Modding:SaveGame Data Storage: Difference between revisions

Let's start by creating a new .cs file for this mod, and adding our imports and the <code>VintageStory.ServerMods</code> namespace to wrap our class in. Additionally, we'll declare the class <code>LookingForGroup</code> that will inheret from <code>ModSystem</code> which is the base class for mod systems. You can read more about this [http://apidocs.vintagestory.at/api/Vintagestory.API.Common.ModSystem.html here].

When the Server side starts, we register a command that players will use to access our list of those looking for group. This will be <code>/lfg</code> with the arguments list, join or leave.

Let's create the delegate <code>OnLfg</code> that will be called when a player enters this command.

== Storing and Retrieving the List ==

Right after our <code>StartServerSide</code> override, let's create our <code>/lfg</code> command delegate:

         private void OnLfg(IServerPlayer player, int groupId, CmdArgs args)

             if (args.Length < 1)

                player.SendMessage(groupId, "/lfg [list|join|leave]", EnumChatType.CommandError);

This has three parameters: the player issuing the command, the group in which this command was entered, and the arguments sent for the command.

The first thing we do is check that there is at least an argument given, with <code>if (args.Length < 1)</code>. If there isn't, we show the player the list of possible arguments and we go no further.

Next, we'll attempt to get our list of players looking for group. The Core Server Api has a member called <code>WorldManager</code> which we use to access everything World related, including our <code>SaveGame</code>.

<syntaxhighlight lang="c#">

        private void OnLfg(IServerPlayer player, int groupId, CmdArgs args)

            if (args.Length < 1)...

            byte[] data = serverApi.WorldManager.SaveGame.GetData("lfg");

            List<string> players = data == null ? new List<string>() : SerializerUtil.Deserialize<List<string>>(data);

We attempt to get our list by exposing the <code>GetData</code> method and passing it an identifier for our custom data, in this case our "lfg" list.

 

'''Hint''': If nothing is found stored under the identifier, the <code>GetData</code> method returns null. In our mod example, this will happen until at least one player enters the list!

 

<code>byte[] data = serverApi.WorldManager.SaveGame.GetData("lfg");</code>

 

As you can see, we're retrieving an array of bytes, which is data type we actually store on the SaveGame. Let's convert it to a <code>List</code> of strings:

 

List<string> players = data == null ? new List<string>() : SerializerUtil.Deserialize<List<string>>(data);

Here we use a ternary operator to assign our <code>players</code> list a new <code>List<string></code> if there was nothing stored under the "lfg" key.

If <code>data</code> is not null, we expose the <code>Deserialize<T></code> method of the <code>SerializerUtil</code> class. This method will deserialize an array of bytes into an instance of the type argument we pass it.

Now that we have our list of players "lfg", let's handle the possible arguments of the command.

We use the <code>PopWord</code> of our <code>CmdArgs</code> parameter to collect the first argument passed (ignoring anything subsequent). We then start a switch statement for our valid arguments, and default to showing these to the player if none of them match.

                     if (players.Contains(player.PlayerUID))

                         player.SendMessage(groupId, "You're already in this list!", EnumChatType.Notification);

                         players.Add(player.PlayerUID);

 

 

                         player.SendMessage(groupId, "Successfully joined!", EnumChatType.Notification);

If <code>/lfg join</code> was entered, we'll first check if the player is already on the "lfg" list, letting the player know if so. Alternatively, we add the player's unique identifier to the list, and use the <code>Serialize</code> method to turn the updated players <code>List<string></code> back to an array of byte.

After, we use the <code>StoreData</code> method to save our new serialized list under the "lfg" key for later retrieval! Upon completion, we let the player know that he is now in the list.

Now let's handle <code>/lfg leave</code>:

                     if (!players.Remove(player.PlayerUID))

                         player.SendMessage(groupId, "You're not in the list!", EnumChatType.Notification);

 

 

                         player.SendMessage(groupId, "Successfully left!", EnumChatType.Notification);

The <code>Remove</code> method returns false if nothing matching the argument passed to it was found to be removed, and true if it was. If the player was in the list, we serialize the updated list, and store the data to the <code>SaveGame</code>, letting the player know their request was successful.

                     if (players.Count == 0)

                         player.SendMessage(groupId, "Noone is looking for group!", EnumChatType.Notification);

                        break;

 

                     string lfgList = "Players looking for group:";

                         lfgList += "\n" + serverApi.World.PlayerByUid(playerUid).PlayerName;

                    });

                    player.SendMessage(groupId, lfgList, EnumChatType.Notification);

In this case we simply let the player know if are no players in the "lfg" list, and if there are then we build a string with all the player names on the list!

             api.RegisterCommand("lfg", "List or join the lfg list", "[list|join|leave]", OnLfg);

         private void OnLfg(IServerPlayer player, int groupId, CmdArgs args)

             List<string> players = data == null ? new List<string>() : SerializerUtil.Deserialize<List<string>>(data);

                     if (players.Contains(player.PlayerUID))

                         player.SendMessage(groupId, "You're already in this list!", EnumChatType.Notification);

                         players.Add(player.PlayerUID);

 

 

                         player.SendMessage(groupId, "Successfully joined!", EnumChatType.Notification);

                     if (!players.Remove(player.PlayerUID))

                         player.SendMessage(groupId, "You're not in the list!", EnumChatType.Notification);

 

 

                         player.SendMessage(groupId, "Successfully left!", EnumChatType.Notification);

                     if (players.Count == 0)

                         player.SendMessage(groupId, "Noone is looking for group!", EnumChatType.Notification);

                        break;

 

                     string lfgList = "Players looking for group:";

                         lfgList += "\n" + serverApi.World.PlayerByUid(playerUid).PlayerName;

                    });

                    player.SendMessage(groupId, lfgList, EnumChatType.Notification);

 

                     break;