(i) About Django
Django is a framework based on MVC constructs. However, in Django, the controller accepts user input from the part of the framework itself , so Django is more concerned about the model (Model), templates (Template) and views (Views), known as the MTV pattern.
Installation under Ubuntu: usually comes with Python. There are more tutorials online ....
dizzy@dizzy-pc:~$ python Python 2.7.3 (default, Apr 20 2012, 22:44:07) [GCC 4.6.3] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import django >>> help(django) VERSION = (1, 6, 4, 'final', 0) # You can view information such as django version.
(ii) The first Django app
# Environment: Python2.7, Django1.6, Ubuntu12.04
Once Python and Django have been successfully installed, you can create a Django project.
(1) Teaching you to start writing the 1st app for Django 1.6
# Create a folder first dizzy@dizzy-pc:~$ mkdir Python dizzy@dizzy-pc:~$ cd Python # Then create the project dizzy@dizzy-pc:~/Python$ startproject mysite dizzy@dizzy-pc:~/Python$ cd mysite # Then the project can start the service dizzy@dizzy-pc:~/Python/mysite$ python runserver Validating models... 0 errors found July 23, 2014 - 14:17:29 Django version 1.6.4, using settings '' Starting development server at http://127.0.0.1:8000/ Quit the server with CONTROL-C. #This way, open your browser and visit: You will see: It Worked! # Inside the newly created project will be: files, mysite folder # Inside the mysite folder there will be: __init__.py,,, four files #__init__.py is an empty file. # is the configuration file for the project. Two changes are needed, here the default SQLite3 database is used LANGUAGE_CODE = 'zh-cn' # Original: en-us TIME_ZONE = 'Asia/Shanghai' # Original: UTC # Once configured, you can create the data table dizzy@dizzy-pc:~/Python/mysite$ python syncdb #Create is also to set up a super administrator for backend login. #After setting up, turn on the service and you'll be able to access the backend management interface: http://127.0.0.1:8000/admin/
(2) Teaching you to start writing the 1st app for Django 1.6
#Create an app for voting. # Go to the mysite project root directory and create the app dizzy@dizzy-pc:~/Python/mysite$ python startapp polls dizzy@dizzy-pc:~/Python/mysite$ ls polls __init__.py # This way. Django has generated, the template files that the app would normally require.
Create two models, Poll and Choice.
dizzy@dizzy-pc:~/Python/mysite$ vim polls/
Modify the file as follows:
from import models
# Create your models here.
from import models
class Poll():
question = (max_length=200)
pub_date = ('date published')
class Choice():
poll = (Poll)
choice_text = (max_length=200)
votes = (default=0)
# The basic process of creating a model is this, the details have to be studied in depth!
Then modify the project's configuration file and add the app you just created under the INSTALLED_APP tuple: polls
dizzy@dizzy-pc:~/Python/mysite$ vim mysite/
INSTALLED_APPS = (
'',
'',
'',
'',
'',
'',
'polls',
)
#You can use python sql polls to view the app's table building SQL
# Create database tables using python syncdb
dizzy@dizzy-pc:~/Python/mysite$ ./ sql polls
BEGIN;
CREATE TABLE "polls_poll" (
"id" integer NOT NULL PRIMARY KEY,
"question" varchar(200) NOT NULL,
"pub_date" datetime NOT NULL
)
;
CREATE TABLE "polls_choice" (
"id" integer NOT NULL PRIMARY KEY,
"poll_id" integer NOT NULL REFERENCES "polls_poll" ("id"),
"choice_text" varchar(200) NOT NULL,
"votes" integer NOT NULL
)
;
COMMIT;
# This allows Django to automatically create database tables by setting up a model
To get in the backgroundadminmiddle managementpolls。Also needs to be modifiedapplower file。
from import admin
# Register your models here.
from import admin
from import Choice,Poll
class ChoiceInLine():
model = Choice
extra = 3
class PollAdmin():
fieldsets = [
(None, {'fields':['question']}),
('Date information', {'fields':['pub_date'],'classes':['collapse']}),
]
inlines = [ChoiceInLine]
(Poll,PollAdmin)
# This part of the code, generally understandable, the specific rules have to be a little later to scrutinize.
## This part of the code, due to a spelling error, resulted in multiple errors. The details make the difference!
This will restart the service again and you will be able to manage the polls application in the background.
(3) View and controller section
The model (M) has already been set up. All that's left is view (V) and urls (C), the view part of Django, which is completed by and templates.
In polls, we will create 4 views:
- "index" list page - shows the latest votes.
- "detail" Poll Page - displays a poll question, and a form that the user can use to vote.
- "results" results page - displays the results of a poll.
- Poll Processing - Processing of a poll form after it has been submitted by a user.
Now modify Create functions for views.
dizzy@dizzy-pc:~/Python/mysite$ vim polls/
from import render,get_object_or_404
# Create your views here.
from import HttpResponse
from import Poll
def index(request):
latest_poll_list = ().order_by('-pub_date')[:5]
context = {'latest_poll_list':latest_poll_list}
return render(request,'polls/',context)
def detail(request,poll_id):
poll = get_object_or_404(Poll,pk=poll_id)
return render(request,'polls/',{'poll':poll})
def results(request,poll_id):
return HttpResponse("you're looking at the results of poll %s." % poll_id)
def vote(request,poll_id):
return HttpResponse("you're voting on poll %s." % poll_id)
# Involves Django's own functions, without going deeper. Do research later!
To make the attempt accessible, there is also configuration .mysite is the URLConf for the whole site, but each app can have its own URLConf, which can be imported into the root configuration by means of an include. Now under polls create a new
from import patterns,url
from polls import views
urlpatterns = patterns('',
#ex:/polls/
url(r'^$',,name='index'),
#ex:/polls/5/
url(r'^(?P<poll_id>\d+)/$',,name='detail'),
#ex:/polls/5/results/
url(r'^(?P<poll_id>\d+)/results/$',,name='results'),
#ex:/polls/5/vote/
url(r'^(?P<poll_id>\d+)/vote/$',,name='vote'),
)
In #url, three parameters. The regular url, the function to process it, and the name of the
#RegularExpressions ！！！！！
Then in the root file, include this file.
dizzy@dizzy-pc:~/Python/mysite$ vim mysite/
from import patterns, include, url
from import admin
()
urlpatterns = patterns('',
# Examples:
# url(r'^$', '', name='home'),
# url(r'^blog/', include('')),
url(r'^polls/', include('',namespace="polls")),
url(r'^admin/', include()),
)
# There are Example: two forms. Because it's a tuple, it starts with " ' ', ".
Then start creating template files. Under polls, create the templates folder. Underneath there are, two files.
<!-- -->
{% if latest_poll_list %}
<ul>
{% for poll in latest_poll_list %}
<li><a href="{% url 'polls:detail' poll_id= %}">{{ }}</a></li>
{% endfor %}
</ul>
{% else %}
<p>No polls are available.</p>
{% endif %}
<!---->
<h1>{{ }}</h1>
<ul>
{% for choice in poll.choice_set.all %}
<li>{{ choice.choice_text }}</li>
{% endfor %}
</ul>
<!-- View setup complete，We'll have to go deeper into the grammar.！ -->
<!-- Now restart the service.， You will see the corresponding view -->
(4) Improvement of voting function
The above is just a simple implementation of the view functionality, and does not really implement the voting functionality. The next step is to improve the functionality.
# Modify template files
dizzy@dizzy-pc:~/Python/mysite$ vim polls/templates/polls/
# need to add the form
<h1>{{ }}</h1>
{% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %}
<form action="{% url 'polls:vote' %}" method="post">
{% csrf_token %}
{% for choice in poll.choice_set.all %}
<input type="radio" name="choice" value="{{ }}" />
<label for="choice{{ }}">{{ choice.choice_text }}</label><br />
{% endfor %}
<input type="submit" value="Vote" />
</form>
Then you need to modify the vote handler in to receive and process the post data.
# Documentation polls/
from import get_object_or_404, render
from import HttpResponseRedirect, HttpResponse
from import reverse
from import Choice, Poll
# ...
def vote(request, poll_id):
p = get_object_or_404(Poll, pk=poll_id)
try:
selected_choice = p.choice_set.get(pk=['choice'])
except (KeyError, ):
# Redisplay the poll voting form.
return render(request, 'polls/', {
'poll': p,
'error_message': "You didn't select a choice.",
})
else:
selected_choice.votes += 1
selected_choice.save()
# Always return an HttpResponseRedirect after successfully dealing
# with POST data. This prevents data from being posted twice if a
# user hits the Back button.
return HttpResponseRedirect(reverse('polls:results', args=(,)))
After a successful vote, redirect the user's browser to the results page.
def results(request, poll_id):
poll = get_object_or_404(Poll, pk=poll_id)
return render(request, 'polls/', {'poll': poll})
Then it's time to create the template .
<!-- polls/templates/polls/ -->
<h1>{{ }}</h1>
<ul>
{% for choice in poll.choice_set.all %}
<li>{{ choice.choice_text }} -- {{ }} vote{{ |pluralize }}</li>
{% endfor %}
</ul>
<a href="{% url 'polls:detail' %}">Vote again?</a>
At this point, restart the service to see the radio buttons, and SUBMIT.