Maya python api multiply node

Question

So I'm creating a basic multiply node which can have multiple inputs.

I want to multiply 2 attributes and get output in third attribute. It is working fine but its not live.

so basically I have created 3 attribute 2 input 1 output and created compound attribute and added all 3 in that.

I can only see output getting updated when I de-select and re-select node in node editor. but its not actively working.

Thanks

    input1VecAttr = om.MObject()
    input2VecAttr = om.MObject()
    outputVecAttr = om.MObject()
    uniqueArrayComp = om.MObject()


    def __init__(self):
        OpenMayaMPx.MPxNode.__init__(self)
    

    def compute(self, plug, dataBlock):
        
        
        if plug == arrayTest2.uniqueArrayComp:


            #input value
            #arrayDataHandle = om.MArrayDataHandle(dataBlock.inputArrayValue(arrayTest2.uniqueArrayComp))
            arrayDataHandle = dataBlock.inputArrayValue(arrayTest2.uniqueArrayComp)
            elementCount = arrayDataHandle.elementCount()



            #output array

            for i in range(elementCount):


    

                bindData = arrayDataHandle.inputValue()

                myElementHandleChildInput1 = bindData.child(arrayTest2.input1VecAttr)
                inVal1 = myElementHandleChildInput1.asFloat()
                myElementHandleChildInput2 = bindData.child(arrayTest2.input2VecAttr)
                inVal2 = myElementHandleChildInput2.asFloat()

                output = inVal1 * inVal2


                myElementHandleChildOutput = bindData.child(arrayTest2.outputVecAttr)
                myElementHandleChildOutput.setFloat(output)
                
                print i
                try:
                    arrayDataHandle.next()
                except:
                    pass


  
            dataBlock.setClean(plug)