topic Re: <arcgis-sketch> Selection event for lasso / rectangle in ArcGIS JavaScript Maps SDK Questions

Selection event for lasso / rectangle

AndrewMurdoch1 — Thu, 12 Mar 2026 19:24:55 GMT

Good Day

What is the event thrown by the Lasso selection tool?

<arcgis-sketch
    hide-settings-menu
    hide-snapping-controls
    hide-create-tools-circle
    hide-create-tools-multipoint
    hide-create-tools-point
    hide-create-tools-rectangle
    hide-create-tools-polyline
    hide-undo-redo-menu
    layout="horizontal"
    (arcgisCreate)="onSketchUpdate($event)"
    (arcgisPropertyChange)="onSketchUpdate($event)"
    (arcgisUpdate)="onSketchUpdate($event)"
    [layer]="sketchLayer"
    referenceElement="mapElement{{_mapId === 1 ? '1' : '2'}}"
    [view]="_view">
</arcgis-sketch>

The property change event seems to throw something, but not the create or update event, so once I finish drawing how do I get the area I just made, so I can run the intersect check?

Thanks

Re: Selection event for lasso / rectangle

WesleyO — Thu, 12 Mar 2026 20:41:01 GMT

Hi @AndrewMurdoch1 ,

After a selection is made, the arcgisUpdate event is triggered. It's important to note that this event is also fired when you update the selected graphic or when you unselect the current graphic. To ensure that your function runs right after the graphic is selected (and not updated or unselected), check that the event's state property is "start".

You can find more details about the arcgisUpdate event here: https://developers.arcgis.com/javascript/latest/references/core/widgets/Sketch/types/#UpdateEvent

I've also created a simple codepen that demonstrates this. Create a polygon to see the arcgisCreate event. Then, select the polygon to observe that the arcgisUpdate event being called.

Codepen: https://codepen.io/woriginales/pen/YPGNZmj

Let me know if this helps.

Re: Selection event for lasso / rectangle

AndrewMurdoch1 — Thu, 12 Mar 2026 20:46:48 GMT

Thanks!

That solution is definitely working, so I must have something off on my production code. Very helpful to have a stable solution. 🙂

Re: Selection event for lasso / rectangle

AndrewMurdoch1 — Fri, 13 Mar 2026 14:57:42 GMT

Thanks for the help yesterday, I came up with a solution to my issue. Basically, I'm trying to select features on StreamLayers / FeatureLayers that are under the Lasso Selection tool. This is now working, and I'm getting the graphics I need, so if anyone else needs help doing this, try this method.

I'm not sure if there is a better method, but this seems to work. On another point, that draw tool was only active because of another issue, I'm only using the Sketch component for the Lasso / Rectangular selections.

this.sketchWidgetPointerDownEvent = this._view.on("pointer-down", (event) => {

    console.log('Got Pointer Down Event');

    const sketch = document.querySelector('arcgis-sketch') as any;
    const activeTool = sketch?.activeTool;

    console.log('Active Tool: ', activeTool);

    if (activeTool !== 'polygon') return;

    this._view.hitTest(event).then((response) => {
        if (response.results.length) {
            this.lassoSet = true;
        }
    })
});

this.sketchWidgetPointerUpEvent = this._view.on("pointer-up", (event) => {

    console.log('Got Pointer Up Event');

    this._view.hitTest(event).then((response: any) => {
        console.log('Response');
        console.log(response);
    })
});