I am also getting exceptions when I try to invoke action methods. I actually reproduced the docs example of print.println('Hello World!')

However, when I go invoke an action method with parameters, it craps out. Any idea of what could cause this, because the documentation says I can do the following syntax:

<s:link value="Cancel" action="#{hotelBooking.cancel()}"/>

...
@Transient
 public Double totalUnitCost() {
 double total = 0;
 for(Item item : items) {
 total += item.getUnitCost();
 }
 return total;
 }
...

...
<!-- Total Unit Cost-->
 <h:column>
 <f:facet name="header">
 <h:outputText value="Total Unit Cost" />
 </f:facet>
 <h:outputText value="#{purchase.totalUnitCost()}" />
 </h:column>
...

12:13:31,140 ERROR [STDERR] Dec 1, 2006 12:13:31 PM com.sun.facelets.FaceletViewHandler handleRenderException
SEVERE: Error Rendering View[/viewPurchases.xhtml]
com.sun.facelets.tag.TagAttributeException: /viewPurchases.xhtml @159,58 value="#{purchase.totalUnitCost()}" Error Parsing: #{purchase.totalUnitCost()}
 at com.sun.facelets.tag.TagAttribute.getValueExpression(TagAttribute.java:259)
 at com.sun.facelets.tag.jsf.ValueHolderRule$DynamicValueBindingMetadata.applyMetadata(ValueHolderRule.java:115)
 at com.sun.facelets.tag.MetadataImpl.applyMetadata(MetadataImpl.java:36)
 at com.sun.facelets.tag.MetaTagHandler.setAttributes(MetaTagHandler.java:62)
 at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:140)
 at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
 at com.sun.facelets.tag.jsf.ComponentHandler.applyNextHandler(ComponentHandler.java:295)
 at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:165)
 at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
 at com.sun.facelets.tag.jsf.ComponentHandler.applyNextHandler(ComponentHandler.java:295)
 at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:165)
 at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
 at com.sun.facelets.tag.jsf.ComponentHandler.applyNextHandler(ComponentHandler.java:295)
 at com.sun.facelets.tag.jsf.ComponentHandler.apply(ComponentHandler.java:165)
 at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
 at com.sun.facelets.tag.ui.DefineHandler.apply(DefineHandler.java:58)
 at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:128)
 at com.sun.facelets.impl.DefaultFaceletContext$TemplateManager.apply(DefaultFaceletContext.java:306)
 at com.sun.facelets.impl.DefaultFaceletContext.includeDefinition(DefaultFaceletContext.java:279)
 at com.sun.facelets.tag.ui.InsertHandler.apply(InsertHandler.java:68)
 at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
 at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
 at com.sun.facelets.tag.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:47)
 at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
 at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:248)
 at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:294)
 at com.sun.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:273)
 at com.sun.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:143)
 at com.sun.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:113)
 at com.sun.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:49)
 at com.sun.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:25)
 at com.sun.facelets.impl.DefaultFacelet.apply(DefaultFacelet.java:95)
 at com.sun.facelets.FaceletViewHandler.buildView(FaceletViewHandler.java:510)
 at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:553)
 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.jboss.seam.servlet.SeamRedirectFilter.doFilter(SeamRedirectFilter.java:32)
 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.SeamExceptionFilter.doFilter(SeamExceptionFilter.java:46)
 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.jboss.web.tomcat.tc5.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:156)
 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:619)
Caused by: javax.el.ELException: Error Parsing: #{purchase.totalUnitCost()}
 at com.sun.el.lang.ExpressionBuilder.createNodeInternal(ExpressionBuilder.java:140)
 at com.sun.el.lang.ExpressionBuilder.build(ExpressionBuilder.java:157)
 at com.sun.el.lang.ExpressionBuilder.createValueExpression(ExpressionBuilder.java:201)
 at com.sun.el.ExpressionFactoryImpl.createValueExpression(ExpressionFactoryImpl.java:74)
 at com.sun.facelets.tag.TagAttribute.getValueExpression(TagAttribute.java:256)
 ... 60 more
Caused by: com.sun.el.parser.ParseException: Encountered "(" at line 1, column 25.
Was expecting one of:
 "}" ...
 "." ...
 "[" ...
 ">" ...
 "gt" ...
 "<" ...
 "lt" ...
 ">=" ...
 "ge" ...
 "<=" ...
 "le" ...
 "==" ...
 "eq" ...
 "!=" ...
 "ne" ...
 "&&" ...
 "and" ...
 "||" ...
 "or" ...
 "*" ...
 "+" ...
 "-" ...
 "?" ...
 "/" ...
 "div" ...
 "%" ...
 "mod" ...

 at com.sun.el.parser.ELParser.generateParseException(ELParser.java:1651)
 at com.sun.el.parser.ELParser.jj_consume_token(ELParser.java:1531)
 at com.sun.el.parser.ELParser.DeferredExpression(ELParser.java:134)
 at com.sun.el.parser.ELParser.CompositeExpression(ELParser.java:61)
 at com.sun.el.lang.ExpressionBuilder.createNodeInternal(ExpressionBuilder.java:103)
 ... 64 more

Hmm, I think I know the problem. I am trying to access action methods with the Enhanced EL in an Entity, which probaly is not going to work since I'm assuming EL assumes everything is field level access.

So the reason I got one of the examples working before is because I did it from an EJB3 and not an entity.

If I am right, maybe the docs should be specific that action methods can not be accessed within entity beans.

Actually, the way I'm getting around this is to define a Transient field with the name of the action method.

so:

...
@Transient private Double totalUnitCost;
...
@Transient
 public Double getTotalUnitCost() {
 double total = 0;
 for(Item item : items) {
 total += item.getUnitCost();
 }
 return total;
 }
...

<!-- Total Unit Cost-->
 <h:column>
 <f:facet name="header">
 <h:outputText value="Total Unit Cost" />
 </f:facet>
 <h:outputText value="#{purchase.totalUnitCost}" />
 </h:column>

I was originally trying to get an action method working:

I wanted purchase.totalUnitCost() to map to the method public Double totalUnitCost()

I only had to convert it to ValueBinding because I couldn't get the action method to work.

Clarification: #{purchase.totalUnitCost()} to map to public Double totalUnitCost()