One final thing, maybe we should call this PojoCommand - since its
both a Pojo and a Command?

Paul

On 8/6/07, Paul Fremantle <[EMAIL PROTECTED]> wrote:
> Asankha
>
> The POJO mediator MUST be instantiated new for each message. Otherwise
> you need to implement some reset() pattern, and I think that makes it
> too complex. Therefore, the model is slightly different to how you
> describe.
>
> CLASS:
> When Synapse calls ClassMediator.init():
> ClassMediator calls
> * m.setX(),
> * m.setY(),
> * optionally init(SynEnv);
>
> When Synapse calls ClassMediator.mediate()
> * ClassMediator calls m.mediate();
>
> POJO
> When Synapse calls PojoMediator.init()
> * PojoMediator can lookup and store Method fields to make invocation
> more efficient.
> [Suppose we define properties X in, Y inout, Z out]
> Synapse calls  PojoMediator.mediate():
> pojoMediator calls:
> *  Mediator.class.newInstance()
> * p.setX(),
> * p.setY(),
> * [optionally init(SynapseEnv)]
> * p.execute(),
> * p.getY(),
> * p.getZ(),
> * [optionally destroy()]
>
> Paul
>
> On 8/6/07, Asankha C. Perera <[EMAIL PROTECTED]> wrote:
> >
> >  Ruwan
> >
> >  Basically this means that the ClassMediator and PojoMediator have almost
> > the same semantics. i.e. all static name/value properties are set on init()
> > by the factory, and all dynamic attributes set before each invocation of the
> > mediate() or the POJO execute method (this name should be configurable via
> > an attribute on the Pojo mediator)
> >
> >  Im +1 for this.. the factories and serializers would handle the persistence
> > appropriately
> >
> >  asankha
> >
> >
> >  Ruwan Linton wrote:
> > Hi Paul,
> >
> >  In order to achieve the serialization we will need to keep the setter
> > informations with both Class and Command (Pojo). That is because, we may set
> > only a set of attributes in those objects rather than setting all of them in
> > the configuration; in which case we must only serialize with the properties
> > that we have set only.
> >
> >  For example if we have a ClassMediator with attributes x, y and z but we
> > set only x and y in the configuration and the CMF (ClassMediatorFactory)
> > will pick these correctly and to serialize the exact behavior we need to
> > know what attributes has been set and what not. So we need to keep this in a
> > list.
> >
> >  Apart from that if we want the expression behavior (that is to set some
> > attributes at the runtime from the message using XPATH) we will have to
> > iterate through the expression set and evaluate those before calling the
> > mediate method (same with the pojo case). If a particular mediator doesn't
> > set any expressions then the behavior is exactly same as the static property
> > case.
> >
> >  If this is OK to proceed, I will go ahead and implement this.
> >
> >  Thanks,
> >  Ruwan.
> >
> >
> > On 8/1/07, Paul Fremantle < [EMAIL PROTECTED]> wrote:
> > > Also I think its clearer. I didn't really understand the point of the
> > > dynamic properties before (Doh!).
> > >
> > > It might be better to call this the <pojo> instead of <command>
> > > because the objects really would be POJOs (i.e. they would not need to
> > > implement any synapse-specific interface.
> > >
> > > For that reason I suggest we use reflection to implement this. (I
> > > looked for a javax....Command interface but couldn't find one). That
> > > means you can write one of these objects without needing any Synapse
> > > JARs in your build path which I think is a good thing.
> > >
> > > Paul
> > >
> > > On 8/1/07, Asankha C. Perera <[EMAIL PROTECTED]> wrote:
> > > > Paul
> > > >
> > > > Yep.. this is certainly good! It would leave the best of both worlds
> > > >
> > > > asankha
> > > >
> > > > Paul Fremantle wrote:
> > > > > I changed the class mediator to only use static properties so that
> > > > > they would be set before the class.init() was called.
> > > > >
> > > > > However, Asankha has pointed out to me that there is another model
> > > > > that the dynamic properties had, which is to use XPath properties to
> > > > > set data on the mediator before it is called, thereby meaning that
> > > > > there is no need for user to need to understand OMElement or
> > > > > MessageContext to write a mediator.
> > > > >
> > > > > I guess I see these as two completely separate ways to write a
> > > > > mediator. In fact I see three potential approaches:
> > > > >
> > > > > 1) mediate(MessageContext mc)
> > > > > 2) set/get XPath data in/out of the message
> > > > > 3) Use ADB or Databinding and write Java based on the message type
> > > > >
> > > > > I'm not sure about the third option - it not very "loosely-coupled"
> > > > > but I can see how it would appeal to Java developers. I'd be happy to
> > > > > leave that till later.
> > > > >
> > > > > However, I think 1 and 2 are really distinct cases.
> > > > >
> > > > > The second model is really something called the Command Pattern. You
> > > > > can read about it here:
> > > > > http://en.wikipedia.org/wiki/Command_pattern
> > > > >
> > http://www.javaworld.com/javaworld/javatips/jw-javatip68.html?page=1
> > > > >
> > > > > Basically this model is where you call:
> > > > >
> > > > > obj.setX(y);
> > > > > obj.setQ(z);
> > > > > obj.setF (e);
> > > > > obj.execute();
> > > > > obj.getX()
> > > > > obj.getQ()
> > > > > obj.getF();
> > > > >
> > > > > It seems like we could define a nice model for this in Synapse:
> > > > > <command class=" org.fremantle.Command"> <!-- class must implement
> > > > > "void execute();" -->
> > > > >    <property name="Name" expression="xpath expression"
> > > > > action="set|get|setAndGet"
> > type="String|float|double|boolean|..."/>
> > > > >    <property name="Symbol" expression="//Symbol" action="get"
> > type="String"/>
> > > > >    <property name="Symbol"
> > expression="/getQuoteResponse/Price[0]"
> > > > > action="set" type="Double"/>
> > > > > </command>
> > > > >
> > > > > Basically what this will do is allow the user to write a real POJO
> > > > > that implements getters and setters as well as the execute(); method.
> > > > > We then call XPaths and set data into the object, then call execute();
> > > > > then we update the message based on data from the getters.
> > > > >
> > > > > Thoughts?
> > > > >
> > > > > Paul
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > ---------------------------------------------------------------------
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> > [EMAIL PROTECTED]
> > > > For additional commands, e-mail: [EMAIL PROTECTED]
> > > >
> > > >
> > >
> > >
> > > --
> > > Paul Fremantle
> > > Co-Founder and VP of Technical Sales, WSO2
> > > OASIS WS-RX TC Co-chair
> > >
> > > blog: http://pzf.fremantle.org
> > > [EMAIL PROTECTED]
> > >
> > > "Oxygenating the Web Service Platform", www.wso2.com
> > >
> > >
> > ---------------------------------------------------------------------
> > > To unsubscribe, e-mail:
> > [EMAIL PROTECTED]
> > > For additional commands, e-mail: [EMAIL PROTECTED]
> > >
> > >
> >
> >
> >
> >  --
> >  Ruwan Linton
> >  http://www.wso2.org - "Oxygenating the Web Services Platform"
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail:
> > [EMAIL PROTECTED] For additional
> > commands, e-mail: [EMAIL PROTECTED]
>
>
> --
> Paul Fremantle
> Co-Founder and VP of Technical Sales, WSO2
> OASIS WS-RX TC Co-chair
>
> blog: http://pzf.fremantle.org
> [EMAIL PROTECTED]
>
> "Oxygenating the Web Service Platform", www.wso2.com
>


-- 
Paul Fremantle
Co-Founder and VP of Technical Sales, WSO2
OASIS WS-RX TC Co-chair

blog: http://pzf.fremantle.org
[EMAIL PROTECTED]

"Oxygenating the Web Service Platform", www.wso2.com

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