A gentle intro to the Django Framework
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Django is a Python-based MVC web framework. It follows an MTV pattern where the Model represents the business logic and database, the Template displays data, and the View connects Models and Templates by handling requests and returning responses. The presentation discusses why use Python and Django, what MVC is, and each component of MTV in Django - Models define database schemas, Views handle requests and return responses using Templates, and the framework handles common tasks like authentication, internationalization, and more. It also introduces Django Admin which automatically generates interfaces to manage database objects.
![the M in the django framework
Example:
from django.db import models
class Company(models.Model):
name = models.CharField(_("Company name"), max_length=64)
phone = models.CharField("URL", max_length=32)
fax = models.CharField("Fax", max_length=32, null=True, blank=True)
email = models.EmailField("E-mail", max_length=32, null=True, blank=True)
ceos = models.ForeignKey('entities.Ceo')
class Meta:
ordering = ['name']
db_table = 'company'
verbose_name = _('Company')
verbose_name_plural = _('Companies')
# Return company's administrators
def get_ceos(self):
return self.ceos
# Returns an instance in a human-readable format
def __unicode__(self):
return self.name](https://image.slidesharecdn.com/gslabsdjango-110529121214-phpapp02/85/A-gentle-intro-to-the-Django-Framework-8-320.jpg)
![the V in the django framework
Example of a view:
from django.shortcuts import render_to_response
def property_details(request, id):
try:
c = {}
c.update(csrf(request))
property = Property.objects.get(pk=id)
c['property'] = property
except Property.DoesNotExist:
raise Http404
return render_to_response('properties/property_details.html', c)
Example of an URLconf:
urlpatterns = patterns('properties.views',
(r'^(?P<id>d+[a-z]*)', 'property_details'),
)](https://image.slidesharecdn.com/gslabsdjango-110529121214-phpapp02/85/A-gentle-intro-to-the-Django-Framework-13-320.jpg)
A gentle intro to the Django Framework
- 1. django python powered MVC framework
- 2. Presentation topics ● why python and why django? ● what is MVC? ● the M in the django framework ● the V in the django framework ● and the C in the django framework ● django admin
- 3. why python and why django? #1, why python? ● python is a "natural" OO language; ● python has functional capabilities; ● "batteries included"!! #2, why django? ● uses python (ahhh!); ● interfaces for common actions (dry); ● pluggable apps; ● you have more time to CREATE! ● you had VALUE to you products;
- 4. what is MVC? A software development pattern where the business logic is separated from the UI. In web development: ● (M)odel: the business logic/rules off the application (mostly the DB); ● (V)iew: the (x)html rendered and presented to the user; ● (C)ontroller: the handler that receives GET or POST requests, works over the domain object and retrieves a response to the user;
- 5. what is MVC? In the Django framework, things are a little bit different... Welcome to "MTV"!! (Model - Template - View)
- 6. the M in the django framework
- 7. the M in the django framework Not much different from the other M... ● It holds the business logic/rules; ● It is related with the DB; ● Describes the DB as classes of objects using a mapper (ORM); ● It holds methods to retrieve data;
- 8. the M in the django framework Example: from django.db import models class Company(models.Model): name = models.CharField(_("Company name"), max_length=64) phone = models.CharField("URL", max_length=32) fax = models.CharField("Fax", max_length=32, null=True, blank=True) email = models.EmailField("E-mail", max_length=32, null=True, blank=True) ceos = models.ForeignKey('entities.Ceo') class Meta: ordering = ['name'] db_table = 'company' verbose_name = _('Company') verbose_name_plural = _('Companies') # Return company's administrators def get_ceos(self): return self.ceos # Returns an instance in a human-readable format def __unicode__(self): return self.name
- 9. the V in the django framework
- 10. the V in the django framework A view, in django, has two parts: #1 A callback that: ● is a normal python method that always receive an HTTP request object... ● ... and always returns an HTTP response object; ● describes which data is presented;
- 11. the V in the django framework #2 An URLconf: ● that is a mapper between url's and the view callbacks; ● that is described by regexes;
- 12. the V in the django framework We can also include the templates here, since it is intrinsically linked to the view callbacks. ● Django has its own template system/language; ● It is pythonic, but very stricted; ● Organized by tags; ● Focus on how you display data; ● You can write your own set of tags;
- 13. the V in the django framework Example of a view: from django.shortcuts import render_to_response def property_details(request, id): try: c = {} c.update(csrf(request)) property = Property.objects.get(pk=id) c['property'] = property except Property.DoesNotExist: raise Http404 return render_to_response('properties/property_details.html', c) Example of an URLconf: urlpatterns = patterns('properties.views', (r'^(?P<id>d+[a-z]*)', 'property_details'), )
- 14. the V in the django framework Example of a template: {% extends "base.html" %} {% load i18n %} {% block highlights %} {% include "horizontal_search.html" %} <div style="margin-top: 25px;"></div> {% endblock %} {% block content %} <div style="padding-left: 9px; padding-right: 6px;"> <div id="text_wrapper"> <h4>{% trans "About" %} {{ property.reference }}</h4> {{ property.description }} </div> {% endblock %}
- 15. the C in the django framework
- 16. the C in the django framework Possibly the most complex part... Basically it's all the django framework! This includes: ● modules that are responsible for user authentication... ● modules that prevents CSRF's... ● that are responsible for the website language (i18n, l7n); ● etc... It's all the machinery between an URLconf and a view. Those modules are called middleware.
- 17. django admin
- 18. django admin django admin is a very usefull app that allows you to save a lot of time. ● Uses class attributes to create forms; ● Common methods included (add, edit, remove); ● Complete admin interface that can be changed; ● User management;
- 19. django admin Default objects list
- 20. django admin Default add form