cfargument ColdFusion 9 Documentation

Description

Creates 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">

History

ColdFusion 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. `yes` `no`
`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.

Usage

This 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>

cfargument