Mirror/doc/Articles/Guides/Sync/SyncDictionary.md
James Frowen b86a611674
Restructure docs (#2249)
* moving all guides to Articles folder

* updating toc for root and articles

* fixing toc

* css on side toc

* fixing links on index
2020-09-16 22:27:05 +01:00

80 lines
2.9 KiB
Markdown

# SyncDictionary
A SyncDictionary is an associative array containing an unordered list of key, value pairs. Keys and values can be of the following types:
- Basic type (byte, int, float, string, UInt64, etc)
- Built-in Unity math type (Vector3, Quaternion, etc)
- NetworkIdentity
- Game object with a NetworkIdentity component attached.
- Struct with any of the above
SyncDictionary works much like [SyncLists](SyncLists.md): when you make a change on the server the change is propagated to all clients and the Callback is called.
To use it, create a class that derives from SyncDictionary for your specific type. This is necessary because the Weaver will add methods to that class. Then add a field to your NetworkBehaviour class.
> Note that by the time you subscribe to the callback, the dictionary will already be initialized, so you will not get a call for the initial data, only updates.</p>
>Note SyncDictionaries must be initialized in the constructor, not in Startxxx(). You can make them readonly to ensure correct usage.
## Simple Example
```cs
using UnityEngine;
using Mirror;
[System.Serializable]
public struct Item
{
public string name;
public int hitPoints;
public int durability;
}
[System.Serializable]
public class SyncDictionaryStringItem : SyncDictionary<string, Item> {}
public class ExamplePlayer : NetworkBehaviour
{
[SerializeField]
public readonly SyncDictionaryStringItem Equipment = new SyncDictionaryStringItem();
public override void OnStartServer()
{
Equipment.Add("head", new Item { name = "Helmet", hitPoints = 10, durability = 20 });
Equipment.Add("body", new Item { name = "Epic Armor", hitPoints = 50, durability = 50 });
Equipment.Add("feet", new Item { name = "Sneakers", hitPoints = 3, durability = 40 });
Equipment.Add("hands", new Item { name = "Sword", hitPoints = 30, durability = 15 });
}
public override void OnStartClient()
{
// Equipment is already populated with anything the server set up
// but we can subscribe to the callback in case it is updated later on
Equipment.Callback += OnEquipmentChange;
}
void OnEquipmentChange(SyncDictionaryStringItem.Operation op, string key, Item item)
{
// equipment changed, perhaps update the gameobject
Debug.Log(op + " - " + key);
}
}
```
By default, SyncDictionary uses a Dictionary to store it's data. If you want to use a different `IDictionary `implementation such as `SortedList` or `SortedDictionary`, add a constructor to your SyncDictionary implementation and pass a dictionary to the base class. For example:
```cs
[System.Serializable]
public class SyncDictionaryStringItem : SyncDictionary<string, Item>
{
public SyncDictionaryStringItem() : base (new SortedList<string,Item>()) {}
}
public class ExamplePlayer : NetworkBehaviour
{
[SerializeField]
public readonly SyncDictionaryStringItem Equipment = new SyncDictionaryStringItem();
}
```