topic Re: Bug? Map fires 'extent-changed' event upon a single mouse click in JS API v3.8 in ArcGIS JavaScript Maps SDK Questions

Bug? Map fires 'extent-changed' event upon a single mouse click in JS API v3.8

Jay_Gregory — Thu, 27 Feb 2014 17:12:15 GMT

I am running into a problem with the JS API v3.8 in which the maps 'extent-change' event is fired with a single mouse click (not double or shift+click, just a simple click on the map), even though a single mouse click does not cause the map's extent to actually change. Normally this isn't a problem unless you have a need to run some real code when the extent actually changes. This behavior is unfortunately preventing my popup window from appearing, because I have a function attached to the 'extent-change' event which actually clears the feature layer. But one click should just show the popup, and not fire the 'extent-change'. UPDATE: this only seems to be affecting Chrome
Regardless, see the following code to reproduce in the simplest manner possible:

<!DOCTYPE html> <html>   <head>     <meta http-equiv="Content-Type" content="text/html; charset=utf-8">     <meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no"/>     <title>Simple Map</title>     <link rel="stylesheet" href="http://js.arcgis.com/3.8/js/esri/css/esri.css">     <style>       html, body, #map {         height: 100%;         width: 100%;         margin: 0;         padding: 0;       }       body {         background-color: #FFF;         overflow: hidden;         font-family: "Trebuchet MS";       }     </style>     <script src="http://js.arcgis.com/3.8/"></script>     <script>       var map;       require(["esri/map",     "dojo/domReady!"],     function(    Map) {   map = new Map("map", {           basemap: "gray",          center: [-97, 38],           zoom: 5,           sliderStyle: "small"         });   map.on('extent-change', function(){console.log('extent changed');});          });     </script>   </head>   <body>     <div id="map"></div>   </body> </html>

Re: Bug? Map fires 'extent-changed' event upon a single mouse click in JS API v3.8

JeffPace — Thu, 27 Feb 2014 20:01:36 GMT

My guess is that chrome is more sensitive and may be interpreting a click as a drag

you could store the extent as a global, say,

oldextent

and then on "extent change"

if (oldextent==map.extent){
do nothing
}else{
oldextent=map.extent;
do stuff
}

Re: Bug? Map fires 'extent-changed' event upon a single mouse click in JS API v3.8

JonathanUihlein — Tue, 04 Mar 2014 21:57:28 GMT

What version of Chrome are you seeing this issue in?
You are not seeing this issue in Firefox or IE, correct?
Also, is this desktop or mobile?

I am using: Version 33.0.1750.146 m.

Using your code, the 'extent-change' event fires once when the the map first loads, as expected.
However, the 'extent-change' event does not fire on a single map click.
I must drag or zoom for the 'extent-change' event to fire.

Re: Bug? Map fires 'extent-changed' event upon a single mouse click in JS API v3.8

Jay_Gregory — Wed, 12 Mar 2014 15:50:47 GMT

hmmm, I don't see the behavior anymore. It must have been fixed in a recent Chrome update.

Re: Bug? Map fires 'extent-changed' event upon a single mouse click in JS API v3.8

JustinShepard — Tue, 22 Apr 2014 16:37:52 GMT

I'm seeing the same behavior in Chrome Version 34.0.1847.116 m.

It wasn't doing this before and sounds kind of sporadic.

Re: Bug? Map fires 'extent-changed' event upon a single mouse click in JS API v3.8

ReneRubalcava — Tue, 22 Apr 2014 16:50:29 GMT

This happens in Chrome version 33.0.1750.154.
I'll have to double-check my version at home.

Re: Bug? Map fires 'extent-changed' event upon a single mouse click in JS API v3.8

JustinShepard — Tue, 22 Apr 2014 20:08:50 GMT

I don't have a solution but I restarted my computer and now it is behaving as expected in Chrome (i.e. it's not trying to move the map every time that I click for an identify)

Re: Bug? Map fires 'extent-changed' event upon a single mouse click in JS API v3.8

Drew — Sat, 11 Dec 2021 06:13:50 GMT

Sorry to wake this thread up almost 2 years later but I am having the same issue in Chrome version 48.0.2564.103 m

Using this thread, I was able to figure out a fix. I thought I would share a complete solution.

 var oldExtent = null;


//ON EXTENT CHANGE - UPDATE IF VISIBLE 
on(this.map, "extent-change", function (event)
{
  var isEqual = false
  if (oldExtent != null)
  isEqual = geometryEngine.equals(oldExtent, event.extent);


  if (isEqual)
  {
  console.log('EXTENT IS THE SAME');
  }
  else
  {
  console.log('EXTENT IS DIFFERENT');
    
  }


  //SET OLD EXTENT
  oldExtent = event.extent;
});

Drew