|
cfargument
DescriptionCreates
a parameter definition within a component definition. Defines a
function argument. Used within a cffunction tag.
Syntax<cfargument
name="string"
default="default value"
displayname="descriptive name"
hint="extended description"
required="yes|no"
type="data type">
HistoryColdFusion
8: Added component as a valid value for the ReturnType attribute.
ColdFusion
MX 7: Added the xml value of type attribute.
ColdFusion
MX: Added this tag.
Attributes
Attribute
|
Req/Opt
|
Default
|
Description
|
name
|
Required
|
|
String; an argument name.
|
default
|
Optional
|
|
If no argument is passed, specifies a default
argument value.
|
displayname
|
Optional
|
name attribute value
|
Meaningful only for CFC method parameters.
A value to display when using introspection to show information
about the CFC.
|
hint
|
Optional
|
|
Meaningful only for CFC method parameters.
Text to display when using introspection to show information about
the CFC. The hint attribute value follows the displayname attribute
value in the parameter description line. Use this attribute to describe
the purpose of the parameter.
|
required
|
Optional
|
no
|
Note: All arguments are required
when invoked as a web service, irrespective of how they are defined.
Specifies
whether the parameter is required to execute the component method.
The parameter is not required if you specify a default attribute.
|
type
|
Optional
|
any
|
String; a type name; data type of the argument.
any
array
binary
boolean
component: the argument must be a ColdFusion
component.
date
guid: the argument must be a UUID or GUID
of the form xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx where each x is
a character representing a hexadecimal number (0-9A-F).
numeric
query
string
struct
uuid: the argument must be a ColdFusion
UUID of the form xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxxxxxx where
each x is a character representing a hexadecimal number (0-9A-F).
variableName: a string formatted according
to ColdFusion variable naming conventions.
xml: XML objects and XML strings
a component name: if the type attribute value is not one
of the preceding items, ColdFusion treats it as the name of a ColdFusion
component. When the function executes, it generates an error if
the argument that is passed in is not a CFC with the specified name.
|
UsageThis tag
must be in a cffunction tag, before any other tags
in the cffunction tag body.
Arguments that
are passed when a method is invoked can be accessed from the method
body in the following ways:
With shorthand syntax: #myargument#
(This
example accesses the argument myargument.)
Using the arguments scope as an array: #arguments[1]#
(This
example accesses the first defined argument in the cffunction.)
Using the arguments scope as a struct: #arguments.myargument#
(This
example accesses the argument myargument in the
array.)
Example<!--- This example defines a function that takes a course number parameter and returns the course description. --->
<cffunction name="getDescription">
<!--- Identify argument. --->
<cfargument name="Course_Number" type="numeric" required="true">
<!--- Use the argument to get a course description from the database. --->
<cfquery name="Description" datasource="cfdocexamples">
SELECT Descript
FROM Courses
WHERE Number = '#Course_Number#'
</cfquery>
<!--- Specify the variable that the function returns. --->
<cfreturn Description.Descript>
</cffunction>
|