What is the best way to call REST API from Activiti? Can I use JavaScript's URL redirection?

[bingw]

I am relatively new to Activiti. My question has to be one of the common ones (but I haven't found an answer by Googling):

What is the best way to REST API from Activiti? I chose to use JavaScript's URL redirection logic:
    <scriptTask id="call_remote_biit" name="Trigger Biit Calc" activiti:autoStoreVariables="false">
      <script>window.location.href = "http://remote_rest_call/?key=val";</script>
    </scriptTask>

FYI - I don't need to get the return code from the remote service. All I want to do is to trigger some event which will be tracked separately.

Is this the way to do it or there is better?

Thanks!


Bing

[bingw]

Forgot to mention: the above code did NOT work for me.

[trademak]

A Java service task would be the typical way to do this. Using a script task is also possible, but you would need to use XMLHttpRequest or something similar.

Best regards,

[vahaj]

Hello Bing,
Can you please confirm if you were able to do that ? If yes than how?

[vahaj]

Tijs
when I tried to use XMLHttpRequest in script task than it was giving below error, can you please explain how to fix it?

Caused by: org.activiti.engine.ActivitiException: problem evaluating script: sun.org.mozilla.javascript.internal.EcmaError: ReferenceError: "XMLHttpRequest" is not defined. (<Unknown source>#1) in <Unknown source> at line number 1
at org.activiti.engine.impl.scripting.ScriptingEngines.evaluate(ScriptingEngines.java:89)
at org.activiti.engine.impl.scripting.ScriptingEngines.evaluate(ScriptingEngines.java:73)
at org.activiti.engine.impl.bpmn.behavior.ScriptTaskActivityBehavior.execute(ScriptTaskActivityBehavior.java:63)
at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:60)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerStart.java:52)
at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionCreateScope.execute(AtomicOperationTransitionCreateScope.java:49)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerTake.execute(AtomicOperationTransitionNotifyListenerTake.java:80)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionDestroyScope.execute(AtomicOperationTransitionDestroyScope.java:116)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerEnd.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerEnd.java:35)
at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:450)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:428)
at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performOutgoingBehavior(BpmnActivityBehavior.java:140)
at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performDefaultOutgoingBehavior(BpmnActivityBehavior.java:66)
at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.leave(FlowNodeActivityBehavior.java:44)
at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.execute(FlowNodeActivityBehavior.java:36)
at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:60)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStartInitial.eventNotificationsCompleted(AtomicOperationProcessStartInitial.java:45)
at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStart.eventNotificationsCompleted(AtomicOperationProcessStart.java:62)
at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:96)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:626)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.start(ExecutionEntity.java:378)
at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:111)
at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:37)
at org.activiti.engine.impl.interceptor.CommandInvoker.execute(CommandInvoker.java:24)
at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:57)
at org.activiti.spring.SpringTransactionInterceptor$1.doInTransaction(SpringTransactionInterceptor.java:47)
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:133)
at org.activiti.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:45)
at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:31)
at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:40)
at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:35)
at org.activiti.engine.impl.RuntimeServiceImpl.startProcessInstanceById(RuntimeServiceImpl.java:101)
at org.activiti.explorer.ui.process.listener.StartProcessInstanceClickListener.buttonClick(StartProcessInstanceClickListener.java:71)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:510)
… 34 more
Caused by: javax.script.ScriptException: sun.org.mozilla.javascript.internal.EcmaError: ReferenceError: "XMLHttpRequest" is not defined. (<Unknown source>#1) in <Unknown source> at line number 1
at com.sun.script.javascript.RhinoScriptEngine.eval(RhinoScriptEngine.java:224)
at com.sun.script.javascript.RhinoScriptEngine.eval(RhinoScriptEngine.java:240)
at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:233)
at org.activiti.engine.impl.scripting.ScriptingEngines.evaluate(ScriptingEngines.java:87)
… 108 more
Caused by: sun.org.mozilla.javascript.internal.EcmaError: ReferenceError: "XMLHttpRequest" is not defined. (<Unknown source>#1)
at sun.org.mozilla.javascript.internal.ScriptRuntime.constructError(ScriptRuntime.java:3770)
at sun.org.mozilla.javascript.internal.ScriptRuntime.constructError(ScriptRuntime.java:3748)
at sun.org.mozilla.javascript.internal.ScriptRuntime.notFoundError(ScriptRuntime.java:3833)
at sun.org.mozilla.javascript.internal.ScriptRuntime.name(ScriptRuntime.java:1760)
at sun.org.mozilla.javascript.internal.Interpreter.interpretLoop(Interpreter.java:1785)
at sun.org.mozilla.javascript.internal.Interpreter.interpret(Interpreter.java:849)
at sun.org.mozilla.javascript.internal.InterpretedFunction.call(InterpretedFunction.java:162)
at sun.org.mozilla.javascript.internal.ContextFactory.doTopCall(ContextFactory.java:430)
at com.sun.script.javascript.RhinoScriptEngine$1.superDoTopCall(RhinoScriptEngine.java:116)
at com.sun.script.javascript.RhinoScriptEngine$1.doTopCall(RhinoScriptEngine.java:109)
at sun.org.mozilla.javascript.internal.ScriptRuntime.doTopCall(ScriptRuntime.java:3160)
at sun.org.mozilla.javascript.internal.InterpretedFunction.exec(InterpretedFunction.java:173)
at sun.org.mozilla.javascript.internal.Context.evaluateReader(Context.java:1169)
at com.sun.script.javascript.RhinoScriptEngine.eval(RhinoScriptEngine.java:214)
… 111 more

[jbarrez]

I wouldn't count on XmlHttpRequest being there by default.

You can do http calls with javascript scriptTask, but it's cumbersome … and needs Java classes to work properly.
See for example here : https://github.com/jbarrez/activiti-advanced-scripting/blob/master/src/test/resources/org/activiti/t... (not that I'm actually creating a script in another script … so kinda complicated. But the urlConnection stuff is in there).