[Sort of release] Validate values with attributes while keeping additional propertydrawers

Here is some code I just made and maybe usefull for anyone else.
Its purpose is to validate fields in the inspector when they get changed.
You could do this with a PropertyAttribute + PropertyDrawer, but it doesn't work when you also want an additional PropertyDrawer.

The spoiler with the tag "Code" contains the required code, and the spoiler beneeth "Example" contains an example. As shown in the example, you use RootBehaviour instead of MonoBehaviour. (For those who are nitpicky; yeah I know the exaple doesn't add anything usefull, but it shows where it is for)

Spoiler: Code

Code (CSharp):

1. using System.Reflection;
2. using UnityEngine;
3.  
4. public abstract class RootBehaviour : MonoBehaviour
5. {
6.     #if UNITY_EDITOR
7.     protected virtual void OnValidate()
8.     {
9.         // Predefine flags
10.         const BindingFlags flags =
11.               BindingFlags.Public
12.             | BindingFlags.NonPublic
13.             | BindingFlags.Instance;
14.  
15.         // Get fields
16.         var type = GetType();
17.         var fields = type.GetFields(flags);
18.         foreach (var field in fields)
19.         {
20.             // Get field value
21.             var attributes = field.GetCustomAttributes(typeof(ValidateAttribute), true);
22.  
23.             // Check if has any attributes to safe some calculations
24.             if (attributes.Length < 1)
25.                 continue;
26.  
27.             // Get the field its value
28.             var value = field.GetValue(this);
29.  
30.             // Validate every field
31.             foreach (var attribute in attributes)
32.             {
33.                 // Convert to validate
34.                 var validateAttribute = attribute as ValidateAttribute;
35.                 if (validateAttribute == null)
36.                     continue;
37.  
38.                 // Perform action
39.                 validateAttribute.Validate(ref value, field.FieldType);
40.             }
41.  
42.             // Apply
43.             field.SetValue(this, value);
44.         }
45.     }
46.     #else
47.     protected virtual void OnValidate() { }
48.     #endif
49. }

Code (CSharp):

1. using System;
2. using System.Diagnostics;
3.  
4. public abstract class ValidateAttribute : Attribute
5. {
6.     [Conditional("UNITY_EDITOR")]
7.     public abstract void Validate(ref object value, Type type);
8. }

Spoiler: Example

Code (CSharp):

1. using System;
2. using UnityEngine;
3.  
4. /// <summary>
5. ///     Makes sure the value is not set to a lower value than the indicated value when altering in the inspector
6. /// </summary>
7. public class MinAttribute : ValidateAttribute
8. {
9.     public readonly float Min;
10.  
11.     /// <summary>
12.     ///     Constructor
13.     /// </summary>
14.     /// <param name="min">Min value of the variable</param>
15.     public MinAttribute(float min = 0.0f)
16.     {
17.         Min = min;
18.     }
19.  
20.     /// <summary>
21.     ///     Constructor
22.     /// </summary>
23.     /// <param name="min">Min value of the variable</param>
24.     public MinAttribute(int min)
25.     {
26.         Min = min;
27.     }
28.  
29.     /// <inheritdoc />
30.     public override void Validate(ref object value, Type type)
31.     {
32.         if (type == typeof(int))
33.         {
34.             var number = (int)value;
35.             if (number < Min)
36.                 number = (int)(Min + 0.5f);
37.             value = number;
38.         }
39.         else if (type == typeof(float))
40.         {
41.             var number = (float)value;
42.             if (number < Min)
43.                 number = Min;
44.             value = number;
45.         }
46.         else
47.             Debug.LogError("<color=blue>[MinAttribute]</color> " + type + " is not supported with this attribute");
48.     }
49. }

Code (CSharp):

1. using UnityEngine;
2.  
3. public class ___Test : RootBehaviour
4. {
5.     [SerializeField, Min, Range(-1, 1)]
6.     float _myPrivateVar;
7. }
8.  

 

An update to this script; It now supports lists and serializable classes.

Code (CSharp):

1. public class Example : RootBehaviour
2. {
3.     [SerializeField] List<MyClass> _myItems;
4.     [SerializeField, Min(5)] int _myInt;
5.     [SerializeField, Min(-10.0f)] List<float> _myItems2;
6.  
7.     [Serializable]
8.     public class MyClass
9.     {
10.         [Min] public float K;
11.     }
12. }