7 Replies Latest reply on Sep 28, 2007 10:06 AM by chawax

Complex EL Expressions in JPDL decisions aren't being evalua

dheggie Sep 19, 2007 11:47 AM

Since upgrading to 2.0.0 CR1 (from BETA1) some of the el expressions in my jpdl decisions are causing exceptions. Example:

org.jbpm.JbpmException: couldn't evaluate expression '#{simpleStateMachine.addressValid and empty simpleStateMachine.addressList}'
 org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:43)
 org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:30)
 org.jbpm.graph.node.Decision.execute(Decision.java:95)
 org.jbpm.graph.def.Node.enter(Node.java:318)
 org.jbpm.graph.def.Transition.take(Transition.java:151)
 org.jbpm.graph.def.Node.leave(Node.java:393)
 org.jbpm.graph.exe.Token.signal(Token.java:194)
 org.jbpm.graph.exe.Token.signal(Token.java:157)
 org.jbpm.graph.exe.ProcessInstance.signal(ProcessInstance.java:282)
 org.jboss.seam.pageflow.Pageflow.signal(Pageflow.java:477)
 org.jboss.seam.pageflow.Pageflow.navigate(Pageflow.java:336)
 org.jboss.seam.jsf.SeamNavigationHandler.handleNavigation(SeamNavigationHandler.java:40)
 org.test.navigation.BackNavigationHandler.handleNavigation(BackNavigationHandler.java:30)
 com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:119)
 javax.faces.component.UICommand.broadcast(UICommand.java:383)
 org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:186)
 org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:164)
 org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:352)
 com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:97)
 com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
 com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
 javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
 org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:307)
 org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:100)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
 org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:85)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:44)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:141)
 org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:281)
 org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:60)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:150)
 org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:147)

root cause

javax.el.ELException: Not a Valid Method Expression: ${simpleStateMachine.addressValid and empty simpleStateMachine.addressList}
 org.jboss.el.lang.ExpressionBuilder.createMethodExpression(ExpressionBuilder.java:210)
 org.jboss.el.ExpressionFactoryImpl.createMethodExpression(ExpressionFactoryImpl.java:57)
 org.jboss.seam.bpm.SeamExpressionEvaluator$1.initMethodExpression(SeamExpressionEvaluator.java:54)
 org.jboss.seam.bpm.SeamExpressionEvaluator$1.evaluate(SeamExpressionEvaluator.java:69)
 org.jboss.seam.bpm.SeamExpressionEvaluator.evaluate(SeamExpressionEvaluator.java:35)
 org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:39)
 org.jbpm.jpdl.el.impl.JbpmExpressionEvaluator.evaluate(JbpmExpressionEvaluator.java:30)
 org.jbpm.graph.node.Decision.execute(Decision.java:95)
 org.jbpm.graph.def.Node.enter(Node.java:318)
 org.jbpm.graph.def.Transition.take(Transition.java:151)
 org.jbpm.graph.def.Node.leave(Node.java:393)
 org.jbpm.graph.exe.Token.signal(Token.java:194)
 org.jbpm.graph.exe.Token.signal(Token.java:157)
 org.jbpm.graph.exe.ProcessInstance.signal(ProcessInstance.java:282)
 org.jboss.seam.pageflow.Pageflow.signal(Pageflow.java:477)
 org.jboss.seam.pageflow.Pageflow.navigate(Pageflow.java:336)
 org.jboss.seam.jsf.SeamNavigationHandler.handleNavigation(SeamNavigationHandler.java:40)
 org.test.navigation.BackNavigationHandler.handleNavigation(BackNavigationHandler.java:30)
 com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:119)
 javax.faces.component.UICommand.broadcast(UICommand.java:383)
 org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:186)
 org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:164)
 org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:352)
 com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:97)
 com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
 com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)
 javax.faces.webapp.FacesServlet.service(FacesServlet.java:244)
 org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:307)
 org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:100)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
 org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:85)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:44)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:141)
 org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:281)
 org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:60)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58)
 org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
 org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:150)
 org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:147)

Looking into this further I noticed that the culprit is this method in the org.jboss.seam.bpm.SeamExpressionResolver

public Object evaluate(VariableResolver resolver) throws ELException
 {
 try
 {
 try
 {
 if (me==null && ve==null) initMethodExpression();
 if (me!=null && ve==null) return me.invoke( createELContext(resolver, mapper), new Object[0] );
 }
 catch (javax.el.MethodNotFoundException mnfe)
 {
 if (ve==null) initValueExpression();
 if (ve!=null) return ve.getValue( createELContext(resolver, mapper) );
 }
 throw new ELException();
 }
 catch (javax.el.ELException vele)
 {
 throw new ELException(vele);
 }
 }

The initMethodExpression() method call tries to create a method expression and fails, throwing a ELException which causes us to miss trying to create a value expression. What I think should be changed is rather than catching the javax.el.MethodNotFoundException we should just catch a javax.el.ELException so we have 2 goes at evaluating the expression.

What do people think?

1. Re: Complex EL Expressions in JPDL decisions aren't being ev

pmuir Sep 19, 2007 1:58 PM (in response to dheggie)

Please file a JIRA issue
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2. Re: Complex EL Expressions in JPDL decisions aren't being ev

chawax Sep 25, 2007 7:46 AM (in response to dheggie)
I have the same problem with the following expression on a decision node in a JPDL :

<decision name="motif délégation ?" expression="#{ligneDemandeAbsence.motif eq 'DEL'}"> <transition name="false" to="saisieDatesAbsence"></transition> <transition name="true" to="saisieDateDelegation"></transition> </decision>

It used to work with 2.0.0 BETA1, but it does not work with 2.0.0 CR1
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3. Re: Complex EL Expressions in JPDL decisions aren't being ev

chawax Sep 25, 2007 7:51 AM (in response to dheggie)

Sorry ... Forgot to ask my question : is there a workaround for this, waiting for that bug (?) to be fixed ?
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4. Re: Complex EL Expressions in JPDL decisions aren't being ev

igx89 Sep 25, 2007 9:43 AM (in response to dheggie)

Create a stateless Seam component with an "areEqual" method that takes two Objects and returns obj1.equals(obj2). Then do "#{mycomponent.areEqual(ligneDemandeAbsence.motif, 'DEL')}"
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5. Re: Complex EL Expressions in JPDL decisions aren't being ev

chawax Sep 28, 2007 9:00 AM (in response to dheggie)

Sorry, it was obvious. Thanks for your help.
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6. Re: Complex EL Expressions in JPDL decisions aren't being ev

chawax Sep 28, 2007 9:42 AM (in response to dheggie)

This has not been filed in JIRA, so I did it :
http://jira.jboss.com/jira/browse/JBSEAM-1994
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7. Re: Complex EL Expressions in JPDL decisions aren't being ev

chawax Sep 28, 2007 10:06 AM (in response to dheggie)
It looks like the problem is not limited to JPDL conditions ...

The following EL expression is used in a task description :

<task name="Validation d'un des responsables finals" description="[Validation RP] #{infosDemandeur} (#{datesDemandeAbsence})">

It used to work with Seam 2.0.0.BETA1. But with Seam 2.0.0.CR1, it throws this exception :

Caused by javax.el.ELException with message: "Not a Valid Method Expression: [Validation RP] ${infosDemandeur} (${datesDemandeAbsence})"
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