Subpackage Loading

As gameplay becomes more and more rich, the amount of code in the game is increasing and developers are wanting to expand the size of their game package. At the same time, WeChat Mini Games also support the function of subpackage loading. So Cocos Creator provides a subpackage loading feature that supports subpackage loading of code and resources. Where resource subpackage is supported from v2.0.7. Subpackage loading currently only supports all kinds of mini games, such as WeChat Mini Games, OPPO Mini Games and so on.

Subpackage Loading, is the the game content being split into several packages according to certain rules. During the first startup, only the necessary packages are downloaded, also called the main package. Other subpackages are downloaded, as triggered, which can effectively reduce the time spent on the first boot.

Configuration method

Cocos Creator's uses a folder structure when configuring a subpackage. When a folder is selected, the relevant configuration options for the folder appear in the Properties tab:

After checking Subpackage, click Apply at the top right, and the code in this folder will be treated as the contents of the subpackage. The Subpackage Name will be passed as the loaded name when the subpackage is loaded. The name of this folder will be used by default.

Note: After being configured as a subpackage, only native resources, such as images and audio, will eventually be placed in the subpackage. JSON types of resources such as Prefab, AnimationClip, etc., will still be placed in the main package.

Building

The function of subpackaging will only be avialable after the project is built. When previewing, it will be loaded according to the whole package. After the project is built, the corresponding subpackage file will be generated in src/assets in the release package directory.

For example: Configuring the cases/01_graphics folder in the example project as a subpackage. The 01_graphics folder will be generated in subpackages in the release package directory after the project is built.

When building, all the code and resources under the cases/01_graphics subpackage folder are handled as follows:

• Code: All code under the cases/01_graphics folder is merged into an entry script file named 01_graphics/game.js, and the code is removed from the main package.
• Resources: The cases/01_graphics subpackage resources are moved from the res/raw-assets folder to the subpackages/01_graphics directory under the release package directory.

Loading a Subpackage

The engine provides a unified API cc.loader.downloader.loadSubpackage to load the resources (including code and other resources) inside the subpackage file. loadSubpackage needs to pass in the name of a subpackage. This name is the name of the subpackage that you configured in the project before. The default is the name of the subpackage folder.

When the subpackage is completed, a callback is triggered, and if the loading fails, an error message is returned.

cc.loader.downloader.loadSubpackage('01_graphics', function (err) {
    if (err) {
        return console.error(err);
    }
    console.log('load subpackage successfully.');
});

If the loading is successful, the script in the subpackage will be executed and the resource loading path of the subpackage will be added to the engine. Developers can access all the resources in this subpackage in exactly the same way as accessing the main package, without having to worry about whether the resources were originally in the main package or in the subpackage.

WeChat Mini Games

When building for the WeChat Mini Game, the configuration of the subpackage will be automatically generated into the game.json configuration file of the WeChat Mini Games release package according to the rules.

Note: WeChat Mini Games require a specific version to support the subpackage feature. WeChat 6.6.7 Client, 2.1.0 and above base library support, please update to the latest client version, developer tools please use version 1.02.1806120 and above. After updating the developer tools, don't forget to modify the version of Details -> Project Settings -> Debug Base library to 2.1.0 and above in the developer tools:

Subpackage Load Packet Size Limit

At present, the size of the WeChat Mini Game subpackage has following restrictions:

• The size of all subpackage of the entire Mini Game can not exceed 8M
• The size of single subpackage / main package can not exceed 4M

Please refer to the WeChat SubPackage Loading documentation for details.