OnElementDataChange: Difference between revisions

From Multi Theft Auto: Wiki
Jump to navigation Jump to search
(Add note to sourceResource parameter.)
(Bold some data.)
Line 14: Line 14:
==Global parameters==
==Global parameters==
*'''source''': The [[event system#Event source|source]] of this event is the [[element]] whose [[element data]] changed.
*'''source''': The [[event system#Event source|source]] of this event is the [[element]] whose [[element data]] changed.
*'''client''': The [[event system#Event client|client]] global variable is set to the client that called [[setElementData]], or nil if it was called on the server.
*'''client''': The [[event system#Event client|client]] global variable is set to the client that called [[setElementData]], or '''nil''' if it was called on the server.
*'''sourceResource''': The [[resource]] which changed the element data - '''nil''' if client synced data, resource otherwise.
*'''sourceResource''': The [[resource]] which changed the element data - '''nil''' if client synced data, '''resource''' element otherwise.


==Cancelling==
==Cancelling==

Revision as of 18:16, 7 June 2023

This event is triggered after an element's data entry is changed. Such changes can be made on the client or the server using setElementData.

Parameters

string theKey, var oldValue, var newValue
  • theKey: The name of the element data entry that has changed.
  • oldValue: The old value of this entry before it changed. See element data for a list of possible datatypes.
  • newValue: the new value of this entry after it changed. This will be equivalent to getElementData(source, theKey).

Global parameters

  • source: The source of this event is the element whose element data changed.
  • client: The client global variable is set to the client that called setElementData, or nil if it was called on the server.
  • sourceResource: The resource which changed the element data - nil if client synced data, resource element otherwise.

Cancelling

This event cannot be cancelled using cancelEvent. To reverse the effect, use setElementData with the old value. See Example.

Example

Click to collapse [-]
Server

This example outputs a message to players when any of their element data values is changed.

function outputChange(theKey, oldValue, newValue)
    if (getElementType(source) == "player") then -- check if the element is a player
        outputChatBox("Your element data '" .. tostring(theKey) .. "' has changed from '" .. tostring(oldValue) .. "' to '" .. tostring(newValue) .. "'", source) -- output the change for the affected player
    end
end
addEventHandler("onElementDataChange", root, outputChange)
Click to collapse [-]
Server

This example checks and possibly reverses an element's data change.

function checkChange(theKey, oldValue)
    -- The client can only set 'special_thing' on its own player
    if (theKey== "special_thing") and (client ~= source) then
        outputChatBox("Illegal setting of " .. tostring(theKey) .. "' by '" .. tostring(getPlayerName(client)))
        setElementData(source, theKey, oldValue) -- Set back the original value
    end
end
addEventHandler("onElementDataChange", root, checkChange)

See Also

Element events


Event functions