Custom Functions

You can create your own custom formula functions by implementing the expression.IExpressionFunction interface. This interface has a single method, Object run(List<Object> args), which receives the arguments passed to the function (if any) and returns the result.

global class MyCustomFunction implements expression.IExpressionFunction {
    global Object run(List<Object> args) {
        // Do something with the arguments and return the result
    }
}

To register your custom function, you need to create a new Custom Metadata record of type Expression Function and specify the name of the function and the Apex class that implements it:

• Go to Setup > Custom Metadata Types and click Manage Records next to Expression Function
• Click New and enter the name of your function and the Apex class that implements it
• Click Save
• Your function is now available to use in formulas using the name you specified