Ben Nadel
On User Experience (UX) Design, JavaScript, ColdFusion, Node.js, Life, and Love.
I am the chief technical officer at InVision App, Inc - a prototyping and collaboration platform for designers, built by designers. I also rock out in JavaScript and ColdFusion 24x7.
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Ben Nadel at the New York ColdFusion User Group (Feb. 2009) with: Joakim Marner

ColdFusion Method Definitions Can Come After The Code That References Them

By Ben Nadel on
Tags: ColdFusion

Well, not always, but sometimes. I always thing about ColdFusion as a top-down processing system. And, it is. But what I forget is that the page gets compiled before it gets run. Because of that (or at least this is what I am assuming), ColdFusion methods that are declared within a given template can come AFTER the code that references them so long as that reference is also in the same template.

In other words, this runs perfectly well:

  • <!--- Get some reassurance. --->
  • #GetReassurance( "Am I good enough?" )#
  •  
  • <cffunction
  • name="GetReassurance"
  • access="public"
  • returntype="string"
  • output="false"
  • hint="Reassures you that you are good enough.">
  •  
  • <cfreturn "Look dude, you are the man! Don't fight it." />
  • </cffunction>

Logically, I would expect that page to fail as the line that calls GetReassurance() is referring to a user defined method that has not yet been defined. But, since this method gets compiled with the page, I guess same-template references do not require a particular order.

If the ColdFusion user defined method was put into a CFInclude, this would fail. This only works if the method is defined IN THE SAME PAGE.



Reader Comments

Right you are. In fact, even if you put a cfabort after your udf call and before your udf definition, I believe your call well execute successfully under most circumstances. Obviously if your udf references global variables defined after the cfabort, that probably wouldn't be the case.

I think UDFs get loaded as actual Java classes right? I guess they get compiled down to separate java byte code before the pages starts running. Of course I know nothing about that aspect, so I may be way off the mark.

Ben, I think you're right. I know that is the case with functions in CFCs, so I would think it would be similar for plain ol' CFM files.