I'm not at liberty to give out any code but the implementation is pretty straight forward.
An iframe (inline frame) is just an HTML tag that allows you to embed one webpage into another. A Google search will get you many examples of it's implementation. The IFrame is in a div that has it's visibility set to hidden. The page in the iframe meta refresh tag that causes it to reload every n seconds. I think we have it set to 60 seconds. Every time the frame refreshes, the servlet queries the database for unread messages. If it finds any, it rewrites page and adds a javascript function which is triggered from the body onload event that fires off a popup window telling the user how many unread messages they have. In our database, we have two attributes for this feature; is_new and is_read. The proc sets the is_new value to false every time it runs so that the user doesn't have to deal with a popup window every time the page refreshes (unless a new message shows up, of course). is_read is pretty self explanatory. When users first log in they are shown a list of unread messages. In our case the popup window is actually a hidden div with gets set to visible when it needs to pop up. This works nicely for us because we can put links to the messages right in the popup window. It's best to keep treads on the list. That way someone else will be able to read the answer and possibly avoid asking the same question. Hope this helps -Ben On Wednesday 13 August 2003 12:39 pm, you wrote: > Ben! > Wah! Great! Could you give me more information about your implementation? > I am not clear with iFrame. > > ----- Original Message ----- > From: "Ben Souther" <[EMAIL PROTECTED]> > To: "Tomcat Users List" <[EMAIL PROTECTED]> > Sent: Thursday, August 14, 2003 12:32 AM > Subject: Re: Question about Notify all online user > > > We're doing something like this with a hidden frame (an iFrame) that > refreshes > it self every n seconds (using the Meta refresh tag). The frame just points > to a servlet which queries the database for new messages. If there is a > new message, the iframe uses javascript to fire off a pop up. message. > > You're other option would be to use an applet that maintains a statefull > connection to your server. A applet list would be a better place to discuss > that approach though. > > On Wednesday 13 August 2003 12:07 pm, engp0510 wrote: > > Hi, all > > How to implement notifying all online user when the record in database > > has been changed? I am using Servlet and JSP to build a small > > Supply-Chain system running on Tomcat with MySQL. > > > > Thanks > > Zhidao -- Ben Souther F.W. Davison & Company, Inc. -- Ben Souther F.W. Davison & Company, Inc. REGISTER NOW FOR THE SCORPEO USER CONFERENCE! September 18-19, 2003 in Boston/Brookline, MA Additional Training Sessions held September 17, 2003 More info >> http://www.fwdco.com/services/Uconf03/default.shtm --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
