title: Django - How to prepopulate admin form fields
body: <p>I know that you can prepopulate admin form fields based on other fields. For example, I have a slug field that is automatically populated based on the title field.</p>
  
  <p>However, I would also like to make other automatic prepopulations based on the date. For example, I have an URL field, and I want it to automatically be set to <a href="http://example.com/20090209.mp3" rel="noreferrer">http://example.com/20090209.mp3</a> where 20090209 is YYYYMMDD. </p>
  
  <p>I would also like to have a text field that automatically starts with something like "Hello my name is author" where author is the current user's name. Of course, I also want the person to be able to edit the field. The point is to just make it so the user can fill out the admin form more easily, and not just to have fields that are completely automatic.</p>