An intriguing (to me) and useless question about CFCs

A test you might like to do in your development environment (for CF on Windows):

1) Download and install Java-Decompiler;

2) Create a folder called classTest in your ColdFusion project (within a test CF instance) and place the following 2 files in it

testPage.cfm

<cfscript>

    obj=createobject("component","Test");

</cfscript>

Test.cfc

component  displayname='Test' name='Test' accessors="true"

{

    property name="property1" type="numeric" default="1" ;

    property name="property2" type="string" default="two" ;

public any function init( ) {

    return this;

}

public numeric function function1() {

    return this.property1;

}

public string function function2(){

    return this.property2;

}

public numeric function myFunction(numeric x ) {

    return arguments.x;

}

}

3) Go to the CF Admin of your ColdFusion instance and switch on the option to save class files;

4) Go to the folder wwwroot/WEB-INF/cfclasses of your ColdFusion instance. Delete all the files in it. (If there is no cfclasses folder, create one.)

5) Restart the ColdFusion instance.

6) Return to wwwroot/WEB-INF/cfclasses of your ColdFusion instance and delete any files in it.

7) Run the CFM page above. ColdFusion should then generate 6 class files in wwwroot/WEB-INF/cfclasses, each having a name starting with cfTest, for example

8) Launch Java-Decompiler and use it to examine the contents of the class files.

A CFC is neither like a dispatch table nor like a switch/case construct. That is because the engine that ColdFusion uses to build CFCs is Java. Java doesn't have pointers, which are required in the use of a dispatch table. A switch/case construct would be inefficient at compiler level. One reason is that it would in theory allow non-unique cases.

Nevertheless, I think that ColdFusion, or rather its underlying Java engine, uses techniques similar to the dispatch table and switch/case when it processes a CFC. As Dave and Charlie have said, the CFC is compiled to a class, as is each of its functions. I would add that ColdFusion gives the classes unique names. It then uses these, within the CFC class, to create an object from the class corresponding to each function. In Java, each such object corresponds, at runtime, to a unique reference (compare with pointers in a dispatch table or cases in switch/case).

I don't know whether this answer is useful, but each CFFUNCTION is compiled into its own class as if it were a .cfm file. There's no corresponding class for the entire .cfc itself, as far as I know.

Dave Watts, Eidolon LLC