how to create a Django-Project?

Install

python2.7

pip install Django==1.11.15

python3

pip3 install Django==1.11.15

Editors

Pycharm Sublime Text Atom Visual Studio code

Create new project

django-admin startproject myblog

Run Server

python manage.py runserver
# custom HOST PORT
python manage.py runserver 8888

File Directory

- wsgi.py(Python Web Server Gateway Interface: Python服务器网关接口，Python应用与Web服务器之间的接口)
- urls.py(URL配置文件)
- settings.py(项目的总配置文件)

Create New Application

Step 1:

python manage.py startapp blog

Step 2: 添加该应用到settings.py中到INSTALLED_APPS。

Step 3: /blog/*

/migrations 数据移植（迁移）模块
  __init__.py
admin.py 该应用后台管理系统到配置文件
apps.py 当前应用的配置
models.py 数据模块，使用ORM框架
tests.py 自动化测试模块
views.py 执行响应的逻辑代码

blog/views.py 界面逻辑：

每个响应对应一个函数，函数必须返回一个响应。函数必须存在一个参数，一般约定为request。每一个响应函数对应一个 URL。

app/urls.py

每个 URL 都以 url 的形式写出来。 url函数放在 urlpatterns 列表中。 url函数有三个参数：URL,method,name

包含其他url，如 'blog/index':

在根 urls.py 中引入 include。在 glob 目录下创建 urls.py，格式与 app/urls.py 相同。

PS:

根 urls.py 针对 APP 配置的 URL 名称，是该 APP 所有 URL 的总路径
配置URL是注意正则表达式结尾符号 $ /

Create 1st HTML template

Django 模版语言， DTL（Django Template language）

DTL初步使用：

render(request, 'template.html', dict{ key: val }) 函数中支持一个 dict 类型参数
该字典是后台传递到模版的参数，键为参数名
在模版中使用 {{参数名}} 来直接使用
创建 templates 目录
创建 templates/{name}.html

PS:

Django 按照 INSTALLED_APPS中的添加顺序查找Templates。
不同APP下的Templates目录中的同名.html文件会造成冲突。

How to resolve?

在APP的templates 目录下创建以 app 为名称的目录。
将 {appName}/templates/{appName}/{name}.html 文件放入新创建的目录下。

Models in Django

Per model mapping a database table.
Model is class based in Django.
It includes some basic fields and actions.

What is ORM?

Object Relation Mapping, like Java Hibernate.
Impls object and database mapping.
Do not use any SQL words.

How to write a model?

Create a new file models.py in root directory, and imports models module.
Create a new class and it extends models.Model, it is a database table in fact.
Create key in Model(It is a field in database table actually), attr = models.CharField(mx_length=64)

How to generates a table in connected database?

get into manage.py use terminal.
type python manage.py makemigrations {appName*} and executes it.
type python manage.py migrate and executes this command again.

Where to find the file after generated and migrated?

Where is the file after migrated? - {appName}/migrations

How to generates SQL sentences?

type python manage.py sqlmigrate {appName} 0001:order and executes it.

How to use dynamic data from SQL DB?

views.py 中 import models
ORM sentence: article = models.Article.objects.get(pk=1)
Render dynamic data: render(request, page, { 'article': 'article 123' })

Admin 管理

Admin 是 Django 自带的一个功能强大的 自动化数据管理界面。
被授权的用户可以直接在 Admin 中管理数据库。
Django 提供了许多针对 Admin 个性化配置。

How to create a user for admin system?

type python manage.py createsuperuser and executes it.
Wanna modify admin web language? modify attr LANGUAGE_CODE='zh_Hans' in app/setting.py.
Customization admin.py model, just import it from self's models then register it to admin.site.register(Article).
Customization model name if u use python3, use __str__(self) otherwise use __unicode__(self).

Complete Blog pages

'/blog/index': blogs list page

{% for item in [] %}
{% endfor %}

'/blog/:id': blog content page

动态传参 url(r'^article/(?P<article_id>[0-9]+)/$', views.article_page)
(?P=) 必须与 views.py 中特定 controller 函数的 def group(request, groupName) 一致

'/blog/edit': create/write/edit new blog

Use dynamic link in Django

After href is the target link
In template could use {% url 'app_name:url_name' param %}

Use dynamic form iin Django

Use request.POST['ParamName'] to get the field data
Use models.Article.objects.create(title, content) to create a new model object.

How to update one dynamic data?

article.title = title // assertion
article.save() // invoke model.save()

Templates filter

a little same with .JSP and express .jade, .ejs.

like Frontend angular, vue MVVM frame-work filter syntax:

{{ value | filter }}

Multiple filters:

{{ value | filter1 | filter2 | ... }}

Example:

<input type="hidden" name="article_d" value={{article.id | default:'0' }}>

What's Django shell?

It's a CLI program.

When to use Django shell?

Test the new method or Look up an object's all properties and methods.

How to custom APP admin properties?

Create a new config class. class ArticleAdmin(admin.ModelAdmin)
Register it. admin.site.register(Article, ArticleAdmin)

givingwu/Django-Demo