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From Leszek Gawron <>
Subject Re: JXTG and caching
Date Wed, 02 Jun 2004 10:03:28 GMT
Upayavira wrote:
> I think you are getting something wrong here.
> If you have two objects bizObj1 and bizObj2, and you pass these to a 
> pipeline that does
> JXT(bizObj1)->tx->tx-\
>                      >-aggregate->tx->serlialize
> JXT(bizObj2)->tx->tx-/
> You would do:
> sendPage("your-pipeline", {"bizObj1": bizObj1, "bizObj2": bizObj2});
It feel like it breaks SoC a little as controller has to know how your view is 
rendered. Also if you change your rendering to 3 aggregate parts you have to 
make appropriate changes in controller.

> Then, your objects would implement:
> bizObj.getValidity()
> And the jxtemplate would ask the business object for its validity as 
> Sylvain has described.
> Thus, if bizObj1 says it can be cached, and bizObj2 says it can't, then 
> at least one of your two aggregated pipelines doesn't need to be 
> generated, which will speed up processing.
> Remember, the jxtemplate pulls the validity from the business object. 
> The flow doesn't need to even know that caching might be happening (and 
> in fact _shouldn't_ know it is happening). If you have to write 
> flowscript to deal with this, then something is probably wrong.
> If your business object takes an age to instantiate, and you can decide 
> whether or not to instantiate it based upon request parameters, then 
> wrap it in a lighter component that does (in pseudocode):
> lightObject.getValidity() {
>  return request.parameters["a"]+ request.parameters["b"];
> }
> lightObject.getHeavyBusinessObject() {
>  if (this.heavyBusinessObject == null) {
>     this.heavyBusinessObject = HeavyBusinessObjectBuilder.newObject();
>  }
>  return this.heavyBusinessObject;
> }
> Then, in your jxt, you use Sylvains 
> jx:cacheKey="lightObject.getValidity()" construct, and then later in 
> your jxt, you access your heavy object with 
> #{/lightObject/HeavyObject/property1}. This latter expression will only 
> be invoked if the page is not cached.
> Does that make sense?
Now it does. I never thought of a wrapper. It's real pleasure to discuss with 
you all.

> It seems to me that Sylvains suggested extension of jxt has a great deal 
> of power in it.
OK. Then I'll continue my work and try to provide the appropriate patch as I 
have already started to make needed changes.

Leszek Gawron                            

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