4.用户账户
4.1 让用户能够输入数据
添加新主题
# untitled/learning_logs/forms.py
from django import forms
from .models import Topic, Entry
class TopicForm(forms.ModelForm):
class Meta:
model = Topic
fields = [\'text\']
labels = {\'text\':\'\'}
"""定义learning_logs的URL模式"""
# untitled/learning_logs/urls.py
from django.conf.urls import url
from . import views
app_name = \'learning_logs\'
urlpatterns = [
# 主页
url(r\'^$\', views.index, name=\'index\'),
url(r\'^topics/$\', views.topics, name=\'topics\'),
url(r\'^topics/(?P<topic_id>\d+)/$\', views.topic, name=\'topic\'),
url(r\'^new_topic/$\', views.new_topic, name=\'new_topic\'),
]
# untitled/learning_logs/views.py
from django.http import HttpResponseRedirect
from django.shortcuts import render
from django.urls import reverse
from learning_logs.forms import TopicForm
from learning_logs.models import Topic
#···
def new_topic(request):
"""添加新主题"""
if request.method != \'POST\':
form = TopicForm()
else:
form = TopicForm(request.POST)
if form.is_valid():
form.save()
return HttpResponseRedirect(reverse(\'learning_logs:topics\'))
context = {\'form\':form}
return render(request, \'learning_logs/new_topic.html\', context)
#···
<!-- untitled/templates/learning_logs/new_topic.html -->
{% extends "learning_logs/base.html" %}
{% block content %}
<p>Add a new topic:</p>
<form action="{% url \'learning_logs:new_topic\' %}" method=\'post\'>
{% csrf_token %}
{{ form.as_p }}
<button name="submit">add topic</button>
</form>
{% endblock content %}
添加新条目
（略）
编辑新条目
（略）
4.2 创建用户账户
应用程序users
# untitled/untitled/settings.py
# ···
INSTALLED_APPS = [
\'django.contrib.admin\',
\'django.contrib.auth\',
\'django.contrib.contenttypes\',
\'django.contrib.sessions\',
\'django.contrib.messages\',
\'django.contrib.staticfiles\',
# 我的应用程序
\'learning_logs\',
\'users\'
]
# ···
# untitled/untitled/urls.py
from django.contrib import admin
from django.urls import path
from django.conf.urls import include, url
urlpatterns = [
path(\'admin/\', admin.site.urls),
url(r\'^users/\', include(\'users.urls\', namespace=\'users\')),
url(r\'\', include(\'learning_logs.urls\', namespace=\'learning_logs\')),
]
4.2.1 登录
由于Django版本的问题，下面的URL模式跟《Python编程从入门到实践》的示例有点不一样。
"""为应用程序users定义URL模式"""
# untitled/users/urls.py
from django.contrib.auth.views import LoginView
from django.urls import path
app_name = \'users\'
urlpatterns = [
path(\'login/\', LoginView.as_view(template_name=\'users/login.html\'), name="login"),
]
<!-- untitled/templates/users/login.html -->
{% extends "learning_logs/base.html" %}
{% block content %}
{% if form.errors %}
<p>Your username and password didn\'t match. Please try again.</p>
{% endif %}
<form method="post" action="{% url \'users:login\' %}">
{% csrf_token %}
{{ form.as_p }}
<button name="submit">log in</button>
<input type="hidden" name="next" value="{% url \'learning_logs:index\' %}" />
</form>
{% endblock content %}
<!-- untitled/templates/learning_logs/base.html -->
<p>
<a href="{% url \'learning_logs:index\' %}">Learning Log</a> -
<a href="{% url \'learning_logs:topics\' %}">Topics</a> -
{% if user.is_authenticated %}
Hello, {{ user.username }}.
{% else %}
<a href="{% url \'users:login\' %}">log in</a>
{% endif %}
</p>
{% block content %}{% endblock %}
4.2.2 注销
# untitled/users/urls.py
from django.contrib.auth.views import LoginView
from django.urls import path
from django.conf.urls import url
from . import views
app_name = \'users\'
urlpatterns = [
path(\'login/\', LoginView.as_view(template_name=\'users/login.html\'), name="login"),
url(r\'^logout/$\', views.logout_view, name=\'logout\'),
]
注意下面导入的是from django.urls import reverse，而不是from django.core.urlresolvers import reverse。
# untitled/users/views.py
from django.http import HttpResponseRedirect
from django.urls import reverse
from django.contrib.auth import logout
def logout_view(request):
"""Log the user out."""
logout(request)
return HttpResponseRedirect(reverse(\'learning_logs:index\'))
4.2.3 注册
# untitled/users/views.py
from django.contrib.auth.forms import UserCreationForm
from django.http import HttpResponseRedirect
from django.shortcuts import render
from django.urls import reverse
from django.contrib.auth import logout, authenticate, login
# ···
def register(request):
if request.method != \'POST\':
form = UserCreationForm()
else:
form = UserCreationForm(data=request.POST)
if form.is_valid():
new_user = form.save()
authenticated_user = authenticate(username=new_user.username, password=request.POST[\'password1\'])
login(request, authenticated_user)
return HttpResponseRedirect(reverse(\'learning_logs:index\'))
context = {\'form\':form}
return render(request, "users/register.html", context)
<!-- untitled/templates/users/register.html -->
{% extends "learning_logs/base.html" %}
{% block content %}
<form method="post" action="{% url \'users:register\' %}">
{% csrf_token %}
{{ form.as_p }}
<button name="submit">register</button>
<input type="hidden" name="next" value="{% url \'learning_logs:index\' %}" />
</form>
{% endblock content %}
4.3 让用户拥有自己的数据
使用@login_required限制访问
# untitled/learning_logs/views.py
from django.contrib.auth.decorators import login_required
from django.http import HttpResponseRedirect
from django.shortcuts import render
# ···
@login_required
def topics(request):
topics = Topic.objects.order_by(\'date_added\')
context = {\'topics\' : topics}
return render(request, \'learning_logs/topics.html\', context)
# ···
# untitled/untitled/settings.py
# ···
LOGIN_URL = \'/users/login/\'
将数据关联到用户
注意这行代码owner = models.ForeignKey(\'auth.User\', on_delete=models.CASCADE)的写法。
# untitled/learning_logs/models.py
from django.db import models
from django.contrib.auth.models import User
class Topic(models.Model):
"""A topic the user is learning about."""
text = models.CharField(max_length=200)
date_added = models.DateTimeField(auto_now_add=True)
owner = models.ForeignKey(\'auth.User\', on_delete=models.CASCADE)
def __str__(self):
"""Return a string representation of the model."""
return self.text
我们迁移数据库时，Django将对数据库进行修改，使其能够存储主题和用户之间的关联。
执行python manage.py makemigrations learning_logs时，我们为外键值指定默认值。
只允许用户访问自己的主题
# untitled/learning_logs/views.py
# ···
@login_required
def topics(request):
topics = Topic.objects.filter(owner=request.user).order_by(\'date_added\')
context = {\'topics\' : topics}
return render(request, \'learning_logs/topics.html\', context)
# ···
保护用户的主题
# untitled/learning_logs/views.py
# ···
@login_required
def topic(request, topic_id):
topic = Topic.objects.get(id=topic_id)
if topic.owner != request.user:
raise Http404
entries = topic.entry_set.order_by(\'-date_added\')
context = {\'topic\': topic, \'entries\': entries}
return render(request, \'learning_logs/topic.html\', context)
# ···
保护页面edit_entry
# untitled/learning_logs/views.py
# ···
@login_required
def edit_entry(request, entry_id):
"""Edit an existing entry."""
entry = Entry.objects.get(id=entry_id)
topic = entry.topic
if topic.owner != request.user:
raise Http404
if request.method != \'POST\':
# Initial request; pre-fill form with the current entry.
form = EntryForm(instance=entry)
else:
# POST data submitted; process data.
form = EntryForm(instance=entry, data=request.POST)
if form.is_valid():
form.save()
return HttpResponseRedirect(reverse(\'learning_logs:topic\',
args=[topic.id]))
context = {\'entry\': entry, \'topic\': topic, \'form\': form}
return render(request, \'learning_logs/edit_entry.html\', context)
将新主题关联到当前用户
# untitled/learning_logs/views.py
# ···
@login_required
def new_topic(request):
"""添加新主题"""
if request.method != \'POST\':
form = TopicForm()
else:
form = TopicForm(request.POST)
if form.is_valid():
new_topic = form.save(commit=False)
new_topic.owner = request.user
new_topic.save()
return HttpResponseRedirect(reverse(\'learning_logs:topics\'))
context = {\'form\':form}
return render(request, \'learning_logs/new_topic.html\', context)
# ···
参考资料：《Python编程从入门到实践》—【美】Eric Matthes 著