Creating A VARIABLES-Scoped Function Of The Same Name

By Ben Nadel

Published 2007-03-12 in ColdFusion — Comments (2)

I have 5 minute before my lunch break is over and I just wanted to try this (not very exciting at all). What happens when you have a VARIABLES-scoped user defined ColdFusion function that has the same name as a built in ColdFusion function. The test:

  
          <!---
        
          	Create a very simple UDF that simply echoes
        
          	back the first argument that it is passed.
        
          --->
        
          <cffunction name="Echo">
        
          	<cfreturn ARGUMENTS[ 1 ] />
        
          </cffunction>
        
          <!--- Assign this UDF to the "Find" key within variables. --->
        
          <cfset VARIABLES.Find = VARIABLES.Echo />
        
          <!--- Now, try to call this both with and without a scope. --->
        
          #VARIABLES.Find(
        
          	"Naughty",
        
          	"Naughty robot!"
        
          	)#
        
          #Find(
        
          	"Naughty",
        
          	"Naughty robot!"
        
          	)#

view raw code-1.cfm hosted with ❤ by GitHub

Running the above code, we get the output:

Naughty
1

Calling the UDF with the original VARIABLES scope calls our UDF. Calling it without the scope invokes the built-in ColdFusion method. Interesting.

Ok, what about if we do the same thing as above, but this time, we do NOT use the VARIABLES scope at all:

  
          <!---
        
          	Set the Echo method directly into the non-scoped
        
          	Find variable.
        
          --->
        
          <cfset Find = VARIABLES.Echo />
        
          <!--- Now, try to call this both with and without a scope. --->
        
          #VARIABLES.Find(
        
          	"Naughty",
        
          	"Naughty robot!"
        
          	)#
        
          #Find(
        
          	"Naughty",
        
          	"Naughty robot!"
        
          	)#

view raw code-2.cfm hosted with ❤ by GitHub

Running the above, we get the output:

Naughty
1

Exactly the same effect whether or not we use the VARIABLES scope. Kind of interesting. Nothing really important here. The only strange thing is that if you do this:

view raw code-3.cfm hosted with ❤ by GitHub

It gives you the UDF meta data and NOT the built in ColdFusion method meta data.

Ok, back to work :)

Want to use code from this post? Check out the license.

Short link: https://bennadel.com/572

Reader Comments

Sean Corfield Mar 13, 2007 at 10:26 AM

122 Comments

Presumably if you do getmetadata( variables.find ) you get the data you expect?

David Fekke Mar 14, 2007 at 2:06 PM

1 Comments

Ben,

Super cool tip. It also looks like a good way to play a practicable joke on a CF developer.

David.

Oh my chickens, this post is old!

Hit me up on Twitter if you want to discuss it further.

	<!---
	Create a very simple UDF that simply echoes
	back the first argument that it is passed.
	--->
	<cffunction name="Echo">
	<cfreturn ARGUMENTS[ 1 ] />
	</cffunction>


	<!--- Assign this UDF to the "Find" key within variables. --->
	<cfset VARIABLES.Find = VARIABLES.Echo />

	<!--- Now, try to call this both with and without a scope. --->
	#VARIABLES.Find(
	"Naughty",
	"Naughty robot!"
	)#

	#Find(
	"Naughty",
	"Naughty robot!"
	)#

	<!---
	Set the Echo method directly into the non-scoped
	Find variable.
	--->
	<cfset Find = VARIABLES.Echo />

	<!--- Now, try to call this both with and without a scope. --->
	#VARIABLES.Find(
	"Naughty",
	"Naughty robot!"
	)#

	#Find(
	"Naughty",
	"Naughty robot!"
	)#