Elevation profile from existing lines

Question

I am trying to pass the geometry of a polyline from a map service layer to the elevation profile widget. Normally, when using a polyline generated from the Draw tool, we can grab the event geometry upon drawing end:

this._toolbar.on("draw-end", (e: any) => this.refreshElevationProfile(e));

refreshElevationProfile(evt): void {
    this._elevationProfileWidget.set("profileGeometry", evt.geometry);
};

Using an identify task, I can get the layers in my map service layer upon map click. But does anyone know how to get specifically the geometry from a feature from one of the layers? (Say the top-most layer for example)

Answer 1

Something like this should do the trick.

    public selectPolyline(){
        this._mapClickHandler = this.map
            .on("click", e => this.executeIdentifyTasks(e, this.map.getLayersVisibleAtScale()));
    }

    public executeIdentifyTasks(event: any, layers: Array<Layer>): void {

        let identifyTasks: Array<Promise<any>> = new Array<Promise<any>>();
        layers.forEach(l => {
            var ids = (<any>l).layerInfos.map(x => x.id);
            let identifyParams = this.getIdentifyParamsForRequest(event.mapPoint, this.map, [ids]);
            let identifyTask = new IdentifyTask(l.url);
            identifyTasks.push(identifyTask.execute(identifyParams));
        });

        let identifiedItems: Array<any> = new Array<any>();
        Observable.forkJoin(identifyTasks).subscribe((responses: Array<IdentifyResult>) => {
            if (responses[0][0].feature.geometry.type === "polyline") {
                console.log("We have a polyline");
            }
            responses.forEach(layerResponse => {
                if (layerResponse[0].geometryType === "esriGeometryPolyline") {
                    this.refreshElevationProfile(layerResponse[0].feature);
                }
            });
        });

    }