how to write GameObject position in the Scene to json file? - json

Question

on Clicking the button, I m loading the function WriteJsonForLevel(). I have placed three GameObject with the tag name "RedCoin" and I want to write the position of the GameObject to a JSON file. I can get the position of the object, but it's all overwritten. I can only see the last GameObject position (i.e the completion of the loop)
public List<GameObject> levelObjects;
public string level;
public Vector3 pos;
// Start is called before the first frame update
void Start()
{
levelObjects = new List<GameObject>();
}
// Update is called once per frame
void Update()
{
}
public void WritejsonForAll()
{
WriteJsonForLevel();
}
public void WriteJsonForLevel()
{
/* FileStream fs = new FileStream(Application.dataPath + "/sample.json",FileMode.Create);
StreamWriter writer= new StreamWriter(fs);*/
GameObject[] coinObjRed = GameObject.FindGameObjectsWithTag("RedCoin");
putAllObjectInList(coinObjRed);
}
public void putAllObjectInList(GameObject[] p)
{
string path = Application.dataPath + "/text.json";
foreach (GameObject q in p)
{
levelObjects.Add(q);
}
for (int i = 0; i < levelObjects.Count; i++)
{
GameObject lvlObj = levelObjects[i];
Vector3 pos = lvlObj.transform.position;
string posOutput = JsonUtility.ToJson(pos);
File.WriteAllText(path,posOutput);
Debug.Log("position:" + posOutput);
}
}
}

Answer 1

You are using WriteAllText which will overwrite the file every time it is called. As it is overwriting each time it is in the loop, it will only write the last object to the file as every other previous write is overwritten. I would consider making a serialized class of data, assigning the data to it, converting it to a JSON string then saving that.
// stores individual locations for saving
[System.Serializable]
public class IndividualLocation
{
public IndividualLocation(Vector3 pos)
{
xPos = pos.x;
yPos = pos.y;
zPos = pos.z;
}
public float xPos;
public float yPos;
public float zPos;
}
// stores all game locations for saving
[System.Serializable]
public class AllGameLocations
{
public List<IndividualLocation> Locations = new List<IndividualLocation>();
}
public void PutAllObjectInList(in GameObject[] p)
{
string path = Application.dataPath + "/text.json";
// create a new object to write to
AllGameLocations data = new AllGameLocations();
// iterate the objects adding each to our structure
foreach(GameObject obj in p)
{
data.Locations.Add(new IndividualLocation(obj.transform.position));
}
// now that the data is filled, write out to the file
File.WriteAllText(path, JsonUtility.ToJson(AllGameLocations));
}
If you need a snippet on how to load the data properly I can add one.
Edit: Here is a load snippet
public void LoadJSONObject()
{
string path = Application.dataPath + "/text.json";
// if the file path or name does not exist
if (!Directory.Exists(Path.GetDirectoryName(path)))
{
Debug.LogWarning("File or path does not exist! " + path);
return
}
// load in the save data as byte array
byte[] jsonDataAsBytes = null;
try
{
jsonDataAsBytes = File.ReadAllBytes(path);
Debug.Log("<color=green>Loaded all data from: </color>" + path);
}
catch (Exception e)
{
Debug.LogWarning("Failed to load data from: " + path);
Debug.LogWarning("Error: " + e.Message);
return;
}
if (jsonDataAsBytes == null)
return;
// convert the byte array to json
string jsonData;
// convert the byte array to json
jsonData = Encoding.ASCII.GetString(jsonDataAsBytes);
// convert to the specified object type
AllGameLocations returnedData;
JsonUtility.FromJsonOverwrite<AllGameLocations>(jsonData, AllGameLocations);
// use returnedData as a normal object now
float firstObjectX = returnedData.Locations[0].xPos;
}
}
Let me know if the Load works, just typed it up untested. Added some error handling as well to assure data exists and the load properly works.