For example, Databinder has conversation (page) support for Hibernate Sessions...
In the next version we might write some code to make it pluggable to things like seam-wicket or your own spring based one.. On Fri, 2011-04-15 at 16:41 -0700, jcgarciam wrote: > Correction to previous post: > I can only imagine having a JPAConversational scope built around a Custom > RequestCycle or is there other things involved on this? > > On Fri, Apr 15, 2011 at 8:37 PM, Juan Carlos Garcia > <[email protected]>wrote: > > > @Igor, this is really interesting. I can only imagine having a > > JPAConversational scope built around a Custom RequestCycle or is there could > > be other thing involved on this? > > > > > > On Fri, Apr 15, 2011 at 11:58 AM, Igor Vaynberg-2 [via Apache Wicket] < > > [email protected]> wrote: > > > >> we use conversations a lot, mostly for keeping a jpa session open > >> across requests. > >> > >> imagine the following situation: > >> > >> you have a person entity that has a one to many relation to an address > >> entity and address has a many to one relationship with a city. you > >> have a page where the user can add multiple addresses to the person, > >> but the requirement is that none of the addresses are saved until the > >> user presses the save button. should the user add two addresses and > >> then press cancel none of the addresses are safe. this is a general > >> "atomic action across multiple requests" example. > >> > >> how do you do this with models? even if your entities are > >> serializable, which they probably should not be, you have a problem > >> with address->city linkage because it will become stale across > >> requests where each request has its own jpa session. so the easiest > >> but messiest way is to reserve to using some sort of dto to keep track > >> of added addresses, remove addresses, edited addresses, etc. the big > >> problem with the dto is now your components have to work with a dto as > >> well. eg you have to support add(new AddressEditor("foo", address)) > >> and add(new AddressEditor("foo", addressDto));, and no - they cant > >> implement some interface unless the address dto knows how to lazy load > >> city from jpa session,etc, etc. look how long it took just to describe > >> this. > >> > >> using a conversation workflows page or pages like this are *no > >> different* then others. we store our jpa session in conversation. when > >> the page loads we mark conversation as persistent so it will survive > >> across requests and is passed from page to page - unless user > >> navigates to a bookmarkable page. we also set the jpa session to flush > >> mode manual. all code works like it normally would, with entity > >> models. it doesnt know that it is working across requests. our entity > >> models are smart enough to know that until the entity has an database > >> id it should be stored in a special conversational store that is > >> basically a map:uuid->object. when the user presses save we flush the > >> session and all of their changes are persisted in a transaction. when > >> the user presses cancel we clear the session and close the converation > >> - which undoes all their changes. this has the added bonus of the > >> session acting as a database cache for the workflow. > >> > >> -igor > >> > >> > >> On Fri, Apr 15, 2011 at 12:45 AM, Carl-Eric Menzel > >> <[hidden > >> email]<http://user/SendEmail.jtp?type=node&node=3452263&i=0&by-user=t>> > >> wrote: > >> > >> > I have to admit I've never quite understood the need for seam-style > >> > conversations in Wicket. Whenever I need to do some kind of > >> > defined workflow, I simply use appropriate IModel instances that get > >> > passed around between the participating components. What is the use > >> > case of using a conversation construct over models? > >> > > >> > Carl-Eric > >> > www.wicketbuch.de > >> > > >> > On Thu, 14 Apr 2011 23:14:14 -0700 > >> > Igor Vaynberg <[hidden > >> > email]<http://user/SendEmail.jtp?type=node&node=3452263&i=1&by-user=t>> > >> wrote: > >> > > >> >> seam-wicket provides a full implementation. > >> >> > >> >> if you want "clean" you can build it yourself, its not too difficult. > >> >> subclass session and inside put a map of <conversationId,conversation> > >> >> and manage that map however you see fit in your app. > >> >> > >> >> -igor > >> >> > >> >> > >> >> On Thu, Apr 14, 2011 at 10:55 PM, YK <[hidden > >> >> email]<http://user/SendEmail.jtp?type=node&node=3452263&i=2&by-user=t>> > >> wrote: > >> >> > Are you planning to develop a conversation/workspace module ? > >> >> > > >> >> > What I mean by "conversation" is a "session portion" or > >> >> > manageable/controllable "mini" session > >> >> > that can be started and finished programmatically. > >> >> > > >> >> > This allows building multi-step programs and/or workflow and permits > >> >> > generally memory (objects in session) management. > >> >> > > >> >> > I know that wicket-seam provides this (partially) but what I would > >> >> > like to know is : could we have a "pure" > >> >> > wicket one ? and if it is feasible. > >> >> > > >> >> > > >> >> > Thanks > >> >> > > >> >> > -- > >> >> > View this message in context: > >> >> > > >> http://apache-wicket.1842946.n4.nabble.com/wicket-conversation-workspace-tp3451294p3451294.html<http://apache-wicket.1842946.n4.nabble.com/wicket-conversation-workspace-tp3451294p3451294.html?by-user=t> > >> >> > Sent from the Forum for Wicket Core developers mailing list archive > >> >> > at Nabble.com. > >> >> > > >> > > >> > > >> > >> > >> ------------------------------ > >> If you reply to this email, your message will be added to the discussion > >> below: > >> > >> http://apache-wicket.1842946.n4.nabble.com/wicket-conversation-workspace-tp3451294p3452263.html > >> To start a new topic under Apache Wicket, email > >> [email protected] > >> To unsubscribe from Apache Wicket, click > >> here<http://apache-wicket.1842946.n4.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=1842946&code=amNnYXJjaWFtQGdtYWlsLmNvbXwxODQyOTQ2fDEyNTYxMzc3ODY=>. > >> > >> > > > > > > > > -- > > Sincerely, > > JC (http://www.linkedin.com/in/jcgarciam) > > --Anyone who has never made a mistake has never tried anything new.-- > > > > > > > > > -- > -- > JC > > > -- > View this message in context: > http://apache-wicket.1842946.n4.nabble.com/wicket-conversation-workspace-tp3451294p3453215.html > Sent from the Forum for Wicket Core developers mailing list archive at > Nabble.com.
