ColdFusion Debugging and Profiling

While I'm thinking about CFUnited I just wanted to point out a few not so well known features in CF.

To be fair, this is inspired by Charlie Aerharts presentation about their new profiler tools. Seeing the crowd's reaction I realized that many people must not know that most of what they showed is already in ColdFusion (as of CF6).

• 1) Dumping the complete struct in debug output

What you may not realize that you can modify the default debug output yourself, and add dump tag output. This output is a just a simple .cfm page located in the "/WEB-INF/debug/" folder.

You can create your own file, or edit the classic.cfm. For instance if you wanted to have a cfdump view of your application scope you can just replace lines 677 with <cfdump var='#application#'>

• 2) logging all errors to a file

This one has a few options. The first, if you're using CF7, you can use the new Application.cfm onError() method. With this you can just use cffile to write the error object to a log file.

The second option, which is doable in CF6+, is to edit the default error template. Just like the ColdFusion debug output the ColdFusion error templates are also .cfm pages. These are located in the "/web-inf/exception" folder. You can modify these to do what ever you need to with the error messages; send them in an email, write the error to a log file, just change the error formatting so it matches the rest of your site when an error happens.

• 3) Profiler

Since CF6 ColdFusion has shipped with two views for your debug output "summary" and "tree".

"Summary" is the default and what you've seen in ColdFusion since the early days of CF (not sure which version it first appeared in, 2 or 3). It provides a listing of all the templates, CFC's and custom tags called with a total execution time for each template.

What you may not of realized is that there is also the "Tree" view, this view provides your with a detailed profiler type of view for the page. It creates a tree of the templates used to create the page. Showing you each individual template, custom tag, cfc execution (with cfc arguments) and the execution path that was taken to get to that page, just like a profiler does. (And you didn't need to buy JProbe. ;)

This "Tree" view allows you figure out exactly which template is slow. For instance perhaps you loop over a custom tag 3 times, with this view you could see that the 3rd time the execution time triples. This would tell you that their must be something different with the arguments of the 3rd request, something that causes your code to take a different slower path.

Note: Like a profiler, not like the "Summary" view, the tree view also displays the template execution time of the .cfm and all of it's children, instead of just the time spend on each template. This allows you to follow the slow running branches easier. If you need to know the just the individual template execution time it a simple matter of adding up the 1st level children and subtracting that from the total for the template.

Granted we do have some area of improvement, for instance we don't drill down to the individual tag counts for each .cfm. If you have any debugging idea for future versions of CF, please send them my way. What we can improve? What we can add? Etc... Perhaps the first thing to do is make the tree view the default for CF :)