Fun with Functions and CFCs II - Object Hacking, There Is No Privacy
posted under category: ColdFusion on December 11, 2007 by Nathan
There are a lot of fun and interesting things you can do with ColdFusion components that languages like Java just don't let you. This is part 2 in my series to explore the interesting things that you can do with ColdFusion components and functions.
Before we begin, let's make a test CFC - here's the one I'm using; Test.cfc:
<cfcomponent>
<cffunction name="init" access="public">
<cfreturn this />
</cffunction>
<cffunction name="privateMethod" access="private">
<cfreturn "This is a Private Method!" />
</cffunction>
<cffunction name="publicMethod" access="public">
<cfreturn "This is a Public Method!" />
</cffunction>
</cfcomponent>
Now we'll make an instance of it in a plain-jane .cfm file:<cfset myCFC = createObject("component","Test").init()>
Now here comes the fun part. I want to get and execute the private method from the .cfm page. Not allowed, right? Not exactly. let's make a free-floating function in my .cfm file (this could be done with a cffunction tag, but I like the familiar script syntax):
<cfscript>
function getCurrentVariables() {return variables;}
</cfscript>
If I call getCurrentVariables() now, it will return the current document's variables scope, which consists of a reference to that function and to my CFC instance's this scope, but what if I put that function onto my test CFC's public interface?<cfset myCFC.getVariables = getCurrentVariables />
now, myCFC.getVariables() gives me the variables scope of the CFC! if I dump myCFC.getVariables(), I can see everything that's going on inside. Woah, now I can play with the internals all I want.#myCFC.getVariables().privateMethod()# returns "This is a Private Method!"