topic Re: How to query only visible Feature Layers with Draw Polygon (3.x) in ArcGIS JavaScript Maps SDK Questions

How to query only visible Feature Layers with Draw Polygon (3.x)

Den-GIS — Fri, 12 Mar 2021 11:13:12 GMT

Hi everyone,

I'm working on a slightly older app with ArcGIS JS API 3.x. I want to send a query only on the visible layers. The query works in such a way that a polygon is drawn by the user and only visible layers are queried. All other layers that are hidden should not be taken into account.
So far I have managed to draw a polygon and send a statistic definition query. It works OK. However, all layers are taken into account. And that's what I don't want

Here is my code. I am grateful for any help!

Re: How to query only visible Feature Layers with Draw Polygon (3.x)

nita14 — Tue, 16 Mar 2021 19:54:45 GMT

Hi Denis,

You can use the 'visible' property of a layer

https://developers.arcgis.com/javascript/3/jsapi/layer-amd.html#visible

if (fc_0.visible){ fc_0.queryFeatures(queryParams, getStats, errback); };

BR,

Adam

Re: How to query only visible Feature Layers with Draw Polygon (3.x)

Den-GIS — Tue, 16 Mar 2021 22:20:03 GMT

Hi Adam,

Thank you for your help! I just tested it and it works. 🙂 Only visible layers are queried. That's great. With that I am one step further. But I have another problem, which I overlooked before: I use Statistic Definition to sum up query layers. However, what I get are separate sums of all query layers. The goal, however, is to create a total that includes all of the sums from all layers. I think my approach to solving this is not a good one. It's not good because I keep repeating the getStats() function. And because of the local variable scope, I can't get it out of function. I posted my code below. How can that solve, only query visible layers and then add their sums together. Thank you for your help in advance.

if (fc_0.visible){ fc_0.queryFeatures(queryParams, getStats, errback); }else { console.log("fc_0 isn't visible"); }; if (fc_1.visible){ fc_1.queryFeatures(queryParams, getStats1, errback); }else { console.log("fc_1 isn't visible"); }; if (fc_2.visible){ fc_2.queryFeatures(queryParams, getStats2, errback); }else { console.log("fc_2 isn't visible"); }; if (fc_3.visible){ fc_3.queryFeatures(queryParams, getStats3, errback); }else { console.log("fc_3 isn't visible"); }; if (fc_4.visible){ fc_4.queryFeatures(queryParams, getStats4, errback); }else { console.log("fc_4 isn't visible"); }; function getStats(results) { var _sumkWh, _sum; arrayUtils.forEach(results.features, function(feature) { _sumkWh = feature.attributes.kwh; _sum = _sumkWh.toFixed(2); console.log("Sum kWH:", _sumkWh); }); dom.byId("sumKWH").innerHTML = _sum + " " + "[kW]"; }; function getStats1(results) { var _sumkWh, _sum; arrayUtils.forEach(results.features, function(feature) { _sumkWh = feature.attributes.kwh; _sum = _sumkWh.toFixed(2); console.log("Sum kWH:", _sumkWh); }); dom.byId("sumKWH").innerHTML = _sum + " " + "[kW]"; }; function getStats2(results) { var _sumkWh, _sum; arrayUtils.forEach(results.features, function(feature) { _sumkWh = feature.attributes.kwh; _sum = _sumkWh.toFixed(2); console.log("Sum kWH:", _sumkWh); }); dom.byId("sumKWH").innerHTML = _sum + " " + "[kW]"; }; function getStats3(results) { var _sumkWh, _sum; arrayUtils.forEach(results.features, function(feature) { _sumkWh = feature.attributes.kwh; _sum = _sumkWh.toFixed(2); console.log("Sum kWH:", _sumkWh); }); dom.byId("sumKWH").innerHTML = _sum + " " + "[kW]"; }; function getStats4(results) { var _sumkWh, _sum; arrayUtils.forEach(results.features, function(feature) { _sumkWh = feature.attributes.kwh; _sum = _sumkWh.toFixed(2); console.log("Sum kWH:", _sumkWh); }); dom.byId("sumKWH").innerHTML = _sum + " " + "[kW]"; };

Re: How to query only visible Feature Layers with Draw Polygon (3.x)

nita14 — Wed, 17 Mar 2021 08:33:15 GMT

Hi Denis,

I reckon you need to take a look on tihis sample to manage your queries:

https://developers.arcgis.com/javascript/3/jssamples/query_deferred_list.html

BR,

Adam

Re: How to query only visible Feature Layers with Draw Polygon (3.x)

Rice_GIS — Tue, 28 Feb 2023 16:56:44 GMT

Adam,

What would the script look like to query only visible features on screen point in 4.x?