Re: CocoonTask

[C�dric Damioli]

Upayavira wrote:

C�dric Damioli wrote:

Upayavira wrote:

C�dric Damioli wrote:

I'm wondering if there's any reasons why there's no access (via 
protected method or fields or whatever) to the CocoonBean.


Basically, the CocoonBean is invoked via reflection, using a 
different classloader. Now, I'm no reflection expert, and calling 
each getter and setter one at a time using reflection seemed 
unreasonably complex. So, I chose to create a Delegate class, 
invoke that with reflection, and have that do the real work. 


I'm ok with the concept of "single entry point", but what I wanted 
is the possibility to act on the CocoonBean before processing the 
different uris.
Imagine you have a Java method returning a Collection of uris to be 
processed, you may want to directly fill the CocoonBean with this 
Collection, instead of dynamically re-creating the CocoonBean 
configuration. 


So you're saying that you've got code running in other Ant tasks, and 
that Java code wants to make collection data available to the 
CocoonTask? How would it get there? Could you include a sample of the 
code that your CocoonAntDelegate would use? 


The AntDelegate I currently use is basically like :

public process (Document xconf, String uriGroup, 
org.apache.tools.ant.Project project)
{
       CocoonBean cocoon = new CocoonBean();

      // Adding some target URIs, coming from anywhere (database, Ant 
properties, environment, ...)
      cocoon.addTarget(...);

      // Adding some listeners
      cocoon.addListener(...);
      BeanConfigurator.configure(...);

       cocoon.initialize();
       cocoon.process();
       cocoon.dispose();
}
I see the AntDelegate as a bridge between Ant and Cocoon worlds : it is 
why I included the Project as third argument. But I think it's not 
enough : the AntDelegate could be extensible, and become a "real" class 
(not only with a single static method), or even an interface with the 
current AntDelegate as a default implementation.

BTW, i don't see why you used an OutputStreamListener as last argument 
of BeanConfigurator.configure()
IIUC, the OutputStreamListener mixes two roles : a role of 
DefaultListener (logging to stdout) and a role of reporter (generating a 
report for broken-links), actually used by the BeanConfigurator. May 
this Listener be split into two : a DefaultListener and a 
BrokenLinksListener ?



I wanted to use it directly to add BeanListeners, eventually add 
targets, and so on...


What sort of listeners would you like to add? If you want to 
specify a different listener, I would suggest coming up with a 
generic way to specify listeners and add that to the 
BeanConfigurator, so that all users of the CLI and Ant task get to 
benefit. 


I wanted to add org.apache.cocoon.bean.BeanListener implementations 
to my instance of CocoonBean.
The problem with adding this at BeanConfigurator level is that we 
can't interact with the Ant Project (or its Properties), for 
example, or whatever is not directly tied to the Bean.


Sorry, I don't understand. What do you mean that you can't interact 
with the Ant project? You can use Ant properties in the Cocoon task. 
Are you looking for a greater integration? 
Let me give an example :
I have a Java class able to retrieve somewhere (in a DB with JDBC, or in 
a XML file, ...) a list of uris to be processed by the CocoonBean.
I have to instanciate this class, set some parameters and finally asking 
it for the URIs list.

I'm not an Ant expert, but I think it would be hard to do it easily in 
pure Ant. With my new AntDelegate, it's very easy.



I think you're getting at something here. What I'd like to see is the 
Ant task using Ant's methods and approaches to configure itself, 
rather than using Java - putting your code into Java can hide it, as 
far as the Ant script is concerned.

IMHO, the best way to "open" the CocoonTask is to allow subclasses 
to change the delegate class 
("org.apache.cocoon.bean.helpers.AntDelegate" at the moment) and 
to give this delegate access to the calling Ant project.


So you supply a piece of java that configures the bean before 
running? Hmmm, I would much rather extend the xconf format to be 
able to add everything you want. The CocoonTask really should not 
assume any Java knowledge in its users. 


Of course, but I think that the xconf format is already very 
complete for users who do not want to write any Java code : all the 
setters of the Bean have their counterparts in the xconf format 
(except the addBuildListener). The next step would be to add a 
syntax to add Java entry points (such as  : <listener class="..."/> 
or <configurator class="..."/>) but users of such a syntax would 
have to write Java code anyway.

What I proposed is to have the possibility to extend the CocoonTask 
(or the AntDelegate, or both) to provide access to users (such as me 
:-) ) who want to have more control over the Bean.


I'm okay with that, but I'd like to see if it is possible to keep that 
sort of configuration out of Java, until really necessary.

I'd love to see ways of dynamically creating your list of URIs, and a 
range of other bean listeners that do other things, other than the 
default one, etc ,etc. 
I have written a few.
The Ant script containing my Cocoon Task is running in a separate Thread 
and executes periodically. The execution may take many hours. I have 
written a BeanListener which stores the current state of the build : 
number of pages currently processed, stats on their contents, ..., so 
that a user connected to the monitoring page may follow the build.



Regards, Upayavira


C�dric