Difference between revisions of "AddCommandHandler"

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(Example)
(Removed the second vehicle color example, as it did not work with new RGB colors (and there are already enough examples))
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<section name="Server" class="server" show="hide">
 
<section name="Server" class="server" show="hide">
'''Example 2:''' This example implements a ''set_vehicle_color'' command.
+
'''Example 2:''' This example makes use of Lua's vararg expression to implement a ''check_parameters'' command to count the number of parameters passed, merge them all into a single string and output it. This is also shows you how you can use table.concat to merge all the passed arguments. This is particularly useful when you want to read in a sentence of text passed from the user.  
<syntaxhighlight lang="lua">
 
-- Define our function that will handle this command
 
function consoleSetVehicleColor ( playerSource, commandName, col1, col2, col3, col4 )
 
-- If a player triggered this in-game
 
if ( playerSource ) then
 
-- Get the player's vehicle
 
local playerVehicle = getPedOccupiedVehicle ( playerSource )
 
-- If the player is in a vehicle and we've got at least 1 parameter
 
if ( playerVehicle and col1 ) then
 
-- Get the vehicle's existing color and use it if fewer than 4 arguments were passed
 
local exCol1, exCol2, exCol3, exCol4 = getVehicleColor ( playerVehicle )
 
 
 
if not col2 then col2 = exCol2 end
 
if not col3 then col3 = exCol3 end
 
if not col4 then col4 = exCol4 end
 
 
 
-- Set the vehicle's color
 
setVehicleColor ( playerVehicle, col1, col2, col3, col4 )
 
else
 
-- If we didn't get at least 1 parameter or the player doesn't have a vehicle, display some help text
 
outputConsole ( "This function will set your current vehicle's colors. A vehicle can have up to 4 colors.", playerSource )
 
outputConsole ( "Syntax: set_vehicle_color color1 [ color2 color3 color4 ]", playerSource )
 
outputConsole ( "You must be in a vehicle to use this function.", playerSource )
 
end
 
end
 
end
 
-- Attach the 'consoleSetVehicleColor' function to the "set_vehicle_color" command
 
addCommandHandler ( "set_vehicle_color", consoleSetVehicleColor )
 
</syntaxhighlight>
 
</section>
 
 
 
<section name="Server" class="server" show="hide">
 
'''Example 3:''' This example makes use of Lua's vararg expression to implement a ''check_parameters'' command to count the number of parameters passed, merge them all into a single string and output it. This is also shows you how you can use table.concat to merge all the passed arguments. This is particularly useful when you want to read in a sentence of text passed from the user.  
 
 
<syntaxhighlight lang="lua">
 
<syntaxhighlight lang="lua">
 
-- Define our function that will handle this command (which can accept a variable number of arguments after commandName)
 
-- Define our function that will handle this command (which can accept a variable number of arguments after commandName)
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<section name="Server" class="server" show="hide">
 
<section name="Server" class="server" show="hide">
'''Example 4:''' This example shows using a single function to handle multiple command handlers. This isn't advised for general usage, as it makes code harder to understand, but where multiple command handlers share some logic, it can be a useful way of reducing duplicated code. Generally, it would be preferable to put this shared logic in a separate function instead, as this gives you more control over the flow.
+
'''Example 3:''' This example shows using a single function to handle multiple command handlers. This isn't advised for general usage, as it makes code harder to understand, but where multiple command handlers share some logic, it can be a useful way of reducing duplicated code. Generally, it would be preferable to put this shared logic in a separate function instead, as this gives you more control over the flow.
 
<!-- commands are case sensitive by default, in this example too -->
 
<!-- commands are case sensitive by default, in this example too -->
 
<syntaxhighlight lang="lua">
 
<syntaxhighlight lang="lua">
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</section>
 
</section>
 
<section name="Server" class="server" show="false">
 
<section name="Server" class="server" show="false">
'''Example 5:''' This example shows you how to create a function inside a commandHandler. This example creates an object, in this case a dildo, and attaches it to the player. Notice that unlike the other examples, we dont add 'addCommandHandler' after the function has been created. We create the function inside the commandHandler. This is not something you have to do, but it can save some work and space in the end in some cases.
+
'''Example 4:''' This example shows you how to create a function inside a commandHandler. This example creates an object, in this case a dildo, and attaches it to the player. Notice that unlike the other examples, we dont add 'addCommandHandler' after the function has been created. We create the function inside the commandHandler. This is not something you have to do, but it can save some work and space in the end in some cases.
  
 
<syntaxhighlight lang="lua">addCommandHandler("give_me_a_willy",function(player) -- Notice our function starts here
 
<syntaxhighlight lang="lua">addCommandHandler("give_me_a_willy",function(player) -- Notice our function starts here

Revision as of 06:41, 1 December 2011

Note: It is strongly advised that you do not use the same name for your handler function as the command name, as this can lead to confusion if multiple handler functions are used. Use a name that describes your handler's purpose more specifically.

This function will attach a scripting function (handler) to a console command, so that whenever a player or administrator uses the command the function is called.

Multiple command handlers can be attached to a single command, and they will be called in the order that the handlers were attached. Equally, multiple commands can be handled by a single function, and the commandName parameter used to decide the course of action.

For users, a command is in the format:

commandName argument1 argument2

This can be triggered from the player's console or directly from the chat box by prefixing the message with a forward slash (/). For server side handlers, the server admin is also able to trigger these directly from the server's console in the same way as they are triggered from a player's console.

Syntax

Click to collapse [-]
Server
bool addCommandHandler ( string commandName, function handlerFunction, [bool restricted = false, bool caseSensitive = true] )

Required Arguments

  • commandName: This is the name of the command you wish to attach a handler to. This is what must be typed into the console to trigger the function.
  • handlerFunction: This is the function that you want the command to trigger, which has to be defined before you add the handler. This function can take two parameters, playerSource and commandName, followed by as many parameters you expect after your command (see below). These are all optional.

Optional Arguments

NOTE: When using optional arguments, you might need to supply all arguments before the one you wish to use. For more information on optional arguments, see optional arguments.

  • restricted: Specify whether or not this command should be restricted by default. Use this on commands that should be inaccessible to everyone as default except special users specified in the ACL (Access Control List). This is to make sure admin commands such as ie. 'punish' won't be available to everyone if a server administrator forgets masking it in ACL. Make sure to add the command to your ACL under the proper group for it to be usefull (i.e <right name="command.killEveryone" access="true"></right>). This argument defaults to false if nothing is specified.
  • caseSensitive: Specifies if the command handler will ignore the case for this command name.


Click to collapse [-]
Client
bool addCommandHandler ( string commandName, function handlerFunction, [bool caseSensitive = true] )

Required Arguments

  • commandName: This is the name of the command you wish to attach a handler to. This is what must be typed into the console to trigger the function.
  • handlerFunction: This is the function that you want the command to trigger, which has to be defined before you add the handler. This function can take two parameters, playerSource and commandName, followed by as many parameters you expect after your command (see below). These are all optional.

Optional Arguments

NOTE: When using optional arguments, you might need to supply all arguments before the one you wish to use. For more information on optional arguments, see optional arguments.

  • caseSensitive: Specifies if the command handler will ignore the case for this command name.

Handler function parameters

These are the parameters for the handler function that is called when the command is used.

Click to collapse [-]
Server
player playerSource, string commandName, [string arg1, string arg2, ...] 
  • playerSource: The player who triggered the command. If not triggered by a player (e.g. by admin), this will be false.
  • commandName: The name of the command triggered. This is useful if multiple commands go through one function.
  • arg1, arg2, ...: Each word after command name in the original command is passed here in a seperate variable. If there is no value for an argument, its variable will contain nil. You can deal with a variable number of arguments using the vararg expression, as shown in Example 4 below.
Click to collapse [-]
Client
 string commandName, [string arg1, string arg2, ...] 
  • commandName: The name of the command triggered. This is useful if multiple commands go through one function.
  • arg1, arg2, ...: Each word after command name in the original command is passed here in a seperate variable. If there is no value for an argument, its variable will contain nil. You can deal with a variable number of arguments using the vararg expression, as shown in Example 4 below.

Returns

Returns true if the command handler was added successfully, false otherwise.

Example

Click to collapse [-]
Server

Example 1: This example defines a command handler for the command createmarker. This will create a red marker at the position of the player player who uses it.

-- Define our function that will handle this command
function consoleCreateMarker ( playerSource )
	-- If a player triggered it (rather than the admin) then
	if ( playerSource ) then
		-- Get that player's position
		local x, y, z = getElementPosition ( playerSource )
		-- Create a size 2, red checkpoint marker at their position
		createMarker ( x, y, z, "checkpoint", 2, 255, 0, 0, 255 )
		-- Output it in his chat box
		outputChatBox ( "You got a red marker", playerSource )
	end
end
-- Attach the 'consoleCreateMarker' function to the "createmarker" command
addCommandHandler ( "createmarker", consoleCreateMarker )
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Server
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Server
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Server
Click to collapse [-]
Client

Example 1: This creates a GUI window and allows a player to change its alpha (transparency) value with a command. Note that, in a clientside script, the player using the command is not passed as a parameter to the handler function, since it is always the local player.

--Create a window
myWindow = guiCreateWindow ( 0.30, 0.10, 0.5, 0.60, "GUI window title", true )

--Add a command handler to change the alpha of the GUI window. Usage example: 'alpha 0.15'
function changeAlpha ( commandName, alphaAmount )
	-- All command parameters are strings, so we'll convert the value to a number first
	alphaAmount = tonumber(alphaAmount)
	guiSetAlpha ( myWindow, alphaAmount )
end
addCommandHandler ( "alpha", changeAlpha )
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Client

See Also