Saver

Saver - is a library for saving and loading save data in Defold projects. It provides a simple API for saving and loading save data, as well as support for migrations and simple key-value storage. The library supports saving and loading data in JSON, Lua, or binary format, and can save and load files to and from the file system.

Features

• Save and Load Game State: Save and load data with a simple API.
• File Management: Save and load data to and from files.
• Auto-Save: Automatically save data at regular intervals.
• Migrations: Apply migrations to data when the migration version changed.
• Storage: Store key-value pairs in the save data.
• Format support: Save and load data in JSON, Lua or binary format.

Setup

Dependency

Open your game.project file and add the following line to the dependencies field under the project section:

Saver

https://github.com/Insality/defold-saver/archive/refs/tags/3.zip

After that, select Project ▸ Fetch Libraries to update library dependencies. This happens automatically whenever you open a project so you will only need to do this if the dependencies change without re-opening the project.

Library Size

Note: The library size is calculated based on the build report per platform

Platform	Library Size
HTML5	5.23 KB
Desktop / Mobile	8.68 KB

Configuration [optional]

You should configure the module in the game.project file:

[saver]
save_name = game.json
save_folder = Defold Saver
autosave_timer = 3
saver_key = saver
storage_key = storage

This configuration section for game.project defines various settings:

• save_name: The name of the save file. Default is game.json.
• save_folder: The folder name where the save file will be stored. Default is your project.title name (with only alphanumeric, underscores or spaces characters).
• autosave_timer: The time interval in seconds between auto-saves. Default is 3.
• saver_key: The key in the save data table that contains the Saver state. Default is saver.
• storage_key: The key in the save data table that contains the Storage state. Default is storage.

Core Concepts

Defold Saver uses the following core concepts:

• Auto-Save: Automatically save data at regular intervals. It used as a default save method. This allows you to specify the data you want to keep in the save file and the library will handle the rest.
• Save State: A Save state contains a set of table references in the save file. You can bind multiple save states. Bindings is done by the saver.bind_save_state(id, table_reference) function. When you bind the table to save state and previous data was saved, the save data will override values in your reference table. So usually you should bind the default table from module or your game data on game loader step.
• Migration: Migrations are used to update the save data if required. Migration is a just list of functions that will be applied to the save data if the migration version in save is less than the migrations count. You can set migrations by saver.set_migrations function before saver.init and apply them by saver.apply_migrations function after.
• Storage: Storage is a simple key-value storage that can be utilized in many ways and you don't want to make a separate save state for it. You can set and get values by storage.set and storage.get functions.

Basic Usage

local saver = require("saver.saver")

local game_data = {
	score = 0,
	level = 1,
}

function init(self)
	saver.init()
	saver.bind_save_state("game", game_data)

	-- Now we can change game_data content and it will be saved automatically via autosave
	game_data.score = game_data.score + 1

	-- Or you can save it manually by saver.save_game_state() if you want to save it immediately
	saver.save_game_state()
end

API Reference

Quick API Reference

local saver = require("saver.saver")
saver.init()
saver.bind_save_state(table_key_id, table_reference)
saver.save_game_state([save_name])
saver.load_game_state([save_name])
saver.set_game_state(game_state)
saver.get_game_state()
saver.delete_game_state([save_name])
saver.save_file_by_path(data, absolute_file_path)
saver.load_file_by_path(absolute_file_path)
saver.delete_file_by_path(absolute_file_path)
saver.save_file_by_name(data, file_name)
saver.load_file_by_name(file_name)
saver.delete_file_by_name(file_name)
saver.set_autosave_timer(seconds)
saver.get_save_path(file_name)
saver.get_save_version()
saver.set_migrations(migration_list)
saver.apply_migrations()
saver.set_logger(logger)
saver.get_current_game_project_folder()
saver.before_save_callback = function() "Called before saver saves data" end

local storage = require("saver.storage")
storage.set(id, value)
storage.get(id, [default_value])
storage.get_number(id, [default_value])
storage.get_string(id, [default_value])
storage.get_boolean(id, [default_value])

API Reference

Read the API Reference file to see the full API documentation for the module.

Use Cases

Read the Use Cases file to see several examples of how to use the this module in your Defold game development projects.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Issues and Suggestions

For any issues, questions, or suggestions, please create an issue.

👏 Contributors

Changelog

V1

• Initial release

V2

• Update docs, missing API for saver.delete_* functions
• Fix error with get_current_game_project_folder while using in HTML5 builds
• Add saver.before_save_callback callback for custom save logic. Can be used to prepare/update data before saving, like transfing from real-time data to save data

V3

• BREAKING: HTML5 data now using sys.serialize instead json.encode due the issue with json.encode (sparse arrays, number keys)

  • I'm not expecting any game in production to use this feature, but if you are using it, please implement migration for your save data

• BREAKING: Change the way to get the project file name. Now it's removing the spaces and special characters from the project title.

  • To get the previous behavior, you should set the save_folder in the game.project file.

• Add saver.save_folder configuration option to README.md.

• Fix saver.delete_file_by_path for HTML5.

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