Monday, July 7, 2008

Scopes in a CFC

Variables Scope:-
The variables scope is available to the entire CFC. A value set in the
variables scope in one method, or in the constructor, will be available
to any other method, or the constructor, in the CFC. I typically use
variables in much the same way I use Application variables in an site.
The This scope acts like the Variables scope in that it is "global" to
the CFC. However, it is also accessible outside the CFC. So if foo is
an instance of the CFC, and you do: = "Rabid" outside of
the CFC, then you have just creating a key called "name" in the This
scope with the value of "Rabid." You can also cfoutput the value of Because of this accessibility, many folks recommend
against using the This scope, and instead suggest relying on
methods to set data (or get data) inside the CFC. These methods
then write to the Variables scope. To repeat:
<cfset = "Rabid"> (where foo is an instance of the CFC) is
the same as <cfset = "Rabid"> inside the CFC.
Var scoped variables exist only for the duration of the method. You
must use the var scope for any variable that should exist only
inside the method, like query names, loop iterators, etc. Sorry to
"shout" but the lack of var scoping is one of the trickiest things to
debug when things go wrong. Unlike other scope, you do not prefix
the scope name in front of the variable.
The arguments scope consists of every argument passed to the
method. So if the calling code did foo(name="King Camden"), then
the foo method will have a variable called
Form, URL,Application,Session, Server,CGI, Client, Request, Cookie:-

These scopes act exactly as they do anywhere else. In general you
should not use these scopes inside a CFC. When you do you are
making your CFCs less portable between applications

Caller, Attributes:-

Caller and Attributes do not exist inside a CFC. They should only be
used inside custom tags


While not a variable scope, the super scope is a pointer to the
methods in the CFC that acts as the parent to the current CFC. So if
a CFC inherits a CFC with similar methods names, the child CFC can
refer to the parent's method by using super. Example: <cfset result =

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