Django视图源码
目录
1，FBV
import json
from django.db.models import Q
from django.views.decorators.csrf import csrf_exempt,csrf_protect
from mysystem.models import Student
from django.http import JsonResponse
# 关闭验证
# @csrf_exempt
def view(request):
if request.method == 'GET':
"""获取多个学生信息"""
# 1. 读取数据库
students_list = list(Student.objects.values())
# 2. 返回数据
return JsonResponse(data=students_list, status=200, safe=False)
elif request.method == 'POST':
"""添加一个学生信息"""
# 1. 接收客户单提交的数据，验证客户端的数据
data = json.loads(request.body)
name = data.get("name")
sex = data.get("sex")
age = data.get("age")
classmate = data.get("classmate")
description = data.get("description")
# 2. 操作数据库，保存数据
instance = Student.objects.create(
name=name,
sex=sex,
age=age,
classmate=classmate,
description=description,
)
# 3. 返回结果
return JsonResponse(data={
"id": instance.pk,
"name": instance.name,
"sex": instance.sex,
"age": instance.age,
"classmate": instance.classmate,
"description": instance.description,
}, status=201)
# 开启验证
# @csrf_protect
def view_detail(request, id):
if request.method == 'DELETE':
"""删除一个学生信息"""
try:
Student.objects.filter(pk=id).delete()
except:
pass
return JsonResponse(data={}, status=204)
elif request.method == 'PUT':
"""更新一个学生信息"""
# 1. 接收客户单提交的数据，验证客户端的数据
data = json.loads(request.body)
name = data.get("name") # alt+j 选中多个一样的
sex = data.get("sex")
age = data.get("age")
classmate = data.get("classmate")
description = data.get("description")
# 2. 操作数据库，保存数据
try:
instance = Student.objects.get(pk=id)
instance.name = name
instance.sex = sex
instance.age = age
instance.classmate = classmate
instance.description = description
instance.save()
except Student.DoesNotExist:
return JsonResponse(data={}, status=404) # 没有内容
# 3. 返回结果
return JsonResponse(data={
"id": instance.id,
"name": instance.name,
"sex": instance.sex,
"age": instance.age,
"classmate": instance.classmate,
"description": instance.description,
}, status=201)
elif request.method == 'GET':
"""获取一条数据"""
try:
instance = Student.objects.filter(
Q(name__icontains=id) | Q(description__icontains=id)
)
results = [
{
'name': item.name,
'age' : item.age,
'description': item.description
}
for item in instance
if item.age > 24
]
return JsonResponse({'res': results},status=200)
# return JsonResponse(data={
# "id": instance.id,
# "name": instance.name,
# "sex": instance.sex,
# "age": instance.age,
# "classmate": instance.classmate,
# "description": instance.description,
# }, status=200)
except Student.DoesNotExist:
return JsonResponse(data=None, status=404) # 没有内容
2,CBV
from django.views import View
from django.http import JsonResponse
from mysystem.models import Student
import json
class StudentView(View):
def get(self, request):
res = list(Student.objects.values())
print(type(res), res)
return JsonResponse(data={'results': res}, status=200)
def post(self, request):
res = json.loads(request.body)
# 1,反序列化数据，
# 2，数据校验
# 3，数据库操作
# 4，异常捕获
# 5，返回响应
Student.objects.create(
name=res['name'],
sex=res['sex'],
age=res['age'],
classmate=res['classmate'],
description=res['description']
)
return JsonResponse(data={}, status=200)
class StudentDetailView(View):
def get(self, request,id):
res = Student.objects.get(name=id)
data = [
res.name,
res.sex,
res.age,
res.classmate,
res.description
]
return JsonResponse(data={'results': data},status=200)
def put(self, request,id):
# 1,数据库操作
# 2，获取request中提交的值
# 3，反序列化
# 4，数据校验
# 5，修改模型类数据的值
# 6，提交到数据库
res = Student.objects.get(pk=id)
instance = json.loads(request.body)
res.name = instance.get('name')
res.sex = instance.get('sex')
res.age = instance.get('age')
res.classmate = instance.get('classmate')
res.description = instance.get('description')
res.save()
return JsonResponse(data={'results': instance},status=200)
def delete(self, request,id):
# 1,验证权限
# 2，操作数据库
Student.objects.filter(pk=id).delete()
return JsonResponse(data={'delete success'}, status=204)
django的view源码，base.py
import logging
from functools import update_wrapper
from django.core.exceptions import ImproperlyConfigured
from django.http import (
HttpResponse, HttpResponseGone, HttpResponseNotAllowed,
HttpResponsePermanentRedirect, HttpResponseRedirect,
)
from django.template.response import TemplateResponse
from django.urls import reverse
from django.utils.decorators import classonlymethod
logger = logging.getLogger('django.request')
class ContextMixin:
"""
A default context mixin that passes the keyword arguments received by
get_context_data() as the template context.
"""
extra_context = None
def get_context_data(self, **kwargs):
kwargs.setdefault('view', self)
if self.extra_context is not None:
kwargs.update(self.extra_context)
return kwargs
class View:
"""
Intentionally simple parent class for all views. Only implements
dispatch-by-method and simple sanity checking.
"""
http_method_names = ['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']
def __init__(self, **kwargs):
"""
Constructor. Called in the URLconf; can contain helpful extra
keyword arguments, and other things.
"""
# Go through keyword arguments, and either save their values to our
# instance, or raise an error.
for key, value in kwargs.items():
setattr(self, key, value)
@classonlymethod
def as_view(cls, **initkwargs):
"""Main entry point for a request-response process."""
for key in initkwargs:
if key in cls.http_method_names:
raise TypeError(
'The method name %s is not accepted as a keyword argument '
'to %s().' % (key, cls.__name__)
)
if not hasattr(cls, key):
raise TypeError("%s() received an invalid keyword %r. as_view "
"only accepts arguments that are already "
"attributes of the class." % (cls.__name__, key))
def view(request, *args, **kwargs):
self = cls(**initkwargs)
self.setup(request, *args, **kwargs)
if not hasattr(self, 'request'):
raise AttributeError(
"%s instance has no 'request' attribute. Did you override "
"setup() and forget to call super()?" % cls.__name__
)
return self.dispatch(request, *args, **kwargs)
view.view_class = cls
view.view_initkwargs = initkwargs
# take name and docstring from class
update_wrapper(view, cls, updated=())
# and possible attributes set by decorators
# like csrf_exempt from dispatch
update_wrapper(view, cls.dispatch, assigned=())
return view
def setup(self, request, *args, **kwargs):
"""Initialize attributes shared by all view methods."""
if hasattr(self, 'get') and not hasattr(self, 'head'):
self.head = self.get
self.request = request
self.args = args
self.kwargs = kwargs
def dispatch(self, request, *args, **kwargs):
# Try to dispatch to the right method; if a method doesn't exist,
# defer to the error handler. Also defer to the error handler if the
# request method isn't on the approved list.
if request.method.lower() in self.http_method_names:
handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
else:
handler = self.http_method_not_allowed
return handler(request, *args, **kwargs)
def http_method_not_allowed(self, request, *args, **kwargs):
logger.warning(
'Method Not Allowed (%s): %s', request.method, request.path,
extra={'status_code': 405, 'request': request}
)
return HttpResponseNotAllowed(self._allowed_methods())
def options(self, request, *args, **kwargs):
"""Handle responding to requests for the OPTIONS HTTP verb."""
response = HttpResponse()
response.headers['Allow'] = ', '.join(self._allowed_methods())
response.headers['Content-Length'] = '0'
return response
def _allowed_methods(self):
return [m.upper() for m in self.http_method_names if hasattr(self, m)]
class TemplateResponseMixin:
"""A mixin that can be used to render a template."""
template_name = None
template_engine = None
response_class = TemplateResponse
content_type = None
def render_to_response(self, context, **response_kwargs):
"""
Return a response, using the `response_class` for this view, with a
template rendered with the given context.
Pass response_kwargs to the constructor of the response class.
"""
response_kwargs.setdefault('content_type', self.content_type)
return self.response_class(
request=self.request,
template=self.get_template_names(),
context=context,
using=self.template_engine,
**response_kwargs
)
def get_template_names(self):
"""
Return a list of template names to be used for the request. Must return
a list. May not be called if render_to_response() is overridden.
"""
if self.template_name is None:
raise ImproperlyConfigured(
"TemplateResponseMixin requires either a definition of "
"'template_name' or an implementation of 'get_template_names()'")
else:
return [self.template_name]
class TemplateView(TemplateResponseMixin, ContextMixin, View):
"""
Render a template. Pass keyword arguments from the URLconf to the context.
"""
def get(self, request, *args, **kwargs):
context = self.get_context_data(**kwargs)
return self.render_to_response(context)
class RedirectView(View):
"""Provide a redirect on any GET request."""
permanent = False
url = None
pattern_name = None
query_string = False
def get_redirect_url(self, *args, **kwargs):
"""
Return the URL redirect to. Keyword arguments from the URL pattern
match generating the redirect request are provided as kwargs to this
method.
"""
if self.url:
url = self.url % kwargs
elif self.pattern_name:
url = reverse(self.pattern_name, args=args, kwargs=kwargs)
else:
return None
args = self.request.META.get('QUERY_STRING', '')
if args and self.query_string:
url = "%s?%s" % (url, args)
return url
def get(self, request, *args, **kwargs):
url = self.get_redirect_url(*args, **kwargs)
if url:
if self.permanent:
return HttpResponsePermanentRedirect(url)
else:
return HttpResponseRedirect(url)
else:
logger.warning(
'Gone: %s', request.path,
extra={'status_code': 410, 'request': request}
)
return HttpResponseGone()
def head(self, request, *args, **kwargs):
return self.get(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
return self.get(request, *args, **kwargs)
def options(self, request, *args, **kwargs):
return self.get(request, *args, **kwargs)
def delete(self, request, *args, **kwargs):
return self.get(request, *args, **kwargs)
def put(self, request, *args, **kwargs):
return self.get(request, *args, **kwargs)
def patch(self, request, *args, **kwargs):
return self.get(request, *args, **kwargs)
DRF的APIView,views.py
"""
Provides an APIView class that is the base of all views in REST framework.
"""
from django.conf import settings
from django.core.exceptions import PermissionDenied
from django.db import connections, models
from django.http import Http404
from django.http.response import HttpResponseBase
from django.utils.cache import cc_delim_re, patch_vary_headers
from django.utils.encoding import smart_str
from django.views.decorators.csrf import csrf_exempt
from django.views.generic import View
from rest_framework import exceptions, status
from rest_framework.request import Request
from rest_framework.response import Response
from rest_framework.schemas import DefaultSchema
from rest_framework.settings import api_settings
from rest_framework.utils import formatting
def get_view_name(view):
"""
Given a view instance, return a textual name to represent the view.
This name is used in the browsable API, and in OPTIONS responses.
This function is the default for the `VIEW_NAME_FUNCTION` setting.
"""
# Name may be set by some Views, such as a ViewSet.
name = getattr(view, 'name', None)
if name is not None:
return name
name = view.__class__.__name__
name = formatting.remove_trailing_string(name, 'View')
name = formatting.remove_trailing_string(name, 'ViewSet')
name = formatting.camelcase_to_spaces(name)
# Suffix may be set by some Views, such as a ViewSet.
suffix = getattr(view, 'suffix', None)
if suffix:
name += ' ' + suffix
return name
def get_view_description(view, html=False):
"""
Given a view instance, return a textual description to represent the view.
This name is used in the browsable API, and in OPTIONS responses.
This function is the default for the `VIEW_DESCRIPTION_FUNCTION` setting.
"""
# Description may be set by some Views, such as a ViewSet.
description = getattr(view, 'description', None)
if description is None:
description = view.__class__.__doc__ or ''
description = formatting.dedent(smart_str(description))
if html:
return formatting.markup_description(description)
return description
def set_rollback():
for db in connections.all():
if db.settings_dict['ATOMIC_REQUESTS'] and db.in_atomic_block:
db.set_rollback(True)
def exception_handler(exc, context):
"""
Returns the response that should be used for any given exception.
By default we handle the REST framework `APIException`, and also
Django's built-in `Http404` and `PermissionDenied` exceptions.
Any unhandled exceptions may return `None`, which will cause a 500 error
to be raised.
"""
if isinstance(exc, Http404):
exc = exceptions.NotFound()
elif isinstance(exc, PermissionDenied):
exc = exceptions.PermissionDenied()
if isinstance(exc, exceptions.APIException):
headers = {}
if getattr(exc, 'auth_header', None):
headers['WWW-Authenticate'] = exc.auth_header
if getattr(exc, 'wait', None):
headers['Retry-After'] = '%d' % exc.wait
if isinstance(exc.detail, (list, dict)):
data = exc.detail
else:
data = {'detail': exc.detail}
set_rollback()
return Response(data, status=exc.status_code, headers=headers)
return None
class APIView(View):
# The following policies may be set at either globally, or per-view.
renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES
parser_classes = api_settings.DEFAULT_PARSER_CLASSES
authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES
throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES
permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES
content_negotiation_class = api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS
metadata_class = api_settings.DEFAULT_METADATA_CLASS
versioning_class = api_settings.DEFAULT_VERSIONING_CLASS
# Allow dependency injection of other settings to make testing easier.
settings = api_settings
schema = DefaultSchema()
@classmethod
def as_view(cls, **initkwargs):
"""
Store the original class on the view function.
This allows us to discover information about the view when we do URL
reverse lookups. Used for breadcrumb generation.
"""
if isinstance(getattr(cls, 'queryset', None), models.query.QuerySet):
def force_evaluation():
raise RuntimeError(
'Do not evaluate the `.queryset` attribute directly, '
'as the result will be cached and reused between requests. '
'Use `.all()` or call `.get_queryset()` instead.'
)
cls.queryset._fetch_all = force_evaluation
view = super().as_view(**initkwargs)
view.cls = cls
view.initkwargs = initkwargs
# Note: session based authentication is explicitly CSRF validated,
# all other authentication is CSRF exempt.
return csrf_exempt(view)
@property
def allowed_methods(self):
"""
Wrap Django's private `_allowed_methods` interface in a public property.
"""
return self._allowed_methods()
@property
def default_response_headers(self):
headers = {
'Allow': ', '.join(self.allowed_methods),
}
if len(self.renderer_classes) > 1:
headers['Vary'] = 'Accept'
return headers
def http_method_not_allowed(self, request, *args, **kwargs):
"""
If `request.method` does not correspond to a handler method,
determine what kind of exception to raise.
"""
raise exceptions.MethodNotAllowed(request.method)
def permission_denied(self, request, message=None, code=None):
"""
If request is not permitted, determine what kind of exception to raise.
"""
if request.authenticators and not request.successful_authenticator:
raise exceptions.NotAuthenticated()
raise exceptions.PermissionDenied(detail=message, code=code)
def throttled(self, request, wait):
"""
If request is throttled, determine what kind of exception to raise.
"""
raise exceptions.Throttled(wait)
def get_authenticate_header(self, request):
"""
If a request is unauthenticated, determine the WWW-Authenticate
header to use for 401 responses, if any.
"""
authenticators = self.get_authenticators()
if authenticators:
return authenticators[0].authenticate_header(request)
def get_parser_context(self, http_request):
"""
Returns a dict that is passed through to Parser.parse(),
as the `parser_context` keyword argument.
"""
# Note: Additionally `request` and `encoding` will also be added
# to the context by the Request object.
return {
'view': self,
'args': getattr(self, 'args', ()),
'kwargs': getattr(self, 'kwargs', {})
}
def get_renderer_context(self):
"""
Returns a dict that is passed through to Renderer.render(),
as the `renderer_context` keyword argument.
"""
# Note: Additionally 'response' will also be added to the context,
# by the Response object.
return {
'view': self,
'args': getattr(self, 'args', ()),
'kwargs': getattr(self, 'kwargs', {}),
'request': getattr(self, 'request', None)
}
def get_exception_handler_context(self):
"""
Returns a dict that is passed through to EXCEPTION_HANDLER,
as the `context` argument.
"""
return {
'view': self,
'args': getattr(self, 'args', ()),
'kwargs': getattr(self, 'kwargs', {}),
'request': getattr(self, 'request', None)
}
def get_view_name(self):
"""
Return the view name, as used in OPTIONS responses and in the
browsable API.
"""
func = self.settings.VIEW_NAME_FUNCTION
return func(self)
def get_view_description(self, html=False):
"""
Return some descriptive text for the view, as used in OPTIONS responses
and in the browsable API.
"""
func = self.settings.VIEW_DESCRIPTION_FUNCTION
return func(self, html)
# API policy instantiation methods
def get_format_suffix(self, **kwargs):
"""
Determine if the request includes a '.json' style format suffix
"""
if self.settings.FORMAT_SUFFIX_KWARG:
return kwargs.get(self.settings.FORMAT_SUFFIX_KWARG)
def get_renderers(self):
"""
Instantiates and returns the list of renderers that this view can use.
"""
return [renderer() for renderer in self.renderer_classes]
def get_parsers(self):
"""
Instantiates and returns the list of parsers that this view can use.
"""
return [parser() for parser in self.parser_classes]
def get_authenticators(self):
"""
Instantiates and returns the list of authenticators that this view can use.
"""
return [auth() for auth in self.authentication_classes]
def get_permissions(self):
"""
Instantiates and returns the list of permissions that this view requires.
"""
return [permission() for permission in self.permission_classes]
def get_throttles(self):
"""
Instantiates and returns the list of throttles that this view uses.
"""
return [throttle() for throttle in self.throttle_classes]
def get_content_negotiator(self):
"""
Instantiate and return the content negotiation class to use.
"""
if not getattr(self, '_negotiator', None):
self._negotiator = self.content_negotiation_class()
return self._negotiator
def get_exception_handler(self):
"""
Returns the exception handler that this view uses.
"""
return self.settings.EXCEPTION_HANDLER
# API policy implementation methods
def perform_content_negotiation(self, request, force=False):
"""
Determine which renderer and media type to use render the response.
"""
renderers = self.get_renderers()
conneg = self.get_content_negotiator()
try:
return conneg.select_renderer(request, renderers, self.format_kwarg)
except Exception:
if force:
return (renderers[0], renderers[0].media_type)
raise
def perform_authentication(self, request):
"""
Perform authentication on the incoming request.
Note that if you override this and simply 'pass', then authentication
will instead be performed lazily, the first time either
`request.user` or `request.auth` is accessed.
"""
request.user
def check_permissions(self, request):
"""
Check if the request should be permitted.
Raises an appropriate exception if the request is not permitted.
"""
for permission in self.get_permissions():
if not permission.has_permission(request, self):
self.permission_denied(
request,
message=getattr(permission, 'message', None),
code=getattr(permission, 'code', None)
)
def check_object_permissions(self, request, obj):
"""
Check if the request should be permitted for a given object.
Raises an appropriate exception if the request is not permitted.
"""
for permission in self.get_permissions():
if not permission.has_object_permission(request, self, obj):
self.permission_denied(
request,
message=getattr(permission, 'message', None),
code=getattr(permission, 'code', None)
)
def check_throttles(self, request):
"""
Check if request should be throttled.
Raises an appropriate exception if the request is throttled.
"""
throttle_durations = []
for throttle in self.get_throttles():
if not throttle.allow_request(request, self):
throttle_durations.append(throttle.wait())
if throttle_durations:
# Filter out `None` values which may happen in case of config / rate
# changes, see #1438
durations = [
duration for duration in throttle_durations
if duration is not None
]
duration = max(durations, default=None)
self.throttled(request, duration)
def determine_version(self, request, *args, **kwargs):
"""
If versioning is being used, then determine any API version for the
incoming request. Returns a two-tuple of (version, versioning_scheme)
"""
if self.versioning_class is None:
return (None, None)
scheme = self.versioning_class()
return (scheme.determine_version(request, *args, **kwargs), scheme)
# Dispatch methods
def initialize_request(self, request, *args, **kwargs):
"""
Returns the initial request object.
"""
parser_context = self.get_parser_context(request)
return Request(
request,
parsers=self.get_parsers(),
authenticators=self.get_authenticators(),
negotiator=self.get_content_negotiator(),
parser_context=parser_context
)
def initial(self, request, *args, **kwargs):
"""
Runs anything that needs to occur prior to calling the method handler.
"""
self.format_kwarg = self.get_format_suffix(**kwargs)
# Perform content negotiation and store the accepted info on the request
neg = self.perform_content_negotiation(request)
request.accepted_renderer, request.accepted_media_type = neg
# Determine the API version, if versioning is in use.
version, scheme = self.determine_version(request, *args, **kwargs)
request.version, request.versioning_scheme = version, scheme
# Ensure that the incoming request is permitted
self.perform_authentication(request)
self.check_permissions(request)
self.check_throttles(request)
def finalize_response(self, request, response, *args, **kwargs):
"""
Returns the final response object.
"""
# Make the error obvious if a proper response is not returned
assert isinstance(response, HttpResponseBase), (
'Expected a `Response`, `HttpResponse` or `HttpStreamingResponse` '
'to be returned from the view, but received a `%s`'
% type(response)
)
if isinstance(response, Response):
if not getattr(request, 'accepted_renderer', None):
neg = self.perform_content_negotiation(request, force=True)
request.accepted_renderer, request.accepted_media_type = neg
response.accepted_renderer = request.accepted_renderer
response.accepted_media_type = request.accepted_media_type
response.renderer_context = self.get_renderer_context()
# Add new vary headers to the response instead of overwriting.
vary_headers = self.headers.pop('Vary', None)
if vary_headers is not None:
patch_vary_headers(response, cc_delim_re.split(vary_headers))
for key, value in self.headers.items():
response[key] = value
return response
def handle_exception(self, exc):
"""
Handle any exception that occurs, by returning an appropriate response,
or re-raising the error.
"""
if isinstance(exc, (exceptions.NotAuthenticated,
exceptions.AuthenticationFailed)):
# WWW-Authenticate header for 401 responses, else coerce to 403
auth_header = self.get_authenticate_header(self.request)
if auth_header:
exc.auth_header = auth_header
else:
exc.status_code = status.HTTP_403_FORBIDDEN
exception_handler = self.get_exception_handler()
context = self.get_exception_handler_context()
response = exception_handler(exc, context)
if response is None:
self.raise_uncaught_exception(exc)
response.exception = True
return response
def raise_uncaught_exception(self, exc):
if settings.DEBUG:
request = self.request
renderer_format = getattr(request.accepted_renderer, 'format')
use_plaintext_traceback = renderer_format not in ('html', 'api', 'admin')
request.force_plaintext_errors(use_plaintext_traceback)
raise exc
# Note: Views are made CSRF exempt from within `as_view` as to prevent
# accidental removal of this exemption in cases where `dispatch` needs to
# be overridden.
def dispatch(self, request, *args, **kwargs):
"""
`.dispatch()` is pretty much the same as Django's regular dispatch,
but with extra hooks for startup, finalize, and exception handling.
"""
self.args = args
self.kwargs = kwargs
request = self.initialize_request(request, *args, **kwargs)
self.request = request
self.headers = self.default_response_headers # deprecate?
try:
self.initial(request, *args, **kwargs)
# Get the appropriate handler method
if request.method.lower() in self.http_method_names:
handler = getattr(self, request.method.lower(),
self.http_method_not_allowed)
else:
handler = self.http_method_not_allowed
response = handler(request, *args, **kwargs)
except Exception as exc:
response = self.handle_exception(exc)
self.response = self.finalize_response(request, response, *args, **kwargs)
return self.response
def options(self, request, *args, **kwargs):
"""
Handler method for HTTP 'OPTIONS' request.
"""
if self.metadata_class is None:
return self.http_method_not_allowed(request, *args, **kwargs)
data = self.metadata_class().determine_metadata(request, self)
return Response(data, status=status.HTTP_200_OK)
DRF的GenericAPIView,generics.py
"""
Generic views that provide commonly needed behaviour.
"""
from django.core.exceptions import ValidationError
from django.db.models.query import QuerySet
from django.http import Http404
from django.shortcuts import get_object_or_404 as _get_object_or_404
from rest_framework import mixins, views
from rest_framework.settings import api_settings
def get_object_or_404(queryset, *filter_args, **filter_kwargs):
"""
Same as Django's standard shortcut, but make sure to also raise 404
if the filter_kwargs don't match the required types.
"""
try:
return _get_object_or_404(queryset, *filter_args, **filter_kwargs)
except (TypeError, ValueError, ValidationError):
raise Http404
class GenericAPIView(views.APIView):
"""
Base class for all other generic views.
"""
# You'll need to either set these attributes,
# or override `get_queryset()`/`get_serializer_class()`.
# If you are overriding a view method, it is important that you call
# `get_queryset()` instead of accessing the `queryset` property directly,
# as `queryset` will get evaluated only once, and those results are cached
# for all subsequent requests.
queryset = None
serializer_class = None
# If you want to use object lookups other than pk, set 'lookup_field'.
# For more complex lookup requirements override `get_object()`.
lookup_field = 'pk'
lookup_url_kwarg = None
# The filter backend classes to use for queryset filtering
filter_backends = api_settings.DEFAULT_FILTER_BACKENDS
# The style to use for queryset pagination.
pagination_class = api_settings.DEFAULT_PAGINATION_CLASS
def get_queryset(self):
"""
Get the list of items for this view.
This must be an iterable, and may be a queryset.
Defaults to using `self.queryset`.
This method should always be used rather than accessing `self.queryset`
directly, as `self.queryset` gets evaluated only once, and those results
are cached for all subsequent requests.
You may want to override this if you need to provide different
querysets depending on the incoming request.
(Eg. return a list of items that is specific to the user)
"""
assert self.queryset is not None, (
"'%s' should either include a `queryset` attribute, "
"or override the `get_queryset()` method."
% self.__class__.__name__
)
queryset = self.queryset
if isinstance(queryset, QuerySet):
# Ensure queryset is re-evaluated on each request.
queryset = queryset.all()
return queryset
def get_object(self):
"""
Returns the object the view is displaying.
You may want to override this if you need to provide non-standard
queryset lookups. Eg if objects are referenced using multiple
keyword arguments in the url conf.
"""
queryset = self.filter_queryset(self.get_queryset())
# Perform the lookup filtering.
lookup_url_kwarg = self.lookup_url_kwarg or self.lookup_field
assert lookup_url_kwarg in self.kwargs, (
'Expected view %s to be called with a URL keyword argument '
'named "%s". Fix your URL conf, or set the `.lookup_field` '
'attribute on the view correctly.' %
(self.__class__.__name__, lookup_url_kwarg)
)
filter_kwargs = {self.lookup_field: self.kwargs[lookup_url_kwarg]}
obj = get_object_or_404(queryset, **filter_kwargs)
# May raise a permission denied
self.check_object_permissions(self.request, obj)
return obj
def get_serializer(self, *args, **kwargs):
"""
Return the serializer instance that should be used for validating and
deserializing input, and for serializing output.
"""
serializer_class = self.get_serializer_class()
kwargs.setdefault('context', self.get_serializer_context())
return serializer_class(*args, **kwargs)
def get_serializer_class(self):
"""
Return the class to use for the serializer.
Defaults to using `self.serializer_class`.
You may want to override this if you need to provide different
serializations depending on the incoming request.
(Eg. admins get full serialization, others get basic serialization)
"""
assert self.serializer_class is not None, (
"'%s' should either include a `serializer_class` attribute, "
"or override the `get_serializer_class()` method."
% self.__class__.__name__
)
return self.serializer_class
def get_serializer_context(self):
"""
Extra context provided to the serializer class.
"""
return {
'request': self.request,
'format': self.format_kwarg,
'view': self
}
def filter_queryset(self, queryset):
"""
Given a queryset, filter it with whichever filter backend is in use.
You are unlikely to want to override this method, although you may need
to call it either from a list view, or from a custom `get_object`
method if you want to apply the configured filtering backend to the
default queryset.
"""
for backend in list(self.filter_backends):
queryset = backend().filter_queryset(self.request, queryset, self)
return queryset
@property
def paginator(self):
"""
The paginator instance associated with the view, or `None`.
"""
if not hasattr(self, '_paginator'):
if self.pagination_class is None:
self._paginator = None
else:
self._paginator = self.pagination_class()
return self._paginator
def paginate_queryset(self, queryset):
"""
Return a single page of results, or `None` if pagination is disabled.
"""
if self.paginator is None:
return None
return self.paginator.paginate_queryset(queryset, self.request, view=self)
def get_paginated_response(self, data):
"""
Return a paginated style `Response` object for the given output data.
"""
assert self.paginator is not None
return self.paginator.get_paginated_response(data)
# Concrete view classes that provide method handlers
# by composing the mixin classes with the base view.
class CreateAPIView(mixins.CreateModelMixin,
GenericAPIView):
"""
Concrete view for creating a model instance.
"""
def post(self, request, *args, **kwargs):
return self.create(request, *args, **kwargs)
class ListAPIView(mixins.ListModelMixin,
GenericAPIView):
"""
Concrete view for listing a queryset.
"""
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
class RetrieveAPIView(mixins.RetrieveModelMixin,
GenericAPIView):
"""
Concrete view for retrieving a model instance.
"""
def get(self, request, *args, **kwargs):
return self.retrieve(request, *args, **kwargs)
class DestroyAPIView(mixins.DestroyModelMixin,
GenericAPIView):
"""
Concrete view for deleting a model instance.
"""
def delete(self, request, *args, **kwargs):
return self.destroy(request, *args, **kwargs)
class UpdateAPIView(mixins.UpdateModelMixin,
GenericAPIView):
"""
Concrete view for updating a model instance.
"""
def put(self, request, *args, **kwargs):
return self.update(request, *args, **kwargs)
def patch(self, request, *args, **kwargs):
return self.partial_update(request, *args, **kwargs)
class ListCreateAPIView(mixins.ListModelMixin,
mixins.CreateModelMixin,
GenericAPIView):
"""
Concrete view for listing a queryset or creating a model instance.
"""
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
return self.create(request, *args, **kwargs)
class RetrieveUpdateAPIView(mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
GenericAPIView):
"""
Concrete view for retrieving, updating a model instance.
"""
def get(self, request, *args, **kwargs):
return self.retrieve(request, *args, **kwargs)
def put(self, request, *args, **kwargs):
return self.update(request, *args, **kwargs)
def patch(self, request, *args, **kwargs):
return self.partial_update(request, *args, **kwargs)
class RetrieveDestroyAPIView(mixins.RetrieveModelMixin,
mixins.DestroyModelMixin,
GenericAPIView):
"""
Concrete view for retrieving or deleting a model instance.
"""
def get(self, request, *args, **kwargs):
return self.retrieve(request, *args, **kwargs)
def delete(self, request, *args, **kwargs):
return self.destroy(request, *args, **kwargs)
class RetrieveUpdateDestroyAPIView(mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
GenericAPIView):
"""
Concrete view for retrieving, updating or deleting a model instance.
"""
def get(self, request, *args, **kwargs):
return self.retrieve(request, *args, **kwargs)
def put(self, request, *args, **kwargs):
return self.update(request, *args, **kwargs)
def patch(self, request, *args, **kwargs):
return self.partial_update(request, *args, **kwargs)
def delete(self, request, *args, **kwargs):
return self.destroy(request, *args, **kwargs)
3,drf的APIView
from rest_framework.views import APIView
from mysystem.serializers import StudentSerializer
from mysystem.models import Student
from rest_framework.response import Response
class StudentView(APIView):
def get(self, request):
ret = Student.objects.all()
ser = StudentSerializer(instance=ret, many=True)
return Response(data=ser.data, status=200)
def post(self, request):
ser = StudentSerializer(data=request.data)
# 后面可以把模型操作和部分代码直接封装到serializer中解耦
if ser.is_valid(raise_exception=True):
ret = Student.objects.create(**ser.validated_data)
return Response(ser.validated_data)
class StudentDetailView(APIView):
def get(self, request, id):
stu = Student.objects.get(pk=id)
ret = StudentSerializer(instance=stu)
return Response(ret.data)
def put(self, request, id):
stu = Student.objects.get(pk=id)
ser = StudentSerializer(instance=stu, data=request.data)
if ser.is_valid(raise_exception=True):
Student.objects.filter(pk=id).update(**ser.validated_data)
return Response(data=ser.data)
def delete(self, request, id):
Student.objects.filter(pk=id).delete()
return Response({'msg': 'delete'})
4,drf的genericAPIView
from rest_framework import status
from rest_framework.generics import GenericAPIView
from mysystem.models import Student
from mysystem.serializers import StudentSerializer, StudentModelSerializer, StuSerializer
from rest_framework.response import Response
class StuGenericApiView(GenericAPIView):
queryset = Student.objects.all()
def get_serializer_class(self):
if self.request.method.lower() == 'GET':
return StudentSerializer
else:
return StuSerializer
def get(self, request):
instance = self.get_queryset()
ser = self.get_serializer(instance=instance, many=True)
return Response(ser.data, status=status.HTTP_200_OK)
def post(self, request):
ret = self.get_serializer(data=request.data)
ret.is_valid(raise_exception=True)
ret.save()
return Response(ret.data, status=status.HTTP_201_CREATED)
class StuGenView(GenericAPIView):
queryset = Student.objects.all()
serializer_class = StuSerializer
def get(self, request, pk):
instance = self.get_object()
ret = self.get_serializer(instance=instance)
return Response(ret.data, status=status.HTTP_200_OK)
def put(self, request, pk):
instance = self.get_object()
ret = self.get_serializer(instance=instance, data=request.data)
ret.is_valid(raise_exception=True)
ret.save()
return Response(ret.data, status=status.HTTP_202_ACCEPTED)
def delete(self, request, pk):
self.get_object().delete()
return Response(status=status.HTTP_204_NO_CONTENT)
drf的mixins
"""
Basic building blocks for generic class based views.
We don't bind behaviour to http method handlers yet,
which allows mixin classes to be composed in interesting ways.
"""
from rest_framework import status
from rest_framework.response import Response
from rest_framework.settings import api_settings
class CreateModelMixin:
"""
Create a model instance.
"""
def create(self, request, *args, **kwargs):
serializer = self.get_serializer(data=request.data)
serializer.is_valid(raise_exception=True)
self.perform_create(serializer)
headers = self.get_success_headers(serializer.data)
return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)
def perform_create(self, serializer):
serializer.save()
def get_success_headers(self, data):
try:
return {'Location': str(data[api_settings.URL_FIELD_NAME])}
except (TypeError, KeyError):
return {}
class ListModelMixin:
"""
List a queryset.
"""
def list(self, request, *args, **kwargs):
queryset = self.filter_queryset(self.get_queryset())
page = self.paginate_queryset(queryset)
if page is not None:
serializer = self.get_serializer(page, many=True)
return self.get_paginated_response(serializer.data)
serializer = self.get_serializer(queryset, many=True)
return Response(serializer.data)
class RetrieveModelMixin:
"""
Retrieve a model instance.
"""
def retrieve(self, request, *args, **kwargs):
instance = self.get_object()
serializer = self.get_serializer(instance)
return Response(serializer.data)
class UpdateModelMixin:
"""
Update a model instance.
"""
def update(self, request, *args, **kwargs):
partial = kwargs.pop('partial', False)
instance = self.get_object()
serializer = self.get_serializer(instance, data=request.data, partial=partial)
serializer.is_valid(raise_exception=True)
self.perform_update(serializer)
if getattr(instance, '_prefetched_objects_cache', None):
# If 'prefetch_related' has been applied to a queryset, we need to
# forcibly invalidate the prefetch cache on the instance.
instance._prefetched_objects_cache = {}
return Response(serializer.data)
def perform_update(self, serializer):
serializer.save()
def partial_update(self, request, *args, **kwargs):
kwargs['partial'] = True
return self.update(request, *args, **kwargs)
class DestroyModelMixin:
"""
Destroy a model instance.
"""
def destroy(self, request, *args, **kwargs):
instance = self.get_object()
self.perform_destroy(instance)
return Response(status=status.HTTP_204_NO_CONTENT)
def perform_destroy(self, instance):
instance.delete()
5，drf的mixinsView
from rest_framework.mixins import ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin, \
DestroyModelMixin
from rest_framework.generics import GenericAPIView
from mysystem.serializers import StudentModelSerializer
from mysystem.models import Student
class StudentMixinApiview(GenericAPIView,ListModelMixin,CreateModelMixin):
serializer_class = StudentModelSerializer
queryset = Student.objects.all()
def get(self,request):
return self.list(request)
def post(self,request):
return self.create(request)
class StudentInfoMixinView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
queryset = Student.objects.all()
serializer_class = StudentModelSerializer
def get(self,request,pk):
return self.retrieve(request, pk=pk)
def put(self,request, pk):
return self.update(request, pk=pk)
def delete(self,request, pk):
return self.destroy(request, pk=pk)
drf的通用视图子类,同样在generics.py中
"""
上面的接口代码还可以继续更加的精简，drf在使用GenericAPIView和Mixins进行组合以后，还提供了视图子类。
视图子类是通用视图类 和 模型扩展类 的子类，提供了各种的视图方法调用mixins操作
ListAPIView = GenericAPIView + ListModelMixin 获取多条数据的视图方法
CreateAPIView = GenericAPIView + CreateModelMixin 添加一条数据的视图方法
RetrieveAPIView = GenericAPIView + RetrieveModelMixin 获取一条数据的视图方法
UpdateAPIView = GenericAPIView + UpdateModelMixin 更新一条数据的视图方法
DestroyAPIView = GenericAPIView + DestroyModelMixin 删除一条数据的视图方法
组合视图子类
ListCreateAPIView = ListAPIView + CreateAPIView
RetrieveUpdateAPIView = RetrieveAPIView + UpdateAPIView
RetrieveDestroyAPIView = RetrieveAPIView + DestroyAPIView
RetrieveUpdateDestroyAPIView = RetrieveAPIView + UpdateAPIView + DestroyAPIView
"""
6,drf的subclassView
from rest_framework.generics import ListAPIView,CreateAPIView,UpdateAPIView,RetrieveAPIView,DestroyAPIView
from mysystem.models import Student
from mysystem.serializers import StudentModelSerializer
class StudentSubView(ListAPIView,CreateAPIView):
queryset = Student.objects.all()
serializer_class = StudentModelSerializer
# 继承的get和post方法,在需要验证方面时再去重写，不然可以直接默认不写
class StudentInfoSubView(UpdateAPIView,RetrieveAPIView,DestroyAPIView):
queryset = Student.objects.all()
serializer_class = StudentModelSerializer
drf的viewsets,
"""
ViewSets are essentially just a type of class based view, that doesn't provide
any method handlers, such as `get()`, `post()`, etc... but instead has actions,
such as `list()`, `retrieve()`, `create()`, etc...
Actions are only bound to methods at the point of instantiating the views.
user_list = UserViewSet.as_view({'get': 'list'})
user_detail = UserViewSet.as_view({'get': 'retrieve'})
Typically, rather than instantiate views from viewsets directly, you'll
register the viewset with a router and let the URL conf be determined
automatically.
router = DefaultRouter()
router.register(r'users', UserViewSet, 'user')
urlpatterns = router.urls
"""
from collections import OrderedDict
from functools import update_wrapper
from inspect import getmembers
from django.urls import NoReverseMatch
from django.utils.decorators import classonlymethod
from django.views.decorators.csrf import csrf_exempt
from rest_framework import generics, mixins, views
from rest_framework.decorators import MethodMapper
from rest_framework.reverse import reverse
def _is_extra_action(attr):
return hasattr(attr, 'mapping') and isinstance(attr.mapping, MethodMapper)
def _check_attr_name(func, name):
assert func.__name__ == name, (
'Expected function (`{func.__name__}`) to match its attribute name '
'(`{name}`). If using a decorator, ensure the inner function is '
'decorated with `functools.wraps`, or that `{func.__name__}.__name__` '
'is otherwise set to `{name}`.').format(func=func, name=name)
return func
class ViewSetMixin:
"""
This is the magic.
Overrides `.as_view()` so that it takes an `actions` keyword that performs
the binding of HTTP methods to actions on the Resource.
For example, to create a concrete view binding the 'GET' and 'POST' methods
to the 'list' and 'create' actions...
view = MyViewSet.as_view({'get': 'list', 'post': 'create'})
"""
@classonlymethod
def as_view(cls, actions=None, **initkwargs):
"""
Because of the way class based views create a closure around the
instantiated view, we need to totally reimplement `.as_view`,
and slightly modify the view function that is created and returned.
"""
# The name and description initkwargs may be explicitly overridden for
# certain route configurations. eg, names of extra actions.
cls.name = None
cls.description = None
# The suffix initkwarg is reserved for displaying the viewset type.
# This initkwarg should have no effect if the name is provided.
# eg. 'List' or 'Instance'.
cls.suffix = None
# The detail initkwarg is reserved for introspecting the viewset type.
cls.detail = None
# Setting a basename allows a view to reverse its action urls. This
# value is provided by the router through the initkwargs.
cls.basename = None
# actions must not be empty
if not actions:
raise TypeError("The `actions` argument must be provided when "
"calling `.as_view()` on a ViewSet. For example "
"`.as_view({'get': 'list'})`")
# sanitize keyword arguments
for key in initkwargs:
if key in cls.http_method_names:
raise TypeError("You tried to pass in the %s method name as a "
"keyword argument to %s(). Don't do that."
% (key, cls.__name__))
if not hasattr(cls, key):
raise TypeError("%s() received an invalid keyword %r" % (
cls.__name__, key))
# name and suffix are mutually exclusive
if 'name' in initkwargs and 'suffix' in initkwargs:
raise TypeError("%s() received both `name` and `suffix`, which are "
"mutually exclusive arguments." % (cls.__name__))
def view(request, *args, **kwargs):
self = cls(**initkwargs)
if 'get' in actions and 'head' not in actions:
actions['head'] = actions['get']
# We also store the mapping of request methods to actions,
# so that we can later set the action attribute.
# eg. `self.action = 'list'` on an incoming GET request.
self.action_map = actions
# Bind methods to actions
# This is the bit that's different to a standard view
for method, action in actions.items():
handler = getattr(self, action)
setattr(self, method, handler)
self.request = request
self.args = args
self.kwargs = kwargs
# And continue as usual
return self.dispatch(request, *args, **kwargs)
# take name and docstring from class
update_wrapper(view, cls, updated=())
# and possible attributes set by decorators
# like csrf_exempt from dispatch
update_wrapper(view, cls.dispatch, assigned=())
# We need to set these on the view function, so that breadcrumb
# generation can pick out these bits of information from a
# resolved URL.
view.cls = cls
view.initkwargs = initkwargs
view.actions = actions
return csrf_exempt(view)
def initialize_request(self, request, *args, **kwargs):
"""
Set the `.action` attribute on the view, depending on the request method.
"""
request = super().initialize_request(request, *args, **kwargs)
method = request.method.lower()
if method == 'options':
# This is a special case as we always provide handling for the
# options method in the base `View` class.
# Unlike the other explicitly defined actions, 'metadata' is implicit.
self.action = 'metadata'
else:
self.action = self.action_map.get(method)
return request
def reverse_action(self, url_name, *args, **kwargs):
"""
Reverse the action for the given `url_name`.
"""
url_name = '%s-%s' % (self.basename, url_name)
namespace = None
if self.request and self.request.resolver_match:
namespace = self.request.resolver_match.namespace
if namespace:
url_name = namespace + ':' + url_name
kwargs.setdefault('request', self.request)
return reverse(url_name, *args, **kwargs)
@classmethod
def get_extra_actions(cls):
"""
Get the methods that are marked as an extra ViewSet `@action`.
"""
return [_check_attr_name(method, name)
for name, method
in getmembers(cls, _is_extra_action)]
def get_extra_action_url_map(self):
"""
Build a map of {names: urls} for the extra actions.
This method will noop if `detail` was not provided as a view initkwarg.
"""
action_urls = OrderedDict()
# exit early if `detail` has not been provided
if self.detail is None:
return action_urls
# filter for the relevant extra actions
actions = [
action for action in self.get_extra_actions()
if action.detail == self.detail
]
for action in actions:
try:
url_name = '%s-%s' % (self.basename, action.url_name)
url = reverse(url_name, self.args, self.kwargs, request=self.request)
view = self.__class__(**action.kwargs)
action_urls[view.get_view_name()] = url
except NoReverseMatch:
pass # URL requires additional arguments, ignore
return action_urls
class ViewSet(ViewSetMixin, views.APIView):
"""
The base ViewSet class does not provide any actions by default.
"""
pass
class GenericViewSet(ViewSetMixin, generics.GenericAPIView):
"""
The GenericViewSet class does not provide any actions by default,
but does include the base set of generic view behavior, such as
the `get_object` and `get_queryset` methods.
"""
pass
class ReadOnlyModelViewSet(mixins.RetrieveModelMixin,
mixins.ListModelMixin,
GenericViewSet):
"""
A viewset that provides default `list()` and `retrieve()` actions.
"""
pass
class ModelViewSet(mixins.CreateModelMixin,
mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
mixins.ListModelMixin,
GenericViewSet):
"""
A viewset that provides default `create()`, `retrieve()`, `update()`,
`partial_update()`, `destroy()` and `list()` actions.
"""
pass
7,drf的viewset，封装了APIView
# 7,drf的普通视图集
path("students5/", viewsetV.StudentViewSet.as_view({
"get": "get_student_list", # 视图类方法，可以是原来的http请求动作，也可以是自定义的方法名
# "post": "post", # 用默认的请求方法名，可以不写路由
})),
re_path("^students5/(?P<pk>\d+)/$", viewsetV.StudentViewSet.as_view({
"get": "get_student_info", # 视图类方法，可以是原来的http请求动作，也可以是自定义的方法名
"put": "update",
# "delete": "delete",
})),
from rest_framework import status
from rest_framework.response import Response
from rest_framework.viewsets import ViewSet
from mysystem.models import Student
from mysystem.serializers import StudentModelSerializer
class StudentViewSet(ViewSet):
def get_student_list(self, request):
"""获取所有学生信息"""
# 1. 从数据库中读取学生列表信息
student_list = Student.objects.all()
# 2. 实例化序列化器，获取序列化对象
serializer = StudentModelSerializer(instance=student_list, many=True)
# 3. 转换数据并返回给客户端
return Response(serializer.data)
def post(self, request):
"""添加一条数据"""
# 1. 获取客户端提交的数据，实例化序列化器，获取序列化对象
serializer = StudentModelSerializer(data=request.data)
# 2. 反序列化[验证数据、保存数据到数据库]
serializer.is_valid(raise_exception=True)
serializer.save()
# 3. 返回新增的模型数据给客户单
return Response(serializer.data, status=status.HTTP_201_CREATED)
def get_student_info(self,request, pk):
"""获取一条数据"""
# 1. 使用pk作为条件获取模型对象
try:
student = Student.objects.get(pk=pk)
except Student.DoesNotExist:
return Response(status=status.HTTP_404_NOT_FOUND)
# 2. 序列化
serializer = StudentModelSerializer(instance=student)
# 3. 返回结果
return Response(serializer.data)
def update(self, request, pk):
"""更新数据"""
# 1. 使用pk作为条件获取模型对象
try:
student = Student.objects.get(pk=pk)
except Student.DoesNotExist:
return Response(status=status.HTTP_404_NOT_FOUND)
# 2. 获取客户端提交的数据
serializer = StudentModelSerializer(instance=student, data=request.data)
# 3. 反序列化[验证数据和数据保存]
serializer.is_valid(raise_exception=True)
serializer.save()
# 4. 返回结果
return Response(serializer.data, status=status.HTTP_201_CREATED)
def delete(self,request,pk):
"""删除数据"""
# 1. 根据PK值获取要删除的数据并删除
try:
Student.objects.get(pk=pk).delete()
except Student.DoesNotExist:
pass
# 2. 返回结果
return Response(status=status.HTTP_204_NO_CONTENT)
8，DRF的genericviewset，封装了genericAPIView
# 视图集: GenericViewSet
path("students6/", views.StudentGenericViewSet.as_view({
"get": "list",
"post": "create",
})),
re_path("^students6/(?P<pk>\d+)/$", views.StudentGenericViewSet.as_view({
"get": "retrieve",
"put": "update",
"delete": "destroy",
})),
# 视图集: GenericViewSet + Mixins
path("students7/", views.StudentMixinViewSet.as_view({
"get": "list",
"post": "create",
})),
re_path("^students7/(?P<pk>\d+)/$", views.StudentMixinViewSet.as_view({
"get": "retrieve",
"put": "update",
"delete": "destroy",
})),
class StudentGenericViewSet(GenericViewSet):
queryset = Student.objects.all()
serializer_class = StudentModelSerializer
def list(self, request):
"""获取所有数据"""
# 1. 从数据库中读取模型列表信息
queryset = self.get_queryset() # GenericAPIView提供的get_queryset
# 2. 序列化
serializer = self.get_serializer(instance=queryset, many=True)
# 3. 转换数据并返回给客户端
return Response(serializer.data)
def create(self,request):
"""添加一个数据"""
# 1. 获取客户端提交的数据，实例化序列化器，获取序列化对象
serializer = self.get_serializer(data=request.data)
# 2. 反序列化[验证数据、保存数据到数据库]
serializer.is_valid(raise_exception=True)
serializer.save()
# 3. 返回新增的模型数据给客户单
return Response(serializer.data, status=status.HTTP_201_CREATED)
def retrieve(self, request, pk):
"""获取一个数据"""
# 1. 使用pk作为条件获取模型对象
instance = self.get_object()
# 2.序列化
serializer = self.get_serializer(instance=instance)
# 3. 返回结果
return Response(serializer.data)
def update(self,request, pk):
"""更新一个数据"""
# 1. 使用pk作为条件获取模型对象
instance = self.get_object()
# 2. 获取客户端提交的数据
serializer = self.get_serializer(instance=instance, data=request.data)
# 3. 反序列化[验证数据和数据保存]
serializer.is_valid(raise_exception=True)
serializer.save()
# 4. 返回结果
return Response(serializer.data, status=status.HTTP_201_CREATED)
def destory(self, request, pk):
"""删除一个数据"""
# 1. 根据PK值获取要删除的数据并删除
self.get_object().delete()
# 2. 返回结果
return Response(status=status.HTTP_204_NO_CONTENT)
"""GenericViewSet 通用视图集 + 混入类"""
class StudentMixinViewSet(GenericViewSet, ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
queryset = Student.objects.all()
serializer_class = StudentModelSerializer
9,drf的modelviewset
# 自动生成路由信息[和视图集一起使用]
from rest_framework.routers import SimpleRouter, DefaultRouter
# 1. 实例化路由类
router = SimpleRouter()
# 2. 给路由去注册视图集
router.register("student9", views.StudentModelViewSet, basename="student9")
print(router.urls)
# 3. 把生成的路由列表 和 urlpatterns进行拼接
urlpatterns += router.urls
"""
上面的接口类继承的父类太多了。
我们可以继续让一些合并的视图集父类让视图继承即可。
ReadOnlyModelViewSet = mixins.RetrieveModelMixin + mixins.ListModelMixin, + GenericViewSet
获取多条数据
获取一条数据
ModelViewSet
实现了5个API接口
"""
from rest_framework.viewsets import ReadOnlyModelViewSet
class StudentReadOnlyMixinViewSet(ReadOnlyModelViewSet, CreateModelMixin, UpdateModelMixin, DestroyModelMixin):
queryset = Student.objects.all()
serializer_class = StudentModelSerializer
from rest_framework.viewsets import ModelViewSet
from rest_framework.decorators import action # 自定义请求接口
class StudentModelViewSet(ModelViewSet):
queryset = Student.objects.all()
serializer_class = StudentModelSerializer
# 路由对象给视图集生成路由信息时，只会生成5个基本api接口，这主要是router只识别5个混入类的原因，
# 而针对我们开发者自定义的视图方法，路由对象不会自动生成路由信息，
# 所以下面这个login，如果希望被外界访问到，则必须通过action装饰器告诉路由对象要给它生成一个路由信息。
@action(methods=["get","post"], detail=False, url_path="login")
# action的参数
# methods, 列表，指定允许哪些http请求方法可以访问当前视图方法
# detail, 布尔值，告诉路由对象在生成路由信息时，是否要自动生成pk值，True表示需要，False表示不需要。
# url_path，字符串，访问视图的url地址，如果不设置，则默认采用视图方法名作为访问后缀
# http://127.0.0.1:8000/demo/student9/login/
def login(self, request):
"""登录视图"""
return Response({"msg":"登录成功"})
@action(methods=["get"], detail=True, url_path="login/log")
# http://127.0.0.1:8000/demo/student9/20/login/log/
def login_log(self,request,pk):
"""用户登录历史记录"""
# 视图集类中比普通的视图类，多一个属性，action
# 可以通过self.method获取本次客户端的http请求
# 可以通过self.action获取本次客户端请求的视图方法名[ViewSet提供的]
print(self.action) # login_log
return Response({"msg": "用户登录历史记录"})
DRF的routers
"""
Routers provide a convenient and consistent way of automatically
determining the URL conf for your API.
They are used by simply instantiating a Router class, and then registering
all the required ViewSets with that router.
For example, you might have a `urls.py` that looks something like this:
router = routers.DefaultRouter()
router.register('users', UserViewSet, 'user')
router.register('accounts', AccountViewSet, 'account')
urlpatterns = router.urls
"""
import itertools
from collections import OrderedDict, namedtuple
from django.core.exceptions import ImproperlyConfigured
from django.urls import NoReverseMatch, re_path
from rest_framework import views
from rest_framework.response import Response
from rest_framework.reverse import reverse
from rest_framework.schemas import SchemaGenerator
from rest_framework.schemas.views import SchemaView
from rest_framework.settings import api_settings
from rest_framework.urlpatterns import format_suffix_patterns
Route = namedtuple('Route', ['url', 'mapping', 'name', 'detail', 'initkwargs'])
DynamicRoute = namedtuple('DynamicRoute', ['url', 'name', 'detail', 'initkwargs'])
def escape_curly_brackets(url_path):
"""
Double brackets in regex of url_path for escape string formatting
"""
return url_path.replace('{', '{{').replace('}', '}}')
def flatten(list_of_lists):
"""
Takes an iterable of iterables, returns a single iterable containing all items
"""
return itertools.chain(*list_of_lists)
class BaseRouter:
def __init__(self):
self.registry = []
def register(self, prefix, viewset, basename=None):
if basename is None:
basename = self.get_default_basename(viewset)
self.registry.append((prefix, viewset, basename))
# invalidate the urls cache
if hasattr(self, '_urls'):
del self._urls
def get_default_basename(self, viewset):
"""
If `basename` is not specified, attempt to automatically determine
it from the viewset.
"""
raise NotImplementedError('get_default_basename must be overridden')
def get_urls(self):
"""
Return a list of URL patterns, given the registered viewsets.
"""
raise NotImplementedError('get_urls must be overridden')
@property
def urls(self):
if not hasattr(self, '_urls'):
self._urls = self.get_urls()
return self._urls
class SimpleRouter(BaseRouter):
routes = [
# List route.
Route(
url=r'^{prefix}{trailing_slash}$',
mapping={
'get': 'list',
'post': 'create'
},
name='{basename}-list',
detail=False,
initkwargs={'suffix': 'List'}
),
# Dynamically generated list routes. Generated using
# @action(detail=False) decorator on methods of the viewset.
DynamicRoute(
url=r'^{prefix}/{url_path}{trailing_slash}$',
name='{basename}-{url_name}',
detail=False,
initkwargs={}
),
# Detail route.
Route(
url=r'^{prefix}/{lookup}{trailing_slash}$',
mapping={
'get': 'retrieve',
'put': 'update',
'patch': 'partial_update',
'delete': 'destroy'
},
name='{basename}-detail',
detail=True,
initkwargs={'suffix': 'Instance'}
),
# Dynamically generated detail routes. Generated using
# @action(detail=True) decorator on methods of the viewset.
DynamicRoute(
url=r'^{prefix}/{lookup}/{url_path}{trailing_slash}$',
name='{basename}-{url_name}',
detail=True,
initkwargs={}
),
]
def __init__(self, trailing_slash=True):
self.trailing_slash = '/' if trailing_slash else ''
super().__init__()
def get_default_basename(self, viewset):
"""
If `basename` is not specified, attempt to automatically determine
it from the viewset.
"""
queryset = getattr(viewset, 'queryset', None)
assert queryset is not None, '`basename` argument not specified, and could ' \
'not automatically determine the name from the viewset, as ' \
'it does not have a `.queryset` attribute.'
return queryset.model._meta.object_name.lower()
def get_routes(self, viewset):
"""
Augment `self.routes` with any dynamically generated routes.
Returns a list of the Route namedtuple.
"""
# converting to list as iterables are good for one pass, known host needs to be checked again and again for
# different functions.
known_actions = list(flatten([route.mapping.values() for route in self.routes if isinstance(route, Route)]))
extra_actions = viewset.get_extra_actions()
# checking action names against the known actions list
not_allowed = [
action.__name__ for action in extra_actions
if action.__name__ in known_actions
]
if not_allowed:
msg = ('Cannot use the @action decorator on the following '
'methods, as they are existing routes: %s')
raise ImproperlyConfigured(msg % ', '.join(not_allowed))
# partition detail and list actions
detail_actions = [action for action in extra_actions if action.detail]
list_actions = [action for action in extra_actions if not action.detail]
routes = []
for route in self.routes:
if isinstance(route, DynamicRoute) and route.detail:
routes += [self._get_dynamic_route(route, action) for action in detail_actions]
elif isinstance(route, DynamicRoute) and not route.detail:
routes += [self._get_dynamic_route(route, action) for action in list_actions]
else:
routes.append(route)
return routes
def _get_dynamic_route(self, route, action):
initkwargs = route.initkwargs.copy()
initkwargs.update(action.kwargs)
url_path = escape_curly_brackets(action.url_path)
return Route(
url=route.url.replace('{url_path}', url_path),
mapping=action.mapping,
name=route.name.replace('{url_name}', action.url_name),
detail=route.detail,
initkwargs=initkwargs,
)
def get_method_map(self, viewset, method_map):
"""
Given a viewset, and a mapping of http methods to actions,
return a new mapping which only includes any mappings that
are actually implemented by the viewset.
"""
bound_methods = {}
for method, action in method_map.items():
if hasattr(viewset, action):
bound_methods[method] = action
return bound_methods
def get_lookup_regex(self, viewset, lookup_prefix=''):
"""
Given a viewset, return the portion of URL regex that is used
to match against a single instance.
Note that lookup_prefix is not used directly inside REST rest_framework
itself, but is required in order to nicely support nested router
implementations, such as drf-nested-routers.
https://github.com/alanjds/drf-nested-routers
"""
base_regex = '(?P<{lookup_prefix}{lookup_url_kwarg}>{lookup_value})'
# Use `pk` as default field, unset set. Default regex should not
# consume `.json` style suffixes and should break at '/' boundaries.
lookup_field = getattr(viewset, 'lookup_field', 'pk')
lookup_url_kwarg = getattr(viewset, 'lookup_url_kwarg', None) or lookup_field
lookup_value = getattr(viewset, 'lookup_value_regex', '[^/.]+')
return base_regex.format(
lookup_prefix=lookup_prefix,
lookup_url_kwarg=lookup_url_kwarg,
lookup_value=lookup_value
)
def get_urls(self):
"""
Use the registered viewsets to generate a list of URL patterns.
"""
ret = []
for prefix, viewset, basename in self.registry:
lookup = self.get_lookup_regex(viewset)
routes = self.get_routes(viewset)
for route in routes:
# Only actions which actually exist on the viewset will be bound
mapping = self.get_method_map(viewset, route.mapping)
if not mapping:
continue
# Build the url pattern
regex = route.url.format(
prefix=prefix,
lookup=lookup,
trailing_slash=self.trailing_slash
)
# If there is no prefix, the first part of the url is probably
# controlled by project's urls.py and the router is in an app,
# so a slash in the beginning will (A) cause Django to give
# warnings and (B) generate URLS that will require using '//'.
if not prefix and regex[:2] == '^/':
regex = '^' + regex[2:]
initkwargs = route.initkwargs.copy()
initkwargs.update({
'basename': basename,
'detail': route.detail,
})
view = viewset.as_view(mapping, **initkwargs)
name = route.name.format(basename=basename)
ret.append(re_path(regex, view, name=name))
return ret
class APIRootView(views.APIView):
"""
The default basic root view for DefaultRouter
"""
_ignore_model_permissions = True
schema = None # exclude from schema
api_root_dict = None
def get(self, request, *args, **kwargs):
# Return a plain {"name": "hyperlink"} response.
ret = OrderedDict()
namespace = request.resolver_match.namespace
for key, url_name in self.api_root_dict.items():
if namespace:
url_name = namespace + ':' + url_name
try:
ret[key] = reverse(
url_name,
args=args,
kwargs=kwargs,
request=request,
format=kwargs.get('format')
)
except NoReverseMatch:
# Don't bail out if eg. no list routes exist, only detail routes.
continue
return Response(ret)
class DefaultRouter(SimpleRouter):
"""
The default router extends the SimpleRouter, but also adds in a default
API root view, and adds format suffix patterns to the URLs.
"""
include_root_view = True
include_format_suffixes = True
root_view_name = 'api-root'
default_schema_renderers = None
APIRootView = APIRootView
APISchemaView = SchemaView
SchemaGenerator = SchemaGenerator
def __init__(self, *args, **kwargs):
if 'root_renderers' in kwargs:
self.root_renderers = kwargs.pop('root_renderers')
else:
self.root_renderers = list(api_settings.DEFAULT_RENDERER_CLASSES)
super().__init__(*args, **kwargs)
def get_api_root_view(self, api_urls=None):
"""
Return a basic root view.
"""
api_root_dict = OrderedDict()
list_name = self.routes[0].name
for prefix, viewset, basename in self.registry:
api_root_dict[prefix] = list_name.format(basename=basename)
return self.APIRootView.as_view(api_root_dict=api_root_dict)
def get_urls(self):
"""
Generate the list of URL patterns, including a default root view
for the API, and appending `.json` style format suffixes.
"""
urls = super().get_urls()
if self.include_root_view:
view = self.get_api_root_view(api_urls=urls)
root_url = re_path(r'^$', view, name=self.root_view_name)
urls.append(root_url)
if self.include_format_suffixes:
urls = format_suffix_patterns(urls)
return urls
