Blog

Brad Wood

August 09, 2012

Spread the word


Share your thoughts

 

ColdBox gives you several ways to deal with unhandled exceptions in your application such as the exceptionHandler event and the onException interception point to name a couple.  With either of those approaches, you can redirect the request to a different event.  If you don't redirect or abort the request though, ColdBox will eventually display the contents of your error template.  
 
By default the error template is /coldbox/system/includes/BugReport.cfm.  This file has the familiar "Oops! Exception Encountered" header.  While BugReport.cfm is chock-full of juicy error details (including the SQL of queries that errored), it isn't the kind of information you want to be revealing to the general public.  
 
This is where your customErrorTemplate setting from the ColdBox config file comes in.  Set this to the path of the page you want your users to see when something goes wrong on the site.  
 
settings.customErrorTemplate = "/includes/sorry.cfm";
 
You'll probably want to display a comforting message, a link to your webmaster's E-mail address, or your customer service number.  If you're feeling cheeky, you could try an octocat, or fail whale.  :)  Remember, your custom error template is NOT a view.  It won't be rendered inside your site layout and it won't have access to variables a view normally gets, but it will have an exceptionBean object passed in.  You can go digging for what you need with getController(), but 1be careful-- you don't know what kind of state the framework is in.  If you create an error on this page, it will bubble up to the onError method in your application.cfc.
 
 
P.S. This is an excellent place to use environment overrides to use the default error page on your dev and staging server, but the pretty one on production.  Just set the path to the pretty page in your main settings block, and override it with an empty string (which means use the default) in your lower environment overrides.

Add Your Comment

(1)

Oct 10, 2013 17:22:57 UTC

by Tim Brown

What if i just want to return the execption information as JSON so it can be gracefully displayed via my client side code?

It doesn't appear I can stop execution within the onException() handler using renderData().noExecution() as renderData is ignored (as stated in the docs). Do I just need to set some headers and return the JSON manually via cfcontent?

Thanks!

Recent Entries

BoxLang 1.18.0 Released :  Every Cloud, Every Node, Every Agent

BoxLang 1.18.0 Released : Every Cloud, Every Node, Every Agent

Azure joins the serverless family. Scheduled tasks become cluster-safe. And the whole platform gets documentation and skills built for developers and AI agents working side by side.

If you run a technology organization, you are being asked to do three things at once: ship faster, keep the estate you already have running, and make AI part of how your teams work. Most stacks make you choose. BoxLang 1.18 is another step toward not having to.

Luis Majano
Luis Majano
October 02, 2026
ColdBox 8.2 Deep Dive, Part 4 of 5 : AI Routing and Gateways

ColdBox 8.2 Deep Dive, Part 4 of 5 : AI Routing and Gateways

We've been building AI into the core of ColdBox since 8.0, because the applications teams are asked to build have changed. They talk to models, stream answers, expose tools to other AI systems, and increasingly host agents that act on behalf of users. None of that should require bespoke plumbing in every project.

Luis Majano
Luis Majano
October 02, 2026