Module dcli.program_commands

Usage

The basic idea is to create a ProgramCommands structure and then define a number of Commands that it can handle and optionally, a set of ProgramOptions that it can handle. Each Command can in turn have it's own ProgramCommands.

Handlers

Handlers are provided to be able to eacily handle when a command is encountered. This will allow you to structure your program with a module based architecture, where each "handler" can e.g. pass the commands to a module that is build specifically for handling that command.

E.g.:

// install.d
void commandHandler(T)(T commands) {
    writeln(commands.install); // prints true
}
// main.d
static import install, build;
void main(string[] args) {
    auto commands = ProgramCommands!(
        Command!"build".handler!(build.commandHandler)
        Command!"install".handler!(install.commandHandler)
    )();
    commands.parse(args);
    commands.executeHandlers();
}
// Run it
$ ./program install
$ >> true

Inner ProgramOptions

The first argument to a ProgramCommands object can optionally be a ProgramOptions object. In this case, the program options are accessible with an internal variable named options

E.g.:

auto commands = ProgramCommands!(
    ProgramOptions!(Options!("opt1", string)),
    Command!"command1",
    Command!"command2".args!(
        ProgramOptions!(Options!("opt2", string))
    )
)();

commands.options.opt1; // access the option
commands.command1; // access the command
commands.command2.op2; // access the options of command2

Inner ProgramCommands

You can also pass in sub commands to a Command object in the args parameter:

auto commands = ProgramCommands!(
    ProgramOptions!(Options!("opt1", string)),
    Command!"command1".args!(
        ProgramCommands!(
            ProgramOptions!(Options!("opt2", string)),
            Command!"sub-command1",
        ),
    ),
)();

commands.options.opt1; // access the option
commands.command1.subCommand1; // access the command
commands.command1.options.op2; // access the options of command2

Example

import dcli.program_options;

alias MainCommands = ProgramCommands!(
    ProgramOptions!(
        Option!("glob1", string).shortName!"a".description!"desc",
    ),
    Command!"cmd1"
        .args!(
            ProgramOptions!(
                Option!("opt1", string).shortName!"b".description!"desc",
            ),
    ),
    Command!"cmd2"
        .handler!(Fixtures.handleCommand2)
        .description!"desc",
    Command!"cmd3"
        .args!(
            ProgramCommands!(
                ProgramOptions!(
                    Option!("opt3", string).shortName!"d".description!"desc",
                ),
                Command!"sub1"
                    .args!(
                        ProgramOptions!(
                            Option!("opt4", string).shortName!"e".description!"desc",
                        ),
                    )
                    .handler!(Fixtures.handleCommand3)
                    .description!"desc",
            ),
        )
        .handler!(Fixtures.handleCommand3Sub1)
        .description!"desc",
);

auto commands = MainCommands();

commands.parse([
    "-ayo",
    "cmd3",
    "-d",
    "hi",
    "sub1",
    "-e",
    "boo",
]);

assert(cast(bool)commands.cmd1 == false);
assert(cast(bool)commands.cmd2 == false);
assert(cast(bool)commands.cmd3 == true);

assert(commands.options.glob1 == "yo");
assert(commands.cmd3.options.opt3 == "hi");
assert(commands.cmd3.sub1.opt4 == "boo");

assert(commands.helpText ==
`Options:
-h  --help    Displays this help message
-a  --glob1   desc
Commands:
cmd1
cmd2  desc
cmd3  desc`
);

commands.executeHandlers;

assert(!Fixtures.checkResetHandledCommand2);
assert( Fixtures.checkResetHandledCommand3);
assert( Fixtures.checkResetHandledCommand3Sub1);