Django 最佳实践-读书笔记 - 第八、九、十章 FBVS & CBVS
第八章 FBVS & CBVS
如何选择 function - views 和 class - views
见流程图： 
urlconf 中不要包含 views 的逻辑
Bad example :
from django.conf.urls import url
from django.views.generic import DetailView
from tastings.models import Tasting
urlpatterns = [
url(r"^(?P<pk>\d+)/$",
DetailView.as_view(
model=Tasting,
template_name="tastings/detail.html"),
name="detail"),
url(r"^(?P<pk>\d+)/results/$",
DetailView.as_view(
model=Tasting,
template_name="tastings/results.html"),
name="results"),
]优点:
- 在 views 避免了重复的代码
- 松耦合
- url 集中处理路由问题
- views 可以得到 class-based views 的所有优点
- 更加灵活
使用url name space 更好的管理 url
url(r'^detail/', include('tastings.urls', namespace='tastings')),
通过 tastings:detail 调用。
url设计原则：
- url 尽量短小，明显
- 更容易搜索，更新，重构
不要在url 中使用 string的 views路径
url(r'^$', 'polls.views.index', name='index'),- 当views 有错误时，导致调试困难
- Instructors have to explain to beginners the need for an empty string at the beginning of the urlpatterns variable。
将业务逻辑移除 views 便于管理复用
尽量不要使用locals() 作为 Views Context
- 有可能会污染 template 变量环境
- 当变量较多时，消耗不必要的资源
第九章 Function-based views 最佳实践
编写function-based views 建议
- 保持views 的最小代码量
- 在views 中不要重复的代码
- views 中保留着表现逻辑，业务逻辑尽可能的在models、form层。
- 使用 function-based views 编写自定义的 错误处理（403, 404, and 500 error handlers.）
- 避免负责逻辑的嵌套。
通过 request、response 对象来传递属性值。
function-based views 可以更好的利用装饰器
第十章 Class-based views 最佳实践
编写class-based views 建议
- 保持views 的最小代码量
- 在views 中不要重复的代码
- views 中保留着表现逻辑，业务逻辑尽可能的在models、form层。
- 不要使用class-based views，使用 function-based views 编写自定义的 错误处理（403, 404, and 500 error handlers.）
- 使 mixins 最小化。
mixins 使用排序： python-object, mixins , base-views
class FruityFlavorView(FreshFruitMixin, TemplateView):
template_name = "fruity_flavor.html"什么时候使用什么视图
| Name | Purpose | Two Scoops Example |
|---|---|---|
| View | Base view or handy view that can be used foranything. | See section 10.6, `Using Justdjango.views.generic.View'. |
| RedirectView | Redirect user to another URL | Send users who visit /log-in/' to/login/'. |
| TemplateView | Display a Django HTML template. | The `/about/' page of our site. |
| ListView | List objects | List of ice cream flavors. |
| DetailView | Display an object | Details on an ice cream flavor. |
| FormView | Submit a form | The site's contact or email form. |
| CreateView | Create an object | Create a new ice cream flavor. |
| UpdateView | Update an object | Update an existing ice cream flavor. |
| DeleteView | Delete an object | Delete an unpleasant ice cream flavorlike Vanilla Steak. |
| Generic date views | For display of objects that occur over a rangeof time. | Blogs are a common reason to usethem. For Two Scoops, we could create a public history of when flavors havebeen added to the database. |
使用 LoginRequiredMixin 来进行用户认证
class FlavorDetailView(LoginRequiredMixin, DetailView):
model = Flavor将多个视图都需要重写的方法放入到 mixin 中，以保证视图的简单清晰
from django.contrib import messages
from django.views.generic import CreateView, UpdateView, DetailView
from braces.views import LoginRequiredMixin
from .models import Flavor
class FlavorActionMixin(object):
fields = ('title', 'slug', 'scoops_remaining')
@property
def success_msg(self):
return NotImplemented
def form_valid(self, form):
messages.info(self.request, self.success_msg)
return super(FlavorActionMixin, self).form_valid(form)
class FlavorCreateView(LoginRequiredMixin, FlavorActionMixin,
CreateView):
model = Flavor
success_msg = "Flavor created!"
class FlavorUpdateView(LoginRequiredMixin, FlavorActionMixin,
UpdateView):
model = Flavor
success_msg = "Flavor updated!"ps： 感觉本书views 这里讲的比较乱, 部分class-based views 可参见另一篇博文： Django class views