I hope I understand what you are asking. A couple of things come to mind about threads and Servlets. If one uses Instance variables in Servlets then each instance of that Servlet has a unique variable and there is no data corruption. However if one uses Class variables then each instance of a servlet shares the variables and then data corruption can occur.
Same with formbeans and wizards. Each formbean is unique to the specific Servlet action. So, if one uses a single formbean for several steps in a wizard then there is no data corruption. Am I understanding what you are asking? --Brad. -----Original Message----- From: Frank W. Zammetti [mailto:[EMAIL PROTECTED] Sent: Wed 11/16/2005 11:46 AM To: Struts Users Mailing List Subject: Wizard page "data corruption" (was: "Re: Form Beans") Imagine you have a single ActionForm with a firstName field. Now imagine you have two wizard pages that are used in sequence, and you want to use the same ActionForm for both. Assume the form is stored in session, as you would expect in a wizard. Now, imagine there is a firstName field on both HTML forms of both wizard pages... you might argue this isn't a good wizard design, and I would tend to agree, but it's something that can happen in some cases. Now, assume a prototypical Struts app, no Struts Dialogs extensions or anything... What happens when the first page submits? The firstName field is populated in the ActionForm. Now what about when the second form is submitted? The value of the firstName field in the ActionForm now has the value from the second form submission, effectively overwriting the value the user entered on the first page, so if the user were to go back to the first wizard page, they would incorrectly see the data from the second page in effect. Easily to explain, but to the user it's a data corruption issue. This is the scenario I was referring to. Does your Dialogs stuff overcome that? If so, how? Whether it does or not, a "normal" Struts app will certainly have this problem, hence my comment about making sure the field names are different... in this case, it might be as simple as making two fields in the ActionForm, one named firstNamePage1 and firstNamePage2. Frank Michael Jouravlev wrote: > On 11/16/05, Frank W. Zammetti <[EMAIL PROTECTED]> wrote: > >>The one thing to keep in mind if you go [one ActionForm] route is >>to be sure you don't have a field on one page >>with the same name as another. I had one junior developer make that >>mistake and it drove him nuts trying to figure out what was wrong >>(obvious in retrospect, but one of those "tricky at the time" problems >>to solve). > > > I don't see right away how does this matter if you have separate > submits from a browser each time. Also would not matter if you > redirect between pages and don't intentionally stuff values into > redirected request. Redirected request comes clean, so same fields or > not - does not matter. This is why my two-phase request processing > works: POST comes with input data, form is populated, then I redirect > to the same action again, GET comes clean, form is not updated because > request contains no data. > > Forwarded request brings all input data with it, and Struts applies > this data to another form. Been there ;) > > Michael. > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > > > -- Frank W. Zammetti Founder and Chief Software Architect Omnytex Technologies http://www.omnytex.com AIM: fzammetti Yahoo: fzammetti MSN: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
