View source for Dice/FunctionRegistry/RegisterFunction (String, FunctionCallback, FunctionScope)

{{APIdoc|FunctionRegistry.RegisterFunction Method (String, FunctionCallback, FunctionScope)}}
Registers the specified callback to the given name and scope.

{{ns}}

== Syntax ==
<syntaxhighlight lang="C#">
public void RegisterFunction(
    string name,
    FunctionCallback callback,
    FunctionScope scope
)
</syntaxhighlight>

=== Parameters ===
; ''name''
: Type: System.String
: Function name to register. Function names are case-insensitive.

; ''callback''
: Type: [[Dice/FunctionCallback|Dice.FunctionCallback]]
: The method to be called whenever the function is called in a dice expression.

; ''scope''
: Type: [[Dice/FunctionScope|Dice.FunctionScope]]
: The scope of the function.

== Exceptions ==
{| class="wikitable"
! Exception !! Condition
|-
| ArgumentNullException || ''name'' is {{cs|null}}.
|-
| ArgumentException || ''name'' is the empty string.
|-
| InvalidOperationException || A function with the same ''name'' and ''scope'' has already been registered.
|}

== Remarks ==
The short-hand FunctionScope.All and FunctionScope.Roll can be used to register the function for multiple scopes simultaneously, obviating the need for multiple calls to RegisterFunction().

Basic- and group-scoped functions are registered with [[Dice/FunctionTiming|FunctionTiming.Last]]. Function timing is not used for global-scoped functions.

There can only be one callback associated with any given function name and scope. It is an error to re-register a function, but a function can be [[../Remove|removed]] and then registered again.

== See Also ==
* [[../RegisterFunction|RegisterFunction overload summary]]