simeple create/edit user question

[mrohad]

I'm tring to develop a user registration module with seam (POC)

I don't want to use JBPM for now.

I created a jsf page with 3 inputs
user.username
user.name
user.password

now I would like to access this page on 2 situation : create user/edit user
1)can I use the same RegisterAction stateless bean for that?

2) how does the stateless knows if I would like to edit or to create?
3) how do I retrive the user information to the page on edit situation?

I read the tutorial and saw only JBPM examples
I am very new to seam - please describe me as much as you can

Thanks a lot!

[pmuir]

This all very much depends on your desgin choices. Look at http://blog.hibernate.org/cgi-bin/blosxom.cgi/Gavin%20King/stages-of-adoption.html which quickly runs over various possible patterns.

My preferred technique is to use a conversation. I use a seperate backing bean for create and edit (which may extend a shared functions bean if necessary). I use a third bean for searching (stateless at the monent), and then use a datamodel row selection to populate the edit bean.

For the 'create' - start the conversation on entering the page, end it on pushing the create button. For 'edit' - start the conversation on entering the page, end it on pushing ok, and have an apply button which will flush current changes to the database but not close the page. For both I provide a cancel button which will end the conversation and navigate away but without flushing any changes. If the user navigates away I let the conversation time out (and not flush anything to the database).

I hope that didn't make you more confused. If you want me to expand on a particular part, ask.

[bfo81]

Stateless beans are only useful if you want to invoke one of their methods without doing anything else with them.

But if you have a state that should be held (e.g. user filled in fields) you need a STATEFUL bean. To distinguish between new and existing entities you can call two different actions - create and edit. There should be corresponding clickable buttons in your application.

I suggest it like that (pseudo code - in your case replace Entity by User):

@Stateful
@Scope(ScopeType.CONVERSATION)
@Name(...)
public class WhatEverBean implements WhatEver {

 private boolean newOne;

 @PersistenceContext(PersistenceContextType.EXTENDED)
 private EntityManager em;

 @In(required=false) @Out(required=false)
 private Entity entity;

 @Begin
 public String create() {
 newOne = true;
 entity = new Entity();
 return "editPageOutcome";
 }

 @Begin
 public String edit() {
 newOne = false;

 entity = em.find(Entity.class, theIdFromRequestParameter);
OR: entity = getFromDataModelSelection...;

 return "editorPageOutcome";
 }

 @End
 public String save() {
 if (newOne)
 em.persist(entity);
 else
 em.merge(entity);
 return "toPreviousPageOutcome";
 }
}

Ok, why do I suggest conversation scope? Cause the bean needs to live as long as the user edits the entity (including redisplays).

[bfo81]

Hm... petemuir was a bit quicker than me. But it seems like our two post complement one another - though we're using slightly different approaches ;).

[pmuir]

As always with design there are a multitude of ways to do the same thing, some of which are vastly different, some of which are very similar. It will be nice when the EJB3/Seam patterns set is a bit more developed!

I would suggest using a Seam Managed Persistence Context rather than an extended one to prevent any LazyInitiaisationExceptions.

[sws42]

"petemuir" wrote:
...
I use a third bean for searching (stateless at the monent), and then use a datamodel row selection to populate the edit bean.
...

Hi Pete!

I'm following the same "pattern" as you, but get a problem doing so.
I've also a Stateless SB for searching, including a DataModel for the resultlist.Works fine for the first time displaying, but whenI leave the search page and get back to it, I get a LazyInitialisationException. And yes, I'm already using the Seam Managed Persistence.

Any suggestions?

Thank you,

Stefan

[pmuir]

How do you 'get back to it'? The back button, or a link?

[sws42]

I go back through a <h:commandButton action="..."/>, calling a method in my SLSB, which returns an outcome for faces-config.

[pmuir]

I'm not sure what your exact problem. But I would guess that you are accessing something that isn't in the stateless scope from your search page, and that there is no persistence context available for it. So if you post some code it will be easier to help ;)

[sws42]

The SearchBean:

@Stateless
@Name("mitarbeiteruebersicht")
@LoggedIn
@Scope(ScopeType.STATELESS)

public class MitarbeiterUebersichtBean
 implements MitarbeiterUebersicht {
...
...
 @In (required=false)
 @Out (required=false)
 private Mitarbeiter aktMitarbeiter;

 @DataModel
 private List<Mitarbeiter> mitarbeiterliste;
 @DataModelSelection
 Mitarbeiter selectedMitarbeiter;

 @Factory("mitarbeiterliste")
 public void zeigeMitarbeiter() {

 List result = new LinkedList();
 mitarbeiterliste = new LinkedList<Mitarbeiter>();


 result = getQuery().getResultList();

 Iterator mitarbeiterIter = result.iterator();
 for (;mitarbeiterIter.hasNext();){
 Mitarbeiter rs = (Mitarbeiter)mitarbeiterIter.next();
 mitarbeiterliste.add(rs);
 }
 }

...
...
 public String ende(){
 return "hauptmenu";
 }

 @Begin
 public String neu(){
 aktMitarbeiter = new Mitarbeiter();
 return "editMitarbeiter";
 }

 @Begin
 public String suchen(){
 return "suchenMitarbeiter";
 }

 @Begin
 public String selectMitarbeiter(){
 aktMitarbeiter= (Mitarbeiter) weiterbildungDatabase.createQuery("SELECT m FROM Mitarbeiter m WHERE id = :id")
 .setParameter("id", selectedMitarbeiter.getId())
 .getSingleResult();
 return "editMitarbeiter";
 }
...
...
}

the SearchJSP
...
...
 <t:dataTable id="mitarbeiter"
 var="varMitarbeiter" value="#{mitarbeiterliste}"
 styleClass="listtable"
 headerClass="listtablehead"
 rowClasses="oddrow,evenrow"
 sortColumn="#{mitarbeiteruebersicht.sortColumn}"
 sortAscending="#{mitarbeiteruebersicht.sortAscending}">

 <t:column sortable="true" styleClass="colLeft" style="width:25%;">
 <f:facet name="header">
 <t:commandSortHeader columnName="personalnummer">
 <h:outputText value="Personalnummer"/>
 </t:commandSortHeader>
 </f:facet>
 <h:commandLink id="aendern"value="#{varMitarbeiter.personalnummer}"
 action="#{mitarbeiteruebersicht.selectMitarbeiter}"/>
 </t:column>
...
...
 <div class="cmdBox">
 <h:commandButton id="cmdNeu"
 style="width:110px;margin:5px;"
 action="#{mitarbeiteruebersicht.neu}"
 value="Neu" />
 </div>
 <div class="cmdBox">
 <h:commandButton id="cmdSuchen"
 style="width:110px;margin:5px;"
 action="#{mitarbeiteruebersicht.suchen}"
 value="Suchen" />
 </div>
 <div class="cmdBox">
 <h:commandButton
 style="width:110px;margin:5px;"
 id="cmdEnde"
 action="#{mitarbeiteruebersicht.ende}"
 value="Zurück" />
 </div>
...
...
The EditBean:

@Name("mitarbeiteredit")
@Stateful
@Conversational(ifNotBegunOutcome="mitarbeiteruebersicht")
@LoggedIn

public class MitarbeiterEditBean
 implements MitarbeiterEdit{

 @In (create=true)
 EntityManager weiterbildungDatabase;

 @In @Out
 private Mitarbeiter aktMitarbeiter;
...
...
 @End
 @Remove @Destroy
 public String ende() {
 if (aktMitarbeiter.getId() != 0){
 weiterbildungDatabase.refresh(aktMitarbeiter);
 }
 return "mitarbeiterUebersicht";
 }
...
...
}

[pmuir]

Please post the exception!

[sws42]

2006-10-24 11:06:49,582 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[/weiterbildung].[Faces Servlet]] Servlet.service() for servlet Faces Servlet threw exception
javax.faces.FacesException: Cannot get value for expression '#{varMitarbeiter.kostenstellen.name}'
 at org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(ServletExternalContextImpl.java:435)
 at org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHandlerImpl.java:234)
 at org.jboss.seam.jsf.SeamViewHandler.renderView(SeamViewHandler.java:59)
 at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:384)
 at javax.faces.webapp.FacesServlet.service(FacesServlet.java:138)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:144)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.jboss.seam.servlet.SeamRedirectFilter.doFilter(SeamRedirectFilter.java:30)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
 at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
 at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
 at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
 at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
 at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
 at java.lang.Thread.run(Thread.java:595)
Caused by: javax.faces.el.EvaluationException: Cannot get value for expression '#{varMitarbeiter.kostenstellen.name}'
 at org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:402)
 at javax.faces.component.UIOutput.getValue(UIOutput.java:77)
 at org.apache.myfaces.shared_impl.renderkit.RendererUtils.getStringValue(RendererUtils.java:217)
 at org.apache.myfaces.renderkit.html.HtmlLabelRenderer.encodeBegin(HtmlLabelRenderer.java:78)
 at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:512)
 at org.apache.myfaces.shared_tomahawk.renderkit.RendererUtils.renderChild(RendererUtils.java:433)
 at org.apache.myfaces.shared_tomahawk.renderkit.RendererUtils.renderChildren(RendererUtils.java:419)
 at org.apache.myfaces.shared_tomahawk.renderkit.RendererUtils.renderChild(RendererUtils.java:440)
 at org.apache.myfaces.renderkit.html.ext.HtmlTableRenderer.renderColumnBody(HtmlTableRenderer.java:588)
 at org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlTableRendererBase.encodeColumnChild(HtmlTableRendererBase.java:282)
 at org.apache.myfaces.renderkit.html.ext.HtmlTableRenderer.encodeColumnChild(HtmlTableRenderer.java:496)
 at org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlTableRendererBase.encodeInnerHtml(HtmlTableRendererBase.java:258)
 at org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlTableRendererBase.encodeChildren(HtmlTableRendererBase.java:123)
 at org.apache.myfaces.renderkit.html.ext.HtmlTableRenderer.encodeChildren(HtmlTableRenderer.java:171)
 at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:524)
 at javax.faces.webapp.UIComponentTag.encodeChildren(UIComponentTag.java:480)
 at javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:361)
 at org.apache.myfaces.shared_tomahawk.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTagBase.java:54)
 at org.apache.jsp.mitarbeiterUebersicht_jsp._jspx_meth_t_dataTable_0(mitarbeiterUebersicht_jsp.java:461)
 at org.apache.jsp.mitarbeiterUebersicht_jsp._jspx_meth_h_form_1(mitarbeiterUebersicht_jsp.java:329)
 at org.apache.jsp.mitarbeiterUebersicht_jsp._jspx_meth_f_view_0(mitarbeiterUebersicht_jsp.java:188)
 at org.apache.jsp.mitarbeiterUebersicht_jsp._jspService(mitarbeiterUebersicht_jsp.java:112)
 at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
 at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332)
 at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
 at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:672)
 at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:463)
 at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:398)
 at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:301)
 at org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(ServletExternalContextImpl.java:416)
 ... 28 more
Caused by: javax.faces.el.EvaluationException: Exception getting value of property name of base of type : de.hydro.gv.weiterbildung.entities.Kostenstellen_$$_javassist_51
 at org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.java:96)
 at org.apache.myfaces.el.ELParserHelper$MyPropertySuffix.evaluate(ELParserHelper.java:532)
 at org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
 at org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:383)
 ... 62 more
Caused by: javax.faces.el.EvaluationException: Bean: de.hydro.gv.weiterbildung.entities.Kostenstellen_$$_javassist_51, property: name
 at org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.java:442)
 at org.apache.myfaces.el.PropertyResolverImpl.getValue(PropertyResolverImpl.java:82)
 ... 65 more
Caused by: java.lang.reflect.InvocationTargetException
 at sun.reflect.GeneratedMethodAccessor204.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
 at java.lang.reflect.Method.invoke(Method.java:585)
 at org.apache.myfaces.el.PropertyResolverImpl.getProperty(PropertyResolverImpl.java:438)
 ... 66 more
Caused by: org.hibernate.LazyInitializationException: could not initialize proxy - the owning Session was closed
 at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:60)
 at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:111)
 at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:196)
 at de.hydro.gv.weiterbildung.entities.Kostenstellen_$$_javassist_51.getName(Kostenstellen_$$_javassist_51.java)
 ... 70 more