Is there a way to have more than eight options?

[ToddRopog]

Right now SetHandler only supports up to eight options. Is there a way to exceed this limit? Or will it be increased in the future?

[KalleOlaviNiemitalo]

In 2.0.0-beta4.22272.1, use an overload that gives the InvocationContext to the handler:

command-line-api/src/System.CommandLine/Handler.Action.cs

Lines 14 to 20 in 209b724

	/// <summary>
	/// Sets a command's handler based on an <see cref="Action{InvocationContext}"/>.
	/// </summary>
	public static void SetHandler(
	this Command command,
	Action<InvocationContext> handle) =>
	command.Handler = new AnonymousCommandHandler(handle);

command-line-api/src/System.CommandLine/Handler.Func.cs

Lines 23 to 29 in 209b724

	/// <summary>
	/// Sets a command's handler based on a <see cref="Func{Task,InvocationContext}"/>.
	/// </summary>
	public static void SetHandler(
	this Command command,
	Func<InvocationContext, Task> handle) =>
	command.Handler = new AnonymousCommandHandler(handle);

Then make the handler read InvocationContext.ParseResult

command-line-api/src/System.CommandLine/Invocation/InvocationContext.cs

Lines 81 to 84 in 209b724

	/// <summary>
	/// The parse result for the current invocation.
	/// </summary>
	public ParseResult ParseResult { get; set; }

and query the values from the ParseResult:

command-line-api/src/System.CommandLine/Parsing/ParseResult.cs

Lines 162 to 168 in 209b724

	/// <inheritdoc cref="GetValueForArgument"/>
	public T GetValueForArgument<T>(Argument<T> argument)
	=> RootCommandResult.GetValueForArgument(argument);
	/// <inheritdoc cref="GetValueForOption"/>
	public T? GetValueForOption<T>(Option<T> option)
	=> RootCommandResult.GetValueForOption(option);

In later versions of System.CommandLine (which are not yet at nuget.org), the SetHandler overloads that take IValueDescriptor<T> parameters have already been deleted, but the InvocationContext approach is still available (although the type isn't called InvocationContext any more).

[donRumatta]

Could you, please, give me another workaround. I have more than 8 params in handler method but several of them are injected services provided with BinderBase. I can switch to InvocationContext to reach options' values, but how can I add services to the context?

[ohads-MSFT]

Sample from docs (#1750):

rootCommand.SetHandler(
    (context) => // InvocationContext, but it's inferred so you don't need to specify it.
    {
        var i = context.ParseResult.GetValueForOption(option);
        var s = context.ParseResult.GetValueForArgument(argument);
        var someDependency = context.GetService(typeof(ILogger)) as ILogger;
        /* Do something exciting! */ 
    });

[calacayir]

How about this? Your whole app:

Cli.Ext.ConfigureServices(services =>
{
    var loggerFactory = LoggerFactory.Create(
        builder => builder
            .AddConsole()
            .SetMinimumLevel(LogLevel.Information));

    services.AddSingleton(loggerFactory);
});


return await Cli.RunAsync<ThumbnailCommand>(args);


[CliCommand]
public class ThumbnailCommand
{
    private readonly ILoggerFactory loggerFactory;

    public ThumbnailCommand(ILoggerFactory loggerFactory)
    {
        this.loggerFactory = loggerFactory;
    }

    [CliOption]
    public TimeSpan StartTime { get; set; }

    [CliOption]
    public TimeSpan Interval { get; set; }

    [CliOption]
    public TimeSpan EndTime { get; set; }

    [CliOption]
    public FileInfo OutputFile { get; set; }

    [CliOption]
    public FileInfo InputFile { get; set; }

    [CliOption]
    public bool FastMode { get; set; }

    [CliOption]
    public FileInfo WebVTT { get; set; }

    [CliOption]
    public string ImagePath { get; set; }

    [CliOption]
    public int FrameWidth { get; set; }

    [CliOption]
    public int FrameHeight { get; set; }

    [CliOption]
    public int Columns { get; set; }

    [CliOption]
    public int Rows { get; set; }

    [CliOption]
    public int BorderWidth { get; set; }

    [CliOption]
    public string BackgroundGradientStart { get; set; }

    [CliOption]
    public string BackgroundGradientEnd { get; set; }

    public async Task<int> RunAsync()
    {
        var opts = new ThumbGenOptions()
            .WithStartTime(StartTime);

        //...

        await thumbnailGenerator.ExecuteAsync(opts);

        return 0;
    }
}

This is possible with DotMake.CommandLine which makes System.CommandLine easy to use and maintain. Check it out!