Working with Persistent Data

Unity’s persistentDataPath provides a location for storing data across sessions. This directory is platform-independent, making it ideal for saving data locally without worrying about platform-specific paths.

Using File.IO is not recommended

Using File.IO is not recommended in cross-platform Unity projects, especially in WebGL, where File.IO lacks compatibility. Instead, leveraging Uxios with the unity+persistent:/// scheme ensures smooth file handling across all platforms, including WebGL.

We endeauvour to include all the hacks and workarounds that you normally would need to do, if you were to build this yourself.

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Step 1: Saving a File to Persistent Storage

1. Prepare the File Data
   Define the content to be stored, such as a string, JSON, or binary data.

2. Use the unity+persistent:/// Scheme
   Create a URI using unity+persistent:/// and the desired file path.

var fileUri = new Uri("unity+persistent:///myFolder/myFile.txt");

Why Three Slashes?

In unity+persistent:///, the three slashes indicate an empty authority (host) section, which is typical in file URIs. This structure (e.g., file:///) designates a root path without a specific server or domain. The three-slash format keeps the URI standard while targeting Unity’s persistentDataPath location.

1. Send the Data Using Uxios
   Use Uxios’s Put method to save data to this URI:

var promise = uxios.Put(fileUri, data);

This approach mirrors a server file upload but instead saves to the local persistent path, ensuring cross-platform compatibility.

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Step 2: Retrieving a File from Persistent Storage

1. Define the URI for the File
   Specify the unity+persistent:/// scheme with the file’s path.

var fileUri = new Uri("unity+persistent:///myFolder/myFile.txt");

1. Retrieve with a GET Request
   Call Uxios’s Get method, passing the URI, to retrieve file contents.

var promise = uxios.Get<string>(fileUri);
promise.Then(response => {
    Debug.Log("File content: " + response.Data);
});

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Summary

Using the unity+persistent:/// scheme:

• Simplifies cross-platform file management in Unity.
• Ensures compatibility with WebGL, mobile, and desktop by relying on persistentDataPath.