Upon development proces you often meet ManyToMany relations that throw errors in templates. I prefer to feed everything to context and play with it there.
This kind of error appears when you iterate through a model's ManyToMany field. To fix it just add a related 'all' manager through dot syntax. Like so:
Model:
View/Tag or else, that creates context:
Template causing the error:
Template without the error:
I wrote this article for myself for remembering. I always forget this little thing. But if this method works for your case fill free to drop a "thankyou" comment or +1.
This kind of error appears when you iterate through a model's ManyToMany field. To fix it just add a related 'all' manager through dot syntax. Like so:
Model:
class BannerImage(models.Model): image = models.ImageField(upload_to="somedir")
def get_image_url(self):
return 'Image url here' class Banner(models.Model): name = models.CharField(max_length=250, null=True) images = models.ManyToManyField(BannerImage)
View/Tag or else, that creates context:
banner = get_object_or_404(Banner, pk=1) return {'banner': banner,}
Template causing the error:
{% for image in banner.images %} <img src="{{ image.get_image_url }}" /> {% endfor %}
Template without the error:
{% for image in banner.images.all %} <img src="{{ image.get_image_url }}" /> {% endfor %}
I wrote this article for myself for remembering. I always forget this little thing. But if this method works for your case fill free to drop a "thankyou" comment or +1.
Thanks - I couldn't figure this out.
ReplyDeleteThanks. Also you need to use .all() to use this in .py files
ReplyDelete