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Unity Engine

applyToCollection

Makes attribute affect collections instead of their items.
Read time 1 minuteLast updated 5 days ago

Definition

  • Type: Property
  • Namespace: UnityEngine
  • Assembly: UnityEngine.CoreModule
public bool applyToCollection { get; }

Remarks

When you apply a 
PropertyAttribute
to a collection, by default Unity applies it to each element of the collection. When 
applyToCollection
is 
true
, the attribute is applied to the collection itself instead.
You can use this in scenarios where the attribute functionality needs to apply to the collection as a whole rather than per element. Some typical scenarios include:
  • A reorderable list header or collection-level label. For example, when creating a drawer that adds a summary line stating the total number of items in the list, or a custom add or remove toolbar.
  • An attribute that makes a list non-reorderable, or locks its size.
  • Validation across the collection. For example, an attribute that checks that a list contains unique entries or that it has at least three items.

Examples

using UnityEditor;using UnityEditor.UIElements;using UnityEngine;using UnityEngine.UIElements;public class Collection : MonoBehaviour{    public int before;    [GreenCollectionDrawer] public int[] collection;    public int after;}public class GreenCollectionDrawerAttribute : PropertyAttribute{    public GreenCollectionDrawerAttribute() : base(true) { }}[CustomPropertyDrawer(typeof(GreenCollectionDrawerAttribute))]public class GreenCollectionDrawer : PropertyDrawer{    public override VisualElement CreatePropertyGUI(SerializedProperty property)    {        return new PropertyField(property)        {            style =            {                backgroundColor = Color.green            }        };    }}