from django.db import models
from django.utils import timezone

class Article(models.Model):
  title = models.CharField('标题', max_length=100)
  text = models.TextField('内容')
  date_added = models.DateTimeField(default=timezone.now)

  def __str__(self):
    return self.title

# form.py

from django.forms import ModelForm
from .models import Article

class ArticleForm(ModelForm):  # 继承ModelForm类
  class Meta:
    model = Article  # 具体要操作那个模型
    fields = ['title', 'text', 'date_added'] # 允许编辑的字段

# views.py

from django.shortcuts import render, redirect 
from .models import Article
from .form import ArticleForm

def articles(request):
 # 查询列表页面，获取Article的所有信息
  articles = Article.objects.all()
  return render(request, 'app1/articles.html', {'articles':articles})
# 与其对应的url,在应用中的urls.py中设置
  path('article/', views.articles, name='article'),

# 添加页面
def new_article(request):
 # 如果不是POST方法访问
  if request.method != 'POST':
    # 创建一个空表单在页面显示
    form = ArticleForm()
  else:
    # 否则为POST方式
    # request.POST方法，将会获取到表单中我们输入的数据
    new_article = ArticleForm(request.POST)
    # 验证其合法性，使用is_valid()方法
    if new_article.is_valid():
      # 验证通过，使用save()方法保存数据
      new_article.save()
      # 保存成功，使用redirect()跳转到指定页面
      return redirect('app1:article')
  return render(request, 'app1/new_article.html', {'form':form})

# 编辑修改页面
def edit_article(request, article_id):
  # 查询到指定的数据
  article = Article.objects.get(id=article_id)
  if request.method != 'POST':
   # 如果不是post,创建一个表单，并用instance=article当前数据填充表单
    form = ArticleForm(instance=article) 
  else:
  # 如果是post,instance=article当前数据填充表单，并用data=request.POST获取到表单里的内容
    form = ArticleForm(instance=article, data=request.POST)
    form.save() # 保存
    if form.is_valid(): # 验证
      return redirect('app1:article') # 成功跳转
  return render(request, 'app1/edit_article.html', {'form':form,'article':article})

# 删除页面
def del_article(request, article_id):
  article = Article.objects.get(id=article_id)
  if request.method == 'POST':
    article.delete()
    return redirect('app1:article')
  return render(request, 'app1/del_article.html', {'article': article})

# 列表
path('article/', views.articles, name='article'),
# 添加
path('new_article/', views.new_article, name='new_article'),
# 修改
path('edit_article/<int:article_id>/', views.edit_article, name='edit_article'),
# 删除
path('del_article/<int:article_id>/', views.del_article, name='del_article'),

# articles.html

 <a href="{% url 'app1:new_article' %}" rel="external nofollow" >添加</a>
  {% for article in articles %}
    <h1>{{ article.title }}</h1>
    <p>{{ article.text }}</p>
    <a href="{% url 'app1:edit_article' article.id %}" rel="external nofollow" >修改</a>
    <a href="{% url 'app1:del_article' article.id %}" rel="external nofollow" >删除</a>
  {% endfor %}


# new_article.html
 <form action="{% url 'app1:new_article' %}" method="post">
    {% csrf_token %}
    {{ form.as_ul }}
    <input type="submit" value="提交">
  </form>