Passing values to a function

Question

Hi, i'm new to Coldfusion, and i'm a little confused in
regards to passing parameters to a function using
<cfinvokeargument>. My question is: Does the name of
parameter in the cfinvokearguments have to be the same name as the
cfargument name that you're passing the value to? Because that
seems to go against the whole "black box" thing i was taught. And
is there a way to pass the values without having to have to know
the name of the variables in the function?

Answer 1

If you are passing variables to the function then yes the
names need to be the same. There are ways around this which goes to
your second question about passing variables without knowing the
name. (see
http://livedocs.macromedia.com/coldfusion/7/htmldocs/wwhelp/wwhimpl/common/html/wwhelp.htm ?context=ColdFusion_Documentation&file=00001056.htm)
As an example I have a document that I want to index and some
indexes will be filled out by the user and some will not so how
would I be able to tell which vars are passed to the
function….So I would loop the Indexes assigned to the
document and check to see if they were passed to the CFC doing
something like this...
EXAMPLE:
<cfquery name="getDocIndexes_rs"
... this is a query to the get the document's indexes ....
</cfquery>
<cfloop query="getDocIndexes_rs">
<!--- check the arguments scope to see if this index var
exist --->
<cfif
isDefined("arguments.Index#getDocIndexes_rs.IndexID#")>
<!--- if defined then get the value ---->
<cfset IndexValue =
arguments["Index"&getDocIndexes_rs.DMIndexID]>
<!--- do something with indexvalue ....... ---->
Ok that was probably a bit much so to simplify this here....
When I sent the variables to the function I did not use the
cfargument to specify the name(s) because I have no idea what they
were at the time.
As an example for yourself pass a variable to a function
using the cfinvokeargument but do not use the cfargument tag. Then
return the variable by doing this.
<!---- THE CFC PAGE (named testreturn.cfc) --->
<cfcomponent>
<cffunction name="myFunction" access="public"
returntype="string">
<cfset myResult= arguments.testvar>
<cfreturn myResult>
</cffunction>
</cfcomponent>
<!---- THE CFM PAGE THAT CALLS THE CFC --->
<cfinvoke component="YourPath.testreturn"
method="myFunction" returnvariable="myResult">
<cfinvokeargument name="testvar" value="HELLO">
</cfinvoke>
<cfoutput>#myResult#</cfoutput>
Hope that wasn’t confusing enough for you...I am tired
so that is my excuse and this is the best I can do at the moment.