSource.sort = sort;
}

columnDefs = [
  {name: 'project.name', title: 'Project Name'},
  {name: 'position', title: 'Position'},
  {name: 'name', title: 'Name'},
  {name: 'test', title: 'Test'},
  {name: 'symbol', title: 'Symbol'}
];

And in html

<ng-container *ngFor="let col of columnDefs" [matColumnDef]="col.name">
      <mat-header-cell *matHeaderCellDef>{{ col.title }}</mat-header-cell>
      <mat-cell *matCellDef="let row">
        {{ getProperty(row, col.name) }}
      </mat-cell>
  </ng-container>

Answer 4

The answer as given can even be shortened, no switch required, as long as you use the dot notation for the fields.

ngOnInit() {
  this.dataSource = new MatTableDataSource(yourData);

  this.dataSource.sortingDataAccessor = (item, property) => {
     if (property.includes('.')) return property.split('.').reduce((o,i)=>o[i], item)
     return item[property];
  };

  this.dataSource.sort = sort;
}

Answer 5

Use MatTableDataSource Check complete MatSort issue solution

in HTML

    <ng-container matColumnDef="createdDate" @bounceInLeft>
      <th mat-header-cell *matHeaderCellDef mat-sort-header class="date"> Created date
      </th>
          <td mat-cell *matCellDef="let element" class="date"> {{element.createdDate
           | date :'mediumDate'}} </td>
   </ng-container>

  <ng-container matColumnDef="group.name">
    <th mat-header-cell *matHeaderCellDef mat-sort-header class="type"> Group </th>
    <td mat-cell *matCellDef="let element" class="type"> {{element.group.name}} </td>
  </ng-container>

@ViewChild(MatSort, { static: true }) sort: MatSort;

    ngOnInit() {
      this.dataSource = new MatTableDataSource(yourData);
      this.dataSource.sortingDataAccessor = (item, property) => {
    switch(property) {
      case 'project.name': return item.project.name;
      default: return item[property];
    }
  };
  this.dataSource.sort = sort;
}