Exceptions

When working with the DH Save System, you may encounter several exceptions. These are typically easy to resolve and often involve either attempting to save data with an existing ID or trying to save to a slot that hasn’t been loaded. Here’s how you can address the issues related to these exceptions:

MissingMethodException#

This exception occurs when a class that is being saved does not have a default constructor. The DH Save System requires a parameterless constructor to instantiate objects during deserialization.

Solution#

Ensure that any class you intend to serialize with the DH Save System includes a default, parameterless constructor. If your class has constructors that take parameters, you must still provide a default constructor.

Example#

public class PlayerData
{
    public int score;
    public string name;

    // Default constructor
    public PlayerData()
    {
    }

    // Constructor with parameters
    public PlayerData(string name, int score)
    {
        this.name = name;
        this.score = score;
    }
}

try
{
    PlayerData playerData = new PlayerData("John Doe", 1000);
    SaveSystem.Save("playerData", playerData, isGlobal: false);
}
catch (MissingMethodException)
{
    // Ensure PlayerData class includes a default constructor
    Console.WriteLine("Ensure the PlayerData class has a default constructor.");
}

Adding a default constructor allows the serialization and deserialization processes to function correctly, avoiding the MissingMethodException and ensuring smooth operation of the DH Save System.

KeyAlreadyExistsException#

Occurs when attempting to save data with an ID that already exists within the specified scope (global or slot-specific).

Solution#

Change the ID you’re using for saving. Ensure it’s unique to avoid conflicts.

Example

try
{
    SaveSystem.Save("playerScore", 5000, isGlobal: false);
}
catch (KeyAlreadyExistsException)
{
    // Change the ID and try again
    SaveSystem.Save("playerScore1", 5000, isGlobal: false);
}

SaveSlotNotLoadedException#

Thrown when attempting to save to a slot that hasn’t been loaded. This can occur if you try to save slot-specific data before a slot is active.

Solution#

Before saving data to a slot, ensure that a slot is loaded. If you need to save data but no slot is loaded, either save it as global data or wait until a slot has been loaded.

Example

try
{
    SaveSystem.Save("playerLocation", new Vector3(0, 0, 0), isGlobal: false);
}
catch (SaveSlotNotLoadedException)
{
    // Load a slot or save as global data instead
    SaveSystem.LoadSaveSlot("SlotName");
    SaveSystem.Save("playerLocation", new Vector3(0, 0, 0), isGlobal: false);
}

InvalidFieldTypeException, InvalidPropertyTypeException#

These exceptions occur when saving custom classes that use unsupported types, such as Dictionary or Transform, without converting them to a serializable form.

Solution#

Convert unsupported types to their serializable counterparts provided by the save system, such as changing Transform to SerializableTransform and Dictionary<TKey, TValue> to SerializableDictionary<TKey, TValue>.

Example

try
{
    var playerData = new CustomPlayerData
    {
        playerTransform = new SerializableTransform(player.transform),
        inventoryItems = new SerializableDictionary<string, int>(inventoryItems)
    };
    SaveSystem.Save("playerData", playerData, isGlobal: false);
}
catch (InvalidFieldTypeException)
{
    // Ensure all fields are using serializable types
}
catch (InvalidPropertyTypeException)
{
    // Ensure all properties are using serializable types
}