《python编程从入门到实践》day39加更

# 昨日知识点回顾

        添加主题、条目

# 今日知识点学习

        19.1.3 编辑条目

                1.URL模式edit——entry

# learning_logs/urls.py
---snip---# 用于编辑条目的页面path('edit_entry/<int:entry_id>/', views.edit_entry, name='edit_entry'),
]

                2.视图函数edit_entry()

# views.py
from django.shortcuts import render, redirect# 导入所需数据相关联的模型
from .models import Topic, Entry
from .forms import TopicForm, EntryForm# Create your views here.
def index(request):"""学习笔记的主页"""# 传递两个实参：对象request以及一个可用于创建页面的模版return render(request, 'learning_logs/index.html')def topics(request):"""显示所有的主题"""topics = Topic.objects.order_by('date_added')# 定义一个将要发送模版的上下文context = {'topics': topics}return render(request, 'learning_logs/topics.html', context)def topic(request, topic_id):"""显示单个主题"及所有的条目"""topic = Topic.objects.get(id=topic_id)entries = topic.entry_set.order_by('-date_added')context = {'topic': topic, 'entries': entries}return render(request, 'learning_logs/topic.html', context)def new_topic(request):"""添加新主题"""if request.method != 'POST':# 未提交数据：创建一个新表单form = TopicForm()else:# POST提交的数据：对数据进行处理form = TopicForm(data=request.POST)if form.is_valid():form.save()return redirect('learning_logs:topics')# 显示空表单后指出表单数据无效context = {'form': form}return render(request, 'learning_logs/new_topic.html', context)def new_entry(request, topic_id):"""在特定主题中添加新条目"""topic = Topic.objects.get(id=topic_id)if request.method != 'POST':# 未提交数据：创建一个空表单form = EntryForm()else:# POST提交的数据：对数据进行处理form = EntryForm(data=request.POST)if form.is_valid():new_entry = form.save(commit=False)new_entry.topic = topicnew_entry.save()return redirect('learning_logs:topic', topic_id=topic_id)# 显示空表单或支出表单数据无效context = {'topic': topic, 'form': form}return render(request, 'learning_logs/new_entry.html', context)def edit_entry(request, entry_id):"""编辑既有条目"""entry = Entry.objects.get(id=entry_id)topic = entry.topicif request.method != 'POST':# 初次请求：使用当前条目填充表单form =EntryForm(instance=entry)else:# POST提交的数据：对数据进行处理form = EntryForm(instance=entry, data=request.POST)if form.is_valid():form.save()return redirect('learning_logs:topic', topic_id=topic.id)context = {'entry': entry, 'topic': topic, 'form': form}return render(request, 'learning_logs/edit_entry.html', context)

                3.模版edit_entry                

# edit_entry。html
{% extends "learning_logs/base.html" %}{% block content %}<p><a href="{% url 'learning_logs:topic'  topic.id %}">{{  topic  }}</a></p><p>Edit entry:</p><form action="{% url 'learning_logs:edit_entry'  entry.id  %}" method='post'>{% csrf_token %}{{  form.as_p  }}<button name="submit">Save changes</button>		</form>{% endblock content %}

                4.链接到页面edit_entry

# topic.html
{% extends 'learning_logs/base.html' %}{% block content %}<p>Topic: {{  topic  }}</p><p>Entries:</p><p><a href="{% url 'learning_logs:new_entry' topic.id %}">Add new entry</a></p><ul>{% for entry in entries %}<li><p>{{  entry.date_added|date:'M d, Y H:i'  }}</p><p>{{  entry.text|linebreaks  }}</p><p><a href="{% url 'learning_logs:edit_entry' entry.id %}">Edit entry</a></p></li>{% empty %}<li>There are no entries for this topic yet.</li>{% endfor %}</ul>{% endblock content %}

                浏览器输入localhost:8000/topics/2/显示：

 19.2 创建用户账户

        19.2.1 应用程序users

                使用命令startapp创建一个名为users的应用程序

        19.2.2 将users添加到settings.py中

# settings.py
---snip---
INSTALLED_APPS = [# 我的应用程序'learning_logs','users',
---snip---

         19.2.3 包含users的URL

# learning_log/urls.py
from django.contrib import admin
from django.urls import path, includeurlpatterns = [path('admin/', admin.site.urls),path('users/', include('users.urls')),path('', include('learning_logs.urls')),
]

        19.2.4 登录界面 

# learning_log\users\urls.py
"""为应用程序users定义URL模式"""from django.urls import path, includeapp_name = 'users'
urlpatterns = [# 包含默认的身份验证URLpath('', include('django.contrib.auth.urls')),
]

                1.模版login.html

# learning_log\users\templates\registration\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 %}<p>Edit entry:</p><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 %}

                2.链接到登录界面        

# 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 content %}

                3.使用登录界面