Catching requesttimeout in ColdFusion templates - coldfusion

Question

I have a ColdFusion template, which will be called via ajax.
The template has timeout of seconds like:
<cfsetting showdebugoutput="true" requesttimeout="2" />
But if the timeout occurs, I get no error message back. Is there a way to catch the timeout and respond properly via Ajax?

Answer 1

I get no error message back
Do you get anything back? Your response should still contain the text ColdFusion produces. Have you used Chrome, or fire bug or any browser with web tools that allow you to see the response to see if you're just getting back something you can't use? Are you using anything with a success/fail callback function that may be suppressing the failure on the client side? If the below suggestion doesn't help, I'd post your JS and re-tag your question.
That being said: any time you do anything after the request timeout has expired you'll want to extend your timeout. onError and try/catch only have a few MS after the timeout to react to the error so sending messages or logging errors will also fail. If you were trying to send an email or write to a file, you're CF error message would then say your cfmail or cffile action timed out which it did (technically) but it isn't what caused the initial error.
You can simply reset the requestTimeout to something a little bigger if you know what the timeout is already.
<cfsetting requesttimeout="2">
<cftry>
<!--- some stuff that takes more than 2 seconds --->
<cfcatch type = "any">
<cfsetting requesttimeout="5">
<!--- logging / error handling for timeout --->
<!--- NOTE!! This does not add 5 seconds, it adds 3. --->
<!--- The value of requestTimeout is the total time of the timeout. --->
</cfcatch>
</cftry>
Or you can add time if you don't know the current timeout value.
<cftry>
<!--- some stuff that takes more than your timeout --->
<cfcatch type = "any">
<!--- You must first create your object to hold the requestMonitor. --->
<cfset monitor = createObject("java", "coldfusion.runtime.RequestMonitor") />
<!--- Then you need to reset your request timeout --->
<!--- add 5 seconds to the timeout --->
<cfsetting requesttimeout=monitor.getRequestTimeout()+5>
<!--- logging / error handling for timeout --->
</cfcatch>
</cftry>
You do not have to do this in a try/catch block either, you can include this in your onError event handler if you have one defined in your application.cfc.

Answer 2

If the ColdFusion template is in a folder for which there is an Application.cfc file, you might be able to do something with the onError function.

Answer 3

You should wrap your entire ColdFusion template that is being called by AJAX in a cftry block. That way if any ColdFusion exception occurs you can handle it and return whatever message you want to the client.
<cftry>
<!--- all of your ColdFusion template code here --->
<cfcatch type="Any">
<!--- return whatever you want here --->
<div>An error has occurred.</div>
<!--- remember that you have the cfcatch structure available to you --->
<!--- which contains the specifics of the error that was thrown --->
</cfcatch>
</cftry>
On the client side, where the AJAX call is being made, you can handle any http connection related errors that might occur (failed connection, timeout, etc.). Your AJAX call will have an error method or some such. I highly recommend using jQuery for this. jQuery AJAX API
You did not give any specific information in your post. If you have a problem it always helpful to actually share the code you are having trouble with. Then the people on StackOverflow can be of more help.