topic Zoom on feature layer problem in ArcGIS JavaScript Maps SDK Questions

Zoom on feature layer problem

RyanSmith1 — Fri, 16 May 2014 13:37:10 GMT

Hi, i have the following code to zoom to an extent depending on the the query result. The zoom works certain times on firefox but
doesn't work on chrome.
What could be the problem?

Thanks

            featureLayer.selectFeatures(query, esri.layers.FeatureLayer.SELECTION_NEW, function (features) {
                    var extent = features[0].geometry.getExtent().expand(1.25);
                    map.setExtent(extent, true);
                }

Re: Zoom on feature layer problem

TracySchloss — Sat, 11 Dec 2021 09:26:24 GMT

I occasionally have problems with both selecting and querying and I always think it relates to the callback function executing before the selection is really complete. Network connectivity, the type and number of features you're selecting can impact whether the selection happens 'instantly' or not. Points seem to be OK, but when I had a project where I was selecting lines with lots of vertices, there was often a problem.

When I have this happen, adding selection-complete listener to your featureLayer and then execute the selection without the callback function takes care of this problem. The syntax changes up a bit. Instead of getting to feature like "results[0]" you have to use "results.features[0]".

     myLayer.on('selection-complete', selectFeatureHandler);
myLayer.selectFeatures(query); 

function selectFeatureHandler (results) {
 var feature = results.features[0];
 map.setExtent(feature.geometry.getExtent().expand(1.25));
}

Re: Zoom on feature layer problem

RyanSmith1 — Sat, 11 Dec 2021 09:26:26 GMT

I occasionally have problems with both selecting and querying and I always think it relates to the callback function executing before the selection is really complete. Network connectivity, the type and number of features you're selecting can impact whether the selection happens 'instantly' or not. Points seem to be OK, but when I had a project where I was selecting lines with lots of vertices, there was often a problem.

When I have this happen, adding selection-complete listener to your featureLayer and then execute the selection without the callback function takes care of this problem. The syntax changes up a bit. Instead of getting to feature like "results[0]" you have to use "results.features[0]".
     myLayer.on('selection-complete', selectFeatureHandler);
myLayer.selectFeatures(query); 

function selectFeatureHandler (results) {
 var feature = results.features[0];
 map.setExtent(feature.geometry.getExtent().expand(1.25));
}

Hi Tracy, thanks for this.
It really has improved processing time of the zoom and seems to be working on firefox but still no luck on chrome.
Not sure why this is happening.