unity3d-class-type-reference

An example npm package that contains some example assets to demonstrate how to create a package for use in games made using the Unity game engine.

$ yarn add rotorz/unity3d-class-type-reference

This package is compatible with the unity3d-package-syncer tool. Refer to the tools' README for information on syncing packages into a Unity project.

Warning

Whilst we have not encountered any platform specific issues yet, the source code in this repository might not necessarily work for all of Unity's platforms or build configurations. It would be greatly appreciated if people would report issues using the issue tracker.

Usage Examples

Type references can be made using the inspector simply by using ClassTypeReference:

using Rotorz.Games.Reflection;
using UnityEngine;

public class ExampleBehaviour : MonoBehaviour
{
    public ClassTypeReference greetingLoggerType;
}

A default value can be specified in the normal way:

public ClassTypeReference greetingLoggerType = typeof(DefaultGreetingLogger);

You can apply one of two attributes to drastically reduce the number of types presented when using the drop-down field.

using Rotorz.Games.Reflection;
using UnityEngine;

public class ExampleBehaviour : MonoBehaviour
{
    // Allow selection of classes that implement an interface.
    [ClassImplements(typeof(IGreetingLogger))]
    public ClassTypeReference greetingLoggerType;

    // Allow selection of classes that extend a specific class.
    [ClassExtends(typeof(MonoBehaviour))]
    public ClassTypeReference someBehaviourType;
}

To create an instance at runtime you can use the System.Activator class from the .NET / Mono library:

using Rotorz.Games.Reflection;
using System;
using UnityEngine;

public class ExampleBehaviour : MonoBehaviour
{
    [ClassImplements(typeof(IGreetingLogger))]
    public ClassTypeReference greetingLoggerType = typeof(DefaultGreetingLogger);


    private void Start()
    {
        if (this.greetingLoggerType.Type == null) {
            Debug.LogWarning("No type of greeting logger was specified.");
        }
        else {
            var greetingLogger = Activator.CreateInstance(this.greetingLoggerType) as IGreetingLogger;
            greetingLogger.LogGreeting();
        }
    }
}

Presentation of drop-down list can be customized by supplying a ClassGrouping value to either of the attributes ClassImplements or ClassExtends.

• ClassGrouping.None - No grouping, just show type names in a list; for instance, "Some.Nested.Namespace.SpecialClass".

• ClassGrouping.ByNamespace - Group classes by namespace and show foldout menus for nested namespaces; for instance, "Some > Nested > Namespace > SpecialClass".

• ClassGrouping.ByNamespaceFlat (default) - Group classes by namespace; for instance, "Some.Nested.Namespace > SpecialClass".

• ClassGrouping.ByAddComponentMenu - Group classes in the same way as Unity does for its component menu. This grouping method must only be used for MonoBehaviour types.

For instance,

using Rotorz.Games.Reflection;
using UnityEngine;

public class ExampleBehaviour : MonoBehaviour
{
    [ClassImplements(typeof(IGreetingLogger), Grouping = ClassGrouping.ByAddComponentMenu)]
    public ClassTypeReference greetingLoggerType;
}

Contribution Agreement

This project is licensed under the MIT license (see LICENSE). To be in the best position to enforce these licenses the copyright status of this project needs to be as simple as possible. To achieve this the following terms and conditions must be met:

• All contributed content (including but not limited to source code, text, image, videos, bug reports, suggestions, ideas, etc.) must be the contributors own work.

• The contributor disclaims all copyright and accepts that their contributed content will be released to the public domain.

• The act of submitting a contribution indicates that the contributor agrees with this agreement. This includes (but is not limited to) pull requests, issues, tickets, e-mails, newsgroups, blogs, forums, etc.