用django创建一个简单的sns

1.首先创建一个工程newsns

django-admin.py startproject newsns

在工程目录下新建一个文件夹templates，在settings.py文件中对该模版路径进行配置：

import os

ROOT_DIR = os.getcwd()


TEMPLATE_DIRS = (
    # Put strings here, like "/home/html/django_templates" or "C:/www/django/templates".
    # Always use forward slashes, even on Windows.
    # Don't forget to use absolute paths, not relative paths.
    ROOT_DIR + '/templates/',
)

然后在templates文件夹下创建一个模版index.html：

<title>newsns -by django</title>
<h1><font color=#{{color}}>Django, my first django program.</font></h1>

参照上篇文章中创建模版的方法，将app目录下的settings.py文件、views.py文件和urls.py文件进行相应设置。

2.创建数据库，配置数据

在app目录下的settings.py中进行如下设置

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql', # Add 'postgresql_psycopg2', 'mysql', 'sqlite3' or 'oracle'.
        'NAME': 'newsns',                      # Or path to database file if using sqlite3.
        'USER': 'root',                      # Not used with sqlite3.
        'PASSWORD': '***',                  #密码.
        'HOST': 'localhost',                      # Set to empty string for localhost. Not used with sqlite3.
        'PORT': '',                      # Set to empty string for default. Not used with sqlite3.
    }
}

增加app newsns:

INSTALLED_APPS = (
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.sites',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    # Uncomment the next line to enable the admin:
    # 'django.contrib.admin',
    # Uncomment the next line to enable admin documentation:
    # 'django.contrib.admindocs',
    'newsns',
)

在控制台中使用mysql命令创建数据库newsns

mysql> create database newsns default character set utf8 collate utf8_general_ci;
Query OK, 1 row affected (0.03 sec)

然后在app目录下创建一个models.py文件，该文件创建了3个类，实际上每个类代表一个表格，类的字段为表的字段。

#coding:utf-8

from django.db import models

class newsns(models.Model):
    name = models.CharField(max_length = 30)
    content = models.CharField(max_length = 140)

#以下代码可以不要
class Publisher(models.Model):
    name = models.CharField(max_length=30)
    address = models.CharField(max_length=50)
    city = models.CharField(max_length=60)
    state_province = models.CharField(max_length=30)
    country = models.CharField(max_length=50)
    website = models.URLField()

class Author(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=40)
    email = models.EmailField()

class Book(models.Model):
    title = models.CharField(max_length=100)
    authors = models.ManyToManyField(Author)
    publisher = models.ForeignKey(Publisher)
    publication_date = models.DateField()

在控制台输入以下命令，按照要求输入帐号、密码，建立上述表格： 

***@Android:~/newsns# python manage.py validate
0 errors found
***@Android:~/newsns# python manage.py syncdb

创建好表格后我们在manage.py shell中进行测试：

***@Android:~/newsns# python manage.py shell
Python 2.7.3 (default, Aug  1 2012, 05:14:39) 
Type "copyright", "credits" or "license" for more information.

IPython 0.13.1 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: from newsns.models import Publisher

In [2]: p = Publisher(name = 'Jim', city = 'beijing')

In [3]: p.save()

In [4]: l = Publisher.objects.all()

In [5]: for n in l:
   ...:     print n.name
   ...:     
Jim

好了，测试无误。

3.创建表单

在app目录下创建forms.py文件，内容和models.py呼应。

#coding:utf-8

from django import forms

class snsform(forms.Form):
        name = forms.CharField(label = "姓名")
        content = forms.CharField(label = "内容", widget = forms.Textarea)

在views.py中添加下述代码：

def home(request):
        if request.method == 'POST':
                data = newsns()
                for i in request.POST.keys():
                        if hasattr(data, i):
                                setattr(data, i, request.POST[i])
                data.save()
        f = snsform()
        ls = newsns.objects.all()
        return render_to_response("home.html", {"ls":ls, "f":f}, context_instance = RequestContext(request))

注意要添加引入模块

#coding:utf-8
from django.http import HttpResponse
from django.template import Template, Context
from django.shortcuts import render_to_response, redirect
from mysns.models import newsns
from django.template import RequestContext
from mysns.forms import snsform

在templates目录下创建default文件夹，在该文件夹下建立一个layout.html文件，添加如下代码：

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link rel="stylesheet" type="text/css" href="/static/bootstrap/css/bootstrap.min.css">
<div class="navbar navbar-fixed-top">
  <div class="navbar-inner">
    <div class="container-fluid">
      <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </a>
      <a class="brand" href="#">Uliweb Zone</a>
      <div class="nav-collapse">

<ul class="nav">

<li><a href="/"><span>首页</span></a></li><li><a href="/forum"><span>论坛</span></a></li><li class="active"><a href="/tutorial"><span>教程</span></a></li><li><a href="/about"><span>关于</span></a></li>



</ul>


<style>
#userinfo.btn-toolbar {margin-top:0;margin-bottom:0;font-size:14px;}
#userinfo.btn-toolbar a{vertical-align:middle;}
#userinfo img {
-webkit-border-radius: 3px;
   -moz-border-radius: 3px;
        border-radius: 3px;
}
#userinfo [class^="icon-"], #userinfo [class*=" icon-"], #userinfo [class^="icon-"]:hover, #userinfo [class*=" icon-"]:hover{
    vertical-align:middle;
    margin-bottom:3px;
}
</style>


        <p class="pull-right user_info">
            <a href="/login">登录</a> | <a href="/register">注册</a>
        </p>


      </div><!--/.nav-collapse -->
    </div>
  </div>
</div>
<div style= 'padding:50px 5px 15px 20px;'>
{% block content %}
{% endblock %}
</div>

然后再创建一个home.html文件，添加代码

{% extends 'default/layout.html' %}
{% block content %}
<form action = "" method = "post">
        {% csrf_token %}
        <table>
                {{f}}
        </table>
        <input type="submit" value="发送" class = 'btn btn-info'>
</form>

<hr>
{%for i in ls%}
<li>{{i.content}}<a class='btn' href = '/delete?id={{i.id}}'>删除</a><a class = 'btn' href = '/edit?id={{i.id}}'>编辑</a></li>
{%endfor%}
</hr>

{% endblock %}

 layout.html文件中的

{% block content %}
{% endblock %}

表示home.html中{% block content %}与{% endblock %}之间的代码。

接下来在urls.py文件中添加url匹配

(r'^home', home),

注意要导入home函数。

我们还需要在views.py文件中实现编辑和删除功能。

编辑功能的实现思路是：获取需要编辑的帖子的id，根据该id从数据库中读取内容，在编辑页面edit.html中显示，让用户对内容进行修改，用户修改后进行post提交，根据id保存至数据库，id为原来的id，即id = int(request.GET['id'])。

删除功能的实现思路是：读取需要删除的帖子的id，根据该id从数据库中读取内容，将其删除。具体实现代码为：

def delete(request):
        if 'id' in request.GET:
                id = int(request.GET['id'])
                delcontent = newsns.objects.get(id = id)
                delcontent.delete()
        return redirect('/home')

def edit(request):
        if request.method == 'GET':
                if 'id' in request.GET:
                        ls = newsns.objects.get(id = int(request.GET['id']))
                        f = snsform(data = {'name':ls.name, 'content':ls.content})
                        return render_to_response("edit.html", {"f":f}, context_instance = RequestContext(request))
        if request.method == 'POST':
                data = newsns.objects.get(id = int(request.GET['id']))
                for i in request.POST.keys():
                        if hasattr(data, i):
                                setattr(data, i, request.POST[i])
                data.save()

现在我们还需要在模版目录下创建edit.html文件：

{%extends 'default/layout.html' %}
{% block content %}
<form action = "" method = "post">
        {% csrf_token %}
        <table>
                {{f}}
        </table>
        <input type="submit" value="发送" class = 'btn btn-info'>
</form>

<hr>
{%for i in ls%}
<li>{{i.content}}
{%endfor%}
</hr>

{% endblock %}

浏览器中输入http://127.0.0.1:8000/home，打开便是一个具备基本增删改查功能的sns了。