Cfc Variables - MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX Develop Manual

Establishing a descriptive naming convention is a good practice, especially if the components will
be installed as part of a packaged application.

CFC variables

This section describes how CFCs use variables and interact with ColdFusion scopes.
Note: Components also have a Super keyword that is sometimes called a scope. For information on
the Super keyword, see
The This scope
The This scope is available within the CFC and is shared by all CFC methods. It is also available
in the page that instantiates the CFC and all CFML pages included by the CFC.
Note: If you use component inheritance, you cannot use the This scope in the base (parent)
component, only in the component that extends it. For more information,
inheritance" on page
Inside the CFC, you define and access This scope variables by using the prefix This, as in the
following line:
<cfset This.color="green">
In the calling page, you can define and access CFC This scope variables by using the CFC
instance name as the prefix. For example, if you create a CFC instance named car and within the
car CFC, specify
CFC could refer to the component's color property as
Variable values in the This scope last as long as the CFC instance exists, and therefore can persist
between calls to methods of a CFC instance.
Note: The This scope identifier corresponds to the This keyword of JavaScript and ActionScript.
CFCs do not follow the Java class model, and the This keyword behaves differently in ColdFusion
MX than in Java.
The Variables scope
The Variables scope in a CFC is private to the CFC. It includes variables defined in the CFC
body (initialization or constructor code) and in the CFC methods. Variables scope variables that
are set in the CFC cannot be seen by pages that invoke the CFC.
The CFC Variables scope does not include any Variables scope variables that are declared or
available in the page that instantiates or invokes the CFC. However, you can make the Variables
scope of the page that invokes a CFC accessible to the CFC by passing Variables as an argument
to the CFC method.
You set a Variables scope variable by assigning a value to a name that has the Variables prefix or no
prefix.
Values in the Variables scope last as long as the CFC instance exists, and therefore can last
between calls to CFC instance methods.
The Variables scope is available to included pages, and Variables scope variables that are declared
in the included page are available in the component page.
242 Chapter 11: Building and Using ColdFusion Components
"Using the Super keyword" on page
245.
<cfset "This.color=green">
246.
see"Using component
, then a ColdFusion page that instantiates the
.
#car.color#