Removing Layer on ArcGIS API For JavaScript>

Question

I am adding a markers layer called layer1 like this to map

function drawPoints(mapInfo) {
 layer1 = new esri.layers.GraphicsLayer();
 for (var i = 0; i < mapInfo.length; i++) {
 var projects = mapInfo[i];
 var project = new esri.geometry.Point(projects.Longitude, projects.Latitude);
 project = esri.geometry.geographicToWebMercator(project);
 var symbol = new esri.symbol.PictureMarkerSymbol("img/map/marker.png", 18, 18);
 projectInfoTemplate = new InfoTemplate();
 projectInfoTemplate.setTitle("Project Details");
 projectInfoTemplate.setContent('<div class="row"></div> ');
 var projectsG = new esri.Graphic(project, symbol).setInfoTemplate(projectInfoTemplate);
 layer1.add(projectsG);
 }
 map.addLayer(layer1);
 }

now in next request I need to clear map so I used the

map.removeLayer(layer1);

but this is causing error because the layer1 still not created at first request. Now I need to check IF the map has a layer called layer1 then removeit. Here is a pseudo code of what I need to do:

if(map.has/contains/include(layer1){
 map.removeLayer(layer1);
}

can you please let me know how to do that?

• timlohnes: A little confused about your request, sounds like you are adding a layer and then immediately removing it automatically. Something else?

Answer 1

You have to make sure it is loaded. I couldn't get layer1 to get recognized when I used 'load', but this works fine. Just click on map and the points will go away.

 map.on("click", function unloadPoints() {
 map.removeLayer(layer1);
 });

I thought this would work, but like I said it didn't see layer1. So explore along these lines.

 layer1.on("load", function unloadPoints() {
 map.removeLayer(layer1);
 });

Read more about events here https://developers.arcgis.com/javascript/jshelp/inside_events.html