InitializeOnEnterPlayModeAttribute

Description

Allow an editor class method to be initialized when Unity enters Play Mode.

Use to reset static fields in Editor classes on Enter Play Mode without Domain Reload.

using UnityEngine;
using UnityEditor;

class MyAnotherClass
{
    static int s_MySimpleValue = 0;

    [InitializeOnEnterPlayMode]
    static void OnEnterPlaymodeInEditor(EnterPlayModeOptions options)
    {
        Debug.Log("Entering PlayMode");

        if (options.HasFlag(EnterPlayModeOptions.DisableDomainReload))
            s_MySimpleValue = 0;
    }
}

Or perform any other logic on Enter Play Mode.

using UnityEngine;
using UnityEditor;

class MyClass
{
    static int s_MyValue = 0;

    static void MyClassPlaymodeSetup()
    {
        s_MyValue = 1000;
        //...
    }

    [InitializeOnEnterPlayMode]
    static void OnEnterPlaymodeInEditor(EnterPlayModeOptions options)
    {
        Debug.Log("Entering PlayMode");
        MyClassPlaymodeSetup();
    }
}