Best practice to deal with form processing

Question

I was wondering what is the best practice to deal with form processing?

In my case I do something like that:

• if the user hasn't submited the form
  • display the form
• else
  • if there are form errors
    • display errors
    • display form again
  • else
    • display a success message
    • (and) display the form again

My problem is that I'm repeating the HTML code for the form for 3 times and I don't think this is a good practice (long file, difficult to read).

Answer 1

Look, it's as simple as an egg!
Just put the same actions in the different order:

• if the user submited the form
  • if there are form errors
    • fill errors array
  • else
    • record data to database
    • 302 regirect, as it required by HTTP standard
    • exit
• if we have some errors
  • display errors
  • fill form field values
• display the form

If you can't live without a success message (a quite useless thing in my opinion) you can display it using get parameter (less preferred) or session (optimal)

oops! it was an old one.