OnElementDestroy: Difference between revisions

From Multi Theft Auto: Wiki
Jump to navigation Jump to search
mNo edit summary
No edit summary
Line 49: Line 49:
end
end
addEventHandler("onElementDestroy", root, getSourceResourceOfElementDestruction) -- All elements
addEventHandler("onElementDestroy", root, getSourceResourceOfElementDestruction) -- All elements
</syntaxhighlight>
This example only works in builds above 1.3.4-5937 and will tell you if a script is causing bugs with other scripts if it's deleting elements from other scripts because element IDs are being re-used and some scripts don't dereference an element after destroying it.
<syntaxhighlight lang="lua">
function checkForNaughtyScriptsThatDeleteRandomElements()
-- Ignore players
if (getElementType(source) == "player") then
return true
end
-- Get the resource that created the element
local sourceResourceRoot = getElementParent(getElementParent(source))
local theResource = false
for ind, res in pairs(getResources()) do
if (getResourceRootElement(res) == sourceResourceRoot) then
theResource = res
break
end
end
-- Output info if the destroying resource isn't the same as the creator resource
if (theResource and theResource ~= sourceResource) then
local destroyerResource = tostring(getResourceName(theResource))
local creatorResource = tostring(getResourceName(sourceResource))
outputDebugString(destroyerResource.." destroyed a "..getElementType(source).." made by "..creatorResource)
end
end
addEventHandler("onElementDestroy", root, checkForNaughtyScriptsThatDeleteRandomElements)
</syntaxhighlight>
</syntaxhighlight>



Revision as of 19:54, 2 December 2013

This event is triggered when an element gets destroyed by destroyElement or when the creator resource is stopping. It is also triggered when a parent element of this element is destroyed.

Parameters

None

Source

The source of this event is the element that is being destroyed.

Example

This example sends a message to the vehicle occupants when it's being destroyed.

addEventHandler("onElementDestroy", getRootElement(), function ()
  if getElementType(source) == "vehicle" then
    local nPassengers = getVehicleMaxPassengers(source)
    for i=0,nPassengers-1 do
      local occupant = getVehicleOccupant(source, i)
      if occupant then
        outputChatBox("The vehicle that you were in has been destroyed by the script", occupant)
      end
    end
  end
end)

This example outputs a message every time an element is destroyed saying which resource created the element

function getSourceResourceOfElementDestruction()
	-- Players aren't destroyed by any resource
	if (getElementType(source) == "player") then
		outputChatBox("Player "..getPlayerName(source).." destroyed")
		return true
	end
	
	local sourceResourceRoot = getElementParent(getElementParent(source)) -- Get the resource root element of the element
	-- Now to get the resource from the resource root element
	local theResource = false
	for ind, res in pairs(getResources()) do -- Loop all resources
		if (getResourceRootElement(res) == sourceResourceRoot) then -- Compare each resources root element to what we've got
			theResource = res -- We've found the source
			break -- End the loop
		end
	end
	if (theResource) then -- Did we find it?
		local resourceName = getResourceName(theResource) -- Get the resources name
		outputChatBox(resourceName.." destroyed a "..getElementType(source)) -- Output the resource name along with element type
	end
end
addEventHandler("onElementDestroy", root, getSourceResourceOfElementDestruction) -- All elements

This example only works in builds above 1.3.4-5937 and will tell you if a script is causing bugs with other scripts if it's deleting elements from other scripts because element IDs are being re-used and some scripts don't dereference an element after destroying it.

function checkForNaughtyScriptsThatDeleteRandomElements()
	-- Ignore players
	if (getElementType(source) == "player") then
		return true
	end
	
	-- Get the resource that created the element
	local sourceResourceRoot = getElementParent(getElementParent(source))
	local theResource = false
	for ind, res in pairs(getResources()) do
		if (getResourceRootElement(res) == sourceResourceRoot) then
			theResource = res
			break
		end
	end
	
	-- Output info if the destroying resource isn't the same as the creator resource
	if (theResource and theResource ~= sourceResource) then
		local destroyerResource = tostring(getResourceName(theResource))
		local creatorResource = tostring(getResourceName(sourceResource))
		outputDebugString(destroyerResource.." destroyed a "..getElementType(source).." made by "..creatorResource)
	end
end
addEventHandler("onElementDestroy", root, checkForNaughtyScriptsThatDeleteRandomElements)

See Also

Element events


Event functions