qinrui777/django-learning

learning django, make a code record

jdango-learning

learning django, make a code record

[![python-version]][python]

---

Source
Full-Featured Web App -> https://www.youtube.com/watch?v=UmljXZIypDc
Code source -> https://github.com/CoreyMSchafer/code_snippets/tree/master/Django_Blog

My Env/Requirements:

• Mac os
• sublime 3.2.2 (注意开启自动保存，tab键转换为空格,python对空格较严格)
• Python 3.7
• Django 3.0

---

01_setup_env

#use python3.7
~ python3 --version
Python 3.7.5

#install django
pip3 install django

#check django version,be sure >2.1
python3 -m django --version

Starting development server

python manage.py runserver

可在浏览器访问

• http://localhost:8000
• http://localhost:8000/admin/ (可访问，但暂时无法登陆;完成步骤 04 后，用户名/密码： admin/admin123 )

02_Applicatinos&Routes

在root目录下，创建子app
python manage.py startapp blog

output:

tree
.
├── blog
│   ├── __init__.py
│   ├── admin.py
│   ├── apps.py
│   ├── migrations
│   │   └── __init__.py
│   ├── models.py
│   ├── tests.py
│   └── views.py
├── db.sqlite3
├── django_demo
│   ├── __init__.py
│   ├── __pycache__
│   │   ├── __init__.cpython-37.pyc
│   │   ├── settings.cpython-37.pyc
│   │   ├── urls.cpython-37.pyc
│   │   └── wsgi.cpython-37.pyc
│   ├── asgi.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
└── manage.py

03_Templates

• 使用template

  • 1.在 blog目录下新建 templates/blog 目录
  • 2.jinja语法( for循环、if else判断）
  • 3.使用 base.html (block)

• 使用bootstrap

  • base.html中插入bootstrap 代码

• 自定义css样式

  • 新建静态文件目录 blog/static/blog/xxx.css
  • 提供的snippets

04_admin_page

➜  python manage.py makemigrations
No changes detected
➜  python manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, sessions
Running migrations:
  Applying contenttypes.0001_initial... OK
  Applying auth.0001_initial... OK
  Applying admin.0001_initial... OK
  Applying admin.0002_logentry_remove_auto_add... OK
  Applying admin.0003_logentry_add_action_flag_choices... OK
  Applying contenttypes.0002_remove_content_type_name... OK
  Applying auth.0002_alter_permission_name_max_length... OK
.....
➜  python manage.py createsuperuser
Username (leave blank to use 'ruqin'): admin
Email address: [email protected]

http://localhost:8000/admin/ (admin/admin123)

05_Database&migrations

django has its own built-in ORM，SQLite for development，Postgres for production

• createPost

# 有新增model时，需要用以下的命令将数据结构导入database中
➜   python manage.py makemigrations
Migrations for 'blog':
  blog/migrations/0001_initial.py
    - Create model Post

➜   python manage.py sqlmigrate blog 0001
BEGIN;
--
-- Create model Post
--
CREATE TABLE "blog_post" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "title" varchar(100) NOT NULL, "content" text NOT NULL, "date_posted" datetime NOT NULL, "author_id" integer NOT NULL REFERENCES "auth_user" ("id") DEFERRABLE INITIALLY DEFERRED);
CREATE INDEX "blog_post_author_id_dd7a8485" ON "blog_post" ("author_id");
COMMIT;
➜  django_demo python manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, blog, contenttypes, sessions
Running migrations:
  Applying blog.0001_initial... OK

##通过shell交互方式操作python object对象
➜   python manage.py shell
Python 3.7.5 (default, Nov  1 2019, 02:16:38)
[Clang 10.0.0 (clang-1000.11.45.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
#导入Post User model
>>> from blog.models import Post
>>> from django.contrib.auth.models import User
>>> User.objects.all()
<QuerySet [<User: admin>]>
>>> User.objects.filter(username='admin')
<QuerySet [<User: admin>]>
>>> User.objects.first()       # 还有last()方法
<User: admin>
>>> user = User.objects.first()  #定义变量 user ,并赋值
>>> user.id
1
>>> Post.objects.all()
<QuerySet []>
>>> post_1 = Post(title='blog 1',content='First post content!',author=user)
>>> Post.objects.all()
<QuerySet []>
>>> post_1.save()    # 需要调用save() 方法，才生效
>>> Post.objects.all()
<QuerySet [<Post: Post object (1)>]>
# 在models.py 定义Post的 __str__方法，以便有返回值
# 然后执行exit()退出，重新进入交互模式

>>> post_2 = Post(title='blog 2',content='second post content',author=user)
>>> post_2.save()
>>> Post.objects.all()
<QuerySet [<Post: blog 1>, <Post: blog 2>]>
>>> post = Post.objects.first()
>>> post
<Post: blog 1>
>>> post.content
'First post content!'
>>> post.date_posted
datetime.datetime(2019, 12, 13, 6, 16, 22, 338009, tzinfo=<UTC>)
>>> post.author.email   #通过外键直接获取 user的email
'[e-mail]'

>>> user.post_set.all()
<QuerySet [<Post: blog 1>, <Post: blog 2>]>
>>> user.post_set.create(title='blog 3',content='Third post content!')
<Post: blog 3>

• 替换之前的post 的dummy data blog/views.py
• 更改post日期格式 blog/templates/home.html (python format date)
• 将Post模型 注册到admin页面, 修改文件blog/admin.py

06_User_registration

为了满足用户注册、登陆等功能，需要新建一个类似blog的子app python manage.py startapp users

• 在 django_demo/setting.py 添加 'users.apps.UsersConfig',
• 在 user/views.py 创建 register() 方法 （直接利用UserCreationForm方法新建表单内容）
• 在目录 users 下新建目录 templates/users,然后新建文件 register.html，完善页面显示内容
• 在 django_demo/urls.py 中添加 register 路径, 打开路径 http://localhost:8000/register/ 测试下
• 在 user/views.py 中加入对 request.method 方法的判断，加入 messages 信息展示集成到 base.html中

  django内建的UserCreationForm能校验部分数据有效性

• 在注册页面添加email字段, 新建 users/form.py
• 利用 django-crispy-forms 美化注册页面
  • install pip3 install django-crispy-forms
  • template packs django-crispy-forms

07_Login_and_logout_system

• import login and logout views django_demo/urls.py

+ from django.contrib.auth import views as auth_views
...
+    path('login/', auth_views.LoginView.as_view(template_name='users/login.html'), name='login'),
+    path('logout/', auth_views.LogoutView.as_view(template_name='users/logout.html'),name='logout'),

• 新建 login.html、logout.html

• login 成功后 redirect到 home page ,编辑 setting.py

LOGIN_REDIRECT_URL = 'blog-home'

• 修改注册后的跳转页面，指到 login 页面， 编辑 users/views.py

- messages.success(request, f'Account created for {username}!')
- return redirect('blog-home')
+ messages.success(request, f'Your account {username} has been created!You are now able to log in')
+ return redirect('login')

• 在 base.html 页面中添加判断用户是否登陆

login required decorator

    <!-- Navbar Right Side -->
    <div class="navbar-nav">
      {% if user.is_authenticated %}
        <a class="nav-item nav-link" href="{% url 'logout' %}">Logout</a>
      {% else %}
        <a class="nav-item nav-link" href="{% url 'login' %}">Login</a>
        <a class="nav-item nav-link" href="{% url 'register' %}">Register</a>
      {% endif %}

• 添加 profile 路由等，用 login required decorator实现当用户成功登陆后才可以看到profile页面

+ from django.contrib.auth.decorators import login_required

+ @login_required
def profile(request):

08_User_Profile_and_Picture

#安装 Pillow， 用于用户头像
pip3 install Pillow

• 新建model Profile, 然后做 migrate

+ from django.contrib.auth.models import User
from django.db import models

+ class Profile(models.Model):
+    user  =  models.OneToOneField(User, on_delete=models.CASCADE)
+    image  = models.ImageField(default='default.jpg', upload_to='profile_pics')

python manage.py makemigrations

python manage.py migrate

• 注册Profile到admin页面

from django.contrib import admin
+ from .models import Profile

+ admin.site.register(Profile)

• 重新定义 用户头像图片的路径，在setting.py 中

#上传的路径
+ MEDIA_ROOT =  os.path.join(BASE_DIR, 'media')

#浏览器的访问路径
+ MEDIA_UL = '/media/'

• 修改 profile.html 页面，添加标签；另外需要编辑 django_demo/urls.py

Django Static File Docs:
https://docs.djangoproject.com/en/2.1/howto/static-files/#serving-files-uploaded-by-a-user-during-development

注意区分生产环境/非生产环境用法

# django_demo/urls.py
+  from django.conf import settings
+  from django.conf.urls.static import static
...
+  if settings.DEBUG:
+      urlpatterns += static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

• 实现默认在新建用户时给用户的头像设置一个 default.jpg
  • 新建 signals.py （sender receiver）
  • users/apps.py 添加代码