I am wondering if/how attributes of a Hosted Feature Layer can be read into a 2d Javascript Array using ArcGIS API for JavaScript 4.x?
I need a 2D Matrix of all attributes values to run some analysis.
1 Answer
I think this example that I made might help you, it retrieves the features and build a matrix with them. You have to consider that this is restricted by the maximum of features per request configure in the service. If this is a problem, then you will have to make several request.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta
name="viewport"
content="initial-scale=1,maximum-scale=1,user-scalable=no"
/>
<title>Intro to FeatureLayer - 4.14</title>
<link
rel="stylesheet"
href="https://js.arcgis.com/4.14/esri/themes/light/main.css"
/>
<script src="https://js.arcgis.com/4.14/"></script>
<style>
html,
body,
#viewDiv {
padding: 0;
margin: 0;
height: 100%;
width: 100%;
}
</style>
<script>
require([
"dojo/on",
"esri/Map",
"esri/views/MapView",
"esri/layers/FeatureLayer"
], function(on, Map, MapView, FeatureLayer) {
var map = new Map({
basemap: "hybrid"
});
var view = new MapView({
container: "viewDiv",
map: map,
extent: {
// autocasts as new Extent()
xmin: -9177811,
ymin: 4247000,
xmax: -9176791,
ymax: 4247784,
spatialReference: 102100
}
});
/********************
* Add feature layer
********************/
// Carbon storage of trees in Warren Wilson College.
var featureLayer = new FeatureLayer({
url:
"https://services.arcgis.com/V6ZHFr6zdgNZuVG0/arcgis/rest/services/Landscape_Trees/FeatureServer/0"
});
var featureMatrix; // [...attributes, esrigeojson]
featureLayer.queryFeatures(featureLayer.createQuery()).then(fs => {
console.log(`Number of rows: ${fs.features.length}`);
featureMatrix = fs.features.map(g =>
[...Object.values(g.attributes), g.geometry.toJSON()]
);
console.log('Matrix:');
console.log(featureMatrix);
});
map.add(featureLayer);
});
</script>
</head>
<body>
<div id="viewDiv"></div>
</body>
</html>
iandjin your 2d matrix?, what type of geometry has the layer?