RestDataSource: Evaluating JSON reply resulted in empty value

[asg2007]

I would like to handle the empty response of the RestDataSource.fetchData command. If the server does not provide any response (json-object in my case) I see in a FireBug an absolutely empty Rresponse tab and a message like this - 17:39:30.320 [ERROR] [...] 17:39:30.321:XRP2:WARN:RestDataSource:isc_PagedRestDataSource_0:Evaluating JSON reply resulted in empty value. JSON text: "" - in a Development Mode console. But niether DSCallback is invoked nor the "transformResponse" is executed. I see that the ISC_DataBinding.js performs logWarn with this message.
I there any way to catch this WARN in the smartGwt application, handle it and show the message in a browser somehow?













(SmartGWT 2.4.)

[atomatom]

the default RestDataSource requires some tags in it, even if there are no results.

http://www.smartclient.com/smartgwt/...ataSource.html

i believe the empty result should look like this. then your callbacks will fire.

{    
    response:{}
}

otherwise, it looks like you need to write a custom datasource. check the showcase for examples of this calling other rest datasources.

[asg2007]

Thanks for your response. Actually if the server responses nothing because of an unhandled exception on the server side there is no even this - "{}". But I see that the ISC_DataBinding.js handles that situation. I would like to catch this also.

[slovekfhu]

Hi.

I have similar problem, and it's obvious that empty response need to have json format.

But I need to secure situation when server response won't have expected format.
for example:

ds - some RestDataSource
ds.fetchData(new Criteria(), new DSCallback() {
	@Override
	public void execute(DSResponse response, Object rawData, DSRequest request) {
		GWT.log("execute");
	}
});

the method "execute" won't fire if response is unexpected causing insecure state of application
I can't notify application's user: "Hey there's a problem on server or elsewhere... stop using it."

I tried to surround some parts of my code with try ... catch - without any success.
Is there any way to prevent such situations ?
(rise some exception, or firing "execute" method with some error status, etc.)