Command Guide

LeviLamina provides an easy-to-use command registration system, divided into compile-time and runtime registration. This guide only introduces the compile-time command registration system. If you want to implement your own scripting engine, runtime command registration might be useful for you. Before this guide includes a section on runtime command registration, you can refer to the implementation of LegacyScriptEngine or the CommandTest in LeviLamina. Additionally, LegacyScriptEngine is a scripting engine that has existed since LiteLoaderBDS v1, and many of its approaches are now outdated.

Usage

1. Include the necessary header files:

   #include "ll/api/command/CommandHandle.h"
   #include "ll/api/command/CommandRegistrar.h"
   

2. Call the CommandRegistrar::getInstance().getOrCreateCommand method to obtain or create a command and assign it to auto& command.
3. Call command.overload to overload the command. If you don't need a command that accepts parameters, you can omit the template parameters, for example: command.overload().
4. Use the required method to add a mandatory parameter. This method and the optional method require passing the variable names from the corresponding structure. Use the optional method to add an optional parameter, but ensure to check whether the user has provided it. Call text to add a subcommand. Other methods can be referenced in ll/api/command/Overload.h and through Intellisense.
5. Call execute to pass in the command's callback function. The callback function parameters can be referenced in the example below.

Example

#include "ll/api/command/CommandHandle.h"
#include "ll/api/command/CommandRegistrar.h"

struct NewCommand {
    enum class NewEnum { a = 0, b = 1, c = 2 } enum1;
    std::string str;
    int         number = 1;
};

void registerCommand() {
    using namespace ll::command;
    auto& command = CommandRegistrar::getInstance().getOrCreateCommand("new", "A example command");
    command.overload<NewCommand>().text("test").required("enum1").required("str").optional("number").execute(
        [](CommandOrigin const& origin, CommandOutput& output, NewCommand const& param) {
            output.success("test! {} {} {}", param.enum1, param.str, param.number);
        }
    );
}

In this example, we define a structure named NewCommand, which stores the command parameters. Using the getOrCreateCommand method, we create a command named new. Through overload method, we overload a subcommand named text, along with an enumeration, a string, and an integer parameter. The in-game usage appears as follows:

/new test <enum1> <str> [number]