I have a page class and a subPage class which extends the page-class.
now i want to decorate the page class with a decorater myPageDecorater.
And the sub class with an other decorater mySubPageDecorater.

In _config.php the decoraters are added like that:

DataObject::add_extension('Page', 'myPageDecorater');
DataObject::add_extension('SubPage ', 'mySubPageDecorater');

The Problem is, the second Decorater is not added. No functions of the DecorationClass can be used...

Is there any other way to add a specific decoration on SubPage?

Thanks for you help, Michael

I'm assuming you didn't put that space after SubPage in your actual code?

e.g. "SubPage " instead of "SubPage"

You're right, that space isn't in the original code...
for further informations, my classes are structed like this:
Page.php

class Page extends SiteTree { ... }

SubPage.php

class SubPage extends Page { ... }

myPageDecorater.php

class myPageDecorater extends DataObjectDecorator{ 
   public function TestFunction(){
      return "TestFunction of myPageDecorater ";
   }
}

mySubPageDecorater.php

class mySubPageDecorater extends DataObjectDecorator{
   public function AnotherTestFunction(){
      return "TestFunction of mySubPageDecorater ";
   }
}

_config.php

...
DataObject::add_extension('Page', 'myPageDecorater');
DataObject::add_extension('SubPage', 'mySubPageDecorater');
...

TestFunction is accessible on both classes, but i can't call AnotherTestFunction.

I'm having a similar problem, so I figured I'd give this thread a bump...

I want to decorate the CalendarEvent class from the Event module, which extends the Page class directly. I've created the extension class:

class MemberEventRole extends DataObjectDecorator {
...
}

and added the extension in the _config.php file of my module:

DataObject::add_extension("CalendarEvent", "MemberEventRole");

The decoration isn't working. Is there something about the order in which DataObjects load that could be causing a problem here? I'm also extending the core Member class in the same _config.php file, and it's working fine...