TurboTable select/unselect programmatically

Question

I have a TurboTable definition with checkbox selection like below:

<p-table [columns]="cols" [value]="dataJSONArray" [paginator]="true" [rows]="10" [scrollable]="true"
  [(selection)]="dtSelectedRows" dataKey="OrderId">
  <ng-template pTemplate="colgroup" let-columns>
    <colgroup>
      <col style="width: 3em">
      <col *ngFor="let col of columns" [ngStyle]="{'width': col.widthPx + 'px'}">
    </colgroup>
  </ng-template>
  <ng-template pTemplate="header">
    <tr>
      <th>
        <p-tableHeaderCheckbox></p-tableHeaderCheckbox>
      </th>
      <th *ngFor="let col of cols">{{col.header}}</th>
    </tr>
  </ng-template>
  <ng-template pTemplate="body" let-rowData let-col>
    <tr [pSelectableRow]="rowData">
      <td>
        <p-tableCheckbox [value]="rowData"></p-tableCheckbox>
      </td>
...

If i change dtSelectedRows array (selection), nothing happens (dtSelectedRows array changes, but checked columns does not change -stay checked-):

this.dtSelectedRows.splice(indx, 1);

But if i assign an array to dtSelectedRows array, changes take affect:

let dummySelectedRow = Object.assign([], this.dtSelectedRows);
dummySelectedRow.splice(indx, 1);
this.dtSelectedRows = dummySelectedRow;

Answer 1

You need to set the selection mode proprty to single in this case the dtSelectedRows will be refrence to object instand of array of selected value.

<p-tableHeaderCheckbox></p-tableHeaderCheckbox> set selection mode to multiple selection , you can solve this is to use p-tableRadioButton (radio button) if you want to support single selection mode

<p-table  [columns]="cols" [value]="data" [paginator]="true" [rows]="10" [scrollable]="true"
  [(selection)]="dtSelectedRows" >
  <ng-template pTemplate="header">
    <tr>
      <th>
      </th>
      <th *ngFor="let col of cols">{{col.header}}</th>
    </tr>
  </ng-template>
  <ng-template pTemplate="body" let-rowData let-col>
    <tr [pSelectableRow]="rowData">
       <td>
        <p-tableRadioButton [value]="rowData"></p-tableRadioButton>
      </td>
      <td *ngFor="let col of cols">{{rowData[col.field]}}<td>
    </tr>
  </ng-template>
</p-table>

set selected item by method

  setSelectedItem(){
    this.dtSelectedRows = this.data[0];
  }

In case of you want to remove an item based on condition in multiple mode

  removeUnvalidItem(){
    if (this.dtSelectedRows) {
      this.dtSelectedRows = this.dtSelectedRows.filter(car => car.year > 2005) 
    }
  }

stackblitz demo