Debugging
First-time setupWriting a Cuberite plugin
-- This article will explain how to write a basic plugin. It details basic requirements - for a plugin, explains how to register a hook and bind a command, and gives plugin - standards details. -
-- Let us begin. In order to begin development, we must firstly obtain a compiled copy - of MCServer, and make sure that the Core plugin is within the Plugins folder, and activated. - Core handles much of the Cuberite end-user experience and gameplay will be very bland without it. -
-Creating the basic template
-- Plugins are written in Lua. Therefore, create a new Lua file. You can create as many files as you wish, with - any filename - Cuberite bungs them all together at runtime, however, let us create a file called main.lua for now. - Format it like so: -
-
-PLUGIN = nil
-
-function Initialize(Plugin)
- Plugin:SetName("NewPlugin")
- Plugin:SetVersion(1)
-
- -- Hooks
-
- PLUGIN = Plugin -- NOTE: only needed if you want OnDisable() to use GetName() or something like that
-
- -- Command Bindings
-
- LOG("Initialised " .. Plugin:GetName() .. " v." .. Plugin:GetVersion())
- return true
-end
-
-function OnDisable()
- LOG(PLUGIN:GetName() .. " is shutting down...")
-end
-
- - Now for an explanation of the basics. -
-
-
- function Initialize is called on plugin startup. It is the place where the plugin is set up. -
- Plugin:SetName sets the name of the plugin. -
- Plugin:SetVersion sets the revision number of the plugin. This must be an integer. -
- LOG logs to console a message, in this case, it prints that the plugin was initialised. -
- The PLUGIN variable just stores this plugin's object, so GetName() can be called in OnDisable (as no Plugin parameter is passed there, contrary to Initialize). - This global variable is only needed if you want to know the plugin details (name, etc.) when shutting down. -
- function OnDisable is called when the plugin is disabled, commonly when the server is shutting down. Perform cleanup and logging here. -
Registering hooks
-- Hooks are things that Cuberite calls when an internal event occurs. For example, a hook is fired when a player places a block, moves, - logs on, eats, and many other things. For a full list, see the API documentation. -
-- A hook can be either informative or overridable. In any case, returning false will not trigger a response, but returning true will cancel - the hook and prevent it from being propagated further to other plugins. An overridable hook simply means that there is visible behaviour - to a hook's cancellation, such as a chest being prevented from being opened. There are some exceptions to this where only changing the value the - hook passes has an effect, and not the actual return value, an example being the HOOK_KILLING hook. See the API docs for details. -
-- To register a hook, insert the following code template into the "-- Hooks" area in the previous code example. -
--cPluginManager.AddHook(cPluginManager.HOOK_NAME_HERE, FunctionNameToBeCalled) --
- What does this code do? -
-
-
- cPluginManager.AddHook registers the hook. The hook name is the second parameter. See the previous API documentation link for a list of all hooks. -
- So in total, this is a working representation of what we have so far covered. -
-
-function Initialize(Plugin)
- Plugin:SetName("DerpyPlugin")
- Plugin:SetVersion(1)
-
- cPluginManager.AddHook(cPluginManager.HOOK_PLAYER_MOVING, OnPlayerMoving)
-
- LOG("Initialised " .. Plugin:GetName() .. " v." .. Plugin:GetVersion())
- return true
-end
-
-function OnPlayerMoving(Player) -- See API docs for parameters of all hooks
- return true -- Prohibit player movement, see docs for whether a hook is cancellable
-end
-
- - So, that code stops the player from moving. Not particularly helpful, but yes :P. Note that ALL documentation is available - on the main API docs page, so if ever in doubt, go there. -
-Binding a command
-Format
-- So now we know how to hook into MCServer, how do we bind a command, such as /explode, for a player to type? That is more complicated. - We firstly add this template to the "-- Command bindings" section of the initial example: -
-
--- ADD THIS IF COMMAND DOES NOT REQUIRE A PARAMETER (/explode)
-cPluginManager.BindCommand("/commandname", "permissionnode", FunctionToCall, " - Description of command")
-
--- ADD THIS IF COMMAND DOES REQUIRE A PARAMETER (/explode Notch)
-cPluginManager.BindCommand("/commandname", "permissionnode", FunctionToCall, " ~ Description of command and parameter(s)")
-
- - What does it do, and why are there two? -
-
-
- PluginManager:BindCommand binds a command. It takes the command name (with a slash), the permission a player needs to execute the command, the function - to call when the command is executed, and a description of the command. -
- So why are there two? Standards. A plugin that accepts a parameter MUST use a format for the description of " ~ Description of command and parms" - whereas a command that doesn't accept parameters MUST use " - Description of command" instead. Be sure to put a space before the tildes or dashes. - Additionally, try to keep the description brief and on one line on the client. -
-Parameters
-- What parameters are in the function Cuberite calls when the command is executed? A 'Split' array and a 'Player' object. -
-The Split Array
-
- The Split array is an array of all text submitted to the server, including the actual command. Cuberite automatically splits the text into the array,
- so plugin authors do not need to worry about that. An example of a Split array passed for the command, "/derp zubby explode" would be:
- /derp (Split[1])
- zubby (Split[2])
- explode (Split[3])
-
- The total amount of parameters passed were: 3 (#Split)
-
The Player Object and sending them messages
-- The Player object is basically a pointer to the player that has executed the command. You can do things with them, but most common is sending - a message. Again, see the API documentation for fuller details. But, you ask, how do we send a message to the client? -
-- There are dedicated functions used for sending a player formatted messages. By format, I refer to coloured prefixes/coloured text (depending on configuration) - that clearly categorise what type of message a player is being sent. For example, an informational message has a yellow coloured [INFO] prefix, and a warning message - has a rose coloured [WARNING] prefix. A few of the most used functions are listed here, but see the API docs for more details. Look in the cRoot, cWorld, and cPlayer sections - for functions that broadcast to the entire server, the whole world, and a single player, respectively. -
-
--- Format: §yellow[INFO] §white%text% (yellow [INFO], white text following it)
--- Use: Informational message, such as instructions for usage of a command
-Player:SendMessageInfo("Usage: /explode [player]")
-
--- Format: §green[INFO] §white%text% (green [INFO] etc.)
--- Use: Success message, like when a command executes successfully
-Player:SendMessageSuccess("Notch was blown up!")
-
--- Format: §rose[INFO] §white%text% (rose coloured [INFO] etc.)
--- Use: Failure message, like when a command was entered correctly but failed to run, such as when the destination player wasn't found in a /tp command
-Player:SendMessageFailure("Player Salted was not found")
-
- - Those are the basics. If you want to output text to the player for a reason other than the three listed above, and you want to colour the text, simply concatenate - "cChatColor.*colorhere*" with your desired text, concatenate being "..". See the API docs for more details of all colours, as well as details on logging to console with - LOG("Text"). -
-Final example and conclusion
-- So, a working example that checks the validity of a command, and blows up a player, and also refuses pickup collection to players with >100ms ping. -
-
-function Initialize(Plugin)
- Plugin:SetName("DerpyPluginThatBlowsPeopleUp")
- Plugin:SetVersion(9001)
-
- cPluginManager.BindCommand("/explode", "derpyplugin.explode", Explode, " ~ Explode a player");
-
- cPluginManager:AddHook(cPluginManager.HOOK_COLLECTING_PICKUP, OnCollectingPickup)
-
- LOG("Initialised " .. Plugin:GetName() .. " v." .. Plugin:GetVersion())
- return true
-end
-
-function Explode(Split, Player)
- if (#Split ~= 2) then
- -- There was more or less than one argument (excluding the "/explode" bit)
- -- Send the proper usage to the player and exit
- Player:SendMessage("Usage: /explode [playername]")
- return true
- end
-
- -- Create a callback ExplodePlayer with parameter Explodee, which Cuberite calls for every player on the server
- local HasExploded = false
- local ExplodePlayer = function(Explodee)
- -- If the player we are currently at is the one we specified as the parameter
- if (Explodee:GetName() == Split[2]) then
- -- Create an explosion at the same position as they are; see API docs for further details of this function
- Player:GetWorld():DoExplosionAt(Explodee:GetPosX(), Explodee:GetPosY(), Explodee:GetPosZ(), false, esPlugin)
- Player:SendMessageSuccess(Split[2] .. " was successfully exploded")
- HasExploded = true;
- return true -- Signalize to Cuberite that we do not need to call this callback for any more players
- end
- end
-
- -- Tell Cuberite to loop through all players and call the callback above with the Player object it has found
- cRoot:Get():FindAndDoWithPlayer(Split[2], ExplodePlayer)
-
- if not(HasExploded) then
- -- We have not broken out so far, therefore, the player must not exist, send failure
- Player:SendMessageFailure(Split[2] .. " was not found")
- end
-
- return true
-end
-
-function OnCollectingPickup(Player, Pickup) -- Again, see the API docs for parameters of all hooks. In this case, it is a Player and Pickup object
- if (Player:GetClientHandle():GetPing() > 100) then -- Get ping of player, in milliseconds
- return true -- Discriminate against high latency - you don't get drops :D
- else
- return false -- You do get the drops! Yay~
- end
-end
-
- - Make sure to read the comments for a description of what everything does. Also be sure to return true for all command handlers, unless you want Cuberite to print out an "Unknown command" message - when the command gets executed :P. Make sure to follow standards - use CoreMessaging.lua functions for messaging, dashes for no parameter commands and tildes for vice versa, - and finally, the API documentation is your friend! -
-- Happy coding ;) -
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