I want an event to fire when a selection is made on a specific layer.
This is my code:
I am in doubt of where I go wrong.
I made a modification (lines 80-84) to one of the samples that uses the selectFeatures method and the alert pops up as expected.
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no">
<title>Select with feature layer</title>
<link rel="stylesheet" href="https://js.arcgis.com/3.29/dijit/themes/tundra/tundra.css">
<link rel="stylesheet" href="https://js.arcgis.com/3.29/esri/css/esri.css">
<style>
html, body, #mapDiv {
padding: 0;
margin: 0;
height: 100%;
}
#messages{
background-color: #fff;
box-shadow: 0 0 5px #888;
font-size: 1.1em;
max-width: 15em;
padding: 0.5em;
position: absolute;
right: 20px;
top: 20px;
z-index: 40;
}
</style>
<script src="https://js.arcgis.com/3.29/"></script>
<script>
var map;
require([
"esri/map", "esri/layers/FeatureLayer",
"esri/tasks/query", "esri/geometry/Circle",
"esri/graphic", "esri/symbols/SimpleMarkerSymbol",
"esri/symbols/SimpleLineSymbol", "esri/symbols/SimpleFillSymbol", "esri/renderers/SimpleRenderer",
"esri/config", "esri/Color", "dojo/dom", "dojo/domReady!"
], function(
Map, FeatureLayer,
Query, Circle,
Graphic, SimpleMarkerSymbol,
SimpleLineSymbol, SimpleFillSymbol, SimpleRenderer,
esriConfig, Color, dom
) {
// Use a proxy page if a URL generated by this page is greater than 2000 characters
//
// This should not be needed as nearly all query & select functions are performed on the client
esriConfig.defaults.io.proxyUrl = "/proxy/";
map = new Map("mapDiv", {
basemap: "streets",
center: [-95.249, 38.954],
zoom: 14,
slider: false
});
// Add the census block points in on demand mode. An outfield is specified since it is used when calculating the total population falling within the one mile radius.
var featureLayer = new FeatureLayer("https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/0",{
outFields: ["POP2000"],
id: 'census'
});
// Selection symbol used to draw the selected census block points within the buffer polygon
var symbol = new SimpleMarkerSymbol(
SimpleMarkerSymbol.STYLE_CIRCLE,
12,
new SimpleLineSymbol(
SimpleLineSymbol.STYLE_NULL,
new Color([247, 34, 101, 0.9]),
1
),
new Color([207, 34, 171, 0.5])
);
featureLayer.setSelectionSymbol(symbol);
// Make unselected features invisible
var nullSymbol = new SimpleMarkerSymbol().setSize(0);
featureLayer.setRenderer(new SimpleRenderer(nullSymbol));
map.addLayer(featureLayer);
lyr = map.getLayer('census');
console.log(lyr);
lyr.on('selection-complete', function(){
alert("lyr selected");
});
var circleSymb = new SimpleFillSymbol(
SimpleFillSymbol.STYLE_NULL,
new SimpleLineSymbol(
SimpleLineSymbol.STYLE_SHORTDASHDOTDOT,
new Color([105, 105, 105]),
2
), new Color([255, 255, 0, 0.25])
);
var circle;
// When the map is clicked create a buffer around the click point of the specified distance
map.on("click", function(evt){
circle = new Circle({
center: evt.mapPoint,
geodesic: true,
radius: 1,
radiusUnit: "esriMiles"
});
map.graphics.clear();
var graphic = new Graphic(circle, circleSymb);
map.graphics.add(graphic);
var query = new Query();
query.geometry = circle.getExtent();
// Use a fast bounding box query. It will only go to the server if bounding box is outside of the visible map.
featureLayer.queryFeatures(query, selectInBuffer);
});
function selectInBuffer(response){
var feature;
var features = response.features;
var inBuffer = [];
// Filter out features that are not actually in buffer, since we got all points in the buffer's bounding box
for (var i = 0; i < features.length; i++) {
feature = features;
if(circle.contains(feature.geometry)){
inBuffer.push(feature.attributes[featureLayer.objectIdField]);
}
}
var query = new Query();
query.objectIds = inBuffer;
// Use an objectIds selection query (should not need to go to the server)
featureLayer.selectFeatures(query, FeatureLayer.SELECTION_NEW, function(results){
var totalPopulation = sumPopulation(results);
var r = "";
r = "<b>The total Census Block population within the buffer is <i>" + totalPopulation + "</i>.</b>";
dom.byId("messages").innerHTML = r;
});
}
function sumPopulation(features) {
var popTotal = 0;
for (var x = 0; x < features.length; x++) {
popTotal = popTotal + features.attributes["POP2000"];
}
return popTotal;
}
});
</script>
</head>
<body>
<span id="messages">Click on the map to select census block points within 1 mile.</span>
<div id="mapDiv"></div>
</body>
</html>