Discord.Net/docs/guides/text_commands/namedarguments.md

uid	title
Guides.TextCommands.NamedArguments	Named Arguments

Named Arguments

By default, arguments for commands are parsed positionally, meaning that the order matters. But sometimes you may want to define a command with many optional parameters, and it'd be easier for end-users to only specify what they want to set, instead of needing them to specify everything by hand.

Setting up Named Arguments

In order to be able to specify different arguments by name, you have to create a new class that contains all of the optional values that the command will use, and apply an instance of NamedArgumentTypeAttribute on it.

Example - Creating a Named Arguments Type

[NamedArgumentType]
public class NamableArguments
{
    public string First { get; set; }
    public string Second { get; set; }
    public string Third { get; set; }
    public string Fourth { get; set; }
}

Usage in a Command

The command where you want to use these values can be declared like so:

[Command("act")]
public async Task Act(int requiredArg, NamableArguments namedArgs)

The command can now be invoked as .act 42 first: Hello fourth: "A string with spaces must be wrapped in quotes" second: World.

A TypeReader for the named arguments container type is automatically registered. It's important that any other arguments that would be required are placed before the container type.

Important

A single command can have only one parameter of a type annotated with NamedArgumentTypeAttribute, and it MUST be the last parameter in the list. A command parameter of such an annotated type is automatically treated as if that parameter has RemainderAttribute applied.

Complex Types

The TypeReader for Named Argument Types will look for a TypeReader of every property type, meaning any other command parameter type will work just the same.

You can also read multiple values into a single property by making that property an IEnumerable<T>. So for example, if your Named Argument Type has the following field,

public IEnumerable<int> Numbers { get; set; }

then the command can be invoked as .cmd numbers: "1, 2, 4, 8, 16, 32"

Additional Notes

The use of [OverrideTypeReader] is also supported on the properties of a Named Argument Type.