How To Use

Prerequisites: Familiarity with basic C# programming in Unity and knowledge about how to use Unity’s built-in attributes.

Importing The Namespace

To start using the editor attributes you must add this using statement in your class:

using EditorAttributes;

If you are using Assembly Definitions in your project make sure you reference the “EditorAttributes” Assembly Definition where needed.

Serialization

Every member the attribute is attached to must be serializable by Unity (with the exception of the Button Attribute and ShowInInspector Attribute), meaning those members must be either public or private with the SerializeField Attribute and valid to the Unity serializer.

Here is a small example of what’s valid and what’s not:

// Valid, public fields are serialized by default
public int field01;

// Valid, is still a public field, we just mark it to be hidden in the inspector
[HideInInspector] public int field02;

// Invalid, private fields are not serialized by default
private int field03;

// Valid, we mark this private field to be serialized by unity
[SerializeField] private int field04;

// Valid, is still serialized, we just hide it in the inspector
[SerializeField, HideInInspector] private int field05;

// Invalid, static, readonly or const fields are not valid to unity's serializer
public static int field06;

// Invalid, Non-Behaivour classes and structs that are not marked as serializable are not serialized by unity
public CustomRawClass field07;

For more details about unity serialization see this

Attribute Order

The logic of all attributes is executed in the order they are written (left to right), meaning an attribute might not work due to the way they are applied. In the following example the ProgressBar Attribute will execute before the HideLabel Attribute causing the label not be removed because the HideLabel Attribute looks for a property field label but it gets a progress bar element instead:

using UnityEngine;
using EditorAttributes;

public class AttributesExample : MonoBehaviour
{
[ProgressBar, HideLabel]
[SerializeField] private int field;
}

To fix this we can change the order by putting the ProgressBar Attribute after the HideLabel Attribute or use the order parameter that every attribute has, to execute the HideLabel Attribute first. C# will first go through the attributes with the lowest order from left to right then to the ones with the higher order the same way. The default order of all attributes is 0:

using UnityEngine;
using EditorAttributes;

public class AttributesExample : MonoBehaviour
{
[ProgressBar, HideLabel(order = -1)]
[SerializeField] private int progressBar;
}

So now the HideLabel Attribute will be executed first and the ProgressBar Attribute will create the progress bar with the label aready hidden.

Finding members

Some attributes like Dropdown Attribute, Validate Attribute or Conditional Attributes will ask for the name of a member to use for their functionality, these members do not abide by Unity’s serialization rules, meaning they can be fields, properties or functions, inherited or nested, marked with any access modifier and be static, readonly or const.

Note

If the member is inherited it has to be public or protected for it to be found.

Note

The Grouping Attributes are the only attributes that abide by Unity’s serialization rules for finding members since they have to draw those members in the inspector.

You can also input members that are inside a different type as long as they are const or static:

using UnityEngine;
using EditorAttributes;

public class AttributesExample : MonoBehaviour
{
        [Dropdown("ExampleClass.GetDropdownValues")]
        [SerializeField] private string dropdown;
}

public class ExampleClass
{
        public static string[] GetDropdownValues() => new string[] { "Option 1", "Option 2", "Option 3" };
}

DO NOT use the nameof expression if you are passing members from another class since it will only return the name of the member itself not its path:

using UnityEngine;
using EditorAttributes;

public class AttributesExample : MonoBehaviour
{
        [Dropdown(nameof(ExampleClass.GetDropdownValues))]
        [SerializeField] private string example01;

        [Dropdown("ExampleClass.GetDropdownValues")]
        [SerializeField] private string example02;
}

public class ExampleClass
{
        public static string[] GetDropdownValues() => new string[] { "Option 1", "Option 2", "Option 3" };
}

If your type containing the member is inside of a namespace you need to input the entire path to that member:

using UnityEngine;
using EditorAttributes;

public class AttributesExample : MonoBehaviour
{
        [Dropdown("ExampleClass.GetDropdownValues")]
        [SerializeField] private string example01;

        [Dropdown("Example.ExampleClass.GetDropdownValues")]
        [SerializeField] private string example02;
}

namespace Example
{
        public class ExampleClass
        {
                public static string[] GetDropdownValues() => new string[] { "Option 1", "Option 2", "Option 3" };
        }
}