LINQ to GameObject

LINQ to GameObject is GameObject extensions for Unity that allows traverse hierarchy and append GameObject like LINQ to XML. You can install from Unity Asset Store - LINQ to GameObject as FREE. Unity Forums support thread, ask me any questions - http://forum.unity3d.com/threads/linq-to-gameobject.292611/

LINQ to GameObject supports Unity 4 and 5 + uGUI's RectTransform.

Axis

The concept of LINQ to GameObject is axis on tree.

Every traverse method returns IEnumerable<GameObject> and deferred exectuion. For example

origin.Ancestors();   // Container, Root
origin.Children();    // Sphere_A, Sphere_B, Group, Sphere_A, Sphere_B
origin.Descendants(); // Sphere_A, Sphere_B, Group, P1, Group, Sphere_B, P2, Sphere_A, Sphere_B
origin.BeforeSelf(); // C1, C2
origin.AfterSelf();  // C3, C4

You can chain query(LINQ to Objects) and use some specified methods(Destroy, OfComponent and others).

// destroy all filtered(tag == "foobar") objects
root.Descendants().Where(x => x.tag == "foobar").Destroy();

// destroy all cloned objects
origin.transform.root.gameObject
    .Descendants()
    .Where(x => x.name.EndsWith("(Clone)"))
    .Destroy();

// get FooScript under self childer objects and self
var fooScripts = root.ChildrenAndSelf().OfComponent<FooScript>(); 

How to use

Import LINQ to GameObject from Unity Asset Store - http://u3d.as/content/neuecc/linq-to-game-object.

All methods are extension of GameObject, using Unity.Linq then you can use all extension methods.

using Unity.Linq;

Operate

LINQ to GameObject have several operate methods, append child(Add, AddFirst, AddBeforeSelf, AddAfterSelf) and destroy object(Destroy).

var root = GameObject.Find("root"); 
var cube = Resources.Load("Prefabs/PrefabCube") as GameObject; 

// add do attach parent, set same layer and fix localPosition/Scale/Rotation.
// added child is cloned and returns child object.
var clone = root.Add(cube);

// choose sibling position and allow append multiple objects.
var clones = root.AddAfterSelf(new[] { cube, cube, cube });  

// destroy do check null and deactive/detouch before destroy. It's more safety.
root.Destroy();

Add method's child is cloned. If you want to move only child, you can use(MoveToLast, MoveToFirst, MoveToBeforeSelf, MoveToAfterSelf) instead of Add.
Operate methods are extension methods of GameObject, too. You need using Unity.Linq.

Functional Construction

GameObjectBuilder construct tree use functional construction pattern.

var cube = Resources.Load("Prefabs/PrefabCube") as GameObject;

var tree = 
    new GameObjectBuilder(cube,
        new GameObjectBuilder(cube),
        new GameObjectBuilder(cube,
            new GameObjectBuilder(cube)),
        new GameObjectBuilder(cube));

var root = tree.Instantiate();

More info, see Functional Construction (LINQ to XML).

Reference

All traverse methods can find inactive object. If not found return type is GameObject methods return null, return type is IEnumerable<GameObject> methods return empty sequence. All collection methods have string name overload that returns filtered collection that have a matching name are included in the collection.

Method	Description
Parent	Gets the parent GameObject of this GameObject. If this GameObject has no parent, returns null.
Child	Gets the first child GameObject with the specified name. If there is no GameObject with the speficided name, returns null.
Children	Returns a collection of the child GameObjects.
ChildrenAndSelf	Returns a collection of GameObjects that contain this GameObject, and the child GameObjects.
Ancestors	Returns a collection of the ancestor GameObjects of this GameObject.
AncestorsAndSelf	Returns a collection of GameObjects that contain this element, and the ancestors of this GameObject.
Descendants	Returns a collection of the descendant GameObjects.
DescendantsAndSelf	Returns a collection of GameObjects that contain this GameObject, and all descendant GameObjects of this GameObject.
BeforeSelf	Returns a collection of the sibling GameObjects before this GameObject.
BeforeSelfAndSelf	Returns a collection of GameObjects that contain this GameObject, and the sibling GameObjects before this GameObject.
AfterSelf	Returns a collection of the sibling GameObjects after this GameObject.
AfterSelfAndSelf	Returns a collection of GameObjects that contain this GameObject, and the sibling GameObjects after this GameObject.

Operate methods have three optional parameter. cloneType configure cloned child GameObject's localPosition/Scale/Rotation. setActive configure activates/deactivates child GameObject. If null, doesn't set specified value. specifiedName configure set name of child GameObject. If null, doesn't set specified value.

Method	Description
Add	Adds the GameObject as children of this GameObject. Target is cloned.
AddFirst	Adds the GameObject as the first children of this GameObject. Target is cloned.
AddBeforeSelf	Adds the GameObject before this GameObject. Target is cloned.
AddAfterSelf	Adds the GameObject after this GameObject. Target is cloned.
Destroy	Destroy this GameObject safety(check null, deactive/detouch before destroy).

There are TransformCloneType that used Add methods.

If target is RectTransform always use SetParent(parent, false) and ignores TransformCloneType

Value	Description
KeepOriginal	Set to same as Original. This is default of Add methods.
FollowParent	Set to same as Parent.
Origin	Set to Position = zero, Scale = one, Rotation = identity.
DoNothing	Position/Scale/Rotation as is.

MoveTo methods similar with Add but don't clone target.

Method	Description
MoveToLast	Move the GameObject as children of this GameObject.
MoveToFirst	Move the GameObject as the first children of this GameObject.
MoveToBeforeSelf	Move the GameObject before this GameObject.
MoveToAfterSelf	Move the GameObject after this GameObject.

There are TransformMoveType that used MoveTo methods.

If target is RectTransform always use SetParent(parent, false) and ignores TransformMoveType

Value	Description
FollowParent	Set to same as Parent.
Origin	Set to Position = zero, Scale = one, Rotation = identity.
DoNothing	Position/Scale/Rotation as is. This is default of MoveTo methods.

IEnumerable<GameObject> Extensions. If multiple GameObjects in the source collection have the same GameObject will be included multiple times in the result collection. To avoid this, use the Distinct(LINQ to Objects) method.

Method	Description
Ancestors	Returns a collection of GameObjects that contains the ancestors of every GameObject in the source collection.
AncestorsAndSelf	Returns a collection of GameObjects that contains every GameObject in the source collection, and the ancestors of every GameObject in the source collection.
Descendants	Returns a collection of GameObjects that contains the descendant GameObjects of every GameObject in the source collection.
DescendantsAndSelf	Returns a collection of GameObjects that contains every GameObject in the source collection, and the descendent GameObjects of every GameObject in the source collection.
Children	Returns a filtered collection of the child GameObjects of every GameObject in the source collection. Only GameObjects that have a matching name are included in the collection.
ChildrenAndSelf	Returns a collection of GameObjects that contains every GameObject in the source collection, and the child GameObjects of every GameObject in the source collection.
Destroy	Destroy every GameObject in the source collection safety(check null, deactive/detouch before destroy).
OfComponent	Returns a collection of specified component in the source collection.

GameObjectBuilder.

Method	Description
Instantiate	Instantiate tree objects.

Author Info

Yoshifumi Kawai(a.k.a. neuecc) is software developer in Japan.
He is Director/CTO at Grani, Inc.
Grani is top social game developer in Japan.
He awarded Microsoft MVP for Visual C# since 2011.
He is known by creator of linq.js(LINQ to Objects for JavaScript) and UniRx(Reactive Extensions for Unity)

Blog: http://neue.cc/ (JPN)
Twitter: https://twitter.com/neuecc (JPN)

License

This library is under MIT License.