Lua How to access ”item” object across events?
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Xikini
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In the 4th.or 5th post merge I do what you're trying to do.
They use the item, then choose a reward with modal window, and then it removes the item that was used.
oen432
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I think it is easy to abuse and cause crash. You are checkingLua - Xikini's Free Scripting Service TFS 1.4.2
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In the 4th.or 5th post merge I do what you're trying to do.
They use the item, then choose a reward with modal window, and then it removes the item that was used.
not usedItem but its not gonna work, if you for example throw that usedItem into into lava/bin after using the item it will still hold userdata so that not usedItem won't be true. Test it to be sure if it is gonna crash or just throw some Lua error.
yo, I was thinking something similar, just trade the item and accept before using it will cause some problem imo
oen432
Legendary OT User
I think trash bin is a container so the item still exists. Trading is also moving the item not recreating it. Try with lava.
Edit: Nvm.
This is weird behavior tho. How is the item returning something with getTopParent if the item doesn't exist anymore?
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Xikini
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View attachment bandicam 2024-04-29 21-27-18-895.mp4
Not sure what to tell you. xD
It seems to work fine and as intended.
-- Edit
Ah, the script in the thread wasn't updated.
changed
LUA:
if not usedItem then
LUA:
if not usedItem or not Item(usedItem.uid) then
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In fact, I was curious, and I tried it...
The first attempts by pure chance the server did not crash, and my expression was wow xd
Then I kept trying, and POFF the server broke
I notice that if you first move the object to a tile and then delete it with lava or the trash, it seems that the object still maintains a reference and that is why it is not deleted, are we witnessing a memory leak?
~If you delete the item directly from inventory, the crash occurs, which should always happen...~
By the way, the correct way to store an item in a list is to add a custom attribute and then use the onMoveItem event to identify if you move the item and then clear the table.
EDIT: It's strange because now it happens completely randomly....
The first attempts by pure chance the server did not crash, and my expression was wow xd
Then I kept trying, and POFF the server broke
I notice that if you first move the object to a tile and then delete it with lava or the trash, it seems that the object still maintains a reference and that is why it is not deleted, are we witnessing a memory leak?
By the way, the correct way to store an item in a list is to add a custom attribute and then use the onMoveItem event to identify if you move the item and then clear the table.
EDIT: It's strange because now it happens completely randomly....
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Your code causes undefined behaviour, you cant store userdata like that. It may be deleted or not, if it is, it doesn't necessarily mean it will crash, its ub.Lua - Xikini's Free Scripting Service TFS 1.4.2
Request whatever you want, within reason. Please do not request for things that require source editing or database queries. ------------------------------------ If I've reacted to your post, it means I've read it. 👍😍🤣😲🙁😡🤔😉 ------------------------------------ Completed Requests A boss that...
In the 4th.or 5th post merge I do what you're trying to do.
They use the item, then choose a reward with modal window, and then it removes the item that was used.
Thus you see unpredictable behaviour. This is also why checking a pointer validity doesn't work.
The pointer is "valid" in terms of being not nullish, it may not be valid in terms of a valid object (not freed memory) at that memory address.
So essentially what you are doing here when an item is deleted, you are dereferencing some random memory address which could have something else there or nothing, either way it will crash or not, that's why it's called undefined behaviour and that is also why .uid "seems to work" - it doesn't, it probably returns different numbers each time.
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Anyway, here I leave a modification of the script that is much safer and should not cause errors in 99.9% of the cases
LUA:
local rewardBagItemId = 1950
local config = {
modalWindow = {
id = 1001, -- needs to be unique number?
title = "Reward Bag",
message = "Choose a reward from the list!",
eventText = "ModalWindow_Reward_Bag",
buttons = {
{text = "Choose", defaultEnterButton = true},
{text = "Cancel", defaultEscapeButton = true},
}
},
rewards = {
{itemId = 2160, amount = 1},
{itemId = 2160, amount = 3}, -- add as many as you want.
{itemId = 2160, amount = 10}
}
}
-- END OF CONFIG
local usedItems = {
-- [playerId] = item
}
local function getItemNameString(item)
return item:getNameDescription(item:getSubType(), true)
end
local function createRewardBagWindow(playerId)
local player = Player(playerId)
if not player then
return
end
player:unregisterEvent(config.modalWindow.eventText)
player:registerEvent(config.modalWindow.eventText)
local modalWindow = ModalWindow(config.modalWindow.id, config.modalWindow.title, config.modalWindow.message)
for id, button in ipairs(config.modalWindow.buttons) do
modalWindow:addButton(id, button.text)
if button.defaultEscapeButton then
modalWindow:setDefaultEscapeButton(id)
elseif button.defaultEnterButton then
modalWindow:setDefaultEnterButton(id)
end
end
for id, v in ipairs(config.rewards) do
local item = Game.createItem(v.itemId, v.amount)
local text = getItemNameString(item)
modalWindow:addChoice(id, text)
end
modalWindow:hasPriority()
modalWindow:sendToPlayer(player)
end
local action = Action()
function action.onUse(player, item, fromPosition, target, toPosition, isHotkey)
local _player = Player(item:getTopParent())
if not _player then
player:sendTextMessage(MESSAGE_STATUS_SMALL, "Reward bag must be in your inventory to be used.")
player:getPosition():sendMagicEffect(CONST_ME_POFF, player)
return true
end
item:setCustomAttribute("onUse_chooseItemReward", true)
usedItems[player:getId()] = item
createRewardBagWindow(player:getId())
return true
end
action:id(rewardBagItemId)
action:register()
local creatureevent = CreatureEvent(config.modalWindow.eventText)
function creatureevent.onModalWindow(player, modalWindowId, buttonId, choiceId)
player:unregisterEvent(config.modalWindow.eventText)
if modalWindowId == config.modalWindow.id then
local buttonChoice = config.modalWindow.buttons[buttonId].text
local playerId = player:getId()
if buttonChoice == "Choose" then
local usedItem = usedItems[playerId]
if not usedItem or not Item(usedItem.uid) then
player:sendTextMessage(MESSAGE_STATUS_SMALL, "Reward bag no longer exists.")
player:getPosition():sendMagicEffect(CONST_ME_POFF, player)
usedItems[playerId] = nil
return true
end
local _player = Player(usedItem:getTopParent())
if not _player or _player:getId() ~= playerId then
player:sendTextMessage(MESSAGE_STATUS_SMALL, "Reward bag must be in your inventory to be used.")
player:getPosition():sendMagicEffect(CONST_ME_POFF, player)
usedItems[playerId] = nil
return true
end
local item = Game.createItem(config.rewards[choiceId].itemId, config.rewards[choiceId].amount)
if not player:addItemEx(item, false) then
player:sendTextMessage(MESSAGE_STATUS_SMALL, "You do not have the room or capacity to receive this item.")
player:getPosition():sendMagicEffect(CONST_ME_POFF, player)
usedItems[playerId] = nil
return true
end
player:say("You received " .. getItemNameString(item), TALKTYPE_MONSTER_SAY, nil, player)
player:getPosition():sendMagicEffect(CONST_ME_HEARTS)
usedItem:remove(1)
usedItems[playerId] = nil
else
-- "Cancel" button
usedItems[playerId] = nil
return true
end
end
return true
end
creatureevent:register()
local event = EventCallback
function event.onMoveItem(player, item, count, fromPosition, toPosition, fromCylinder, toCylinder)
if item:getCustomAttribute("onUse_chooseItemReward") then
item:removeCustomAttribute("onUse_chooseItemReward")
usedItems[player:getId()] = nil
end
return RETURNVALUE_NOERROR
end
event:register()
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Xikini
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That's just removing a random item instead of the item that was used, tho?
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X
Xikini
Guest
Player experience.
They click item in backpack 5, you expect that is the item that will be consumed.
Scripting wise, 2 items with same itemid but with custom attributes applied.
1 is legendary, 1 is common.
Common is in backpack 5, but legendary item would be consumed in backpack 1.
Thank you for all the answers! It was more advanced than I thought.
Unfortunately, it doesn't work with itemid. I am in the process of creating a script for imbuing, where one uses their item on a stone ("shrine"). It is crucial that it is exactly the item that was chosen initially, as it could be really bad if the wrong item gets imbued.
Perhaps there are better ways to create this script? I would appreciate any suggestions
Thanks again!
Unfortunately, it doesn't work with itemid. I am in the process of creating a script for imbuing, where one uses their item on a stone ("shrine"). It is crucial that it is exactly the item that was chosen initially, as it could be really bad if the wrong item gets imbued.
Perhaps there are better ways to create this script? I would appreciate any suggestions
Thanks again!
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OEN is right. The items id should be stored, not the userdata... this is basic stuff we all know already?
If we want to make sure its a specific item in a specific location, we can check if its in same slot as what we expected it to be in, or we could assign a unique id, or action id , or custom attribute, to the item in the onUse, and then in the modal window, check to make sure it has the same thing... ie, the same position, action or uid, or custom attribute
If we want to make sure its a specific item in a specific location, we can check if its in same slot as what we expected it to be in, or we could assign a unique id, or action id , or custom attribute, to the item in the onUse, and then in the modal window, check to make sure it has the same thing... ie, the same position, action or uid, or custom attribute