Re: Re: your method for validating forms

On Wed, 2003-10-01 at 20:26, Manuel Lemos wrote: > Hello, > > On 10/01/2003 08:43 PM, Chris W. Parker wrote: > > $_SESSION['form_errors'] = validateFormData($formdata); > > > > > > redirect("to_the_previous_page.php"); > > You may want to study how this classic form validation and generation > class works. It generates the necessary Javascript to validate on the > client side and uses the class methods to validate on the server side. > > > It makes it simple to generate, validate and process a form in the same > script, thus avoiding needless server access roundtrips that only slow > down the sites for the users. While there is overhead in making that round trip, I wanted to note a few reasons that I prefer server side validation. Some input validation cannot be easily done with Javascript (like checking for existing usernames in a database) so you end up showing error messages in two ways. Sometimes the user sees a Javascript alert and other times a message within the browser. Validating server side also gives you an opportunity to gather information about the way your application is being used. Supposed you have a logging mechanism that writes validation errors to a log. You might notice that there is a high frequency of failure for one kind of validation. Maybe the instructions for a file upload are confusing and users are constantly messing it up. Also, hardware is very fast for what it costs (I know, don't solve a problem by throwing money at it). Anyway, just some things to consider. - Brad