Experience Hot Reload

Preparation Before Starting the Sample

Overview

This sample keeps Unity in Play Mode, runs conversion again, then reloads basic.bytes with the R key to confirm the changed item master data.

Steps:

  1. Create C# code for hot reload
  2. Press Unity's Play button and confirm the log output
  3. Open Excel and edit the item data
  4. Run conversion while Unity is still playing
  5. Press the R key and confirm the changed data

Enable Automatic Asset Refresh

This sample reads Assets/Resources/basic.bytes. Enable Unity's automatic asset refresh so Unity detects the updated basic.bytes while Play Mode is running.

Open Edit > Preferences > Asset Pipeline, then enable Auto Refresh.

Warning

If Auto Refresh is disabled, Resources.Load may read the old asset after Assets/Resources/basic.bytes is updated during Play Mode. In that case, use the StreamingAssets sample later on this page.

Create the C# Code

Change the Sample.cs from the item master sample as follows. It outputs logs once at startup, then reloads basic.bytes and outputs the logs again whenever you press R.

Sample.cs

using UnityEngine;
using Wiener;
using WienerLib;
#if ENABLE_INPUT_SYSTEM
using UnityEngine.InputSystem;
#endif

public class Sample : MonoBehaviour
{
    private WienerManager _wm;

    void Start()
    {
        ReloadAndOutput();
    }

    void Update()
    {
        if (IsReloadKeyPressed())
        {
            ReloadAndOutput();
        }
    }

    bool IsReloadKeyPressed()
    {
#if ENABLE_INPUT_SYSTEM
        return Keyboard.current != null && Keyboard.current.rKey.wasPressedThisFrame;
#else
        return Input.GetKeyDown(KeyCode.R);
#endif
    }

    void ReloadAndOutput()
    {
        var textAsset = Resources.Load<TextAsset>("basic");
        if (textAsset == null)
        {
            Debug.LogError("basic.bytes was not found in Resources.");
            return;
        }

        try
        {
            _wm = new WienerManager();
            var result = _wm.LoadBasicPack(textAsset.bytes);
            if (result != Result.Success)
            {
                Debug.LogError($"Failed to load basic pack: {result}");
                return;
            }

            Debug.Log("---- Reload master data");
            OutputItem();
        }
        finally
        {
            Resources.UnloadAsset(textAsset);
        }
    }

    void OutputItem()
    {
        foreach (var item in _wm.Item.Values)
        {
            Debug.Log($"Id: {item.Id}, Name: {item.Name}, Value: {item.Value}");
        }
    }
}

Check While Unity Is Playing

Press Unity's Play Button

Press Unity's Play button and confirm that the item master logs are output to the Console.

Unity Console output before hot reload

Edit Excel

Keep Unity playing, then open Assets/Wiener/Data/excel/Item/Item.xlsx in Excel.

For example, change the value of Potion (S) from 100 to 150, then save the workbook.

Item.xlsx value for Potion (S) before editing

↓

Item.xlsx value for Potion (S) changed to 150

Run Conversion During Play Mode

Keep Unity playing, then open Tools > Wiener > Open Converter.

Unity Tools menu with Open Converter selected

Press Run Develop Binary Only to run conversion and update Assets/Resources/basic.bytes.

Converter Run Develop Binary Only button

Reload with the R Key

Focus the Game view and press the R key.

Confirm that the item master is output again in the Console and that the value changed to the one you saved in Excel.

Unity Console output after reloading updated item data

Sample with StreamingAssets

If you do not want to use automatic Resources updates, you can also read basic.bytes from StreamingAssets.

StreamingAssets can also be used in runtime builds. However, the loading method differs by runtime environment; for example, Android requires access through UnityWebRequest. Resources.Load uses the same call pattern on every environment, so the basic Wiener samples recommend Resources.

This section shows direct file loading code for checking the flow in Unity Editor.

For this method, change the Converter's bytes output directory (basic.bytes) to Assets/StreamingAssets, then run conversion.

Assets
+-- Resources
+-- StreamingAssets
|   +-- basic.bytes
+-- Scenes
+-- Scripts

Sample.cs

using System.IO;
using UnityEngine;
using Wiener;
using WienerLib;
#if ENABLE_INPUT_SYSTEM
using UnityEngine.InputSystem;
#endif

public class Sample : MonoBehaviour
{
    private WienerManager _wm;

    void Start()
    {
        ReloadAndOutput();
    }

    void Update()
    {
        if (IsReloadKeyPressed())
        {
            ReloadAndOutput();
        }
    }

    bool IsReloadKeyPressed()
    {
#if ENABLE_INPUT_SYSTEM
        return Keyboard.current != null && Keyboard.current.rKey.wasPressedThisFrame;
#else
        return Input.GetKeyDown(KeyCode.R);
#endif
    }

    void ReloadAndOutput()
    {
#if UNITY_EDITOR
        var path = Path.Combine(Application.streamingAssetsPath, "basic.bytes");
        if (!File.Exists(path))
        {
            Debug.LogError($"basic.bytes was not found: {path}");
            return;
        }

        var bytes = File.ReadAllBytes(path);
        _wm = new WienerManager();
        var result = _wm.LoadBasicPack(bytes);
        if (result != Result.Success)
        {
            Debug.LogError($"Failed to load basic pack: {result}");
            return;
        }

        Debug.Log("---- Reload master data");
        OutputItem();
#else
        Debug.LogError("This sample reads StreamingAssets directly only in Unity Editor. Use a platform-specific loading method for runtime builds.");
#endif
    }

    void OutputItem()
    {
        foreach (var item in _wm.Item.Values)
        {
            Debug.Log($"Id: {item.Id}, Name: {item.Name}, Value: {item.Value}");
        }
    }
}

Tips

In Unity Editor, files under StreamingAssets can be read directly, so this check does not depend on Unity's Resources asset refresh timing.

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