Plone override the logo viewlet in plone 5.2 & 6

1

Hi!

in this guide: Tutorial: Overriding Viewlets — Plone Documentation v5.2

the code is:

class TitleViewlet(ViewletBase):
    index = ViewPageTemplateFile('title.pt')

    def update(self):
          [...]

while in plone 5.2 and plone 6 the original code is:

class LogoViewlet(ViewletBase):
    index = ViewPageTemplateFile("logo.pt")

    def update(self):
        super(LogoViewlet, self).update()
        [...]

What is the right approach? Is the super part mandatory?

2

Possibly not since you derive from the same base class.

3

Yes, but calling .update() on the base class set some local properties. If I remove it:

AttributeError: 'LogoViewlet' object has no attribute 'portal_state'

the super update method does this:

def update(self):
    self.portal_state = getMultiAdapter(
        (self.context, self.request), name=u"plone_portal_state"
    )
    self.site_url = self.portal_state.portal_url()
    self.navigation_root_url = self.portal_state.navigation_root_url()
4

Then you need to replicate the related code from the update() implementation

1 Like
5

The TitleViewlet should use super() as well. It currently redefines portal_state in plone.app.layout/common.py at cc88fde5ec40ccec8d5128ee5db17f226125b661 · plone/plone.app.layout · GitHub.

As a rule of thumb: if the base class has a method you want to extend or use a return value from it, use super(); If you want to override it, don't.

2 Likes