The `Class.DragDetector` instance facilitates and encourages interaction with
3D objects in an experience, such as opening doors and drawers, sliding a part
around, and much more. Key features include:

- Place a `Class.DragDetector` under any `Class.BasePart` or `Class.Model` to
  make it draggable via all inputs (mouse, touch, gamepad, and VR), all
  without a single line of code.

- Choose from several `Class.DragDetector.DragStyle|DragStyle` options, define
  how the object responds to motion via
  `Class.DragDetector.ResponseStyle|ResponseStyle`, and optionally apply axis
  or movement limits.

- Scripts can respond to manipulation of dragged objects to drive UI or make
  logical decisions, such as adjusting the light level in a room based on a
  sliding wall switch dimmer.

- Players can manipulate anchored parts or models and they'll stay exactly
  where you put them upon release.

- `Class.DragDetector|DragDetectors` work in Studio as long as you're **not**
  using the **Select**, **Move**, **Scale**, or **Rotate** tools, making it
  easier to test and adjust draggable objects while editing.

See the [3D Drag Detectors](/ui/3D-drag-detectors) guide for
details and usage examples.


Fires when a user continues dragging the object after
`Class.DragDetector.DragStart|DragStart` has been initiated.


DragDetector.DragContinue

playerWhoDragged

The `Class.Player` who initiated the drag through
`Class.DragDetector.DragStart|DragStart` and is now continuing the
drag.


cursorRay

`Datatype.Ray` emanating from the cursor, aimed into the scene.


viewFrame

`Datatype.CFrame` of the user's `Class.Camera`.


vrInputFrame

If using a VR input device, the `Datatype.CFrame` of the hand holding
the cursor/pointer/controller.


isModeSwitchKeyDown

If the drag detector's `Class.DragDetector.DragStyle|DragStyle` has
both primary and secondary modes of motion, this parameter indicates
whether the user is pressing the modifier input defined through
`Class.DragDetector.KeyboardModeSwitchKeyCode|KeyboardModeSwitchKeyCode`,
`Class.DragDetector.GamepadModeSwitchKeyCode|GamepadModeSwitchKeyCode`,
or `Class.DragDetector.VRSwitchKeyCode|VRSwitchKeyCode`.


Fires when a user stops dragging the object.


DragDetector.DragEnd

The `Class.Player` who initiated the drag through
`Class.DragDetector.DragStart|DragStart` and has now ended (released)
the drag.


Fires when a user starts dragging the object.


DragDetector.DragStart

hitFrame

The hit frame of the cursor raycast that initiated the drag.


clickedPart

The part that was hit by the cursor raycast that initiated the drag.


Adds a function to modify or constrain proposed motion. The function takes
an input `Datatype.CFrame` of **proposed** motion and returns a
`Datatype.CFrame` of **modified** or unmodified motion. Both the input and
output are expressed relative to the reference frame. You can add multiple
functions which will be called in order by `priority`, passing the results
along in a chain.

To remove an added constraint function, call
`Datatype.RBXScriptConnection:Disconnect()|Disconnect()` on the returned
connection object.


DragDetector:AddConstraintFunction

priority

The order of priority for functions added via this method. Higher
values take precedence over lower values.


function

Function for modifying or constraining proposed motion. This function
takes an input `Datatype.CFrame` of **proposed** motion and returns a
`Datatype.CFrame` of **modified** or unmodified motion, both relative
to the reference frame.


Use this connection object to remove the constraint function.


Adds a function to modify or constrain proposed motion.


Returns the reference `Datatype.CFrame` in which motion is expressed; see
the `Class.DragDetector.ReferenceInstance|ReferenceInstance` property for
more details.


DragDetector:GetReferenceFrame

The reference `Datatype.CFrame` in which motion is expressed.


Returns the reference `Datatype.CFrame` in which motion is expressed.


May be invoked from a script to restart the drag using new parameters, if
parameters such as `Class.DragDetector.DragStyle|DragStyle`,
`Class.DragDetector.Axis|Axis`, or
`Class.DragDetector.SecondaryAxis|SecondaryAxis` change.


DragDetector:RestartDrag

May be invoked from a script to restart the drag using new parameters.


Passes a function to be used if and only if
`Class.DragDetector.DragStyle|DragStyle` is set to
`Enum.DragDetectorDragStyle.Scriptable`. The given function is called when
responding to a `Class.DragDetector.DragContinue|DragContinue` signal, it
receives the signal's world space cursor ray with type `Datatype.Ray`, and
it returns a `Datatype.CFrame` containing the desired location and
orientation of the pivot in world space.

If the function returns `nil`, the object will not be moved. This is
useful if the script has not yet collected all the information it needs to
give the correct answer, or in temporary cases where you want the object
to stay where it is.


DragDetector:SetDragStyleFunction

Function for monitoring `Class.DragDetector.DragContinue|DragContinue`
signals. This function receives the signal's world space cursor ray
and it returns a `Datatype.CFrame` containing the desired location and
orientation of the pivot in world space. If this function returns
`nil`, the object will not be moved.


Passes a function to be used if and only if
`Class.DragDetector.DragStyle|DragStyle` is set to
`Enum.DragDetectorDragStyle.Scriptable`.


Passes a function to be used if and only if
`Class.DragDetector.PermissionPolicy|PermissionPolicy` is set to
`Enum.DragDetectorPermissionPolicy.Scriptable`. The given function accepts
a `Class.Player` parameter for enabling/disabling the detector for a
specific player. It also receives a `part` parameter indicating which
specific `Class.BasePart` was clicked, such as one part within a draggable
`Class.Model`; this is useful for enabling/disabling the detector based on
that part's `Class.Instance.Name|Name`, `Class.BasePart.Color|Color`,
`Class.Instance:HasTag()|HasTag()` value, or other details.

```lua
local dragDetector = script.Parent.DragDetector
dragDetector.PermissionPolicy = Enum.DragDetectorPermissionPolicy.Scriptable

dragDetector:SetPermissionPolicyFunction(function(player, part)
	if player and player:GetAttribute("IsInTurn") then
		return true
	elseif part and not part:GetAttribute("IsDraggable") then
		return false
	else
		return true
	end
end)
```


DragDetector:SetPermissionPolicyFunction

Function for setting the detector's interactivity. This function
accepts a `Class.Player` parameter for enabling/disabling the detector
for a specific player. It also receives a `part` parameter indicating
which specific `Class.BasePart` was clicked, such as one part within a
draggable `Class.Model`; this is useful for enabling/disabling the
detector based on that part's `Class.Instance.Name|Name`,
`Class.BasePart.Color|Color`, `Class.Instance:HasTag()|HasTag()`
value, or other details.


Passes a function to be used if and only if
`Class.DragDetector.PermissionPolicy|PermissionPolicy` is set to
`Enum.DragDetectorPermissionPolicy.Scriptable`.


DragDetector

Sets the cursor icon to display when the mouse is activated over the
parent of this `Class.DragDetector`. If this property is left blank, the
detector will use the default icon.

To change the activated cursor icon, set this property to the asset ID of
the image you'd like to use.


DragDetector.ActivatedCursorIcon

Sets the cursor icon to display when the mouse is activated over the
parent of this `Class.DragDetector`.


When false (default), constraint force is applied at the point the user
clicks on. When true, force is applied at the object's center of mass.
Only relevant if `Class.DragDetector.ResponseStyle|ResponseStyle` is
`Enum.DragDetectorResponseStyle.Physical` and the parent object is
unanchored.


DragDetector.ApplyAtCenterOfMass

Whether constraint force is applied to the object's center of mass.


The primary axis of motion, expressed relative to the reference frame. For
a `Class.DragDetector.DragStyle|DragStyle` of
`Enum.DragDetectorDragStyle.TranslateLine`, the direction of translation;
for `Enum.DragDetectorDragStyle.TranslatePlane`, the normal to the plane
of motion; for `Enum.DragDetectorDragStyle.RotateAxis`, the axis of 1D
rotation. Changing this value automatically updates
`Class.DragDetector.Orientation|Orientation` and vice versa.


DragDetector.Axis

The primary axis of motion, expressed relative to the reference frame.


If `Class.DragDetector.ReferenceInstance|ReferenceInstance` is set, the
`Datatype.CFrame` of the pivot relative to the reference frame; otherwise,
the `Datatype.CFrame` of the pivot relative to its frame at the beginning
of the drag.


DragDetector.DragFrame

The `Datatype.CFrame` of the pivot, dependent on the drag detector's
`Class.DragDetector.ReferenceInstance|ReferenceInstance`.


The paradigm used to generate proposed motion, given a stream of cursor
rays. See `Enum.DragDetectorDragStyle` for options.


DragDetector.DragStyle

The paradigm used to generate proposed motion.


If true, the `Class.DragDetector` responds to user input; if false, it
does not.


DragDetector.Enabled

Whether the `Class.DragDetector` responds to user input.


During gamepad input, the `Enum.KeyCode` for toggling the secondary mode
of motion. Only applies if the drag detector's
`Class.DragDetector.DragStyle|DragStyle` has both primary and secondary
modes of motion.


DragDetector.GamepadModeSwitchKeyCode

During gamepad input, the modifier `Enum.KeyCode` for the secondary mode
of motion.


During keyboard input, the `Enum.KeyCode` for toggling the secondary mode
of motion. Only applies if the drag detector's
`Class.DragDetector.DragStyle|DragStyle` has both primary and secondary
modes of motion.


DragDetector.KeyboardModeSwitchKeyCode

During keyboard input, the modifier `Enum.KeyCode` for the secondary mode
of motion.


If this is greater than `Class.DragDetector.MinDragAngle|MinDragAngle`,
translation will be clamped within that range.

This is not a constraint; it merely impedes the drag detector's attempts
to generate motion in order to remain within limits. See
`Class.DragDetector:AddConstraintFunction()|AddConstraintFunction()` to
add custom constraint to a drag.

Only relevant if `Class.DragDetector.DragStyle|DragStyle` is
`Enum.DragDetectorDragStyle.RotateAxis`.


DragDetector.MaxDragAngle

Along with `Class.DragDetector.MinDragAngle|MinDragAngle`, impedes the
drag detector's attempts to generate motion.


In any dimension, if this is greater than
`Class.DragDetector.MinDragTranslation|MinDragTranslation`, translation
will be clamped within that range.

This is not a constraint; it merely impedes the drag detector's attempts
to generate motion in order to remain within limits. See
`Class.DragDetector:AddConstraintFunction()|AddConstraintFunction()` to
add custom constraint to a drag.


DragDetector.MaxDragTranslation

Along with `Class.DragDetector.MinDragTranslation|MinDragTranslation`,
impedes the drag detector's attempts to generate motion.


Maximum force applied for the object to reach its goal. Only relevant if
`Class.DragDetector.ResponseStyle|ResponseStyle` is
`Enum.DragDetectorResponseStyle.Physical` and the parent object is
unanchored.


DragDetector.MaxForce

Maximum force applied for the object to reach its goal.


Maximum torque applied for the object to reach its goal. Only relevant if
`Class.DragDetector.ResponseStyle|ResponseStyle` is
`Enum.DragDetectorResponseStyle.Physical` and the parent object is
unanchored.


DragDetector.MaxTorque

Maximum torque applied for the object to reach its goal.


If this is less than `Class.DragDetector.MaxDragAngle|MaxDragAngle`,
translation will be clamped within that range.

This is not a constraint; it merely impedes the drag detector's attempts
to generate motion in order to remain within limits. See
`Class.DragDetector:AddConstraintFunction()|AddConstraintFunction()` to
add custom constraint to a drag.

Only relevant if `Class.DragDetector.DragStyle|DragStyle` is
`Enum.DragDetectorDragStyle.RotateAxis`.


DragDetector.MinDragAngle

Along with `Class.DragDetector.MaxDragAngle|MaxDragAngle`, impedes the
drag detector's attempts to generate motion.


In any dimension, if this is less than
`Class.DragDetector.MaxDragTranslation|MaxDragTranslation`, translation
will be clamped within that range.

This is not a constraint; it merely impedes the drag detector's attempts
to generate motion in order to remain within limits. See
`Class.DragDetector:AddConstraintFunction()|AddConstraintFunction()` to
add custom constraint to a drag.


DragDetector.MinDragTranslation

Along with `Class.DragDetector.MaxDragTranslation|MaxDragTranslation`,
impedes the drag detector's attempts to generate motion.


Specifies the **YXZ** rotation of axes of motion relative to the reference
frame (does not change the orientation of the reference frame itself).
Linear translation and axial rotation will be on this reoriented **Y**
axis, and planar translation in the **XZ** plane. Changing this value
automatically updates `Class.DragDetector.Axis|Axis` and vice versa.


DragDetector.Orientation

Specifies the **YXZ** rotation of axes of motion relative to the reference
frame.


Controls the permission level for which players can interact with the
`Class.DragDetector`. Default is
`Enum.DragDetectorPermissionPolicy.Everybody`.


DragDetector.PermissionPolicy

Controls the permission level for which players can interact with the
`Class.DragDetector`.


An instance whose `Datatype.CFrame` is the reference frame for the drag
detector. The `Class.DragDetector.DragFrame|DragFrame` is expressed
relative to this `Datatype.CFrame` which may be retrieved via the
`Class.DragDetector:GetReferenceFrame()|GetReferenceFrame()` method.

If this instance is a `Class.PVInstance`, the reference frame will be its
pivot; if an `Class.Attachment`, then its world `Datatype.CFrame`. If it
is `nil` or neither of the former, the reference frame will be based on
the pivot of the drag detector's parent `Class.BasePart` or `Class.Model`.


DragDetector.ReferenceInstance

An instance whose `Datatype.CFrame` is the reference frame for the drag
detector.


Once the proposed motion has been computed and potentially constrained,
this is the paradigm used to move, or not move, the objects affected by
the `Class.DragDetector`. See `Enum.DragDetectorResponseStyle` for
options.


DragDetector.ResponseStyle

The paradigm used to move, or not move, the objects affected by the drag
detector.


Higher values cause the object to reach its goal more rapidly. Only
relevant if `Class.DragDetector.ResponseStyle|ResponseStyle` is
`Enum.DragDetectorResponseStyle.Physical` and the parent object is
unanchored.


DragDetector.Responsiveness

Higher values cause the object to reach its goal more rapidly.


If false (default), the client sends replicated signals
(`Class.DragDetector.DragStart|DragStart`,
`Class.DragDetector.DragContinue|DragContinue`,
`Class.DragDetector.DragEnd|DragEnd`) to the server which processes cursor
rays, makes changes to the data model, and replicates them onwards to
clients.

If true, the client processes those signals itself and does not replicate
them to the server. Client `Class.LocalScript|LocalScripts` may be used to
respond to these events and `Class.RemoteEvent|RemoteEvents` may be used
to send any resulting changes that should be replicated to the server.


DragDetector.RunLocally

Whether user input on a `Class.DragDetector` replicates to the server or
remains local to the specific client.


The secondary axis of the motion. Relates to orientation using the same
paradigm as `Class.Attachment|Attachments`.


DragDetector.SecondaryAxis

When the cursor is outside the trackball, the `Class.DragDetector` can
apply a radial pull rotation that turns the ball as if it were trying to
roll out toward the cursor. This property is a 0 to 1 multiplier for
adding that rotation as a contribution to the total. Only relevant if
`Class.DragDetector.DragStyle|DragStyle` is
`Enum.DragDetectorDragStyle.RotateTrackball`.


DragDetector.TrackballRadialPullFactor

If `Class.DragDetector.DragStyle|DragStyle` is
`Enum.DragDetectorDragStyle.RotateTrackball`, multiplier for adding a
radial pull rotation as a contribution to the total.


When the cursor is outside the trackball, the `Class.DragDetector` can
apply a roll rotation that turns the ball as if it were mounted on a vinyl
record facing the viewer. This property is a 0 to 1 multiplier for adding
that roll rotation to the total. Only relevant if
`Class.DragDetector.DragStyle|DragStyle` is
`Enum.DragDetectorDragStyle.RotateTrackball`.


DragDetector.TrackballRollFactor

If `Class.DragDetector.DragStyle|DragStyle` is
`Enum.DragDetectorDragStyle.RotateTrackball`, multiplier for adding roll
rotation to the total.


During VR input, the `Enum.KeyCode` for toggling the secondary mode of
motion. Only applies if the drag detector's
`Class.DragDetector.DragStyle|DragStyle` has both primary and secondary
modes of motion.


DragDetector.VRSwitchKeyCode

During VR input, the modifier `Enum.KeyCode` for the secondary mode of
motion.


The `Class.DragDetector.Axis|Axis` expressed in world space. Relates to
orientation using the same paradigm as `Class.Attachment|Attachments`.


DragDetector.WorldAxis

The `Class.DragDetector.Axis|Axis` expressed in world space.


The `Class.DragDetector.SecondaryAxis|SecondaryAxis` expressed in world
space. Relates to orientation using the same paradigm as
`Class.Attachment|Attachments`.


DragDetector.WorldSecondaryAxis

The `Class.DragDetector.SecondaryAxis|SecondaryAxis` expressed in world
space.


Instance which facilitates and encourages interaction with 3D objects in an
experience.


Place this code inside a `Class.Script` inside a `Class.ClickDetector`. The
code sample creates a reference to the parent and defines a function to show a
message that greets a player. Finally, it connects the
`Class.ClickDetector.MouseClick|MouseClick` event to the defined function.

This code sample will allow a part to be clicked to toggle its anchored property. When toggled, the visual appearance of the part is updated (red means anchored, yellow means free).

`ClickDetector` allows `Class.Script|Scripts` and
`Class.LocalScript|LocalScripts` to receive pointer input on 3D objects
through their `Class.ClickDetector.MouseClick|MouseClick` event. They work
when parented to `Class.BasePart`, `Class.Model`, or `Class.Folder` objects.
They detect basic mouse events: enter, leave, left click and right click.
Touch input on `Class.UserInputService.TouchEnabled|TouchEnabled` devices also
fires click events.

The default control scripts bind `Enum.KeyCode|ButtonR2` to interact with
`Class.ClickDetector|ClickDetectors` using
`Class.ContextActionService:BindActivate()`, which can also be used to
override this. When using gamepads, the center dot triggers
`Class.ClickDetector.MouseHoverEnter|MouseHoverEnter` and
`Class.ClickDetector.MouseHoverLeave|MouseHoverLeave`. The bound activation
button fires `Class.ClickDetector.MouseClick|MouseClick`.

`Class.ClickDetector.MaxActivationDistance|MaxActivationDistance` can be used
to limit the distance a player may be from a click detector before it is no
longer clickable.

`Class.ClickDetector` events fire on both the client and the server. Since a
`Class.LocalScript` will only run if it descends from a `Class.Player` or
player `Class.Player.Character|Character`, it's usually not useful to put a
`Class.LocalScript` inside a `Class.ClickDetector`, since the script won't run
or the object won't be clickable. If you need a `Class.LocalScript` to detect
`Class.ClickDetector` events, `Class.StarterPlayerScripts` may be a better
place instead.

#### Input Priority

If multiple `Class.ClickDetector|ClickDetectors` may detect user input, only
the deepest will fire events. If two `Class.ClickDetector|ClickDetectors` are
siblings, the first will take priority.

If an action bound with `Class.ContextActionService` uses the same input as a
`Class.ClickDetector`, the action bound with `Class.ContextActionService` will
take priority over the click detector's events.

`Class.UserInputService.InputBegan` will fire before `Class.ClickDetector`
events.


This event fires from either a `Class.Script` or `Class.LocalScript` when
a player interacts with a `Class.ClickDetector` or `Class.DragDetector`
via the following inputs:

- On platforms with a mouse, when the player left mouse clicks.
- On `Class.UserInputService.TouchEnabled|TouchEnabled` platforms, when
  the player taps.
- On `Class.UserInputService.GamepadEnabled|GamepadEnabled` platforms,
  when the center dot is over the same model and the **A** button is
  pressed and released.

Note that the player's `Class.Player.Character|Character` must be within
the `Class.ClickDetector.MaxActivationDistance|MaxActivationDistance` of
the detector.


ClickDetector.MouseClick

playerWhoClicked

The `Class.Player` who clicked on the parent of a
`Class.ClickDetector` or `Class.DragDetector`.


Fires when a player interacts with the parent of a `Class.ClickDetector`
or `Class.DragDetector`.


The following code will print "[PlayerName] hovered over my parent!" when a player's cursor hovers over the `Class.ClickDetector` parent. It will also print "[PlayerName] hovered off my parent!" when the player's cursor moves off the `Class.ClickDetector` parent.

In order for this example to work as expected, it must be placed in a `Script` or `LocalScript` whose parent is a `Class.ClickDetector`.

This event fires from either a `Class.Script` or `Class.LocalScript` when
the parent of a `Class.ClickDetector` or `Class.DragDetector` is hovered
over by a player. This does not entail explicit interaction with the
detector, for which you can listen to either
`Class.ClickDetector.MouseClick|MouseClick` and
`Class.ClickDetector.RightMouseClick|RightMouseClick` events.

Due to the nature of user input, you should not depend on all
`Class.ClickDetector.MouseHoverEnter|MouseHoverEnter` events firing a
corresponding `Class.ClickDetector.MouseHoverLeave|MouseHoverLeave` event.


ClickDetector.MouseHoverEnter

playerWhoHovered

The `Class.Player` who started hovering over the parent of a
`Class.ClickDetector` or `Class.DragDetector`.


Fires when the parent of a `Class.ClickDetector` or `Class.DragDetector`
is hovered over by a player.


This event fires from either a `Class.Script` or `Class.LocalScript` when
a player's cursor hovers off the parent of a `Class.ClickDetector` or
`Class.DragDetector`. This does not entail explicit interaction with the
detector, for which you can listen to either
`Class.ClickDetector.MouseClick|MouseClick` and
`Class.ClickDetector.RightMouseClick|RightMouseClick` events.

Due to the nature of user input, you should not depend on all
`Class.ClickDetector.MouseHoverLeave|MouseHoverLeave` events firing after
a corresponding `Class.ClickDetector.MouseHoverEnter|MouseHoverEnter`
event.


ClickDetector.MouseHoverLeave

The `Class.Player` whose cursor hovered off the parent of a
`Class.ClickDetector` or `Class.DragDetector`.


Fires when a player's cursor hovers off the parent of a
`Class.ClickDetector` or `Class.DragDetector`.


This event fires from either a `Class.Script` or `Class.LocalScript` when
a player right clicks their mouse cursor on a `Class.ClickDetector` or
`Class.DragDetector`. Note that the player's
`Class.Player.Character|Character` must be within the
`Class.ClickDetector.MaxActivationDistance|MaxActivationDistance` of the
detector.


ClickDetector.RightMouseClick

The `Class.Player` who right clicked their mouse cursor on the parent
of a `Class.ClickDetector` or `Class.DragDetector`.


Fires when a player right clicks their mouse cursor on a
`Class.ClickDetector` or `Class.DragDetector`.


ClickDetector.mouseClick

ClickDetector

Sets the cursor icon to display when the mouse is hovered over the parent
of this `Class.ClickDetector` or `Class.DragDetector`. If this property is
left blank, the detector will use the default icon.

To change the cursor icon, set this property to the asset ID of the image
you'd like to use.


ClickDetector.CursorIcon

Sets the cursor icon to display when the mouse is hovered over the parent
of this `Class.ClickDetector` or `Class.DragDetector`.


This property controls the maximum distance, in studs, between a
`Class.Player.Character|Character` and the `Class.ClickDetector` or
`Class.DragDetector` for the player to be able to interact with it. For
instance, a character within 10 studs of a `Class.ClickDetector` or
`Class.DragDetector` with a max activation distance of 5 would not be able
to use the detector because they are out of range.


ClickDetector.MaxActivationDistance

Maximum distance between a character and the `Class.ClickDetector` or
`Class.DragDetector` for the player to be able to interact with it.


An object that provides user input on in-experience `Class.BasePart|BaseParts`
and `Class.Model|Models`.


`Instance` is the base class for all classes in the Roblox class hierarchy
which can be part of the `Class.DataModel` tree.

It is not possible to directly create root `Instance` objects, but the special
`Datatype.Instance.new()` constructor creates objects via code, taking the
name of the class as a parameter and returning the created object.


Demonstrates detecting changes to an instance's ancestry by connecting to the `Class.Instance.AncestryChanged` event.

The ChangingPart's Parent is set to different values overtime. The parent of the part is the part's ancestor, so the `Class.Instance.AncestryChanged` event will fire whenever it changes.

Fires when the `Class.Instance.Parent` property of the object or one of
its ancestors is changed.

This event includes two parameters: `child` refers to the `Class.Instance`
whose `Class.Instance.Parent` was actually changed, while `parent` refers
to this instance's new `Class.Instance.Parent`.

You can use this event to track the deletion of an instance in Studio,
such as manual deletion in the Explorer or through a plugin. If you need
to detect when an instance is destroyed using `Class.Instance:Destroy()`,
use the `Class.Instance.Destroying` event instead.


Instance.AncestryChanged

child

The `Class.Instance` whose `Class.Instance.Parent` has been changed.


parent

The new `Class.Instance.Parent` of the `Class.Instance` whose
`Class.Instance.Parent` was changed.


Fires when the `Class.Instance.Parent` property of the object or one of
its ancestors is changed.


This event fires whenever any attribute is changed on the instance,
including when an attribute is set to `nil`. The name of the changed
attribute is passed to the connected function.

For example, the following code snippet connects the `attributeChanged()`
function to fire whenever one of the part's attributes changes:

```lua
local Workspace = game:GetService("Workspace")

local part = Workspace.Part

local function attributeChanged(attributeName)
	print(attributeName, "changed")
end

part.AttributeChanged:Connect(attributeChanged)
```

See also `Class.Instance:GetAttributeChangedSignal()` which returns an
event that fires when a specific given attribute changes.


Instance.AttributeChanged

attribute

The name of the attribute that has been changed.


Fires whenever an attribute is changed on the `Class.Instance`.


This snippet prints the names of objects as they are added to the Workspace:

Fires after an object is parented to this `Class.Instance`.

Note, when using this function on a client to detect objects created by
the server it is necessary to use `Class.Instance:WaitForChild()` when
indexing these object's descendants. This is because the object and its
descendants are not guaranteed to replicate from the server to the client
simultaneously. For example:

```
local Workspace = game:GetService("Workspace")

Workspace.ChildAdded:Connect(function(child)
	-- Use WaitForChild() since descendants may not have replicated yet
	local head = child:WaitForChild("Head")
end)
```

Note, this function only works for immediate children of the
`Class.Instance`. For a function that captures all descendants, use
`Class.Instance.DescendantAdded`.

See also `Class.Instance.ChildRemoved`.


Instance.ChildAdded

The `Class.Instance` that has been added.


Fires after an object is parented to this `Class.Instance`.


This snippet prints the names of objects as they are removed from the
Workspace:

Fires after a child is removed from this `Class.Instance`.

Removed refers to when an object's parent is changed from this
`Class.Instance` to something other than this `Class.Instance`. Note, this
event will also fire when a child is destroyed (using
`Class.Instance:Destroy()`) as the destroy function sets an object's
parent to `nil`.

This function only works for immediate children of the `Class.Instance`.
For a function that captures all descendants, use
`Class.Instance.DescendantRemoving`.

See also `Class.Instance.ChildAdded`.


Instance.ChildRemoved

The `Class.Instance` that has been removed.


Fires after a child is removed from this `Class.Instance`.


This following example will print the name of any object that is added to the
Workspace:

This event fires after a descendant is added to the `Class.Instance`.

As it fires for every descendant, parenting an object to the
`Class.Instance` will fire the event for this object and all of its
descendants individually.

If you're only concerned with the **direct children** of the
`Class.Instance`, use `Class.Instance.ChildAdded` instead.

See also `Class.Instance.DescendantRemoving`.


Instance.DescendantAdded

descendant

Fires after a descendant is added to the `Class.Instance`.


The following example prints the name of any descendant as it is being removed
from the Workspace:

This event fires **immediately before** the parent `Class.Instance`
changes such that a **descendant** instance will no longer be a
descendant. `Class.Instance:Destroy()|Destroy()` changes an instance's
`Class.Instance.Parent|Parent` to `nil`, so calling that method on a
descendant of the parent will cause this event to fire.

Since this event fires **before** the descendant's removal, the parent of
the descendant will be unchanged at the time of this event firing. If the
descendant is also a **direct child** of the parent, this event will fire
before `Class.Instance.ChildRemoved`.

If a descendant has children, this event fires with the descendant first,
followed by its descendants.

##### Warning

This event fires with the descendant object that is being removed.
Attempting to set the `Class.Instance.Parent|Parent` of the descendant to
something else will fail. Below is an example that demonstrates this:

```
local Workspace = game:GetService("Workspace")

Workspace.DescendantRemoving:Connect(function(descendant)
	-- Do not manipulate the parent of the descendant in this function!
	-- This event fires BECAUSE the parent was manipulated, and the change hasn't happened yet
	-- Therefore, it is problematic to change the parent like this:
	descendant.Parent = game
end)

local part = Instance.new("Part")
part.Parent = Workspace
part.Parent = nil
```

See also `Class.Instance.DescendantAdded|DescendantAdded`.


Instance.DescendantRemoving

The `Class.Instance` that is being removed.


Fires immediately before a descendant of the `Class.Instance` is removed.


This sample demonstrates how, when using Immediate signal behavior, an Instance being destroyed remains in place until the connected function yields.

This sample demonstrates how, when using Deferred signal behavior,
an Instance is destroyed before the signal fires.

The `Class.Instance` will never be deleted from memory while a connected
function is still using it. However, if the function yields at any point,
the `Class.Instance` and its descendants will be parented to `nil`.

If the `Class.Workspace.SignalBehavior` property is set to
`Enum.SignalBehavior.Immediate`, this event fires immediately before the
`Class.Instance` or one of its ancestors is destroyed with
`Class.Instance:Destroy()`.

If the `Class.Workspace.SignalBehavior` property is set to
`Enum.SignalBehavior.Deferred`, this event fires at the next resumption
point, which will be after the `Class.Instance` or one of its ancestors is
destroyed with `Class.Instance:Destroy()`.

With `Enum.SignalBehavior.Deferred|Deferred` behavior, connecting a script
to its own `Class.Instance.Destroying` event is problematic, as the script
will be destroyed before the callback can be called (meaning it will not
execute).

When deleting an `Class.Instance` in Studio, such as manually deleting
through the [Explorer](/studio/explorer) or through a plugin,
the `Class.Instance` isn't destroyed. Instead, the parent is set to `nil`
which you can track with `Class.Instance.AncestryChanged`.


Instance.Destroying

Fires immediately before (or is deferred until after) the instance is
destroyed via `Class.Instance:Destroy()`.


This event fires whenever any style property is changed on the instance,
including when a property is set to `nil`.

```lua
local Players = game:GetService("Players")

local player = Players.LocalPlayer
local playerGui = player.PlayerGui
local HUDContainer = playerGui:WaitForChild("HUDContainer")
local meterBar = HUDContainer.MeterBar

local function stylePropertyChanged()
	print("Styled properties changed")
end

meterBar:StyledPropertiesChanged():Connect(stylePropertyChanged)
```


Instance.StyledPropertiesChanged

Fires whenever any style property is changed on the instance, including
when a property is set to `nil`.


Instance.childAdded

This method applies a tag to the instance, with no effect if the tag is
already applied. Successfully adding a tag will fire a signal created by
`Class.CollectionService:GetInstanceAddedSignal()` with the given tag.

##### Warnings

- An instance's tags that were added client-side will be dropped if the
  server later adds or removes a tag on that instance because the server
  replicates all tags together and overwrites previous tags.

- When tagging an instance, it is common that some resources are used to
  give the tag its functionality, for example event connections or tables.
  To prevent memory leaks, it's a good idea to clean these up (disconnect,
  set to `nil`, etc.) when no longer needed for a tag. Do this when
  calling `Class.Instance:RemoveTag()`, calling
  `Class.Instance:Destroy()`, or in a function connected to a signal
  returned by `Class.CollectionService:GetInstanceRemovedSignal()`.


Instance:AddTag

This function destroys all of an instance's children and descendants.

```
local part = Instance.new("Part")

-- Add some sparkles
for i = 1, 3 do
	local sparkles = Instance.new("Sparkles")
	sparkles.Parent = part

  local sc = Instance.new("Sparkles")
  sc.Parent = sparkles
end

print("Children:", #part:GetChildren())  --> Children: 3

part:ClearAllChildren()

print("Children:", #part:GetChildren())  --> Children: 0
```

If you do not wish to destroy **all** children and descendants, use either
`Class.Instance:GetChildren()` or `Class.Instance:GetDescendants()` to
loop through those children/descendants and select what to destroy. For
example, the following code sample will destroy all
`Class.BasePart|BaseParts` descending from a `Class.Model`:

```
local Workspace = game:GetService("Workspace")

local model = Workspace:FindFirstChild("TestModel")

for _, descendant in model:GetDescendants() do
	if descendant:IsA("BasePart") then
		descendant:Destroy()
	end
end
```


Instance:ClearAllChildren

This function destroys all of an instance's children.


Instance

`Instance` is the base class for all classes in the Roblox class hierarchy
which can be part of the `Class.DataModel` tree.


/reference/engine/classes/DragDetector.yaml

DragDetector

Summary

Properties

Properties

Methods

Events

Events

Properties

Methods

Events