Removing Polyline in cesium js - cesiumjs

Question

How to remove a polyline in cesiumjs,
var p = this.viewer.entities.add({
polyline: {
material: new Cesium.PolylineGlowMaterialProperty({
glowPower: 0.7,
color: Cesium.Color.ORANGE.withAlpha(0.7)
}),
positions: Cesium.Cartesian3.fromDegreesArrayHeights(points),
width: 15,
}
});
I used entities.removeAll(), but it is deleting entire data from the cesium conatiner(including models,etc). I want to delete only Polyline.

Answer 1

Save the return value from entities.add, this is a reference to the newly created entity.
var polylineEntity = viewer.entities.add({
//...
});
Later, you can remove a specific entity by reference.
viewer.entities.remove(polylineEntity);

Answer 2

var pathDone; //Store dataSource so later can be removed.
viewer.dataSources.remove(pathDone,true); // Removing old data.
Cesium.GeoJsonDataSource.load(data, { // Data contains geojson, linestring z.
stroke: Cesium.Color.HOTPINK,
fill: Cesium.Color.PINK.withAlpha(0.5),
strokeWidth: 2
}).then(function(geoData){
viewer.dataSources.add(geoData); //Adding new one.
pathDone=geoData;//Storing new reference.
});
This worked for me.

Answer 3

you can also remove entity by giving entity an id.
check cesium api doc here. https://cesium.com/learn/cesiumjs/ref-doc/EntityCollection.html?classFilter=entity#id
var p = this.viewer.entities.add({
id: "polylinId", // this is where you should add. give entity an id you can use.
polyline: {
material: new Cesium.PolylineGlowMaterialProperty({
glowPower: 0.7,
color: Cesium.Color.ORANGE.withAlpha(0.7)
}),
positions: Cesium.Cartesian3.fromDegreesArrayHeights(points),
width: 15,
}
});
// then remove entity by id you've given
viewer.entity.removeById("polylinId")