a hands on guide to django

Hands on to django

November 15, 2009

() Hands on to django November 15, 2009 1 / 36

disclaimer

this is based on my brief experience in django

a lot is from my job experience

a lot of the code does not look this way, i just clean it up

and cram a lot of space


the slide and code is on the web

the code is bitbucket.org

http://bitbucket.org/sweemeng/barcamp-malacca/

slide is on slideshare.net

http://www.slideshare.net/sweemenghacker/a-hands-on-guide-to-django


What is django

Django is a Web framework

Build on the python programming language


What you will need

You will need

python, I use python 2.6, because ubuntu uses it

a database, I use mysql

python-mysql for mysql

and thats pretty much everything


Lets start

To start a django project

The command on terminal

python django-admin startproject example

begin demo 1


A little setup Part 1

A few files is created form the command previously

File list

manage.py settings.py templates urls.py

Now we concern on settings.pyBefore that create a database in mysql

create database

create database exampledb;


A little setup Part 2

DATABASE ENGINE = ’ mysql ’DATABASE NAME = ’ exampledb ’DATABASE USER = ’ root ’DATABASE PASSWORD = ’ root ’


Let start an app

A django project is consist of multiple applications

To start an app, use manage.py

start a django apps

python manage.py startapp exampleapp

The newly create app folder should have

example content

init .py models.py tests.py urls.py views.py


What ORM?

django talk to database using ORM

ORM == Object Relational Mapper

It is used to model a database table into object

start create one in exampleapp/models.py

from django . db i m p o r t models# C r e a t e your models h e r e .c l a s s Example ( models . Model ) :

name = models . T e x t F i e l d ( )s c o r e = models . I n t e g e r F i e l d ( )

Django models field also have field like email, and image


lets prepare our application

before we can run our application

a little setup

INSTALLED APPS = (’ d jango . c o n t r i b . auth ’ ,’ d jango . c o n t r i b . c o n t e n t t y p e s ’ ,’ d jango . c o n t r i b . s e s s i o n s ’ ,’ d jango . c o n t r i b . s i t e s ’ ,’ exampleapp ’ ,

)


setup redux

now setting up the database

creating the table

python manage.py syncdb

when prompt to create new superuser, just type yes

and fill in the infor what ever you wanted


now to create a basic view

in exampleapps/views.py

from django . h t t p i m p o r t HttpResponsefrom django . h t t p i m p o r t H t t p R e s p o n s e R e d i r e c tfrom django . s h o r t c u t s i m p o r t r e n d e r t o r e s p o n s e# C r e a t e your v i e w s h e r e .from models i m p o r t ∗d e f e x a m p l e v i e w ( r e q u e s t ) :

i f r e q u e s t . method == ’POST ’ :data = Example (

name = r e q u e s t .POST. g e t ( ’ p o s t i n g ’ ) ,s c o r e = 0)

data . s a v e ( )r e s = Example . o b j e c t s . a l l ( )r e t u r n r e n d e r t o r e s p o n s e ( ’ example / t e m p l a t e . html ’ ,

{ ’ r e s ’ : r e s })


add this extra views

d e f e x a m p l e l i k e ( r e q u e s t , i d ) :data = Example . o b j e c t s . g e t ( i d=i d )data . s c o r e = data . s c o r e + 1data . s a v e ( )r e t u r n H t t p R e s p o n s e R e d i r e c t ( ’ / example / ’ )


add this extra views

d e f e x a m p l e h a t e ( r e q u e s t , i d ) :data = Example . o b j e c t s . g e t ( i d=i d )data . s c o r e = data . s c o r e − 1data . s a v e ( )r e t u r n H t t p R e s p o n s e R e d i r e c t ( ’ / example / ’ )


now create template

<html><head></head><body><br/><a h r e f =’/ example / l o g o u t /’> l o g o u t </a><form method=’ post ’ a c t i o n =’/ example /’>F i l l i n your s t a t u s

<br/>< t e x t a r e a name=’ p o s t i n g ’></ t e x t a r e a ><br/>< i n p u t t y p e =’ submit ’ v a l u e =’ submit ’/></form><br/>{% f o r d i n r e s %}

{{d . name}} {{d . s c o r e }}<br/><a h r e f =”/example / l i k e /{{d . i d }}/”> l i k e </a> <ah r e f =”/example / hat e /{{d . i d }}/”>hate </a><br/>

{% e n d f o r %}</body></html>


almost there

first create urls.py in exampleapps

from django . c o n f . u r l s . d e f a u l t s i m p o r t ∗from v i e w s i m p o r t ∗u r l p a t t e r n s = p a t t e r n s ( ’ ’ ,

( r ’ ˆ $ ’ , e x a m p l e v i e w ) ,( r ’ ˆ l i k e /(\d+)/$ ’ , e x a m p l e l i k e ) ,( r ’ ˆ hat e /(\d+)/$ ’ , e x a m p l e h a t e ) ,)


still going

and add a new entry in the main urls.py

from django . c o n f . u r l s . d e f a u l t s i m p o r t ∗

# Uncomment t he n e x t two l i n e s to e n a b l e the admin :#from django . c o n t r i b i m p o r t admin#admin . a u t o d i s c o v e r ( )

u r l p a t t e r n s = p a t t e r n s ( ’ ’ ,( r ’ ˆ example / ’ , i n c l u d e ( ’ exampleapp . u r l s ’ ) ) ,( r ’ ˆ admin / ’ , i n c l u d e ( admin . s i t e . u r l s ) ) ,

)


now run the program

run the internal server

python manage.py runserver

and test the app by pointing your browser

point browser to this address

localhost:8000/examples/


Now to add some login

before we continue

django have many application that make live easier

here we first look at the authentication framework


first we import some modules

from django . c o n t r i b . auth . d e c o r a t o r s i m p o r t l o g i n r e q u i r e dfrom django . c o n t r i b . auth i m p o r t a u t h e n t i c a t efrom django . c o n t r i b . auth i m p o r t l o g i nfrom django . c o n t r i b . auth i m p o r t l o g o u tfrom django . c o n t r i b . auth . models i m p o r t User

BTW the apps is installed by default


lets enable registration.

The user registration just need the username,password,email

here is the view

d e f e x a m p l e r e g i s t e r ( r e q u e s t ) :i f r e q u e s t . method == ’POST ’ :

username = r e q u e s t .POST. g e t ( ’ username ’ )password = r e q u e s t .POST. g e t ( ’ password ’ )e m a i l = r e q u e s t .POST. g e t ( ’ emai l ’ )u s e r = User . o b j e c t s . c r e a t e u s e r ( username ,

emai l , password )u s e r . s a v e ( )r e t u r n H t t p R e s p o n s e R e d i r e c t (

’/ example / l o g i n / ’ )e l s e :

r e t u r n r e n d e r t o r e s p o n s e (’ example / r e g i s t e r . html ’ , { } )


the templates

d e f e x a m p l e r e g i s t e r ( r e q u e s t ) :i f r e q u e s t . method == ’POST ’ :

username = r e q u e s t .POST. g e t ( ’ username ’ )password = r e q u e s t .POST. g e t ( ’ password ’ )e m a i l = r e q u e s t .POST. g e t ( ’ emai l ’ )u s e r = User . o b j e c t s . c r e a t e u s e r ( username

, e m a i l, password )

u s e r . s a v e ( )r e t u r n H t t p R e s p o n s e R e d i r e c t (


r e t u r n r e n d e r t o r e s p o n s e (’ example / r e g i s t e r . html ’ , { } )


lets login

d e f e x a m p l e l o g i n ( r e q u e s t ) :i f r e q u e s t . method == ’POST ’ :

username = r e q u e s t .POST. g e t ( ’ username ’ )p a s s w o r d = r e q u e s t .POST. g e t ( ’ password ’ )u s e r = a u t h e n t i c a t e ( username = username ,

password = p a s s w o r d )#c o n t i n u e d n e x t page


continued

#from p r e v i o u s pagei f u s e r i s not None :

i f u s e r . i s a c t i v e :l o g i n ( r e q u e s t , u s e r )r e t u r n H t t p R e s p o n s e R e d i r e c t (

’/ example / ’ )e l s e :

r e t u r n H t t p R e s p o n s e R e d i r e c t (’/ example / l o g i n / ’ )

e l s e :r e t u r n H t t p R e s p o n s e R e d i r e c t (


r e t u r n r e n d e r t o r e s p o n s e (’ example / l o g i n . html ’ , { } )


and the login page

<html><head></head><body><form a c t i o n =’/ example / l o g i n / ’ method=’ post ’><br/>< l a b e l >username :</ l a b e l >< i n p u t t y p e =’ t e x t ’ name=’ username ’/><br/>< l a b e l >password :</ l a b e l >< i n p u t t y p e =’ password ’ name=’ password ’/><br/>< i n p u t t y p e =’ submit ’ v a l u e =’ submit ’/></form>

</body></html>


logout

d e f e x a m p l e l o g o u t ( r e q u e s t ) :l o g o u t ( r e q u e s t )r e t u r n H t t p R e s p o n s e R e d i r e c t (

’/ example / l o g i n / ’ )


now to make it works

u r l p a t t e r n s = p a t t e r n s ( ’ ’ ,( r ’ ˆ $ ’ , e x a m p l e v i e w ) ,( r ’ ˆ l o g i n /$ ’ , e x a m p l e l o g i n ) ,( r ’ ˆ r e g i s t e r /$ ’ , e x a m p l e r e g i s t e r ) ,( r ’ ˆ l o g o u t /$ ’ , e x a m p l e l o g o u t ) ,( r ’ ˆ l i k e /(\d+)/$ ’ , e x a m p l e l i k e ) ,( r ’ ˆ hat e /(\d+)/$ ’ , e x a m p l e h a t e ) ,)


to apply it to our apps

to apply login needed for our views

just add a line called @login required

it will force a login


a little setup again

add the following line to settings.py

LOGIN URL = ’/ example / l o g i n / ’LOGOUT URL = ’/ example / l o g i n / ’


the best part of django

admin page is free on django

meaning you can just use enable it


still going

uncomment admin stuff in in the main urls.py

from django . c o n f . u r l s . d e f a u l t s i m p o r t ∗

from django . c o n t r i b i m p o r t adminadmin . a u t o d i s c o v e r ( )

u r l p a t t e r n s = p a t t e r n s ( ’ ’ ,( r ’ ˆ example / ’ , i n c l u d e ( ’ exampleapp . u r l s ’ ) ) ,

( r ’ ˆ admin / ’ , i n c l u d e ( admin . s i t e . u r l s ) ) ,)


now to create admin.py

from django . c o n t r i b i m p o r t adminfrom models i m p o r t ∗admin . s i t e . r e g i s t e r ( Example )


install the admin apps

INSTALLED APPS = (’ d jango . c o n t r i b . auth ’ ,’ d jango . c o n t r i b . c o n t e n t t y p e s ’ ,’ d jango . c o n t r i b . s e s s i o n s ’ ,’ d jango . c o n t r i b . s i t e s ’ ,’ d jango . c o n t r i b . admin ’ ,’ exampleapp ’ ,

)


now to finish up

run syncdb

python manage.py syncdb


in the end

this is just a demo on a few thing on django

django offer a lot more

builtin feed syndication,commenting,tagging,GIS


that’s all folks

So Long And Thanks For All The Fish


a hands on guide to django

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