问题
In a Django model that cannot subclass Page
, I want to convert an existing ImageField to use Wagtail images. I have redefined the field as:
avatar = models.ForeignKey(
'wagtailimages.Image', null=True, on_delete=models.SET_NULL, related_name='+'
)
The user needs to be able to upload an image to their profile view. In forms.py for the Django view, I have:
avatar = forms.ImageField(
label='Your Photo', required=False,
error_messages={'invalid': "Image files only"}, widget=forms.FileInput())
When I upload an image to the view, it crashes on:
Cannot assign "<InMemoryUploadedFile: filename.jpg (image/jpeg)>":
"UserProfile.avatar" must be a "Image" instance.
I'm pretty sure the problem is the field definition in the form, but I can't figure out what the right definition should be.
I know that I'll need to manually attach the image to the UserProfile and the Collection, but need to get past this error first. Or is it a bad idea to try and use individual WT fields in a non-WT model? Thanks.
回答1:
The problem here is that the avatar
ForeignKey field on your model is expecting to receive an instance of the wagtailimages.Image
model. The ImageField
on the form isn't capable of providing this - it only provides a file object. To make this work, you'll need to set up your form (which I'm assuming is a ModelForm) to create the wagtailimages.Image
object at the same time as your own model. It should be possible to do this with a custom save
method as follows:
- Rename
avatar = forms.ImageField
to something that doesn't clash with theavatar
model field, such asavatar_image
- Ensure that
avatar_image
is included in your ModelForm'sfields
definition, butavatar
isn't. At this point,avatar_image
is just an extra field on the form, with no connection to the model. Define the following
save
method on the ModelForm:from wagtailimages.models import Image def save(self, commit=False): if not commit: raise Exception("This form doesn't support save(commit=False)") # build the instance for this form, but don't save it to the db yet instance = super(MyForm, self).save(commit=False) # create the Image object avatar = Image.objects.create( file=self.cleaned_data['avatar_image'], title="Image title" # you may need to add more fields such as collection to make it a valid image... ) # attach the image to your final model, and save instance.avatar = avatar instance.save() return instance
来源:https://stackoverflow.com/questions/42544797/uploading-wagtail-images-from-outside-of-wagtail