Example decision node with bean shell script| JBoss.org Content Archive (Read Only)

1. Re: Example decision node with bean shell script

ziya Sep 14, 2005 8:16 AM (in response to ziya)

Hi there,

This is the example:

 <decision name="edit">
 <transition name="edityes" to="editing">
 <condition>[CDATA[ not okay ]]</condition>
 </transition>
 <transition name="editno" to="publish">
 <condition>[CDATA[ okay ]]</condition>
 </transition>
 </decision>

--Ziya

2. Re: Example decision node with bean shell script

eruiz Sep 16, 2005 2:08 AM (in response to ziya)

We are using conditions like this:

 <decision name="isNull">
 <transition name="tr1" to="tr1">
 <condition>
 executionContext.getVariable("techReserves") != null
 </condition>
 </transition>
 <transition name="tr2" to="tr2">
 <condition>
 executionContext.getVariable("techReserves") == null
 </condition>
 </transition>
 </decision>

3. Re: Example decision node with bean shell script

sak Sep 22, 2005 1:00 AM (in response to ziya)

hi

im not been abel to implement the decision node as its giving me error my processdefinition.xml file is

........

<decision name="Check color">
 <transition name="tr1" to="select color again">
 <condition>executionContext.getVariable("color")=="red"
 </condition>
 </transition>
 <transition name="tr2" to="Check color slected">
 <condition>
 executionContext.getVariable("color")=="blue"
 </condition>
 </transition>
 </decision>

<task-node name="Check color slected">
 <task swimlane="Head">
 <controller>
 <variable name="color"/>
 </controller>
 </task>
 <transition name="tr1" to="end1"></transition>
 </task-node>
 <task-node name="select color again">
 <task swimlane="Employee">
 <controller>
 <variable name="color"/>
 </controller>
 </task>

The error i get is

run(Thread.java:534)
java.lang.RuntimeException: decision 'Check color' selected non existing transition 'null'
 at org.jbpm.graph.node.Decision.execute(Decision.java:92)
 at org.jbpm.graph.def.Node.enter(Node.java:284)
 at org.jbpm.graph.def.Transition.take(Transition.java:92)
 at org.jbpm.graph.def.Node.leave(Node.java:349)
 at org.jbpm.graph.node.TaskNode.leave(TaskNode.java:167)
 at org.jbpm.graph.exe.Token.signal(Token.java:127)
 at org.jbpm.graph.exe.Token.signal(Token.java:92)
 at org.jbpm.taskmgmt.exe.TaskInstance.end(TaskInstance.java:341)
 at org.jbpm.taskmgmt.exe.TaskInstance.end(TaskInstance.java:272)
 at org.jbpm.webapp.bean.TaskBean.saveAndClose(TaskBean.java:122)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
 at java.lang.reflect.Method.invoke(Method.java:324)
 at org.apache.myfaces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:138)
 at org.apache.myfaces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:62)
 at javax.faces.component.UICommand.broadcast(UICommand.java:106)

do you have different implementation of decision node?
please help i`m stuck

thanks

4. Re: Example decision node with bean shell script

kukeltje Sep 22, 2005 2:57 AM (in response to ziya)

if both conditions resolve to 'false' there is no transition taken and probably you get this error (just a first quick guess)

5. Re: Example decision node with bean shell script

sak Sep 22, 2005 3:57 AM (in response to ziya)

Hi
Thanks first for prompt reply Ronalds..you are correct to point that the both of the conditions in decision must be evaluating to false but i donno know why its happeniong although im fufilling one of the condition (i:e making it true) here is the stck trace

13:15:03,834 DEBUG [TaskBean] Submitted button:Save and Close Task
13:15:03,834 DEBUG [GraphElement] event 'task-end' on 'Task(start)' for 'Token(/)'
13:15:03,834 DEBUG [TaskInstance] completion of task 'start' results in taking the default transition
13:15:03,850 DEBUG [GraphElement] event 'before-signal' on 'StartState(start)' for 'Token(/)'
13:15:03,850 DEBUG [GraphElement] event 'node-leave' on 'StartState(start)' for 'Token(/)'
13:15:03,850 DEBUG [GraphElement] event 'transition' on 'Transition(1fef1a0)' for 'Token(/)'
13:15:03,850 DEBUG [GraphElement] event 'node-enter' on 'Decision(Check color)' for 'Token(/)'
13:15:03,850 DEBUG [Script] script input: {taskInstance=null, color=blue, node=Decision(Check color), my favourite=nothing, token=Token(/), task=null,
 executionContext=ExecutionContext[Token(/)]}
13:15:04,006 DEBUG [Script] script output: {decision_condition_result=false}
13:15:04,006 DEBUG [Script] script input: {taskInstance=null, color=blue, node=Decision(Check color), my favourite=nothing, token=Token(/), task=null,
 executionContext=ExecutionContext[Token(/)]}
13:15:04,006 DEBUG [Script] script output: {decision_condition_result=false}
13:15:04,006 ERROR [MethodBindingImpl] Exception while invoking expression #{taskBean.saveAndClose}
java.lang.RuntimeException: decision 'Check color' selected non existing transition 'null' at org.jbpm.graph.node.Decision.execute(Decision.java:92)
 at org.jbpm.graph.def.Node.enter(Node.java:284)
 at org.jbpm.graph.def.Transition.take(Transition.java:92)
 at org.jbpm.graph.def.Node.leave(Node.java:349)
 at org.jbpm.graph.node.StartState.leave(StartState.java:73)

as you see its reading the process variable color as blue and in the decison ode i have specified the transition.
please comment on that
any help will be appreciated..

6. Re: Example decision node with bean shell script

kukeltje Sep 22, 2005 4:15 AM (in response to ziya)

wrong programming language ;-)

== "blue" must be .equals("blue")

Probaly needs some casting to string as well.

7. Re: Example decision node with bean shell script

sak Sep 22, 2005 8:06 AM (in response to ziya)

Thank you again Ronalds i corrected the error and itsworking fine..!!!!
here is the code for others if needed

<decision name="Check color">
<transition name="tr1" to="select color again">
 <condition>
 executionContext.getVariable("color").toString().equals("red")
 </condition>
</transition>
 <transition name="tr2" to="Check color slected">
 <condition>
 executionContext.getVariable("color").toString().equals("blue")
 </condition>
</transition>
 </decision>

The values must be casted to String!!!!

8. Re: Example decision node with bean shell script

sak Sep 22, 2005 9:07 AM (in response to ziya)

hi
is it possible to check two conditions inside the decision node ?
like

executionContext.getVariable("color").toString().equals("red")||executionContext.getVariable("color")==null

that is if the process variable is null or the process variable equals to red(say)?
when i am doing its throwing up errors

 18:16:18,846 INFO [STDOUT] Caused by: Sourced file: inline evaluation of: ``decision_condition_result = ( executio
xt.getVariable("color").toStr . . . '' : null : at Line: 2 : in file: inline evaluation of: ``decision_condition_result = (
executionContext.getVariable("color").toStr . . . '' : .toString ( )

Target exception: java.lang.NullPointerException: Attempt to invoke method toString on null value
18:16:18,846 INFO [STDOUT] at bsh.UtilTargetError.toEvalError(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.UtilEvalError.toEvalError(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.Reflect.invokeObjectMethod(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.BSHPrimarySuffix.doName(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.BSHPrimarySuffix.doSuffix(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.BSHPrimaryExpression.eval(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.BSHPrimaryExpression.eval(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.BSHBinaryExpression.eval(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.BSHPrimaryExpression.eval(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.BSHPrimaryExpression.eval(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.BSHAssignment.eval(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.Interpreter.eval(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.Interpreter.eval(Unknown Source)
18:16:18,846 INFO [STDOUT] at bsh.Interpreter.eval(Unknown Source)
18:16:18,846 INFO [STDOUT] at org.jbpm.graph.action.Script.eval(Script.java:108)
18:16:18,846 INFO [STDOUT] ... 53 more
18:16:18,846 ERROR [[/jbpm]] Root cause: can't evaluate beanshell script 'decision_condition_result = (
 executionContext.getVariable("color").toString().equals("red")||executionContext.getVariable("color")==null
 );'
java.lang.RuntimeException: can't evaluate beanshell script 'decision_condition_result = (
 executionContext.getVariable("color").toString().equals("red")||executionContext.getVariable("color")==null
 );'
tion.Script.eval(Script.java:117)

is there examples to implement the decision using scripts or handler class??
any help will be highly appreciated..
thanks

9. Re: Example decision node with bean shell script

kukeltje Sep 22, 2005 1:24 PM (in response to ziya)

like many opensource projects, jBPM contains lots of tests (I'm suspecting Tom to have a test-fetish, he once 'ordered' me to say 10 hail-maries because I only *said* to not like writing tests)

If you read the docs http://docs.jboss.com/jbpm/v3/userguide/processmodelling.html#nodetypedecision you can read that what you ask is possible. If you then search the tests, you will find a case under src\java.jbpm.test\org\jbpm\jpdl\exe

hth

JBossDeveloper

Example decision node with bean shell script