C#•2y ago

Help, how to make this unity save and load system work?

using UnityEngine;
using System.Collections.Generic;
using System.IO;

public class TestSaveSyst : MonoBehaviour
{
    public List<GameObject> ListOfGameObjects;
    public List<NormalObject> objectsToSave;
    public List<NormalObject> LoadedObjects;
    public string fileName = "savedObjects.json";

    public ListObjectToSave listObjectToSave;

    void Awake()
    {
        listObjectToSave = new ListObjectToSave();
    }

    void OnEnable()
    {
        objectsToSave = listObjectToSave.objectsToSave;
    }

    public void GOListToNOList() // Turns ListOfGameObjects to objectsToSave
    {
        foreach(GameObject go in ListOfGameObjects)
        {
            objectsToSave.Add(TurnGameObjectToNormalObject(go));
        }
    }

    public NormalObject TurnGameObjectToNormalObject(GameObject go)
    {
        NormalObject newNorm = new NormalObject();
        newNorm.name = go.name;
        newNorm.x = go.transform.position.x;
        newNorm.y = go.transform.position.y;
        return newNorm;
    }

    public void Save()
    {
        string json = JsonUtility.ToJson(objectsToSave);
        File.WriteAllText(Application.dataPath + "/" + fileName, json);
    }

    public void Load()
    {
        if (File.Exists(Application.dataPath + "/" + fileName))
        {
            string json = File.ReadAllText(Application.dataPath + "/" + fileName);
            LoadedObjects = JsonUtility.FromJson<List<NormalObject>>(json);
        }
        else
        {
            Debug.Log("File not found!");
        }
    }
}

public class ListObjectToSave
{
    public List<NormalObject> objectsToSave;
}

[System.Serializable]
public class NormalObject
{
    public int id;
    public string name;
    public float x;
    public float y;
}

using UnityEngine;
using System.Collections.Generic;
using System.IO;

public class TestSaveSyst : MonoBehaviour
{
    public List<GameObject> ListOfGameObjects;
    public List<NormalObject> objectsToSave;
    public List<NormalObject> LoadedObjects;
    public string fileName = "savedObjects.json";

    public ListObjectToSave listObjectToSave;

    void Awake()
    {
        listObjectToSave = new ListObjectToSave();
    }

    void OnEnable()
    {
        objectsToSave = listObjectToSave.objectsToSave;
    }

    public void GOListToNOList() // Turns ListOfGameObjects to objectsToSave
    {
        foreach(GameObject go in ListOfGameObjects)
        {
            objectsToSave.Add(TurnGameObjectToNormalObject(go));
        }
    }

    public NormalObject TurnGameObjectToNormalObject(GameObject go)
    {
        NormalObject newNorm = new NormalObject();
        newNorm.name = go.name;
        newNorm.x = go.transform.position.x;
        newNorm.y = go.transform.position.y;
        return newNorm;
    }

    public void Save()
    {
        string json = JsonUtility.ToJson(objectsToSave);
        File.WriteAllText(Application.dataPath + "/" + fileName, json);
    }

    public void Load()
    {
        if (File.Exists(Application.dataPath + "/" + fileName))
        {
            string json = File.ReadAllText(Application.dataPath + "/" + fileName);
            LoadedObjects = JsonUtility.FromJson<List<NormalObject>>(json);
        }
        else
        {
            Debug.Log("File not found!");
        }
    }
}

public class ListObjectToSave
{
    public List<NormalObject> objectsToSave;
}

[System.Serializable]
public class NormalObject
{
    public int id;
    public string name;
    public float x;
    public float y;
}

It is a unity script. I added a group of gameObjects in the ListOfGameObjects. Manually called GOListToNOList()(Worked) then called Save(). Save() worked also, but only gave me an empty json, just a pair of brackets. Thanks

5 Replies

Auros•2y ago

According to the Unity documentation https://docs.unity3d.com/ScriptReference/JsonUtility.ToJson.html, it appears you are not allowed to serialize an array and presumably List<T> directly, as it tries to serialize the public fields on the List object itself, not the contents within. You need to wrap the list in a separate serializable class or struct, which you seem to already have with ListObjectToSave but aren't using. Try replacing this line in your Save method from

string json = JsonUtility.ToJson(objectsToSave);

string json = JsonUtility.ToJson(objectsToSave);

string json = JsonUtility.ToJson(listObjectToSave);

string json = JsonUtility.ToJson(listObjectToSave);

and change the type and assignment of the JsonUtility.FromJson call in your Load method. You might also need to add a [System.Serializable] attribute to the ListObjectToSave class.

.OP•2y ago

Omg, I guess that worked. You guys are op. You figured that out just from the documentation even if you are not into unity.... I was staring at that for like 2 hours already. Alright, cheer thanks!!

Auros•2y ago

I do Unity, but I've never touched the JsonUtility class. I used to use Newtonsoft but now I use System.Text.Json

.OP•2y ago

oh, wierd you're not in unity discord. And Im not familiar with those 2 json library, but might be worth studying for the next time

Auros•2y ago

Oh I never realized there was an official Unity discord server

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Help, how to make this unity save and load system work?