Separating Form Display from Processing

[doubledee]

Can someone give me some guidance of how to separate Form Display from Form Processing?

 

I have always used forms that submitted back to themselves which isn't so bad, but then trying to cram in code to display the form, validation errors, and messages after the form is processed all in one file is insane?!

 

Currently I am working on a simple "Add a Comment" form.

 

It would be nice to have a separate form processing script, but I don't know where to begin...

 

 

Debbie

 

[sunfighter]

I place my js validating section in the head of the page that holds the form just to make sure errors and omissions are caught before the form is processed.

 

In the <form action="PUT FORM PROCESSING FILE NAME HERE" ...  Do the same thing in this file as you were did in the one page form. Get your form variables and validate and  process. Then go to next web page.

[Psycho]

I typically have one page, but that page will include() the code necessary to either validate and/or display the form

 

Rough example on the "main" page (e.g. 'myform.php')

//Var to hold validation error (if form was posted)
$errors = array();

if(isset($_POST['someformfield']))
{
    //Include the file that does the form validation
    include('form_processing_page.php');

    //If any validation errors occur, they will be added to the $errors array

    //If validation passes the validation page can process/save the data OR call another page to do that logic
    //But, at the end of processing, user is redirected to a confirmation page using header() followed by exit()
    //so the remaining code on this page is not executed
}

//Include the html form page
// This only happens if the form was not submitted or if there were validation errors
include('form_html.php');

//The html content page will include logic to display the errors if the exist

[doubledee]

I typically have one page, but that page will include() the code necessary to either validate and/or display the form

 

Rough example on the "main" page (e.g. 'myform.php')

//Var to hold validation error (if form was posted)
$errors = array();

if(isset($_POST['someformfield']))
{
    //Include the file that does the form validation
    include('form_processing_page.php');

    //If any validation errors occur, they will be added to the $errors array

    //If validation passes the validation page can process/save the data OR call another page to do that logic
    //But, at the end of processing, user is redirected to a confirmation page using header() followed by exit()
    //so the remaining code on this page is not executed
}

//Include the html form page
// This only happens if the form was not submitted or if there were validation errors
include('form_html.php');

//The html content page will include logic to display the errors if the exist

 

That is basically what I do now, except for another script printing out the results.

 

My big problem - and I don't see how your approach is immune - is if the user hits Back/Forward/Back/Forward then you get into Double-Submission issues...  :-\

 

 

Debbie

 

[KevinM1]

Do a google search on the PRG Pattern (I'd type more, but I'm on my PS3).

[doubledee]

Do a google search on the PRG Pattern (I'd type more, but I'm on my PS3).

 

From what I've read, it is a poor pattern...

 

 

Debbie

 

 

[KevinM1]

How so?  Its purpose is to stop double form submissions.

[doubledee]

How so?  Its purpose is to stop double form submissions.

 

I don't have the link, but what I read last night said that that pattern wasn't such hot stuff and had flaws in it.

 

It might have been on wiki?  Don't remember.

 

 

Debbie

 

[KevinM1]

All patterns have strengths and weaknesses.  That's why they're patterns and not silver bullets.  Each pattern is a common, tested, working approach to solve a particular problem.  Your problem is double submissions.  The PRG Pattern exists to solve that particular problem.