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Django class based views for beginners
This document discusses Django class-based views and mixins. It begins by explaining function-based views and how they work by taking an HTTP request and returning a response. It then introduces class-based views, which are based on classes and use mixins to add functionality. Mixins provide reusable functionality that can be inherited by multiple classes. The document outlines common Django generic class-based views and how they work with mixins. It notes some potential downsides of mixins, such as losing track of method origins. Finally, it provides guidelines on choosing function-based or class-based views and keeping views and mixins simple.
Django class based views for beginners
- 1. Django Class-based Views forBeginners Spin Lai
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- 3. Function-based View What isFunction-based View? ▸ A Django views is a function that : ▸ Take an HTTP request as the input ▸ Turn it into a HTTP response ▸ a.k.a Function-based Views (FBVs)
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- 6. Function-based View How doesit work? Request Django FBV post_list() Response
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- 8. Class-based View What isClass-based View? ▸ Django views based on class ▸ Actually called as Function ▸ Using mixins to add functionality
- 9. Class-based View What doesit look like?
- 10. Class-based View How doesit work? Request Django CBV as_view() dispatch() get() / post() / put() … Response
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- 12. Mixins Image source :http://atwinkyaday.blogspot.tw/2012_12_01_archive.html
- 13. Mixins Flavour Image source :http://thebakingbird.com/ice-cream/humphry-slocombe-the-hipster-ice-cream-parlor-of-ice-cream-parlors/
- 14. Mixins + Flavour Mix-ins Image source :http://coldstoneofaberdeen.com/ice-cream/mix-go/
- 15. Mixins + = Flavour Mix-ins Image source: http://www.thecomfortofcooking.com/2014/04/amazing-no-churn-ice-cream-6-flavors.html
- 16. Mixins What is Mixinin Python? ▸ Actually, mixins are ordinary Python classes ▸ Provides functionality to be inherited ▸ But isn’t meant to be instantiated on its own
- 17. Mixins Why? ▸ Adding functionalityto classes ▸ Improve modularity
- 18. Mixins When to use? ▸Reuse code / features across multiple classes
- 19. Mixins Rule of thumb ▸Base view classes provided by Django always go to the right. ▸ Mixins go to the left of the base view. ▸ Mixins should inherit from Python’s built-in object type ▸ Keep shallow inheritance chain
- 20. Mixins - Ruleof thumb Base view classes provided by Django always go to the right
- 21. Mixins - Ruleof thumb Mixins go to the left of the base view
- 22. Mixins - Ruleof thumb Mixins should inherit from Python’s built-in object type
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- 24. Built-in Class-based GenericViews Category of Built-in Class-based Generic Views ▸ Base ▸ List ▸ Detail ▸ Edit
- 25. Built-in Class-based GenericViews Base Generic Views ▸ django.views.generic.View ▸ django.views.generic.TemplateView ▸ django.views.generic.RedirectView
- 26. Built-in Class-based GenericViews List Generic Views ▸ django.views.generic.list.ListView
- 27. Built-in Class-based GenericViews Detail Generic Views ▸ django.views.generic.detail.DetailView
- 28. Built-in Class-based GenericViews Edit Generic Views ▸ django.views.generic.FormView ▸ django.views.generic.CreateView ▸ django.views.generic.UpdateView ▸ django.views.generic.DeleteView
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- 34. CBVs and Mixins TemplateView TemplateView ViewContextMixin TemplateResponseMixin
- 35. CBVs and Mixins ListView ListView ViewTemplateResponseMixin ContextMixin MultipleObjectMixin BaseListView MutipleObjectTemplateResponseMixin
- 36. CBVs and Mixins DetailView DetailView ViewTemplateResponseMixin ContextMixin SingleObjectMixin BaseDetailView SingleObjectTemplateResponseMixin
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- 39. The Dark Side TheDark Side of Mixins ▸ Easy to lose track of the origin of your methods ▸ You may actually polluting the class namespace
- 40. The Dark Side TheDark Side of Generic CBVs ▸ Flow control is totally hidden ▸ The order of execution may not be obvious to anyone else ▸ More difficult to debug ▸ To understand what’s going on. You have to read the API docs, or even the source code of CBVs … ▸ Remember? “Explicit is better than implicit”
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- 43. Takeaways FBVs or CBVs? ▸ Does the Generic CBVs closely match what you need? ▸ Can you use a CBV just by overriding some attributes? ▸ Do you need to subclass your views to create some views?
- 44. Takeaways Guidelines ▸ Keep yourview simple ▸ Never repeat code in your views ▸ Only handle presentation logic in views ▸ Keep your mixins simpler ▸ Don’t use CBVs to write 403, 404… error handlers. Use FBVs instead
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- 46. Resources Links ▸ https://docs.djangoproject.com/ja/1.9/topics/class-based- views/ ▸ https://ccbv.co.uk/ ▸http://django-vanilla-views.org/
- 47. Resources Books ▸ 「Two Scoopsof Django: Best Practices for Django 1.8」 ▸ Chap 8 Function-and-Class-Based Views ▸ Chap 9 Best Practices for Function-Based Views ▸ Chap 10 Best Practices for Class-Based Views
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