CollectionService
CollectionService manages groups (collections) of instances with tags. Tags are sets of strings applied to instances that replicate from the server to the client. They are also serialized when places are saved.
The primary use of CollectionService is to register instances with specific tags that you can use to extend their behavior. If you find yourself adding the same script to many different instances, a script that uses CollectionService may be better.
Tags can be added or removed through this class' methods such as AddTag() or RemoveTag(). They can also be managed directly in Studio through the Tags section of an instance's properties, or through the built‑in Tag Editor tool.
Replication
When tags replicate, all tags on an instance replicate at the same time. Therefore, if you set a tag on an instance from the client then add/remove a different tag on the same instance from the server, the client's local tags on the instance are overwritten. In StreamingEnabled places, instances can be unloaded as they leave the client's streamed area. If such an instance re-enters the streamed area, properties and tags will be re-synchronized from the server. This can cause changes made by LocalScripts to be overwritten/removed.
Summary
Methods
Applies a tag to an Instance.
Returns an array of all tags in the experience.
Returns a signal that fires when a given tag is added to an instance.
Returns a signal that fires when a given tag is removed from an instance.
Returns an array of instances in the game with a given tag.
Gets an array of all tags applied to a given instance.
Check whether an instance has a given tag.
Removes a tag from an instance.
Events
Fires when a tag is added to an instance and the added tag is the only occurrence of that tag in the place.
Fires when a tag is removed from an instance and the removed tag is no longer used anywhere in the place.
Properties
Methods
GetInstanceAddedSignal
Parameters
Returns
Code Samples
local CollectionService = game:GetService("CollectionService")
local tag = "Deadly"
local function onDeadlyPartTouched(otherPart)
if not otherPart.Parent then
return
end
local humanoid = otherPart.Parent:FindFirstChildOfClass("Humanoid")
if humanoid then
humanoid.Health = 0
end
end
-- Save the connections so they can be disconnected when the tag is removed
local connections = {}
local function onInstanceAdded(object)
-- Confirm that the object with this tag is a BasePart
if object:IsA("BasePart") then
connections[object] = object.Touched:Connect(onDeadlyPartTouched)
end
end
local function onInstanceRemoved(object)
-- If there is a stored connection on this object, disconnect/remove it
if connections[object] then
connections[object]:Disconnect()
connections[object] = nil
end
end
-- Listen for this tag being applied to objects
CollectionService:GetInstanceAddedSignal(tag):Connect(onInstanceAdded)
CollectionService:GetInstanceRemovedSignal(tag):Connect(onInstanceRemoved)
-- Also detect any objects that already have the tag
for _, object in pairs(CollectionService:GetTagged(tag)) do
onInstanceAdded(object)
endGetInstanceRemovedSignal
Parameters
Returns
Code Samples
local CollectionService = game:GetService("CollectionService")
local tag = "Deadly"
local function onDeadlyPartTouched(otherPart)
if not otherPart.Parent then
return
end
local humanoid = otherPart.Parent:FindFirstChildOfClass("Humanoid")
if humanoid then
humanoid.Health = 0
end
end
-- Save the connections so they can be disconnected when the tag is removed
local connections = {}
local function onInstanceAdded(object)
-- Confirm that the object with this tag is a BasePart
if object:IsA("BasePart") then
connections[object] = object.Touched:Connect(onDeadlyPartTouched)
end
end
local function onInstanceRemoved(object)
-- If there is a stored connection on this object, disconnect/remove it
if connections[object] then
connections[object]:Disconnect()
connections[object] = nil
end
end
-- Listen for this tag being applied to objects
CollectionService:GetInstanceAddedSignal(tag):Connect(onInstanceAdded)
CollectionService:GetInstanceRemovedSignal(tag):Connect(onInstanceRemoved)
-- Also detect any objects that already have the tag
for _, object in pairs(CollectionService:GetTagged(tag)) do
onInstanceAdded(object)
endGetTagged
Parameters
Returns
Code Samples
local CollectionService = game:GetService("CollectionService")
local tag = "Deadly"
local function onDeadlyPartTouched(otherPart)
if not otherPart.Parent then
return
end
local humanoid = otherPart.Parent:FindFirstChildOfClass("Humanoid")
if humanoid then
humanoid.Health = 0
end
end
-- Save the connections so they can be disconnected when the tag is removed
local connections = {}
local function onInstanceAdded(object)
-- Confirm that the object with this tag is a BasePart
if object:IsA("BasePart") then
connections[object] = object.Touched:Connect(onDeadlyPartTouched)
end
end
local function onInstanceRemoved(object)
-- If there is a stored connection on this object, disconnect/remove it
if connections[object] then
connections[object]:Disconnect()
connections[object] = nil
end
end
-- Listen for this tag being applied to objects
CollectionService:GetInstanceAddedSignal(tag):Connect(onInstanceAdded)
CollectionService:GetInstanceRemovedSignal(tag):Connect(onInstanceRemoved)
-- Also detect any objects that already have the tag
for _, object in pairs(CollectionService:GetTagged(tag)) do
onInstanceAdded(object)
endGetTags
Parameters
Returns
Code Samples
local CollectionService = game:GetService("CollectionService")
local Workspace = game:GetService("Workspace")
local object = Workspace.Part
-- Add a tag
CollectionService:AddTag(object, "Deadly")
-- Query for a tag
if CollectionService:HasTag(object, "Deadly") then
print(object:GetFullName() .. " is deadly")
end
-- List tags on an object
local tags = CollectionService:GetTags(object)
print("The object " .. object:GetFullName() .. " has tags: " .. table.concat(tags, ", "))
-- Remove a tag
CollectionService:RemoveTag(object, "Deadly")HasTag
Parameters
Returns
Code Samples
local CollectionService = game:GetService("CollectionService")
local Workspace = game:GetService("Workspace")
local object = Workspace.Part
-- Add a tag
CollectionService:AddTag(object, "Deadly")
-- Query for a tag
if CollectionService:HasTag(object, "Deadly") then
print(object:GetFullName() .. " is deadly")
end
-- List tags on an object
local tags = CollectionService:GetTags(object)
print("The object " .. object:GetFullName() .. " has tags: " .. table.concat(tags, ", "))
-- Remove a tag
CollectionService:RemoveTag(object, "Deadly")RemoveTag
Parameters
Returns
Code Samples
local CollectionService = game:GetService("CollectionService")
local Workspace = game:GetService("Workspace")
local object = Workspace.Part
-- Add a tag
CollectionService:AddTag(object, "Deadly")
-- Query for a tag
if CollectionService:HasTag(object, "Deadly") then
print(object:GetFullName() .. " is deadly")
end
-- List tags on an object
local tags = CollectionService:GetTags(object)
print("The object " .. object:GetFullName() .. " has tags: " .. table.concat(tags, ", "))
-- Remove a tag
CollectionService:RemoveTag(object, "Deadly")