Creating a Unity Package

This guide explains how to create a Unity package using the Facebook SDK as an example. Follow these steps to create your own package.

Step-by-Step Instructions

1. Extract the Facebook SDK

1. Import the Facebook SDK .unitypackage into your Unity project.
2. After importing, collect all the created folders and files (including meta files).
3. Move these folders and files to a directory outside your Unity project. For example, create a folder named FacebookSDK on your drive and move them there.

2. Create the package.json File

Create a package.json file in the FacebookSDK folder with the following content:

{
    "name": "com.facebook",
    "version": "17.0.1",
    "displayName": "Facebook SDK",
    "keywords": [
      "Facebook",
      "SDK"
    ],
    "author": {
      "name": "Facebook",
      "url": "https://developers.facebook.com/docs/unity/downloads/"
    },
    "description": "Facebook SDK (custom created package by @davitmk)",
    "unity": "2021.1",
    "dependencies": {
      "com.google.external-dependency-manager": "1.2.181"
    }
}

3. Pack the Package into a Tarball and Export to git package

1. Open any Unity project.
2. Open any script in the Unity project.
3. Call the following method in the script to create a .tgz file:
   UnityEditor.PackageManager.Client.Pack("C:/FacebookSDK", "C:/FacebookSDK");
4. Export the .tgz file content into a package folder next to it

4. Import the Package

Option 1: Open Unity Package Manager > Add package from git URL :
https://github.com/Davidnovarro/Unity-Packages.git?path=/Facebook/17.0.1/package

Option 2: Modify the manifest.json to import the local .tgz as a package by adding the following line file:
"com.facebook": "file:../Assets/Packages/com.facebook.tgz"

⚠️ Warning: Unity ignores link.xml files located in the Packages folder, which are used to preserve assembly files.

One of the ways to fix it is to include the following Editor script in the package.

#if UNITY_EDITOR
using System.IO;
using UnityEditor.Build;
using UnityEditor.Build.Reporting;
using UnityEditor.UnityLinker;

namespace Facebook.Unity.PostProcess
{
    public class PreservePackageXmLinkFile : IUnityLinkerProcessor
    {
        int IOrderedCallback.callbackOrder => 0;
        string IUnityLinkerProcessor.GenerateAdditionalLinkXmlFile(BuildReport report, UnityLinkerBuildPipelineData data) => Path.GetFullPath("Packages/com.facebook/link.xml");
    }
}
#endif