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pythondjangobuttonquerying

Creating a like button in django social media network


I'm new to django and I'm trying to create a like button for my blog posts. In my HomeFeed app

However, I received this error when i click on the like button that i have created:

ValueError invalid literal for int() with base 10: 'uien-jdhn-fds'

I am given a pointer that the problem comes from this statement:

post = get_object_or_404(BlogPost, id=request.POST.get('blog_post_slug'))

Is it because they are expecting all integers in the url but it is getting character values? I am unsure of how to change it.

Views.py

def LikeView(request, slug):
    context = {}
    post = get_object_or_404(BlogPost, id=request.POST.get('blog_post_slug'))
    if post.likes.filter(id=request.user.id).exists():
        post.likes.remove(request.user)
    else:
        post.likes.add(request.user)

    return HttpResponseRedirect(reverse('HomeFeed:detail',args=[str(BlogPost.slug)]))

def detail_blog_view(request, slug):

    context = {}
#need to import a package get_object_or_404. return object or throw 404
    blog_post = get_object_or_404(BlogPost, slug=slug)
    total_likes = blog_post.total_likes()
    context['blog_post'] = blog_post
    context['total_likes'] = total_likes
    return render(request, 'HomeFeed/detail_blog.html', context)

models.py

class BlogPost(models.Model):
 chief_title                    = models.CharField(max_length=50, null=False, blank=False)
 body                   = models.TextField(max_length=5000, null=False, blank=False)
 likes = models.ManyToManyField(settings.AUTH_USER_MODEL, related_name='blog_posts', blank=True)
 slug                   = models.SlugField(blank=True, unique=True)

 def __str__(self):
  return self.chief_title

 def total_likes(self):
   return self.likes.count()
   

urls.py

from .views import(
detail_blog_view,
LikeView,
)

urlpatterns = [
    path('<slug>/detail/', detail_blog_view, name= "detail"),
    path('<slug>/edit/', edit_blog_view, name= "edit"),
    path('<slug>/like/', LikeView, name='like_post'),
]

detail_blog.html

     <form action="{% url 'HomeFeed:like_post' blog_post.slug %}" method="POST" >{% csrf_token %} <button type="submit" name="blog_post_slug" value="{{blog_post.slug}}" class='btn btn-primary btn-sm'>Like</button> {{ total_likes }} Likes</form>

the following is the traceback:

Internal Server Error: /HomeFeed/uien-jdhn-fds/like/
Traceback (most recent call last):
  File "lib/python3.8/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/lib/python3.8/site-packages/django/core/handlers/base.py", line 115, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "lib/python3.8/site-packages/django/core/handlers/base.py", line 113, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "views.py", line 195, in LikeView
    post = get_object_or_404(BlogPost, id=request.POST.get('blog_post_slug'))
  File "/lib/python3.8/site-packages/django/shortcuts.py", line 93, in get_object_or_404
    return queryset.get(*args, **kwargs)
  File "lib/python3.8/site-packages/django/db/models/query.py", line 399, in get
    clone = self.filter(*args, **kwargs)
  File "/lib/python3.8/site-packages/django/db/models/query.py", line 892, in filter
    return self._filter_or_exclude(False, *args, **kwargs)
  File "lib/python3.8/site-packages/django/db/models/query.py", line 910, in _filter_or_exclude
    clone.query.add_q(Q(*args, **kwargs))
  File "/lib/python3.8/site-packages/django/db/models/sql/query.py", line 1290, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
  File "/lib/python3.8/site-packages/django/db/models/sql/query.py", line 1315, in _add_q
    child_clause, needed_inner = self.build_filter(
  File "/lib/python3.8/site-packages/django/db/models/sql/query.py", line 1251, in build_filter
    condition = self.build_lookup(lookups, col, value)
  File "lib/python3.8/site-packages/django/db/models/sql/query.py", line 1116, in build_lookup
    lookup = lookup_class(lhs, rhs)
  File "lib/python3.8/site-packages/django/db/models/lookups.py", line 20, in __init__
    self.rhs = self.get_prep_lookup()
  File "/lib/python3.8/site-packages/django/db/models/lookups.py", line 70, in get_prep_lookup
    return self.lhs.output_field.get_prep_value(self.rhs)
  File "lib/python3.8/site-packages/django/db/models/fields/__init__.py", line 972, in get_prep_value
    return int(value)
ValueError: invalid literal for int() with base 10: 'uien-jdhn-fds'

Solution

  • You submitted the slug, not the primary key, so:

    def LikeView(request, slug):
        context = {}
        post = get_object_or_404(BlogPost, slug=request.POST.get('blog_post_slug'))
        # …

    It is however not necessary to submit this through the button, you already do this through the path, so you can make use of:

    def LikeView(request, slug):
        context = {}
        post = get_object_or_404(BlogPost, slug=slug)
        # …

    Furthermore you should also use post.slug, or simply slug when you reverse, so:

    from django.shortcuts import redirect
    
    def LikeView(request, slug):
        # …
        return redirect('HomeFeed:detail', slug=slug)