[Zope] How about create another method other than index_html to get content in OFS::File?

[iap_y2fun.com]

Dear all,
My problem is that : I have a ZClass based on OFS::File.
I need to override the default index_html for my own purpose.
After I created my own index_html, I found myself can't access the content
of that object.
Since:
1. I have no way to access the original method index_html of the base class
2. In OFS::File, There is no other method than index_html to access the
content of this object.
That's why I modify Image.py and add one line:
getContent=index_html
It's work for me.
I don't think it's a good idea, since it's quick and dirty.
Is there any better way to do this?

Thanks

Iap, Singuan