River Taig,
Sure just use the map.getLayer("your dynamic layers ID"). If you do not know the layers exact id or the id was not specified when the layer was added so it got an map generated id then you can use the map.layerIds array and loop though those till you find your layerId. The you would get the layerInfos array and loop thought that to get the sublayer names and minScale and maxScale.
Here is a sample to show this in action:
<!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>Create Map with Custom ArcGISDynamicMapServiceLayer Layer
Definitions</title>
<link rel="stylesheet"
href="https://js.arcgis.com/3.16/esri/css/esri.css"/>
<style>
html, body, #mapDiv {
padding: 0;
margin: 0;
height: 100%;
}
</style>
<script src="https://js.arcgis.com/3.16/"></script>
<script>
var map, dynamicMapServiceLayer;
require([
"esri/map",
"esri/layers/ArcGISDynamicMapServiceLayer",
"dojo/on",
"dojo/_base/lang",
"dojo/_base/array",
"dojo/domReady!"
],
function (Map, ArcGISDynamicMapServiceLayer, on, lang, array) {
map = new Map("mapDiv", {
basemap: "streets",
center: [-98.258, 38.236],
zoom: 7
});
dynamicMapServiceLayer = new ArcGISDynamicMapServiceLayer("https://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer");
map.addLayers([dynamicMapServiceLayer]);
on(map, "layers-add-result", function(){
getLayerInfoFromMap(map, dynamicMapServiceLayer.id, "Detailed Counties");
});
function getLayerInfoFromMap (themap, dlid, subLyrName) {
var dLyr = themap.getLayer(dlid);
var minscale, maxscale;
array.some(dLyr.layerInfos, function(lyrInfo){
if(lyrInfo.name === subLyrName){
minscale = lyrInfo.minScale;
maxscale = lyrInfo.maxScale;
return true;
}
}, this);
console.info(minscale, maxscale);
}
});
</script>
</head>
<body>
<div id="mapDiv"></div>
</body>
</html>
