I've been testing out Arcade expressions with the intent to create some graphs but I'm finding even simple math expressions I cannot get to work. I could just be missing something basic but I'm not starting to wonder if maybe the CSVLayer is incompatible with certain bits of Arcade, specifically some global variables like $layer.
I cut down as much as possible and I still can't get a function like Count($layer) to work even though I can access individual features like $feature.year. If I do Count([0,1]) the popup has a 2 like I'd expect. I believe I've gotten Count($layer) to work with a portal item so I think it's something specific to CSVLayer. Is there any work around or something I'm missing to get $layer to work with an in-memory CSVLayer?
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no"/>
<title>Test</title>
<style>
html,
body,
#viewDiv {
padding: 0;
margin: 0;
height: 100%;
width: 100%;
}
</style>
<link rel="stylesheet" href="https://js.arcgis.com/4.22/esri/themes/dark/main.css" />
<script src="https://js.arcgis.com/4.22/"></script>
<script>
require([
"esri/Map",
"esri/views/MapView",
"esri/layers/CSVLayer",
"esri/layers/Layer"
], (Map, MapView, CSVLayer, Layer) => {
const map = new Map({
basemap: "dark-gray-vector"
});
const view = new MapView({
map: map,
container: "viewDiv",
center: [-121.96, 37.87],
scale: 2000
});
//var num = Count($layer);
//var num = $feature.year;
const popupTemplate = {
content: "{expression/test}",
expressionInfos: [{
name: "test",
expression: `
var num = Count($layer);
return num;
`
}
]
};
const csv = `name|year|Longitude|latitude
aspen|2020|-121.96|37.87
birch|2018|-121.961|37.871`;
const blob = new Blob([csv], {
type: "plain/text"
});
let url = URL.createObjectURL(blob);
const csvLayer = new CSVLayer({
url: url,
renderer: {
type: "simple", // autocasts as new SimpleRenderer()
symbol: {
type: "simple-marker", // autocasts as new SimpleMarkerSymbol()
size: 10,
color: "red"
}
}
});
csvLayer.popupTemplate = popupTemplate;
map.add(csvLayer);
});
</script>
</head>
<body>
<div id="viewDiv"></div>
</body>
</html>
