Data loaders

A data loader reads a file into memory once, at startup. Moongate loads all of its world data this way — skills, professions, regions, item and mobile templates — and a plugin can add its own loader for its own files.

The interface

public interface IDataLoader
{
    ValueTask LoadAsync(CancellationToken ct = default);
}

LoadAsync runs once during startup. A loader typically resolves a file under the server root, parses it, and hands the result to a registry service the rest of the plugin reads from.

Locating and parsing the file

Inject DirectoriesConfig to resolve a path under the server root, and use YamlUtils to parse — both from SquidStd.Core. RegisterDirectory returns the absolute path and creates the directory if it is missing, so the file simply sits under <root>/plugins/myshard/. This is the same shape as the built-in SkillLoader.

using Moongate.Server.Abstractions.Interfaces.Loading;
using SquidStd.Core.Directories;
using SquidStd.Core.Yaml;

namespace MyShard.Motd.Loading;

/// <summary>Loads plugins/myshard/motd.yaml (a list of lines) into the MOTD registry.</summary>
public sealed class MotdLoader : IDataLoader
{
    private readonly DirectoriesConfig _directories;
    private readonly MotdRegistry _registry;

    public MotdLoader(DirectoriesConfig directories, MotdRegistry registry)
    {
        _directories = directories;
        _registry = registry;
    }

    public ValueTask LoadAsync(CancellationToken ct = default)
    {
        var directory = _directories.RegisterDirectory("plugins/myshard");
        var path = Path.Combine(directory, "motd.yaml");

        if (!File.Exists(path))
        {
            return ValueTask.CompletedTask;
        }

        var lines = YamlUtils.DeserializeFromFile<List<string>>(path) ?? [];
        _registry.SetLines(lines);

        return ValueTask.CompletedTask;
    }
}

The registry is an ordinary singleton the loader fills and everything else injects:

namespace MyShard.Motd;

/// <summary>Holds the message-of-the-day lines loaded at startup.</summary>
public sealed class MotdRegistry
{
    private IReadOnlyList<string> _lines = [];

    public IReadOnlyList<string> Lines => _lines;

    public void SetLines(IReadOnlyList<string> lines)
        => _lines = lines;
}

A matching plugins/myshard/motd.yaml:

- "Welcome to MyShard!"
- "Server resets nightly at 04:00."

Registering and ordering

container.Register<MotdRegistry>(Reuse.Singleton);
container.RegisterDataLoader<MotdLoader>(priority: 1000);

Loaders run in ascending priority. Moongate's own loaders occupy the low numbers (up to 150), so pick a priority above them — 1000 here — to load once the core world data your file might reference is already in place.

Table of Contents

Data loaders

The interface

Locating and parsing the file

Registering and ordering