Django tutorial

Fossmeet @ NITC 2010

Transcript

1. Django Workshop Rapid Web application Development Sarath Lakshman http://www.sarathlakshman.info FOSSMeet @ NITC 2010
2. Django Workshop
3. Django Workshop Overview of this Tutorial ➔ Brief introduction and philosophy ➔ Views ➔ URL Conf ➔ Templates ➔ Admin interface ➔ Hands-on code ➔ Building a quick blog application
4. Django Workshop Django's Mission Statement “Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design.”
5. Django Workshop MVC Model View Controller
6. Django Workshop Django Requirements ➔ Python (2.3+) ➔ PostgreSQL / MySQL / SQLite / ... ➔ Apache + mod_python / FastCGI / ...
7. Django Workshop Installation $ sudo apt-get install python-django OR $ wget http://www.djangoproject.com/download/1.1.1/tarball/ $ tar xzvf Django-1.1.1.tar.gz $ cd Django-1.1.1 $ sudo python setup.py install
8. Django Workshop “Projects” $ django-admin.py startproject $ django-admin.py startproject myproject myproject
9. Django Workshop myproject/ myproject/ __init__.py __init__.py manage.py manage.py settings.py settings.py urls.py urls.py
10. Django Workshop $ ./manage.py runserver $ ./manage.py runserver Validating models... 0 errors found. Django version 1.1.1, using settings 'myproject.settings' Development server is running at http://127.0.0.1:8000/ Quit the server with CONTROL-C. Development server
11. Django Workshop
12. Django Workshop “Apps” $ django-admin.py startapp helloweb $ django-admin.py startapp helloweb INSTALLED_APPS INSTALLED_APPS 'myproject.helloweb' 'myproject.helloweb'
13. Django Workshop myproject/ helloweb/ __init__.py models.py views.py __init__.py manage.py settings.py urls.py
14. Django Workshop Project settings settings.py
15. Django Workshop URL Conf Collection URL maps which describes which url show map to which view function arranged in urls.py
16. Django Workshop “Views” Collection of functions which return html data for different pages arranged in views.py
17. Django Workshop Templates Template is what 'template' means. html..css..javascript..etc kept in a file for repeated usage.
18. Django Workshop “Models” In Django, Models are the Data store. Models are high level object oriented interfaces for databases where the object schema is defined in model.py Forget about messes with “SELECT * FROM TABLE.. blah blah”
19. Django Workshop Concept to Code 1. Create project – django-admin createproject 2. Settings - settings.py 3. Create application - ./manage.py startapp 4. Write Models scheme – models.py 5. Sync database - ./manage syncdb 6. Views & templates – view.py 7. URLConf – urls.py 8. Done
20. Django Workshop Code Hands-on A helloweb application
21. Django Workshop Views from django.http import HttpResponse from django.http import HttpResponse def index(request): def index(request): html = “<h1>Hello Web !</h1>” html = “<h1>Hello Web !</h1>” return HttpResponse(html) return HttpResponse(html) views.py
22. Django Workshop URL Conf from django.conf.urls.defaults import * from django.conf.urls.defaults import * urlpatterns = patterns('', urlpatterns = patterns('', (r'^helloweb/$', 'helloweb.views.index'), (r'^helloweb/$', 'helloweb.views.index'), ) ) urls.py
23. Django Workshop More on Views # Processing GET # Processing GET request request def process_get(request): def process_get(request): html = “Not a GET request” html = “Not a GET request” if request.GET.has_key('page_no'): if request.GET.has_key('page_no'): html = “You have requested %d” % html = “You have requested %d” % request.GET['page_no'] request.GET['page_no'] return HttpResponse(html) return HttpResponse(html) Other dictionary objects Other dictionary objects request.POST request.POST request.session request.session
24. Django Workshop Using Templates settings.py TEMPLATE_DIRS = ( "/home/slynux/helloweb/html_templates" ) /home/slynux/helloweb/html_templates/template1.html <html> <head><title>HelloWeb django</title></head> <body> <p> This is a sample page</p> <table> <tr><td>Student</td><td>Roll No</td></tr> <tr><td>Sarath</td><td>22</td></tr> <tr><td>Slynux</td><td>44</td></tr> </table> </body> </html>
25. Django Workshop Using Templates File: /home/slynux/helloweb/html_templates/template2.html <html> <head><title>HelloWeb django</title></head> <body> <p> This is a sample page</p> <table> <tr><td>Student</td><td>Roll No</td></tr> {% for name,rollno in student_list.items() %} <tr> <td>{{ name }}</td> <td>{{ rollno }}</td> </tr> {% endfor %} </table> </body> </html>
26. Django Workshop View with Template def template_view1(request): from django.shortcuts import render_to_response return render_to_response('template1.html',{}) def template_view2(request): from django.shortcuts import render_to_response students = { 'Sarath':22, 'Slynux':34 } return render_to_response('template2.html', {'student_list':students } )
27. Django Workshop Using Models / Datastore settings.py DATABASE_ENGINE = 'sqlite3' DATABASE_NAME = '/home/slynux/fossmeet.in/db.sqlite' models.py from django.db.models class StudentRegister(models.Model): name = models.CharField(max_length=30) rollno = models.IntegerField() admission_date = models.DateTimeField() $ ./manage.py syncdb Creating student_studentregister Loading 'initial_data' fixtures... No fixtures found. $./manage.py sql helloweb
28. Django Workshop Using Models in Views students = { 'Sarath':22, 'Slynux':34 } is static. We can use dynamic content from database from helloweb.student.models import StudentRegister slist = StudentRegister.objects.all() students = {} for s in slist: students[s.name] = s.rollno
29. Django Workshop Using Models The django python shell $ ./manage shell >>> from helloweb.student.models import StudentRegister >>> sobj = StudentRegister() >>> sobj.name = “Slynux” >>> sobj.rollno = 40 >>> sobj.admission_date = '2009-11-01' >>> sobj.save() >>> StudentRegister.objects.all() [<StudentRegister: StudentRegister object>] >>> sob = StudentRegister.objects.get(name='Slynux') >>> sob.delete()
30. Django Workshop Admin interface Django comes with a builtin Admin interface which can be further customized.
31. Django Workshop Admin interface
32. Django Workshop Activating Admin settings.py Add 'django.contrib.admin', to INSTALLED_APPS tuple urls.py #Uncomment from django.contrib import admin admin.autodiscover() (r'^admin/', include(admin.site.urls)), $ ./manage.py syncdb
33. Django Workshop Adding Models to Admin Application directory/admin.py from django.contrib import admin from myproject.hellweb.models import StudentRegister admin.site.register(StudentRegister)
34. Django Workshop Hands-on code Writing a Blogging web application • Using template.html • Models title,post,category,date • Admin interface • Content search • Filter post by category
35. Django Workshop Google Appengine http://code.google.com/appengine
36. Django Workshop Thank you for listening. Sarath Lakshman sarathlakshman@slynux.com http://www.sarathlakshman.info http://twitter.com/t3rm1n4l
37. Django Workshop