function UpdateStorages()
for index, value in pairs(storages) do
value.Items.ChildAdded:connect(function()
print("did it")
UpdateGui()
end)
end
end
I know how events work, but I have a constantly changing table and I want an event on each. This obviously doesn't work. Any ideas on how to do it?
What I would do in this event is create a connections table and a regular table. The regular table would be equivalent to your 'storages' table.
I made an example to test how this can work:
connections = {}
storages = {}
setmetatable(storages, {__newindex = function(self,ind,val)
connections[#connections + 1] = val.ChildAdded:connect(function(a)
print("Did it!")
end)
end})
function insert(tab,thing)
tab[#tab + 1] = thing
end
local f = Instance.new("Folder",workspace)
insert(storages,f)
wait(1)
Instance.new("Script",f)
In the test scenario above, each time something new is added to 'storages', it gives it an event which is added to connections. I do believe I am over-complicating what you may be asking, but this is a good concept on how to add new things to a table with an event without having to constantly loop and reset the connections.
If I didn't get what you were asking for, PLEASE comment. I truly am here to help.
If the storage has a fluctuating size, you should delete the connections when they are no longer needed. You can do this without metatables:
storages = {} --I'm treating storages as a dictionary where the storage object is the key and the event it is connected to is the value
function AddToStorages(obj)
if storages[obj] then return end --already have this object recorded
storages[obj] = obj.ChildAdded:connect(UpdateGui)
end
function RemoveFromStorages(obj)
local con = storages[obj]
if not con then return end --obj not in storage
con:disconnect() --disconnect the event to prevent it from firing
storages[obj] = nil --remove obj from storage
end
--If you need to iterate over the contents of storage, do:
for obj, con in pairs(storages) do
--obj is the storage object, 'con' is the connection to the ChildAdded event
end
Though you could use metatables, you'd have to come up with some convention, like "storages[obj] = true means add to storage and storages[obj] = false means remove it", or perhaps use the __call metamethod and then you could do "storages(obj, true) or storages(obj, false)" to add/remove it the obj from the storages list. (EDIT: Note that you'd also have to use a table other than 'storages' to store the actual content, or else the metamethods would not get invoked. See http://www.lua.org/pil/13.4.4.html for details.) In either case, it isn't obvious what's going on by just looking at the calling code -- "AddToStorages(obj)" is clearer than "storages[obj] = true"; thus, I recommend just using the functions.
When I try this out there is an error at line 4, "ChildsAdded is not a valid member", I was not aware before that you could set the value of a table as an event, was it a simple mistype? Or something else?
I found a bug in my script where I said "pairs(storage)" instead of "pairs(storages)" [missed an 's'], but other than it works for me (I've updated the answer to fix that typo). It looks like you accidentally added an "s" to "ChildAdded" (you said the error is "ChildsAdded"). As for tables, yes - they can use anything as a key except nil, and can store anything (though you can't store "nil" ...
... because all values are nil by default, indicating that the key does not exist. There's no way to tell the difference between a non-existent value and a nil value.)
This discussion is preserved as it was. New answers, comments, and votes are closed.
2 comments
Thanks for the help! I'll look in more on metatables and tell you if I have any more questions. I didn't realize we had to get this complicated to fix my script, but nonetheless I thank you for your help and will start the learning process. (I probably should know how to use metatables anyway :3 )
After taking a couple days off from scripting I came back and finished implementing the script into my game! THANK YOU for the help. Metatables was something I tried to learn before but was unable to grasp at the concept, but your help here has given me a boost into understanding metatables. I hope someday I can return the favor!