IsCustomFunction

Description

Determines whether a name represents a custom function.

Returns

True, if name can be called as a custom function; False, otherwise.

Category

Decision functions

Function syntax

IsCustomFunction(name)

Parameters

Parameter

Description

name

Name of a custom function. Must not be in quotation marks. If not a defined variable or function name, ColdFusion generates an error.

Usage

The IsCustomFunction function returns True for any function that can be called as a custom function, including functions defined using CFScript function declarations and cffunction tags, and functions that are ColdFusion component methods. For CFC methods, first instantiate the component.

Note: To prevent undefined variable exceptions, always precede IsCustomFunction with an IsDefined test, as shown in the example.

Example

<h3>IsCustomFunction Example</h3> 
<cfscript> 
function realUDF() { 
    return 1; 
} 
</cfscript> 
<cfset X = 1> 
 
<!--- Example that fails existence test ---> 
<cfif IsDefined("Foo") AND IsCustomFunction(Foo)> 
    Foo is a UDF.<br> 
</cfif> 
 
<!--- Example that passes existence test but fails IsCustomFunction ---> 
<cfif IsDefined("X") AND IsCustomFunction(X)> 
    X is a UDF.<br> 
</cfif> 
 
<!--- Example that passes both tests---> 
<cfif IsDefined("realUDF") AND IsCustomFunction(realUDF)> 
    realUDF is a function.<br> 
</cfif> 
 
<!--- Example using a CFC, defined in TestCFC.cfc---> 
<cfobject component="TestCFC" name="myTestCFCobject"> 
<CFIF IsDefined("myTestCFCobject.testFunc") AND  
        IsCustomFunction(myTestCFCobject.testFunc)> 
    myTestCFCobject.testFunc is a function. 
</CFIF>