Re: Can't understand what is form rewinding.
"Ahmed Aly" <[email protected]> Fri, 21 Feb 2003 14:19:57 -0500
| Newsgroups | gmane.comp.java.tapestry.devel |
|---|---|
| Message-ID | <[email protected]> |
<html><div style='background-color:'><DIV> <P>Hi all,</P> <P>While we're on the subject of form rewinding...in my application, when the form rewinds all PropertySelection compnents doesn't select (add SELECTED attribute to OPTION elements) the previously selected value when the form was submitted. I tried implementing a custom PropertySelectionRenderer but in renderOption(...) , < obj > parameter is always n null. Any ideas on how to preserve the selected value???</P></DIV> <DIV>-Ahmed</DIV> <DIV> </DIV> <DIV></DIV> <DIV></DIV> <DIV></DIV> <DIV></DIV>>From: Eric Everman <[email protected]> <DIV></DIV>>To: "Elankath, Tarun (Cognizant)" <[email protected]>, [email protected] <DIV></DIV>>Subject: Re: [Tapestry-developer] Can't understand what is form rewinding. <DIV></DIV>>Date: Fri, 21 Feb 2003 11:18:19 -0600 <DIV></DIV>> <DIV></DIV>>Tarun- <DIV></DIV>> <DIV></DIV>>I can take a stab at that question. <DIV></DIV>> <DIV></DIV>>Form rewinding is the process of recreating the same conditions <DIV></DIV>>during form submit, that a particular component saw during form <DIV></DIV>>render. <DIV></DIV>> <DIV></DIV>>For rewinding is key in understanding iterative form components. <DIV></DIV>>For instance, say you have an arbitrary list of items with 'edit' <DIV></DIV>>and 'delete' buttons next to each item. Your template might look <DIV></DIV>>something like this (in pseudo code) <DIV></DIV>> <DIV></DIV>><FOR item each> <DIV></DIV>><INSERT item name /><CREATE button edit /><CREATE button delete /> <DIV></DIV>></FOR item each> <DIV></DIV>> <DIV></DIV>>All the delete buttons call the delete() method, but do not specify <DIV></DIV>>which item to delete. When the user clicks a 'Delete' button, the <DIV></DIV>>conditions that the form saw when the button were rendered are <DIV></DIV>>recreated - that is, if your page had a currentItem property, that <DIV></DIV>>property is reset to the currentItem when the button was rendered. <DIV></DIV>>Your delete method is called by Tapestry and your code deletes the <DIV></DIV>>item in currentItem, know that it is the correct item. <DIV></DIV>> <DIV></DIV>>This is all optional and not ideal in some cases. You can use the <DIV></DIV>>Direct service, which puts the burden on you to give actions a <DIV></DIV>>meaningful identifier by which you can locate the correct item to <DIV></DIV>>act on. <DIV></DIV>> <DIV></DIV>>Does that help? <DIV></DIV>> <DIV></DIV>>Eric Everman <DIV></DIV>> <DIV></DIV>>At 2/21/2003, Elankath, Tarun (Cognizant) wrote: <DIV></DIV>>>Hi list, <DIV></DIV>>> <DIV></DIV>>>Sorry for this newbie-style question. I have read the tutorial and <DIV></DIV>>>the user <DIV></DIV>>>manual. I understand the advantages that Tapestry offers, but its <DIV></DIV>>>complexity <DIV></DIV>>>is mind-boggling. I have been just totally unable to understand <DIV></DIV>>>what is form <DIV></DIV>>>rewinding/rewind cycle and its principle. <DIV></DIV>>> <DIV></DIV>>>Could someone please explain what rewind is ? <DIV></DIV>>> <DIV></DIV>>>All help/pointers gratefully appreciated, <DIV></DIV>>>Tarun <DIV></DIV>>> <DIV></DIV>> <DIV></DIV>> <DIV></DIV>> <DIV></DIV>>------------------------------------------------------- <DIV></DIV>>This SF.net email is sponsored by: SlickEdit Inc. Develop an edge. <DIV></DIV>>The most comprehensive and flexible code editor you can use. <DIV></DIV>>Code faster. C/C++, C#, Java, HTML, XML, many more. FREE 30-Day <DIV></DIV>>Trial. <DIV></DIV>>www.slickedit.com/sourceforge <DIV></DIV>>_______________________________________________ <DIV></DIV>>Tapestry-developer mailing list <DIV></DIV>>[email protected] <DIV></DIV>>https://lists.sourceforge.net/lists/listinfo/tapestry-developer <DIV></DIV></div><br clear=all><hr>MSN 8 with <a href="http://g.msn.com/8HMFENUS/2740">e-mail virus protection service: </a> 2 months FREE*</html> ------------------------------------------------------- This SF.net email is sponsored by: SlickEdit Inc. Develop an edge. The most comprehensive and flexible code editor you can use. Code faster. C/C++, C#, Java, HTML, XML, many more. FREE 30-Day Trial. www.slickedit.com/sourceforge