Hide Table of Contents
Analysis
Data Reviewer
Dynamic Layers
Editing
Feature Layers
Feature Table
Graphics
Map
Mobile
Online and Portal
Popups and Info Windows
Query and Select
Renderers, Symbols, Visualization
Search
Generalize
Explore in the sandbox
Share
View live sample
Download as a zip file
Description
How to use the maxAllowableOffset FeatureLayer option to generalize features for display. This option is useful when you want to display a generalized version of the features for optimized display. For example, at small scales you may not need to display detail feature boundaries but as end-users zoom into larger scales you can display additional detail as needed. In this sample, the maximum allowable offset is calculated when the map is zoomed.
Code
<!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>FeatureLayer: Changing MaxAllowableOffset (based on zoom level)</title>
<link rel="stylesheet" href="https://js.arcgis.com/3.26/dijit/themes/claro/claro.css">
<link rel="stylesheet" href="https://js.arcgis.com/3.26/esri/css/esri.css">
<style>
html, body { height: 100%; width: 100%; margin: 0; padding: 0; }
#map {
padding:0;
}
#status {
background-color: black;
color: white;
padding: 3px;
border: solid 1px white;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
}
</style>
<script>var dojoConfig = {parseOnLoad: true};</script>
<script src="https://js.arcgis.com/3.26/"></script>
<script>
dojo.require("dijit.layout.BorderContainer");
dojo.require("dijit.layout.ContentPane");
dojo.require("esri.map");
dojo.require("esri.layers.FeatureLayer");
dojo.require("dijit.form.CheckBox");
var map, featureLayer;
var featureLayerUrl = "https://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Petroleum/KSPetro/MapServer/1";
function init() {
map = new esri.Map("map", {
basemap: "topo",
center: [-99.5, 38.027],
zoom: 7
});
map.on("load", mapLoaded);
map.on("update-start", function(){
esri.show(dojo.byId("status"));
});
map.on("update-end", function(){
esri.hide(dojo.byId("status"));
});
}
function mapLoaded() {
featureLayer = new esri.layers.FeatureLayer(featureLayerUrl);
featureLayer.on("update-start", function(){
dojo.style(dojo.byId("status"), "display", "");
});
featureLayer.on("update-end", function(){
dojo.style(dojo.byId("status"), "display", "none");
});
map.addLayers([featureLayer]);
}
function toggleLayer(val){
if(val.name === 'checkBM'){
var basemap = map.getLayer(map.layerIds[0]);
basemap.visible ? basemap.hide(): basemap.show();
} else {
featureLayer.visible ? featureLayer.hide():featureLayer.show();
}
}
dojo.ready(init);
</script>
</head>
<body class="claro">
<div data-dojo-type="dijit.layout.BorderContainer" data-dojo-props="design:'headline',gutters:false" style="width: 100%; height: 100%; margin: 0;">
<div data-dojo-type="dijit.layout.ContentPane" data-dojo-props="region:'right'" style="width:200px;">
<p>
Run the sample with Firebug's net panel open and notice that the maxAllowableOffset is different based on the zoom level.
</p>
<label for="checkBM">Basemap</label>
<input data-dojo-type="dijit.form.CheckBox" checked="basemap.layer.visible" name="checkBM" onChange="toggleLayer(this);"/>
<br />
<label for="checkFL">Feature Layer</label>
<input data-dojo-type="dijit.form.CheckBox" checked="featureLayer.layer.visible" name="checkFL" onChange="toggleLayer(this);"/>
</div>
<div id="map" data-dojo-type="dijit.layout.ContentPane" data-dojo-props="region:'center'" style="border:1px solid #000;padding:0;">
<span id="status" style="position: absolute; z-index: 100; right: 5px; top: 5px;">
Loading...
</span>
</div>
</div>
</body>
</html>