Displaying "Like" and "Dislike" buttons if user has liked a post with Django

Question

thank you for taking the time to read this.

I'm working on a project for CS50W in which I have to display a series of posts which users can like and then dislike.

I can successfully display the number of likes but I can't get the "Like" Button to change into "Dislike" once this is done.

Here's the relevant code:

views.py

def index(request):
    return render(request, "network/index.html", {
        "posts": Post.objects.all().order_by('time'),
        "form": NewPost(),
        "likes": Like.objects.all(),
    })

...

def like(request, post_id):
    if request.method == "POST":
        #make sure user can't like the post more than once. 
        user = User.objects.get(username=request.user.username)
        #find whatever post is associated with like
        post = Post.objects.get(id=post_id)
        #access liked values: 

        if Like.objects.filter(user=user, post=post).exists():
            Like.alreadyLiked = True
            return HttpResponseRedirect(reverse('index'))
        else: 
            newLike = Like(user=user, post=post)
            newLike.alreadyLiked = True
            post.likes += 1
            post.save()
            newLike.save()
            return HttpResponseRedirect(reverse('index'))
    

Then models.py

from django.contrib.auth.models import AbstractUser
from django.db import models
import datetime


class User(AbstractUser):
    pass

class Post(models.Model):
    text = models.CharField(max_length=127)
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name="author")
    time = models.TimeField(auto_now=False, auto_now_add=True)
    likes = models.PositiveIntegerField(default=0)

    def __str__(self):
        if self.likes == 1:
            return f"{self.user} ({self.time}): {self.text} - {self.likes} Like"
        elif self.likes == 0:
            return f"{self.user} ({self.time}): {self.text} - No Likes"
        else:
            return f"{self.user} ({self.time}): {self.text} - {self.likes} Likes"

class Like(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name="users")
    post = models.ForeignKey(Post, on_delete=models.CASCADE, related_name="posts")
    alreadyLiked = models.BooleanField(default=False)

    def __str__(self):
        return f"{self.user} liked {self.post}"

Finally, index.html where the button is displayed.

{% extends "network/layout.html" %}

{% block body %}



<form action="/newPost" method="post" name="newPost">
{% csrf_token %}
{{ form.content }}
<input type="submit">
</form>


{% for post in posts %}


<div id="post{{post.id}}">{{ post }}

{% if likes.post == post and likes.user == user.username %}

    <form action="{% url 'dislike' post.id  %}" method="post" name="dislike" id="dislikeform">
        {% csrf_token %}
        <button type='submit' name='dislike' value="{{ post.id }}" class="btn btn-primary">Dislike</button>
    </form>

{% else %}    

    <form action="{% url 'like' post.id  %}" method="post" name="like" id="likeform">
        {% csrf_token %}
        <button type='submit' name='like' value="{{ post.id }}" class="btn btn-primary">Like</button>
    </form>

{% endif %}

{% if follows.following == True %}

    <form action="{% url 'unfollow' post.user  %}" method="post" name="follow">
        {% csrf_token %}
        <button type='submit' name='follow' value="{{ post.user }}" class="btn btn-primary">Follow</button>
    </form>

{% else %}

    <form action="{% url 'follow' post.user  %}" method="post" name="follow">
        {% csrf_token %}
        <button type='submit' name='follow' value="{{ post.user }}" class="btn btn-primary">Follow</button>
    </form>

{% endif %}

</div>

{% endfor %}

{% endblock %}

My idea is that in the part of the form for liking and disliking, django template's should determine whether or not the logged in user has already liked the post, in which case it will display a Dislike button instead of the Like button. Most importantly this segment:

{% if likes.post == post and likes.user == user.username %}

    <form action="{% url 'dislike' post.id  %}" method="post" name="dislike" id="dislikeform">
        {% csrf_token %}
        <button type='submit' name='dislike' value="{{ post.id }}" class="btn btn-primary">Dislike</button>
    </form>

{% else %}    

    <form action="{% url 'like' post.id  %}" method="post" name="like" id="likeform">
        {% csrf_token %}
        <button type='submit' name='like' value="{{ post.id }}" class="btn btn-primary">Like</button>
    </form>

{% endif %}

I have a similar issue with the Follow and Unfollow buttons but I feel that if I can implement the first problem's solution I can apply it too.

Answer 1

Figured it out after rethinking the model relationships.

I added a new field to my Post model:

class Post(models.Model):
    text = models.CharField(max_length=127)
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name="author")
    time = models.TimeField(auto_now=False, auto_now_add=True)
    likes = models.PositiveIntegerField(default=0)
    user_likes = models.ManyToManyField(User)

User is now related to post as a ManytoManyField, which allows me to create relationships between these models.

then in views.py:

def like(request, post_id):
    if request.method == "POST":
        #make sure user can't like the post more than once. 
        user = User.objects.get(username=request.user.username)
        #find whatever post is associated with like
        post = Post.objects.get(id=post_id)

        newLike = Like(user=user, post=post)
        newLike.alreadyLiked = True

        post.likes += 1
        #adds user to Post 
        post.user_likes.add(user)
        post.save()
        newLike.save()
        return HttpResponseRedirect(reverse('index'))

I did the same thing for dislike and will try the same for follow and unfollow.

Lastly, in index.html:

{% if user in post.user_likes.all %}

    <form action="{% url 'dislike' post.id  %}" method="post" name="dislike" id="dislikeform">
        {% csrf_token %}
        <button type='submit' name='dislike' value="{{ post.id }}" class="btn btn-primary">Dislike</button>
    </form>

{% else %}    

    <form action="{% url 'like' post.id  %}" method="post" name="like" id="likeform">
        {% csrf_token %}
        <button type='submit' name='like' value="{{ post.id }}" class="btn btn-primary">Like</button>
    </form>

{% endif %}

Now it's working perfectly.