While creating my image-metadata module, I was looking for a way to "hook" into the Zip-Upload in DMS.

Unfortunately, there is currently no way to extend the ZipUpload with custom functionality, other than replacing the whole class.

My Use-Case is the following: when a user uploads a ZIP-File with images, I want to automatically perform my metadata import (EXIF & XMP tags) for all contained images.

Problem is that the class info.magnolia.module.dms.gui.ZipUpload (DMS module) does not provide a hook which is called per processed file, and declares it's methods processFile and processEntry as private, making it impossible to extend the class.

Solution:

Add a method like
protected void postProcessFile(Content dmsNode){}
to class ZipUpload, and make sure it gets called from within processFile for each file handled.

Alternatively, just make processFile and processEntry protected rather than private.