Is there a form submission pattern?

Question

In PHP, Are there any patterns people use to submit forms? A form submission best practices.. etc.

Example, I am trying to achieve a CRUD operation. Initially I have been using a same function for handling form-display and form-submission

class Somecontroller extends Controller {

  function form1_add() {
    // if submit exist save it in database
    // else
    // display the form
  }

  function form1_edit() {
    // if submit exist save it in database
    // else
    // display the same form
  }
}

What I do not like.. about this practice is, the login to check if there is a submit or whether it is brand new form is in the same function.

I have thought about making two different functions

form1_add() and form1_add_submit()

to handle these operations. But other issues appear for example, on unsuccessful validation, I would have to call form1_add() from form1_add_submit() again to display those validation errors.

What other practices do people use for this kind of operation? Are there any specific patterns for these?

Answer 1

The general principle, as with any programming, is to keep your functions as atomic as possible. Performing multiple tasks within a single function just makes your job harder, and makes it more difficult to debug. Calling functions from other function is a perfectly good idea, and will at least make your code easier to understand.

In terms of a specific example, I always separate from display and form submission/validation from each other, because they're totally different pieces of functionality. If you want 'pretty' validation, perhaps consider using JavaScript on the form itself, and then just displaying a list of 'errors' with PHP, just above the form, if the form submission still doesn't comply with the input (allowing the user to correct them).

Answer 2

I'm not aware of any "best practice" or "standard way to do" this.

Personally, I use external functions to handle this.
If user submitted then i call userSubmited(), and so forth. I also separate these into separate files, so I can keep the one with the form cleaner (just the header, etc).

Also, it might be a good idea to keep the form-processing part in one file, and the UI-display in another, to keep this even cleaner.