These are the slides for the talk I gave at the PloneSA group meeting in Cape Town on Wednesday 6 July 2011

2. [email_address]

3. http://opkode.com

7. ZTK uses Zope Component Architecture (ZCA)

8. ZCA also used by Pyramid/Pylons

10. Object Database (ZODB)

11. Object publishing and traversal

13. Components are objects with Interfaces

14. Many-to-one mapping between objs and Interfaces, can be interchanged.

18. ZCML = glue or wiring

19. Grok lets you use python statements instead of ZCML

20. Keeps glue and code together

21. Makes it easier to see what registrations are in effect

22. Reduces need to context switch files/syntaxes

24. In use in Plone, BlueBream, Grok, Pyramid

25. BrowserView is a multi-adapter (i.e ZCA component)

26. Python class containing ”display logic”, registered as a multi-adapter for Request and content-type.

27. Normally has template, but not required (i.e Ajax)

28. Doesn't always return anything (i.e redirects)

29. See: plonesa.grok/browser/*

31. Adapts an object of specific Interface, to also provide functionality specified by the adapter's interface.

32. Analogous to Type Casting

33. Real world analogy: Wall plug adapters

34. plonesa/grok/adapter.py

36. Similarities with BrowserViews

37. Render inside ViewletManagers

38. plonesa/grok/browser/viewlet.py

40. Zope provides an events system

41. Components notify the subscribers of a particular event.

42. Code execution is blocked until all subscribers are done.

43. plonesa/grok/events.py

45. Plone uses IAnnotations from zope.annotation which has a dict-like API.

46. Grok's pattern can cause problems when code is moved or uninstalled (which happens often in Plone)

47. http://pypi.python.org/pypi/grokcore.annotation

49. In Plone we define permissions in GS-XML configuration files rather than code.

51. For local, Grok uses grokcore.site

52. In Plone we use componentregistry.xml GS-XML

54. Can also use grok.DirectoryResource instead of <browser.resourceDirectory/> directive.

55. See http://pypi.python.org/pypi/grokcore.view

57. In Plone we use browserlayer.xml in GenericSetup

58. Alternatively SkinLayers via plone.theme package and configure.zcml

62. Plone uses plone.app.viewletmanager and GS-XML instead.

64. Can be accessed via TAL: view/static/stylesheet.css

65. In Plone this will always be relative to the context, rather than relative to site navigation root, which means it doesn't cache well.

66. Construct URL manually instead.

67. See: http://pypi.python.org/pypi/grokcore.view