如何在 Django 中限制每个帖子的点赞数

Question

我目前是Django 的初学者。 我想在我的这种发帖类型的应用中限制每个帖子一个赞，您可以在其中发布文本，用户可以喜欢或不喜欢相同的内容。现在我启用了登录，我希望登录的用户只喜欢一次帖子，但我没有成功。

Models.py

from django.db import models
from django.contrib.auth.models import User

# Create your models here.

class Todo(models.Model):
    text = models.CharField(max_length=100)
    complete = models.BooleanField(default=False)
    like=models.IntegerField(default=0)
    user = models.ForeignKey(User)

    def __str__(self):
        return self.text

观看次数，py

def like(request,todo_id):
    if Todo.objects.filter(todo_id = todo_id, user_id=request.user.id).exists():
        return redirect('index')
    else:
        todo = Todo.objects.get(pk=todo_id)
        todo.like += 1
        todo.save()
        return redirect('index')

Answer 1

基本上我缺少的是保存与用户相对应的喜欢。正如 Paolo 所指出的，通过创建一个用户和主模型作为外键的模型很容易解决这个问题。

models.py

from django.db import models
from django.contrib.auth.models import User

class Todo(models.Model):
    text = models.CharField(max_length=100)
    complete = models.BooleanField(default=False)

    def __str__(self):
        return self.text

class Todo_likes(models.Model):
    todo = models.ForeignKey(Todo, on_delete=models.CASCADE)
    user = models.ForeignKey(User, on_delete=models.CASCADE)

views.py

from django.shortcuts import render,redirect
from .models import Todo,Todo_likes
from .forms import TodoForm

def like(request,todo_id):
    user = request.user
    todo = Todo.objects.get(id=todo_id)
    like, created = Todo_likes.objects.get_or_create(   # get_or_create will 
                                                        # itself do the job of 
                                                        # finding and creating if not exist
        user = user,
        todo = todo
    )
    if not created:
        return redirect('index') #I don't wanted to show any error if existed earlier.
                                 #I just wanted to redirect.

    else:
        return redirect('index') 

然后通过简单地转到我的索引视图并插入来计算我的点赞数

def index(request):
    form = TodoForm()
    todo_list = Todo.objects.order_by('id')
    likes = Todo_likes.objects.count()  # Adding this line
    context= {'todo' : todo_list, 'form':form, 'likes' : likes} 
    return render(request,'todolistapp/index.html',context)

并在我的模板中显示“喜欢”对象。

Answer 2

我想尝试一下并扩展我的评论。

我的建议是，创建一个新模型 Todo_Likes，它将 Todo 和 User 模型作为 Foreign Keys，以便能够跟踪谁喜欢 Todo。

models.py

from django.db import models
from django.contrib.auth.models import User

# Create your models here.

class Todo(models.Model):
    text = models.CharField(max_length=100)
    complete = models.BooleanField(default=False)
    # Got rid of the user FK and like since I would count likes using
    # Todo_Like.objects.count()

    def __str__(self):
        return self.text

class Todo_Like(models.Model):
    todo = models.ForeignKey(Todo)
    user = models.ForeignKey(User)

views.py

def like(request,todo_id):
    # Get user
    user = request.user
    # Get Todo object
    todo = Todo.objects.get(id=todo_id)

    # Check/Validate if current user has already liked the Todo. 
    # If not create a new Todo_Like object.

    todo_like = Todo_Like.objects.get(todo=todo, user=user)

    if not todo_like:
        # If the user haven't like the Todo object yet create a Todo_Like object.
        t = Todo_Like (
            todo=todo,
            user=user
            )
        t.save()
    else:
        # If the user has already liked the Todo then proceed to do
        # Whatever you want, redirect? message?

我也想提前回答一个问题。

1. 您可能会问您现在如何计算点赞数？回答：使用 Todo_Like.objects.count()，并确保按 Todo 进行计数。