Django视graph and 模板

Django视graph

视graph is Djangoapplication core, 它processingHTTPrequest并返回HTTPresponse. Django视graph可以 is function视graph or class视graph.

function视graph

function视graph is 最 simple 视graphclass型, 它 is a 接收HTTPrequest并返回HTTPresponse Pythonfunction.

# blog/views.py
from django.http import HttpResponse
from django.shortcuts import render

#  simple  视graphfunction
def hello_world(request):
    return HttpResponse("Hello, Django World!")

# using模板 视graphfunction
def post_list(request):
    # 获取所 has 博客文章
    posts = BlogPost.objects.all()
    # 渲染模板并返回response
    return render(request, 'blog/post_list.html', {'posts': posts})

class视graph

class视graph is 基于class 视graph, 它providing了更 many flexible性 and codereusability. Djangoproviding了 many 种 in 置 class视graph, such asListView, DetailView, CreateView, UpdateView, DeleteViewetc..

# blog/views.py
from django.views.generic import ListView, DetailView
from .models import BlogPost

# usingListView显示所 has 博客文章
class PostListView(ListView):
    model = BlogPost
    template_name = 'blog/post_list.html'
    context_object_name = 'posts'  # 模板inusing variable名
    ordering = ['-pub_date']  # 按release日期降序sort

# usingDetailView显示单个博客文章
class PostDetailView(DetailView):
    model = BlogPost
    template_name = 'blog/post_detail.html'

URLrouting

URLrouting用于将URLpathmap to 相应 视graphfunction or class视graph.

applicationURLconfiguration

首先 in applicationTable of Contents under creationurls.pyfile, configurationapplication URLrouting:

# blog/urls.py
from django.urls import path
from . import views

urlpatterns = [
    path('', views.PostListView.as_view(), name='post_list'),
    path('post//', views.PostDetailView.as_view(), name='post_detail'),
    path('hello/', views.hello_world, name='hello_world'),
]

URL模式in parameter说明:

• <int:pk>: 捕获整数class型 主键值, 传递给视graph.
• name: URL模式 名称, 用于 in 模板in反向生成URL.

projectURLconfiguration

然 after in project urls.pyfileinpackage含application URLconfiguration:

# mysite/urls.py
from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path('blog/', include('blog.urls')),  # package含blogapplication URLconfiguration
]

现 in 可以访问以 under URL:

• http://127.0.0.1:8000/blog/: 显示所 has 博客文章
• http://127.0.0.1:8000/blog/post/1/: 显示ID for 1 博客文章
• http://127.0.0.1:8000/blog/hello/: 显示Hello Worldmessage

Django模板system

Django模板system用于生成HTML页面, It supportsvariable, filter器, tag, 模板inheritanceetc.functions.

模板Table of Contents

首先需要 in applicationTable of Contents under creationtemplatesTable of Contents, 并 in 其increationapplication名称 子Table of Contents:

blog/
├── templates/
│   └── blog/
│       ├── post_list.html
│       └── post_detail.html

然 after in settings.pyin确保模板Table of Contents已configuration:

# settings.py
TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,  # 启用applicationTable of Contents under  模板find
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

模板语法

Django模板using双 big 括号{{ }}来表示variable, using big 括号加百分号{% %}来表示tag.

variable

<h1>{{ post.title }}</h1>
<p>{{ post.content }}</p>
<p>release日期: {{ post.pub_date }}</p>

filter器

filter器用于modifyvariable 值, using竖线|分隔variable and filter器.

<!-- format日期 -->
<p>release日期: {{ post.pub_date|date:"Y-m-d" }}</p>

<!-- 截取string -->
<p>{{ post.content|truncatechars:100 }}</p>

<!-- 转换 for  big 写 -->
<p>{{ post.title|upper }}</p>

tag

tag用于控制模板 逻辑流程, such as条件判断, 循环etc..

条件判断

{% if post.is_published %}
    <p>这篇文章已release</p>
{% else %}
    <p>这篇文章未release</p>
{% endif %}

循环

{% for post in posts %}
    <h2><a href="{% url 'post_detail' pk=post.pk %}">{{ post.title }}</a></h2>
    <p>{{ post.content|truncatechars:100 }}</p>
    <p>release日期: {{ post.pub_date|date:"Y-m-d" }}</p>
{% endfor %}

URL反向解析

<a href="{% url 'post_detail' pk=post.pk %}">查看详情</a>
<a href="{% url 'post_list' %}">返回list</a>

模板inheritance

模板inheritance允许creation一个Basics模板, 然 after in other模板ininheritance并scale它, implementationcode复用.

Basics模板 (base.html)

<!-- blog/templates/blog/base.html -->
<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>{% block title %}My Blog{% endblock %}</title>
</head>
<body>
    <header>
        <h1><a href="{% url 'post_list' %}">My Blog</a></h1>
    </header>
    
    <main>
        {% block content %}
        {% endblock %}
    </main>
    
    <footer>
        <p>© 2023 My Blog</p>
    </footer>
</body>
</html>

子模板 (post_list.html)

<!-- blog/templates/blog/post_list.html -->
{% extends 'blog/base.html' %}

{% block title %}博客list{% endblock %}

{% block content %}
    {% for post in posts %}
        <article>
            <h2><a href="{% url 'post_detail' pk=post.pk %}">{{ post.title }}</a></h2>
            <p>{{ post.content|truncatechars:100 }}</p>
            <p>release日期: {{ post.pub_date|date:"Y-m-d" }}</p>
        </article>
    {% endfor %}
{% endblock %}

子模板 (post_detail.html)

<!-- blog/templates/blog/post_detail.html -->
{% extends 'blog/base.html' %}

{% block title %}{{ post.title }}{% endblock %}

{% block content %}
    <article>
        <h1>{{ post.title }}</h1>
        <p>{{ post.content }}</p>
        <p>release日期: {{ post.pub_date|date:"Y-m-d H:i:s" }}</p>
        {% if post.is_published %}
            <p>status: 已release</p>
        {% else %}
            <p>status: 未release</p>
        {% endif %}
    </article>
    <a href="{% url 'post_list' %}">返回list</a>
{% endblock %}

静态file

静态fileincludingCSS, JavaScript, graph片etc.. Djangoproviding了静态filemanagementfunctions.

静态fileTable of Contents

in applicationTable of Contents under creationstaticTable of Contents, 并 in 其increationapplication名称 子Table of Contents:

blog/
├── static/
│   └── blog/
│       ├── css/
│       │   └── style.css
│       ├── js/
│       │   └── main.js
│       └── images/
│           └── logo.png

in 模板inusing静态file

首先需要 in 模板in加载statictag, 然 after usingstatictag引用静态file:

<!--  in 模板顶部加载statictag -->
{% load static %}

<!-- 引用CSSfile -->
<link rel="stylesheet" href="{% static 'blog/css/style.css' %}">

<!-- 引用JavaScriptfile -->
<script src="{% static 'blog/js/main.js' %}"></script>

<!-- 引用graph片 -->
<img src="{% static 'blog/images/logo.png' %}" alt="Logo">