If I am understanding and using this correctly, a variable in a cfc that is
declared into the "Variables" scope will be visible to all other methods on
the CFC, but not to callers outside of the cfc. A variable in a cfc that is
declared into the "This" scope is also visible to all other methods, but
also visible and changeable from the calling code. So in the example A (see
below) variable "A" will be visible to the caller, but variable "B" will
not. So if we were to utilize the following code:
<cfset testObj = createObject("component","test")>
<cfinvoke component="#testObj#" method="init">
<!--- this will work --->
<cfoutput>#testObj.A#</cfoutput>
<!--- this will throw an error --->
<cfoutput>#testObj.B#</cfoutput>
Ok, I believe I have a pretty good handle on all that, but I wanted to
explain my current understanding, so that if anybody notices something
flawed in my logic, please let me know. Now onto the interesting part I
stumbled upon when I was practicing the above. If one adds code such as
below, things can get confusing.
<cfset testObj.C = "new Value">
<cfoutput>#testObj.C#</cfoutput>
This will work, it is in effect adding a new variable to my object. Is this
expected and correct behavior? Should any old programmer be able to add new
values to any old component object? Would there ever be a good reason to
use and/or rely on this behavior? Or is it just a potential gotcha of which
to be aware? Doesn't seem to cause a problem, since the new variable is
cleanly in the "This" scope of the component, it doesn't seem to clash with
similarly named variables in the "Variables" scope. But could it be a
problem if one wasn't following the best practice of always scoping one's
variables?
--------------
Ian Skinner
Web Programmer
BloodSource
Sacramento, CA
*****************************
*** simple code example A ***
*****************************
<cfcomponent hint="sample a">
<cffunction name="init">
<cfset this.A = "Hello">
<cfset variables.B = "World">
</cffunction>
</cfcomponent>
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