topic Re: LabelClass minScale and maxScale issue in ArcGIS JavaScript Maps SDK Questions

LabelClass minScale and maxScale issue

KonstantinArbogastEBP — Wed, 15 Feb 2023 14:12:38 GMT

Dear community,

I have a Feature Layer with two separate label classes. One that should be visible up to a scale of 1:10000, and the other one from that scale. So for one label class, I have added 10000 as maxScale and for the other as minScale.

I now expect to see Label Class 1 at 1:9999 and Label Class 2 at 1:10001. However, reality shows Label Class 1 from 1:10500 and Label Class 2 up to 1:13500. At around 1:11000, there are no labels at all. Below you can find a code example with a default scale of 1:11000 showing no labels at all. Zooming in will show "Class 1", zooming out will show "Class 2".

<html> <head> <meta charset="utf-8"> <meta name="viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no"> <title>ArcGIS Maps SDK for JavaScript Tutorials: Add a feature layer</title> <style> html, body, #viewDiv { padding: 0; margin: 0; height: 100%; width: 100%; } </style> <link rel="stylesheet" href="https://js.arcgis.com/4.25/esri/themes/light/main.css"> <script src="https://js.arcgis.com/4.25/"></script> <script> require([ "esri/config", "esri/Map", "esri/views/MapView", "esri/layers/FeatureLayer" ], function(esriConfig,Map, MapView, FeatureLayer) { esriConfig.apiKey = "<YOUR API KEY>"; const map = new Map({ basemap: "" }); const view = new MapView({ container: "viewDiv", map: map, center: [-118.80543,34.04000], scale: 11000 }); const labelClass1 = { // autocasts as new LabelClass() symbol: { type: "text", // autocasts as new TextSymbol() color: "white", haloColor: "blue", haloSize: 1, font: { // autocast as new Font() family: "Ubuntu Mono", size: 14, weight: "bold" } }, labelPlacement: "above-right", labelExpressionInfo: { expression: "'Class 1'" }, maxScale: 0, minScale: 10000 }; const labelClass2 = { // autocasts as new LabelClass() symbol: { type: "text", // autocasts as new TextSymbol() color: "white", haloColor: "blue", haloSize: 1, font: { // autocast as new Font() family: "Ubuntu Mono", size: 14, weight: "bold" } }, labelPlacement: "above-right", labelExpressionInfo: { expression: "'Class 2'" }, maxScale: 10000, minScale: 0 }; //Trails feature layer (lines) const trailheadsLayer = new FeatureLayer({ url: "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trails/FeatureServer/0", labelingInfo: [labelClass1, labelClass2] }); map.add(trailheadsLayer); }); </script> </head> <body> <div id="viewDiv"></div> </body> </html>

Am I missing something? Or is this a bug?

Re: LabelClass minScale and maxScale issue

Noah-Sager — Wed, 15 Feb 2023 16:15:11 GMT

Hi @KonstantinArbogastEBP, thanks for posting your question here. I looked at your sample code, and I think there's an issue with the min/max scales. For example, for label class 2, the minscale is smaller than the maxscale. However, I'm not 100% sure if setting the scale to zero should be a factor or not.

https://developers.arcgis.com/javascript/latest/api-reference/esri-layers-support-LabelClass.html#minScale

Here is an updated test-app, that appears to handle better in my testing.

updated test-app

https://codepen.io/noash/pen/JjaoKGY?editors=1000

See if this helps, otherwise, can you share an app that more clearly demonstrates the issue with min/max label scaling?

Re: LabelClass minScale and maxScale issue

KonstantinArbogastEBP — Thu, 16 Feb 2023 08:53:55 GMT

Hi @Noah-Sager,

thank you for your input! At first it did look like the problem might be solved, but unfortunately it's just because the basemap forces certain zoom levels. If I remove the basemap, the problem remains.

Our application unfortunately needs custom zoom levels, and at 1:11000 or 1:12000, there are no labels, even though they should be there according to the LabelClasses

Re: LabelClass minScale and maxScale issue

Noah-Sager — Thu, 16 Feb 2023 14:38:21 GMT

Hmm, in my test app, I see labels at both 1:11000 and 1:12000.

Re: LabelClass minScale and maxScale issue

KonstantinArbogastEBP — Thu, 16 Feb 2023 14:54:49 GMT

While the basemap is active, you won't actually be at the scales 1:11000 and 1:12000, those are rounded to the next defined zoom level which is at around 1:18000. There it works.

Have you tried disabling the basemap and trying again with these scales?