List to Dictionary and back again-CodePudding

I have read many posts about dictionaries and serialization etc. and they all have different ways of doing things. Being new to coding (to an extent) I am having trouble figuring out how to get my dictionary to a list or serialized to get it saved then reloaded on play. This is Unity BTW. So here is what I am using. I have an application manager that is mainly just a set of BOOL values that tells my mission system if something has been completed or not. Something like "GetWeapon FALSE" (then when they pick it up it changes to TRUE which tells the mission system to move to the next objective or complete) So I have a starting list of keys,values...these then get placed into a dictionary and the values are changed within that. I need to be able to save those values and reload them on LOAD (default PLAY mode is newgame--as you see below it resets the dictionary and copies in the starting states). I know it can't be as difficult as I am making it, just not understanding the whole serialize thing. Most sites are showing a dictionary like {key,value} so I am getting lost on iterating through the dictionary and capturing the pairs and saving them.

Here is partial code for the appmanager (it is a singleton):

// This holds any states you wish set at game startup
[SerializeField] private List<GameState> _startingGameStates = new List<GameState>();

// Used to store the key/values pairs in the above list in a more efficient dictionary
private Dictionary<string, string> _gameStateDictionary = new Dictionary<string, string>();

void Awake()
{
    // This object must live for the entire application
    DontDestroyOnLoad(gameObject);

    ResetGameStates();

}

void ResetGameStates()
{
    _gameStateDictionary.Clear();

    // Copy starting game states into game state dictionary
    for (int i = 0; i < _startingGameStates.Count; i  )
    {
        GameState gs = _startingGameStates[i];
        _gameStateDictionary[gs.Key] = gs.Value;
    }

    OnStateChanged.Invoke();
}

public GameState GetStartingGameState(string key)
{
    for (int i = 0; i < _startingGameStates.Count; i  )
    {
        if (_startingGameStates[i] != null && _startingGameStates[i].Key.Equals(key))
            return _startingGameStates[i];
    }

    return null;
}

// Name    :  SetGameState
// Desc    :  Sets a Game State
public bool SetGameState(string key, string value)
{
    if (key == null || value == null) return false;

    _gameStateDictionary[key] = value;
   
    OnStateChanged.Invoke();

    return true;
}

Tried something similar to this:

Dictionary<string, string> _gameStateDictionary = new Dictionary<string, string>
    {
     for (int i = 0; i < _gameStateDictionary.Count; i  )
     string json = JsonConvert.SerializeObject(_gameStateDictionary, Formatting.Indented);
     Debug.Log(json);
    {


}

However all I got was the first item in the list. (I did modify the above in a for loop) I know the above is wrong, I did other iterations to just to get the dictionary to print out in the console. Anyway, just asking for a little code help to save and load a dictionary.

CodePudding user response：

You can iterate the dictionary by using its Keys collection.

foreach (var key in myDictionary.Keys)
{
    var val = myDictionary[key];
}

Populate your data structure with the key/value pairs and serialize the list of items.

var missionItems = new List<MissionItem>();

foreach (var key in myDictionary.Keys)
{
    var missionItem = new MissionItem();

    missionItem.Key = key;
    missionItem.Value = myDictionary[key];

    missionItems.Add(missionItem);
}

var json = JsonUtility.ToJson(missionItems);

Loading is straight forward, deserialize your data, then loop through all the items and add each one to the empty dicitionary.

var missionItems = JsonUtility.FromJson<List<MissionItem>>(json);

foreach (var item in missionItems)
{
    myDictionary.Add(item.Key, item.Value);
}

CodePudding user response：

Since you want to save and load those persistent anyway, personally I would not use the Inspector and bother with Unity serialization at all but rather directly serialize/deserialize from and to json.

Simply place your default dictionary as a simple json file like e.g.

{
    "Key1" : "Value1",
    "Key2" : "Value2",
    "Key3" : "Value3",
    ...
}

within the folder Assets/StreamingAssets (create it if it doesn't exists). This will be your default fallback file if none exists so far.

On runtime you will load it from Application.streamingAssetsPath.

Then when saving you will not put it there but rather to the Application.persistentDataPath

using Newtonsoft.Json;
 
...

[SerializeField] private string fileName = "example.json";
private string defaultStatesPath => Path.Combine(Application.streamingAssetsPath, fileName);
private string persistentStatesPath => Path.Combine(Application.persistentDataPath, fileName);

private Dictionary<string, string> _gameStateDictionary 

public void Load()
{
    var filePath = persistentStatesPath;

    if(!File.Exists(filePath))
    {
        filePath = defaultStatesPath;
    }

    var json = File.ReadAllText(filePath);

    _gameStateDictionary = JsonConvert.DeserializeObject<Dictionary<string, string>>(json);
}

public void Save()
{
    var filePath = persistentStatesPath;

    if(!Directory.Exists(Application.persistentDataPath))
    {
        Directory.CreateDirectory(Application.persistentDataPath);
    }

    var json = JsonConvert.SerializeObject(_gameStateDictionary, Formatting.intended);

    File.WriteAllText(filePath, json);
}

If you then still want to edit the default via the Inspector you could merge both and instead of using StreamingAssets do

[SerializeField] private GameState[] defaultStates;

public void Load()
{
    var filePath = persistentStatesPath;

    if(!File.Exists(filePath))
    {
        LoadDefaults();
        return;
    }

    var json = File.ReadAllText(filePath);

    _gameStateDictionary = JsonConvert.DeserializeObject<Dictionary<string, string>>(json);
}

public void LoadDefaults()
{
    _gameStateDictionary = defaultStates.ToDictionary(gameState => gameState.Key, gameState => gameState.Value);
}

And then btw you could do

public string GetState(string key, string fallbackValue = "")
{
    if(_gameStateDictionary.TryGetValue(key, out var value))
    {
        return value;
    }

    return fallbackValue;
}