SerializedProperty Extensions

Write editor properties in one line — and reach the actual C# field the property shows in the Inspector.

Quick start

Before — Unity API	After — FastTools
var manaCost = serializedObject .FindProperty("_manaCost"); serializedObject.Update(); manaCost.intValue = 42; serializedObject .ApplyModifiedProperties();	var manaCost = serializedObject .FindProperty("_manaCost"); manaCost .Update() .SetIntAndApply(42);

Writing values

Before — Unity API	After — FastTools
manaCost.intValue = 42;	manaCost.SetInt(42);
manaCost.intValue = 42; manaCost.serializedObject .ApplyModifiedProperties();	manaCost.SetIntAndApply(42);
manaCost.intValue = 42; manaCost.serializedObject .ApplyModifiedPropertiesWithoutUndo();	manaCost .SetIntAndApplyWithoutUndo(42);

Supported types

Values	Setters
Numbers	SetInt, SetUint, SetLong, SetUlong, SetFloat, SetDouble
Text, bool and hash	SetString, SetBool, SetHash128
Vectors	SetVector2, SetVector2Int, SetVector3, SetVector3Int, SetVector4, SetQuaternion
Areas	SetRect, SetRectInt, SetBounds, SetBoundsInt
Unity types	SetColor, SetGradient, SetAnimationCurve
Object IDs	SetEntityId

Each has a SetValue overload: SetValue(42) calls SetInt, so the argument type must match the field type.

Enums, arrays and references

Unity	FastTools
enumValueIndex = 1	SetEnumIndex(1)
enumValueFlag = flags	SetEnumFlag(flags)
arraySize = 5	SetArraySize(5)
arraySize += n	AddArraySize(n = 1)
arraySize -= n	RemoveArraySize(n = 1)
managedReferenceValue = value	SetManagedReference(value)
objectReferenceValue = value	SetObjectReference(value)
boxedValue = value	SetBoxed(value)
exposedReferenceValue = value	SetExposedReference(value)

Update() and Apply…()

Unity	FastTools
serializedObject.Update()	Update()
serializedObject.UpdateIfRequiredOrScript()	UpdateIfRequiredOrScript()
serializedObject.ApplyModifiedProperties()	ApplyModifiedProperties()
serializedObject.ApplyModifiedPropertiesWithoutUndo()	ApplyModifiedPropertiesWithoutUndo()

They are called on the property and, like every setter, return it.

The C# field from the Inspector

Three methods find the C# field the property shows in the Inspector: its type, the field itself and the object that holds it.

public class AbilityBook : MonoBehaviour
{
    [SerializeField]
    private List<Ability> _abilities = new() { new Ability() };

    [SerializeReference]
    private IAbilityEffect _effect = new BurnEffect();
}

[Serializable]
public class Ability { public string Name = "Fireball"; }

[Serializable]
public class BurnEffect : IAbilityEffect { public float Damage = 5f; }

Property path	GetPropertyType()	GetFieldInfo()	GetDeclaringInstance()
_abilities	List<Ability>	AbilityBook._abilities	the AbilityBook
_abilities[0]	Ability	AbilityBook._abilities	the AbilityBook
_abilities[0].Name	string	Ability.Name	the Ability at index 0
_effect	IAbilityEffect	AbilityBook._effect	the AbilityBook
_effect.Damage	float	BurnEffect.Damage	the BurnEffect instance

• if the field is not found, GetPropertyType() and GetFieldInfo() return null, and GetDeclaringInstance() does only when the owning object is not found;
• the methods read only the first target object and only applied values.

warning

When the field's owner is a struct, GetDeclaringInstance() returns a boxed copy. Changes to that copy never reach the original; write values through the SerializedProperty instead.

Member name and drawing checks

Property path	GetMemberName()	IsArrayElement()	HasFoldout()
_abilities[0]	"_abilities"	true	true
_abilities[0].Name	"Name"	false	false
_effect	"_effect"	false	false

note

HasFoldout() returns true for a plain compound field with visible children, so it can differ from the Inspector: a [SerializeReference] field gets a foldout in the Inspector but false here, and custom PropertyDrawers are not taken into account.

Persistent()

Persistent() returns a copy of the property on its own SerializedObject, so it can be used later, for example in EditorApplication.delayCall.

Before — Unity API	After — FastTools
var source = manaCost.serializedObject; var independentObject = new SerializedObject( source.targetObjects, source.context); var independent = independentObject .FindProperty(manaCost.propertyPath);	var independent = manaCost.Persistent();

• the copy belongs to the caller: dispose it together with its serializedObject;
• unapplied writes of the source property do not reach the copy;
• if the property is missing on the targets, the method returns null.

var independent = manaCost.Persistent();
if (independent == null) return;

EditorApplication.delayCall += () =>
{
    using (independent.serializedObject)
    using (independent)
        independent.Update().SetIntAndApply(42);
};

Package sample

In EditorTools, the Halve cooldown, +5 MP button writes two properties with SetFloat and SetIntAndApply.