Help Generator

EntryPoint provides an automatic Help generator, which always owns the -h and --help Options in both CliCommands and CliArguments instances.

When --help is invoked by the user, .HelpInvoked is set on CliCommands/CliArguments, and the virtual method OnHelpInvoked(string helpText) is invoked.

• By default OnHelpInvoked will print the help text to screen, and call Environment.Exit(0)
• By overriding OnHelpInvoked on a CliCommands/CliArguments implementation, you change the implementation to something more appropriate to your program flow.

EntryPoint does not try to control your usage of this, but be aware that invoking --help will disable Required attributes; if you neither exit or check .HelpInvoked, then your program may continue running with invalid state.

Basic Usage

The Help Generator consumes the following information for each class type.

CliCommands

[Help("This will be displayed as an initial blurb for the utility")]
class ExampleHelpCliCommands : BaseCliCommands {

    // [DefaultCommand]
    [Command("command1")]
    [Help("Some command that can be used")]
    public void Command1(string[] args) {
        // ...etc
    }
}

class CommandsHelpProgram {
    public void main(string[] args) {
        var commands = Cli.Execute<ExampleHelpCliCommands>(args);
        // Execution would not reach this point if --help is invoked, 
        // since OnHelpInvoked would run and exit the program

        // However, if you override and don't exit at OnHelpInvoked, 
        // you could also do this:
        if (commands.HelpInvoked) {
            // Return here, or run something else
        }

        // Normal Post-Command Application code...
    }
}

CliArguments

[Help("This will be displayed as an initial blurb for the command/utility")]
class ExampleHelpCliArguments : BaseCliArguments {
    public ExampleHelpCliArguments()
        : base(utilityName: "MyFirstUtility") { }

    [OptionParameter(LongName: "value1")]
    [Help("Some value to set")]
    public bool Value1 { get; set; }
}

class ArgumentsHelpProgram {
    public void main(string[] args) {
        var arguments = Cli.Parse<ExampleHelpCliArguments>(args);
        // Execution would not reach this point if --help is invoked, 
        // since OnHelpInvoked would run and exit the program

        // However, if you override and don't exit at OnHelpInvoked, 
        // you could also do this:
        if (arguments.HelpInvoked) {
            // Return here, or run something else
        }

        // Normal Application code...
    }
}

Overriding OnHelpInvoked(...)

Below is a brief example of overriding the help method.

[Help("This will be displayed as an initial blurb for the utility")]
class OverrideHelpCliCommands : BaseCliCommands {

    // [DefaultCommand]
    [Command("command1")]
    [Help("Some command that can be used")]
    public void Command1(string[] args) {
        // ...etc
    }

    // Now the following code will be executed when 
    // help is invoked against this CliCommands class
    public override void OnHelpInvoked(string helpText) {
        Console.WriteLine(helpText);
        Console.WriteLine("Press Enter to exit");
        Console.ReadLine();
        Environment.Exit(0);
    }
}