topic Layer onLoad event, how to handle an error in ArcGIS JavaScript Maps SDK Questions

Layer onLoad event, how to handle an error

mikewebster — Wed, 03 Nov 2010 18:40:41 GMT

So to load a layer is straight forward as taken from the "JavaScript API Concepts" page. Sniplet below...

function init() {
var layer = new esri.layers.ArcGISDynamicMapServiceLayer(...);
dojo.connect(layer, "onLoad", printInitialExtent);
}

How do you catch an event if the layer never gets loaded? Maybe the service is down. If the layer does not get loaded I want to inform the user (rather than a blank map).

Check Layer error through xmlHttpObject ?

MarcelKleinmann — Thu, 04 Nov 2010 12:07:47 GMT

Good question.

I would be interrested in a solution to that problem as well.

My first approach was, checking the url seperately by an independent request through a xmlHttpObject. But I couldn't get it running from my jsp till now.

Has anyone a solution?

Cheers

Re: Layer onLoad event, how to handle an error

StewartMcCall — Thu, 04 Nov 2010 13:52:08 GMT

I use the following...

dojo.connect(layer, "onError", errorHandling);

...with errorHandling a function that tells the user the GIS isn't available. I do a redirect to a standard GIS unavailable page.

Hope this is what you are looking for...

Cheers

Re: Layer onLoad event, how to handle an error

mikewebster — Thu, 04 Nov 2010 15:32:23 GMT

OK, that is what I expected. That is the first thing I tried and my onError event for that layer never gets called.

function init() {
var layer = new esri.layers.ArcGISDynamicMapServiceLayer(...);
dojo.connect(layer, "onError", errorHandling);
dojo.connect(layer, "onLoad", loadHandling);
}

I will try it again in a simple app and see if I can get it working.

Thanks

MarcelKleinmann — Thu, 04 Nov 2010 16:01:38 GMT

This dojo.connect(layer, "onError", errorHandling); does it for me.

Cheers

Re: Layer onLoad event, how to handle an error

mikewebster — Thu, 04 Nov 2010 19:54:41 GMT

yes it was this simple. i had a elementary mistake in my code. now the onError event works as expected. thanks for confirming the event works as expected.

Re: Layer onLoad event, how to handle an error

HemingZhu — Fri, 17 Dec 2010 18:33:09 GMT

So to load a layer is straight forward as taken from the "JavaScript API Concepts" page. Sniplet below...

function init() {
var layer = new esri.layers.ArcGISDynamicMapServiceLayer(...);
dojo.connect(layer, "onLoad", printInitialExtent);
}

How do you catch an event if the layer never gets loaded? Maybe the service is down. If the layer does not get loaded I want to inform the user (rather than a blank map).

try this:
function init() {
var layer = new esri.layers.ArcGISDynamicMapServiceLayer(...);
dojo.connect(layer, "onLoad", printInitialExtent);
dojo.connect(layer, "onError", function(error){
alert ("There is a problem on loading the layer!");
});
}