how to i can change wagtail cms page tag before save

Question

How can I change wagtail page tag before saving?

I can change the title by overriding save() like this-

class ProductPageTag(TaggedItemBase):
    content_object = ParentalKey('product.ProductPage',related_name='tagged_items')

class ProductPage(Page):
    body = StreamField(BodyStreamBlock)
    tags = ClusterTaggableManager(through=ProductPageTag, blank=True)
    def save(self, *args, **kwargs):
      self.title = "my title" # work
      self.tags = "test,test2,test3" #not work
      super(ProductPage, self).save()

but I don't know how to change the tag list.

Answer 1

I Found the Answer :D

just need change

self.tags = "test,test2,test3"

to

self.tags.add('test',"test2","test3")

final code

class ProductPageTag(TaggedItemBase):
    content_object =ParentalKey('product.ProductPage',related_name='tagged_items')

class ProductPage(Page):
    body = StreamField(BodyStreamBlock)
    tags = ClusterTaggableManager(through=ProductPageTag, blank=True)

    def save(self, *args, **kwargs):
      self.title = "my title" # work
      self.tags.add('test',"test2","test3") #work
      super(ProductPage, self).save()