How do you use rest parameters in Foundry's typescript functions

Question

I have been trying to create a function in Foundry that will take n number of parameters and concatenate the strings with a given delimiter.

When using a rest parameter, the input defaults to requiring data type array, not string. It also only accepts one array as an input parameter, not multiple string values:

Example function:

@Function()
public stringAppendFunction(delimiter: string, ...names: string[]): string{
    let output = names.join(delimiter)
    return output
}

Within Foundry, the function above ends up only having two inputs: delimiter (string) and names (array).

Does anyone have any working functions in Foundry with n number of input parameters?

score 2 · Answer 1 · answered Jul 22 '22 at 10:01

Unfortunately it's not possible at the moment. Functions need to have deterministic pre-defined inputs and outputs. Using rest operator makes the number of inputs non predictable, so it's not supported at the moment.

A work around would be to have multiple functions with different inputs, but it doesn't look very clean.

public stringAppendFunction(delimiter: string, ...names: string[]): string{
    let output = names.join(delimiter)
    return output
}

@Function()
public stringAppendFunction1P(delimiter: string, name1: string): string{
    return this.stringAppendFunction(delimiter, name1)
}

@Function()
public stringAppendFunction2P(delimiter: string, name1: string, name2: string): string{
    return this.stringAppendFunction(delimiter, name1, name2)
}

How do you use rest parameters in Foundry's typescript functions

1 Answers1