Contents
About the Author
Acknowledgments
Preface
Introduction
CHAPTER 1 Understanding Django
Philosophy
Django's Interpretation of the MVC Pattern
Loose Coupling
Don't Repeat Yourself (DRY)
A Focus on Readability
Failing Loudly
Community
Management of the Framework
News and Resources
Reusable Applications
Getting Help
Now What?
CHAPTER 2 Django Is Python
How Python Builds Classes
Building a Class Programmatically
Metaclasses Change It Up
Using a Base Class with a Metaclass
Declarative Syntax
Common Duck-Typing Protocols
Callables
Dictionaries
Files
Iterables
Sequences
Augmenting Functions
Excess Arguments
Decorators
Descriptors
__get__(self, instance, owner)
__set__(self, instance, value)
Keeping Track of Instance Data
Introspection
Common Class and Function Attributes
Identifying Object Types
Function Signatures
Docstrings
Applied Techniques
Tracking Subclasses
A Simple Plugin Architecture
Now What?
CHAPTER 3 Models
How Django Processes Model Classes
Setting Attributes on Models
Getting Information About Models
Class Information
Field Definitions
Primary Key Fields
Configuration Options
Accessing the Model Cache
Using Model Fields
Common Field Attributes
Common Field Methods
Subclassing Fields
Deciding Whether to Invent or Extend
Performing Actions During Model Registration
Altering Data Behavior
Controlling Database Behavior
Dealing with Files
get_directory_name(self)
get_filename(self, filename)
generate_filename(self, instance, filename)
save_form_data(self, instance, data)
delete_file(self, instance, sender)
attr_class
Customizing the File Class
Signals
class_prepared
pre_init and post_init
pre_save and post_save
pre_delete and post_delete
post_syncdb
Applied Techniques
Loading Attributes on Demand
Creating Models Dynamically at Runtime
Now What?
CHAPTER 4 URLs and Views
URLs
Standard URL Configuration
Resolving URLs to Views
Resolving Views to URLs
Views
Templates Break It Up a Bit
Anatomy of a View
Writing Views to Be Generic
View Decorators
Using an Object As a View
Applied Techniques
Dual-Format Decorator
Now What?
CHAPTER 5 Forms
Declaring and Identifying Fields
Binding to User Input
Validating Input
Custom Fields
Validation
Controlling Widgets
Defining HTML Behavior
Custom Widgets
Customizing Form Markup
Accessing Individual Fields
Customizing the Display of Errors
Applied Techniques
Pending and Resuming Forms
Now What?
CHAPTER 6 Templates
What Makes a Template
Exceptions
The Process at Large
Content Tokens
Parsing Tokens into Nodes
Template Nodes
Rendering Templates
Context
Simple Variable Resolution
Complex Variable Lookup
Including Aspects of the Request
Retrieving Templates
Shortcuts to Load and Render Templates
Adding Features for Templates
Setting Up the Package
Variable Filters
Template Tags
Adding Features to All Templates
Applied Techniques
Embedding Another Template Engine
Enabling User-Submitted Themes
Now What?
CHAPTER 7 Handling HTTP
Requests and Responses
HttpRequest
HttpResponse
Writing HTTP Middleware
MiddlewareClass.process_request(self, request)
MiddlewareClass.process_view(self, request, view, args, kwargs)
MiddlewareClass.process_response(self, request, response)
MiddlewareClass.process_exception(self, request, exception)
Deciding Between Middleware and View Decorators
HTTP-Related Signals
django.core.signals.request_started
django.core.signals.request_finished
django.core.signals.got_request_exception
Applied Techniques
Signing and Validating Cookies
Now What?
CHAPTER 8 Backend Protocols
Database Access
django.db.backends
Creation of New Structures
Introspection of Existing Structures
DatabaseClient
DatabaseError and IntegrityError
Authentication
get_user(user_id)
authenticate(**credentials)
Storing User Information
Files
The Base File Class
Handling Uploads
Storing Files
Session Management
Caching
Specifying a Backend
Using the Cache Manually
Template Loading
load_template_source(template_name, template_dirs=None)
load_template_source.is_usable
Context Processors
Applied Techniques
Loading Templates Using a Different Engine
Scanning Incoming Files for Viruses
Now What?
CHAPTER 9 Common Tools
Core Exceptions
django.core.exceptions.ImproperlyConfigured
django.core.exceptions.MiddlewareNotUsed
django.core.exceptions.MultipleObjectsReturned
django.core.exceptions.ObjectDoesNotExist
django.core.exceptions.PermissionDenied
django.core.exceptions.SuspiciousOperation
django.core.exceptions.ViewDoesNotExist
Text Modification
get_text_list(items, last_word='or')
javascript_quote(s, quote_double_quotes=False)
normalize_newlines(text)
phone2numeric(phone)
recapitalize(text)
smart_split(text)
truncate_words(s,num)
truncate_html_words(s, num)
wrap(text, width)
Data Structures
django.utils.datastructures.MergeDict
django.utils.datastructures.MultiValuedDict
django.utils.datastructures.SortedDict
Functional Utilities
django.utils.functional.curry
django.utils.functional.memoize
django.utils.functional.wraps
Signals
How It Works
Defining a Signal
Sending a Signal
Capturing Return Values
Defining a Listener
Registering Listeners
Forcing Strong References
Now What?
CHAPTER 10 Coordinating Applications
Contacts
contacts.models.Contact
contacts.forms.UserEditorForm
contacts.forms.ContactEditorForm
contacts.views.edit_contact
Admin Configuration
URL Configuration
Real Estate Properties
properties.models.Property
properties.models.Feature
properties.models.PropertyFeature
properties.models.InterestedParty
Admin Configuration
URL Configuration
Now What?
CHAPTER 11 Enhancing Applications
Recording the Current User
The Thread-Local Approach—Useful but Dangerous
The Admin Approach
Introducing the CurrentUserField
Keeping Track of CurrentUserField Instances
The CurrentUserMiddleware
Performance Considerations
Keeping Historical Records
Intended Usage
Overview of the Process
Step 1: Copy the Model
Step 2: Register Signal Handlers
Step 3: Assign a Manager
Now What?
APPENDIX Contributing to Django
Reporting a Ticket
Supplying a Patch
Writing Tests
Writing Documentation
Development Sprints
Publishing Code
Releasing an Application
Index
