When entering an invalid email in Mail's **NSTokenField** one get's this (a **mix of token** and **plain string values**):

![alt text](https://i.stack.imgur.com/RtiPo.png)

Is there any recommendable way to accomplish this?  

Is NSTokenField even the right tool for this? Or would I be abusing it?

In this particular project I need to allow the user to enter a file name pattern  

*(there are several other use cases though)*, with support for predefined tokens.

Right now I'm requiring the input to be entered like this:

```
Glue Text %[Tag]Other Glue Text%[Another Tag]More Text

```

I'd like to change this to some fool-proof graphical solution like this:
![alt text](https://i.stack.imgur.com/Pb2EI.png)

NSTokenField always(!) turns entered text into tokens.

Either I'm using the wrong keywords in my web searches,  

or I'm really the first to need this (mixed) behaviour?!

I did read thru Apple's NSTokenField Guide, but couldn't find any info on my problem.