WaitForEndOfFrame replacing WaitForNewFrame - unity3d

Question

The following strategy was suggested, in order to allow some time for a big system to finish all the loading, etc...
So, the idea is to make sure I have waited for long enough for everything to be loaded, and then do my own command. Let's call it CMD() for now.
void Start()
{
StartCoroutine( TakeYourTime() );
}
IEnumerator TakeYourTime()
{
yield return new WaitForNewFrame();
yield return new WaitForNewFrame();
yield return new WaitForNewFrame();
yield return new WaitForNewFrame();
CMD();
}
But of course, Unity3D does not recognize WaitForNewFrame()!
After googling, I realized there is only WaitForEndOfFrame() available, so I replaced it in the above, thinking that it would achieve the same, but my CMD() does not take effect.
So, I am wondering if this existing command is not the same as the originally-suggested one, or if I am not waiting long enough?

Answer 1

yield return null;
is the command that will get the method to return on next frame and continue.
But this is no good practice as you cannot know if one , two or more frames are required.
You should have some kind of control over the flow of your program. If some actions are long and spread over several frames, provide a callback to the coroutine:
void Awake()
{
StartCoroutine(Loading(CMD));
}
private void CMD(){ //Other actions }
private IEnumerator Loading (Action action)
{
// Many long action with yield
if(action != null) { action(); }
}

Answer 2

If CMD() is also an IEnumerator function, you have to do another StartCoroutine() function on it, or it will not work. Based on the information available that's the only issue I can think of to explain why CMD() would not start.
If you have additional logic after that requires to wait on the completion of CMD(), you can yield return the StartCoroutine() call to pause TakeYourTime() from continuing until CMD() is completed.
void Start()
{
StartCoroutine( TakeYourTime() );
}
IEnumerator TakeYourTime()
{
yield return new WaitForEndOfFrame();
yield return new WaitForEndOfFrame();
yield return new WaitForEndOfFrame();
yield return new WaitForEndOfFrame();
yield return StartCoroutine(CMD());
//Do the rest.
}
IEnumerator CMD()
{
//Do whatever.
}
If CMD() is not an IEnumerator function, then I apologize for this incorrect answer. You can troubleshoot further using Debug.Log() calls to determine where the application is getting stuck. I would put them before, after, and on the first line of CMD()
From your comments, though, I would recommend you do something else.
You mention that when you wait longer, it works. That means you're just waiting on something to complete, and there's no issue with methods firing.
You should do something like this instead:
IEnumerator TakeYourTime()
{
while(!otherThingIsFinished())
{
yield return new WaitForEndOfFrame();
}
CMD();
}
otherThingIsFinished() should be a call to check to see if the stuff you're waiting for has completed whatever it's doing. You can have a public method that you can call that checks some private boolean that gets set when it's completed.
You can also just have the other stuff call this method directly, although that may not be the best option either. It all depends on what exactly you're trying to do.