Pluggable Patterns. For Reusable Django Applications

Transcription

1 Pluggable Patterns For Reusable Django Applications

2 Project

3 Project Configuration URL routing Templates

4 Project Application Application Application Application Application Application Application Application Application Configuration URL routing Templates

5 Here there be power! Project Application Application Application Application Application Application Application Application Application Configuration URL routing Templates

6 We need a better definition for Django Application

7 An app should not be a monolithic pile of code For example, most blog apps available provide too much functionality MyBlog App Categories Custom Tagging Custom Comments Comment Moderation Assumption of text markup type Single blogs Multiple Sites ACME MONOLITHS

8 An application should be pluggable

9 A pluggable app is Focused Write programs that do one thing and do it well. Doug McIlroy (inventor of UNIX pipes)

10 A pluggable app is Self-Contained Batteries are included Dependencies are declared

11 A pluggable app is Easily Adaptable Corey s Law: The less adaptable you make your code, the sooner you will be tasked to adapt it.

12 A pluggable app is Easily Installed pip install coolapp You did declare your dependencies, right?

13 How do we make a pluggable application?

14 Stop thinking like this

15 and think like this

16 Applications can have very different purposes

17 Application Types Data. Manages specific data and access to it Utility. Provide a way of handling a specific problem for any application Decorator. Adds functionality to one or aggregates functionality of many applications

18 Data Apps

19 Situation 1 Lots of variations Each implementation is different (e.g. blogs)

20 Abstract Models GLAMKit EntryBase FeaturableEntryMixin StatusableEntryMixin TaggableEntryMixin HTMLFormattableEntryMixin

21 Situation 2 A few, well-known of variations (e.g. Use django.contrib.sites?)

22 Optional Field Settings

23 Situation 3 Optionally use another application (e.g. Use django-tagging?)

24 Optional Integration

25 Optional Integration

26 Situation 3 You want to reference different models (e.g. Customizable author field)

27 Configurable Foreign Keys Viewpoint

28 Situation 3 You want to provide hooks for other applications (e.g. While processing in a view)

29 Emit Signals Satchmo

30 Utility Apps

31 Utility apps are just code libraries

32 Projects with template tags need one

33 Does it need to be in? Yes, if you have: Templates Template Tags Management Commands

34 Decorator Apps

35 CoolApp New Method Custom Manager New Field New Admin

36 Registering for Decoration

37 Simple Model Registry

38 Model-Data Registry

39 Lazy Registration

40 Situation 4 You want to add a field to a model (e.g. Link to another model)

41 Simple Model Registry

42 Situation 5 You want to add a method to a model (e.g. Link to another model)

43 Adding methods

44 Situation 6 You want to customize a model s ModelAdmin (e.g. Change the widget of a field)

45 Lazy Registration of a Custom ModelAdmin

46 Lazy Registration of a Custom ModelAdmin

47 Lazy Registration of a Custom ModelAdmin

48 Touch Points

49 Touch Points of an App The parts of an application that usually need tweaking URLs Templates Configurable options View responses

50 Situation 7 You want the URLs of your app to live under any prefix (e.g. /blogs/ vs. /weblogs/)

51 Name your URLs

52 Reference your URLs by name

53 Situation 8 You want your templates to be easily overridable

54 Namespace Templates coolapp templates coolapp base.html

55 Namespace Templates coolapp templates All templates in a template name space coolapp base.html

56 Namespace Templates coolapp templates coolapp All templates extend a single template base.html

57 Namespace Templates coolapp templates coolapp This template simply base.html

58 Import your blocks Allows you to override any of the templates extra_head.html content.html base.html

59 Situation 9 You want to configure your app without modifying its code (e.g. API keys)

60 Configurable Options Django Supertagging Internal Name Setting Name Default Value

61 Configurable Options Django Debug Toolbar

62 Define a Storage Option

63 Situation 10 You want to alter the data your views use (e.g. Extra context, different template)

64 Add keyword arguments Django Registration

65 Class-based Views

66 To be continued

67 My github.com/coordt github.com/washingtontimes opensource.washingtontimes.com