Django how to iterate querysets of two subclasses in template? - django

Question

I am using django-model-utils for inheritance Managers. I want to get result of both sub-classes with one dictionary without getting duplicates.
models.py
class Images(models.Model):
user = models.ForeignKey(settings.AUTH_USER_MODEL, related_name='images_created', on_delete=models.CASCADE)
created = models.DateTimeField(auto_now_add=True, null=True, blank=True)
objects = InheritanceManager()
class Postimg(Images):
user_img= models.ImageField(upload_to='images/%Y/%m/%d', null=True, blank=True)
class Postsms(Images):
user_message = models.CharField(max_length=500,blank=True)
views.py
def home(request):
all_post = Images.objects.all().order_by('-created').select_subclasses()
return render(request, 'copybook/home.html',{ 'all_post':all_post})
copybook/home.html
{% for foo in all_post %}
<hr>
<br> SMS by: <p>{{ foo.user}} __ {{ foo.created }}</p>
<h2>{{ foo.user_message }}</h2>
<hr>
<br> IMAGE by: <p>{{ foo.user}} __ {{ foo.created }}</p>
<img src="{{ foo.user_img.url }}"width="250">
{% endfor %}
I expect the result when I upload an image or message that should get top at home page, but now when I upload an image, a blank message also gets iterated.
I think the problem is in my home.html, because I do not know how to iterate
over two sub-classes with a single for loop without getting duplicates.

Answer 1

In your template, you are processing every item as if it were both a message and an image. That's why you get empty image sections for messages and empty message sections for images.
The simplest workaround would be to check if user_img or user_message evaluates to True:
{% for foo in all_post %}
<hr>
{% if foo.user_message %}
<br> SMS by: <p>{{ foo.user}} __ {{ foo.created }}</p>
<h2>{{ foo.user_message }}</h2>
{% else %}
<br> IMAGE by: <p>{{ foo.user}} __ {{ foo.created }}</p>
<img src="{{ foo.user_img.url }}"width="250">
{% endif %}
{% endfor %}
Instead of else you can do a separate if foo.user_img to avoid message objects with empty messages to be interpreted as images.