Use File field for other content types than Image or File

[espenmn]

No description provided.

[CLAassistant]

All committers have signed the CLA.

[espenmn]

I have a better approach to this, because:

1. Someone could turn off 'required' for file type
2. File attachment could 'disappear' since files are stored on the file system. This is unlikely, but better have a check for it anyway.

So I suggest:

def getFileExt(context):
portal_type = context.portal_type
# First set 'filename' to None, this will prevent error local variable 'filename' referenced before assignment if file is missing
filename = None

#This makes it possible to use with all content that has a 'file'
if hasattr(context, 'file'):
    #Check if content has uploaded file, in case required setting is disabled
    if context.file is not None:
        #Check if file contains data, for use with other content types than Image and File
        filename = context.file.filename if context.file.getSize() and context.file.getSize() > 1 else None

if portal_type == "Image" : 
    filename = context.image.filename if hasattr(context, "image") else None

if portal_type == "File" or portal_type == "Document" :
    filename = context.file.filename if hasattr(context, "file") else None

if filename :
    return filename[filename.rfind('.') + 1:].lower()