现在是时候建立我们的报纸应用了。我们将有一个文章页面,记者可以在那里发布文章,设置权限,最后还可以让其他用户在每篇文章上写评论。
创建文章应用
$ python manage.py startapp articles
$ vi config/settings.py
# config/settings.py
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
# 3rd Party
'crispy_forms',
# Local
'accounts',
'pages',
'articles', # new
]
LANGUAGE_CODE = 'zh-hans'
TIME_ZONE = 'Asia/Shanghai'
接下来我们定义我们的数据库模型,它包含四个字段:标题、正文、日期和作者。注意,我们让Django根据我们的TIME_ZONE设置来自动设置时间和日期。对于作者字段,我们要引用我们的自定义用户模型 "accounts.CustomUser",我们在config/settings.py文件中设置了AUTH_USER_MODEL。
articles/models.py
# articles/models.py
from django.conf import settings
from django.contrib.auth import get_user_model
from django.db import models
from django.urls import reverse
class Article(models.Model):
title = models.CharField(max_length=255)
body = models.TextField()
date = models.DateTimeField(auto_now_add=True)
author = models.ForeignKey()
get_user_model(),
on_delete=models.CASCADE,
)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('article_detail', args=[str(self.id)] )
数据迁移
$ python manage.py makemigrations articles
$ python manage.py migrate
articles/admin.py
# articles/admin.py
from django.contrib import admin
from .models import Article
admin.site.register(Article)
现在我们启动服务器。
$ python manage.py runserver
导航到 http://127.0.0.1:8000/admin/ 并登录。
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URLs和视图
config/urls.py
# config/urls.py
from django.contrib import admin
from django.urls import path, include
urlpatterns = [
path('admin/', admin.site.urls),
path('accounts/', include('accounts.urls')),
path('accounts/', include('django.contrib.auth.urls')),
path('articles/', include('articles.urls')), # new
path('', include('pages.urls')),
]
articles/urls.py
# articles/urls.py
from django.urls import path
from .views import ArticleListView
urlpatterns = [
path('', ArticleListView.as_view(), name='article_list'),
]
articles/views.py
from django.views.generic import ListView
from .models import Article
class ArticleListView(ListView):
model = Article
template_name = 'article_list.html'
templates/article_list.html
<!-- templates/article_list.html -->
{% extends 'base.html' %}
{% block title %}Articles{% endblock title %}
{% block content %}
{% for article in object_list %}
<div class="card">
<div class="card-header">
<span class="font-weight-bold">{{ article.title }}</span> ·
<span class="text-muted">by {{ article.author }} |
{{ article.date }}</span>
</div>
<div class="card-body">
{{ article.body }}
</div>
<div class="card-footer text-center text-muted">
<a href="#">Edit</a> | <a href="#">Delete</a>
</div>
</div>
<br />
{% endfor %}
{% endblock content %}
在http://127.0.0.1:8000/articles/,查看我们的页面。
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编辑/删除
articles/urls.py
articles/urls.py
# articles/urls.py
from django.urls import path
from .views import (
ArticleListView,
ArticleUpdateView, # new
ArticleDetailView, # new
ArticleDeleteView, # new
)
urlpatterns = [
path('<int:pk>/edit/',
ArticleUpdateView.as_view(), name='article_edit'), # new
path('<int:pk>/',
ArticleDetailView.as_view(), name='article_detail'), # new
path('<int:pk>/delete/',
ArticleDeleteView.as_view(), name='article_delete'), # new
path('', ArticleListView.as_view(), name='article_list'),
]
articles/views.py
# articles/views.py
from django.views.generic import ListView, DetailView # new
from django.views.generic.edit import UpdateView, DeleteView # new
from django.urls import reverse_lazy # new
from .models import Article
class ArticleListView(ListView):
model = Article
template_name = 'article_list.html'
class ArticleDetailView(DetailView): # new
model = Article
template_name = 'article_detail.html'
class ArticleUpdateView(UpdateView): # new
model = Article
fields = ('title', 'body',)
template_name = 'article_edit.html'
class ArticleDeleteView(DeleteView): # new
model = Article
template_name = 'article_delete.html'
success_url = reverse_lazy('article_list')
templates/article_detail.html
<!-- templates/article_detail.html -->
{% extends 'base.html' %}
{% block content %}
<div class="article-entry">
<h2>{{ object.title }}</h2>
<p>by {{ object.author }} | {{ object.date }}</p>
<p>{{ object.body }}</p>
</div>
<p><a href="{% url 'article_edit' article.pk %}">Edit</a> |
<a href="{% url 'article_delete' article.pk %}">Delete</a></p>
<p>Back to <a href="{% url 'article_list' %}">All Articles</a>.</p>
{% endblock content %}
templates/article_edit.html
<!-- templates/article_edit.html -->
{% extends 'base.html' %}
{% block content %}
<h1>Edit</h1>
<form action="" method="post">{% csrf_token %}
{{ form.as_p }}
<button class="btn btn-info ml-2" type="submit">Update</button>
</form>
{% endblock content %}
templates/article_delete.html
<!-- templates/article_delete.html -->
{% extends 'base.html' %}
{% block content %}
<h1>Delete</h1>
<form action="" method="post">{% csrf_token %}
<p>Are you sure you want to delete "{{ article.title }}"?</p>
<button class="btn btn-danger ml-2" type="submit">Confirm</button>
</form>
{% endblock content %}
templates/article_list.html
<!-- templates/article_list.html -->
...
<div class="card-footer text-center text-muted">
<a href="{% url 'article_edit' article.pk %}">Edit</a> |
<a href="{% url 'article_delete' article.pk %}">Delete</a>
</div>
...
好了,我们准备好查看我们的工作了。用python manage.py runserver启动服务器,并在http://127.0.0.1:8000/articles/,导航到文章页面。点击第一篇文章上的 "编辑 "链接,你将被重定向到http://127.0.0.1:8000/articles/1/edit/。
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创建页面
articles/views.py
# articles/views.py
...
from django.views.generic.edit import (
UpdateView, DeleteView, CreateView # new
)
...
class ArticleCreateView(CreateView): # new
model = Article
template_name = 'article_new.html'
fields = ('title', 'body', 'author',)
注意,我们的字段有author,因为我们想把新文章和作者联系起来,但是一旦文章被创建,我们不希望用户能够改变作者,这就是为什么ArticleUpdateView只有字段['title', 'body',]。
用视图的新路线更新我们的URLS文件。
articles/urls.py
# articles/urls.py
from django.urls import path
from .views import (
ArticleListView,
ArticleUpdateView,
ArticleDetailView,
ArticleDeleteView,
ArticleCreateView, # new
)
urlpatterns = [
path('<int:pk>/edit/',
ArticleUpdateView.as_view(), name='article_edit'),
path('<int:pk>/',
ArticleDetailView.as_view(), name='article_detail'),
path('<int:pk>/delete/',
ArticleDeleteView.as_view(), name='article_delete'),
path('new/', ArticleCreateView.as_view(), name='article_new'), # new
path('', ArticleListView.as_view(), name='article_list'),
]
templates/article_new.html
<!-- templates/article_new.html -->
{% extends 'base.html' %}
{% block content %}
<h1>New article</h1>
<form action="" method="post">{% csrf_token %}
{{ form.as_p }}
<button class="btn btn-success ml-2" type="submit">Save</button>
</form>
{% endblock content %}
最后,我们应该在导航条上添加一个创建新文章的链接,这样,登录的用户就可以在网站的任何地方访问它。
templates/base.html 增加if部分内容
<!-- templates/base.html -->
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<a class="navbar-brand" href="{% url 'home' %}">Newspaper</a>
{% if user.is_authenticated %}
<ul class="navbar-nav mr-auto">
<li class="nav-item">
<a href="{% url 'article_new' %}">+ New</a>
</li>
</ul>
{% endif %}
templates/home.html
<!-- templates/home.html -->
{% extends 'base.html' %}
{% block title %}Home{% endblock title %}
{% block content %}
<br/>
<div class="jumbotron">
<h1 class="display-4">Newspaper app</h1>
<p class="lead">A Newspaper website built with Django.</p>
<p class="lead">
<a class="btn btn-primary btn-lg" href="{% url 'article_list' %}"
role="button">View All Articles</a>
</p>
</div>
{% endblock content %}
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小结
我们已经创建了一个具有CRUD功能的专用文章应用程序。但是还没有任何权限或授权,这意味着任何人都可以做任何事情! 一个已登录的用户可以访问所有的URL,任何已登录的用户都可以对现有的文章进行编辑或删除,即使是不属于他们自己的文章。下一章,我们将为我们的项目添加权限和授权来解决这个问题。
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