Angular Data GridAG Grid and NgZone

AG Grid implements performance optimisations to avoid Zone Pollution as recommended by the Angular team.

NgZone and Change Detection

Angular uses Zone.js to manage change detection by capturing all asynchronous operations and scheduling change detection to run when they complete. However, if an application / library uses asynchronous operations that do not require change detection to run, it can be beneficial to run these operations outside of NgZone.

The official term for this is Zone Pollution as documented by Angular.

AG Grid Features Run In / Out of NgZone

AG Grid minimises unnecessary change detection by running all internal operations outside of NgZone while ensuring that wherever AG Grid may trigger a change in the Angular application that this code will be executed inside NgZone. This behaviour should be invisible to the vast majority of developers.

Operations Run Inside NgZone

The majority of application code run by AG Grid will be executed inside NgZone including:

• Event handlers, grid, row, column, etc
• Menu actions triggers
• Custom components
  • Angular lifecycle methods
  • agInit, refresh, etc

onCellClicked(event: CellClickedEvent) {
  // This code will run inside NgZone
  console.log("Inside NgZone", NgZone.isInAngularZone())   
}

<ag-grid-angular (cellClicked)="onCellClicked($event)">

Operations Run Outside NgZone

For performance gains the following operations are run outside of NgZone:

• grid callbacks

getRowId(params: GetRowIdParams) {
  // This code will run outside NgZone
  console.log("Outside NgZone", NgZone.isInAngularZone());
  return String(params.data.id);
}

<ag-grid-angular [getRowId]="getRowId">

Grid callbacks should only be used to provide configuration to the grid and should not be used to update application state. However, if you need to work around this restriction you can use NgZone.run to force code to execute inside NgZone.

gridCallback(params: GridCallbackParams) {
  this.ngZone.run(() => {
    // This code will run inside NgZone
    console.log("Inside NgZone", NgZone.isInAngularZone());
  });
}

The majority of developers will not need to worry about this as the grid is designed to work seamlessly with Angular applications. However, if you are experiencing issues with change detection or performance you may need to consider the above information.