如何将图像文件传递到 API 端点

Question

我有一个带有 DRF 的 Web 服务，我让 POSTMAN 成功传递了正确的所有字段，包括图像文件 ['avatar'] []1

现在我如何从 Django 表单传递图像文件，但我不断收到错误 400，错误请求。请问我如何编码要传递到 API 端点的图像文件。

html

<form method="post" action="#" enctype="multipart/form-data">
                          {% csrf_token %}
                              <label for="phone">Enter Phone</label>
                              {{ form.phone }} <br />
                              <label for="bvn">Enter BVN</label>
                              {{ form.bvn }} <br />
                              <label for="avatar">Upload Avatar</label>
                              {{ form.avatar }} <br />
                              <button type="submit" class="btn btn-primary" >Submit</button>

                          </form>

views.py

def form_valid(self, form):
    token = self.request.session['session_token']
    headers = {"Content-Type": 'application/json', "Authorization": "Token " + token}

    parameters = {
        'bvn': form.cleaned_data['bvn'],
        'phone': form.cleaned_data['phone'],
        'avatar': self.request.FILES['avatar']
    }
    response = requests.put(str(settings.API_END_POINT + '/customer_profile_api/'), data=parameters,
                             headers=headers)
    if response.status_code in settings.SUCCESS_CODES:
        messages.success(self.request, 'Successfully updated profile')
    else:
        messages.error(self.request, 'API Error %s' % response.status_code)

    return super(CustomerDashboard, self).form_valid(form)

form.py

class ProfileUpdateForm(forms.Form):
    """customer profile update form"""
    phone = forms.CharField(required=False, widget=NumberInput(attrs={'class': 'form-control',
                                                                      'type': 'number', 'id': 'phone',
                                                                      'placeholder': 'Enter Phone Number'}))
    bvn = forms.CharField(required=False, widget=NumberInput(attrs={'class': 'form-control',
                                                                      'type': 'number', 'id': 'bvn',
                                                                      'placeholder': 'Enter BVN'}))
    avatar = forms.ImageField(required=False, widget=ClearableFileInput(attrs={'class': 'form-control',
                                                                      'type': 'file', 'id': 'avatar',
                                                                      'placeholder': 'Upload Avatar'}))

Answer 1

你的标题是错误的。

headers = {"Content-Type": 'application/json', "Authorization": "Token " + token}

改为：

headers = {"Content-Type": 'multipart/form-data', "Authorization": "Token " + token}

当你上传一些文件时，你应该使用multipart/form-data 而不是application/json （如果您确定不将文件作为 base64 发送）

Answer 2

如果其他人遇到同样的问题，我能够解决的唯一方法是使用单独的视图来处理图像和其他文本字段。到目前为止我所做的一切都有效。 如果您注意到，处理图像的视图的内容类型标头没有插入，只需将其删除并让您的 API 自行处理，几次我将其设置为 multipart/form-data，我将点击响应代码 200 /201，但文件永远不会被保存。

我的 API 视图.py

class CustomerApiView(generics.UpdateAPIView, generics.ListAPIView):
    """Customer Api View to update customer profile"""
    http_method_names = ['put', 'get']
    renderer_classes = [renderers.JSONRenderer]
    authentication_classes = [authentication.TokenAuthentication]
    serializer_class = CustomerSerializer
    queryset = Profile.objects.all()
    permission_classes = [IsAuthenticated]

    def get_queryset(self):
        user = self.request.user
        return self.queryset.filter(user=user)

    def get_object(self):
        queryset = self.filter_queryset(self.get_queryset())
        # make sure to catch 404's below
        obj = queryset.get(user_id=self.request.user.id)
        self.check_object_permissions(self.request, obj)
        return obj

class CustomerAvatarApiView(generics.UpdateAPIView):
    """Customer Avatar/DP API View"""
    serializer_class = CustomerAvatarSerializer
    queryset = Profile.objects.all()
    authentication_classes = [authentication.TokenAuthentication]
    permission_classes = [IsAuthenticated]
    renderer_classes = [renderers.JSONRenderer]
    http_method_names = ['put', 'get']

    def get_object(self):
        queryset = self.filter_queryset(self.get_queryset())
        # make sure to catch 404's below
        obj = queryset.get(user_id=self.request.user.id)
        self.check_object_permissions(self.request, obj)
        return obj

serializer.py

class CustomerSerializer(serializers.ModelSerializer):
    """Customer Profile Serializer"""

    class Meta:
        """Class Meta"""
        model = Profile
        fields = ('pk', 'phone', 'bvn', 'avatar')
        extra_kwargs = {'pk': {'read_only': True}, }


class CustomerAvatarSerializer(serializers.ModelSerializer):
    """Separate Serializer to handle upload of file"""

    class Meta:
        """Class Meta"""
        model = Profile
        fields = ('avatar', )

我的观点.py

class CustomerDashboard(LoginRequiredMixin, generic.FormView):
    """customer dashboard view"""
    template_name = 'customer/dashboard.html'
    form_class = ProfileUpdateForm
    raise_exception = False
    success_url = reverse_lazy('customer_dashboard')

    def get_profile_api(self):
        """get profile api call to fetch profile; passing in the token from session"""
        token = self.request.session['session_token']
        headers = {"Content-Type": 'application/json', "Authorization": "Token " + token}
        response = requests.get(str(settings.API_END_POINT + '/customer_profile_api/'), headers=headers)
        json_response = response.json()
        return json_response

    def get_initial(self):
        initial = ''
        try:
            initial = super(CustomerDashboard, self).get_initial()
            initial['phone'] = self.get_profile_api()[0]['phone']
            initial['bvn'] = self.get_profile_api()[0]['bvn']
        except:
            pass

        return initial

    def get_context_data(self, **kwargs):
        """overriding get_context_data to pass data to template"""
        context = super(CustomerDashboard, self).get_context_data()
        if self.get_profile_api()[0]['bvn'] != '':  # if BVN has been filled before pass True or False to template
            context['bvn_initial'] = True  # Todo Validate BVN from API Before calling save method on it
        else:
            context['bvn_initial'] = False

        return context

    def form_valid(self, form):
        token = self.request.session['session_token']

        if 'updateAvatar' in self.request.POST:

            headers = {"Authorization": "Token " + token}
            avatar = form.cleaned_data['avatar']

            file = {'avatar': (str(avatar), avatar)}

            response = requests.put(str(settings.API_END_POINT + '/customer_profile_avi_api/'), files=file,
                                    headers=headers)
            message = 'Avatar changes successfully'

            if response.status_code in settings.SUCCESS_CODES:
                messages.success(self.request, message)
            else:
                messages.error(self.request, 'API Error %s' % response)

        elif 'updateProfile' in self.request.POST:

            headers = {"Content-Type": "application/json", "Authorization": "Token " + token}
            parameters = {
                'bvn': form.cleaned_data['bvn'],
                'phone': form.cleaned_data['phone'],
            }

            response = requests.put(str(settings.API_END_POINT + '/customer_profile_api/'), json=parameters,
                                    headers=headers)
            message = 'Profile changes successfully'

            if response.status_code in settings.SUCCESS_CODES:
                messages.success(self.request, message)
            else:
                messages.error(self.request, 'API Error %s' % response)

        return super(CustomerDashboard, self).form_valid(form)