OnElementDataChange

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.

[[{{{image}}}|link=|]]	Note: These predefined variables are special in this event: 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.

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).

Cancelling

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

ADDED/UPDATED IN VERSION 1.7.0 r25731:

This event can be cancelled using cancelEvent. If a client sent the cancelled change to the server, the server will send the client the server's version of the element data.

Source

The source of this event is the element whose element data changed.

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)

This example blocks all element data changes from clients. In MTA 1.7+ only.

function checkChange(theKey, oldValue, newValue)
    if (client) then -- if there's a client variable, it means it came from a player.
        cancelEvent()
    end
end
addEventHandler("onElementDataChange", root, checkChange)

See Also

Element events

• onElementClicked
• onElementColShapeHit
• onElementColShapeLeave
• onElementDataChange
• onElementDestroy
• onElementDimensionChange
• onElementInteriorChange
• onElementModelChange
• onElementStartSync
• onElementStopSync

Event functions

• addEvent
• addEventHandler
• cancelEvent
• cancelLatentEvent
• getEventHandlers
• getLatentEventHandles
• getLatentEventStatus
• removeEventHandler
• triggerEvent
• wasEventCancelled