Django 使用forms进行POST字段校验(文件上传校验)

一、前言

​ POST中有多个字段、甚至有文件上传时的验证方式。(使用forms进行验证)

​ django 中的forms不仅可以用来渲染页面表单（我不喜欢用），还可以用来校验提交的表单请求（yes, i do）。

二、具体实现

​ 此处我们假设有5个普通字段，1个文件字段。要求：采用ajax方式防川文件，并对文件格式进行校验并重命名

• models.py

  class MainModelFile(models.Model):
      '''
      存储印花税/附加税文件
      '''
      name = models.CharField(max_length=50, verbose_name="表名")
      type = models.CharField(max_length=20, verbose_name="类型")
      belong_date = models.CharField(max_length=50, verbose_name="所属期")
      add_date = models.DateField(verbose_name="填表日期")
      add_date_time = models.DateTimeField(verbose_name="申报时间")
      content_file = models.FileField(upload_to="xxx", verbose_name="PDF文件")
  

  注：关于upload_to的路径之media的设定参考：官方网站搜索【MEDIA_URL】

• forms.py

  class AddDataFormFileModelForm(forms.ModelForm):
      class Meta:
          model = models.MainModelFile
          fields = "__all__"
  
      def clean_content_file(self): #对于某个字段的验证使用clean_字段的方式命名
          '''
          校验文件格式并重命名文件名
          '''
          file = self.cleaned_data["content_file"]
          ext = file.name.split(".")[-1].lower()
          if ext != "pdf":
              raise forms.ValidationError("仅允许上传PDF文件")
          new_file_name = random.randint(111111111,9999999999)
          file.name = "%d.pdf"%new_file_name
  
          return file
  

• views.py

  class AddDataView(TemplateView):
      template_name = "new_app/add_data.html"
      def get(self, request, *args, **kwargs):
          ...
      def post(self,request,*args,**kwargs): 
          check_form = AddDataFormFileModelForm(request.POST,request.FILES)
          if not check_form.is_valid():
              return JsonResponse({'message': check_form.errors, "code": 400})
          instance = check_form.save()
  
          return JsonResponse({'message': instance.name + "，保存成功","code":200})
  

• html.py js部分

  function getCookie(name) {
      let cookieValue = null;
      if (document.cookie && document.cookie !== '') {
          const cookies = document.cookie.split(';');
          for (let i = 0; i < cookies.length; i++) {
              const cookie = cookies[i].trim();
              // Does this cookie string begin with the name we want?
              if (cookie.substring(0, name.length + 1) === (name + '=')) {
                  cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
                  break;
              }
          }
      }
      return cookieValue;
  }
  
  function upload_pdf() {
      const csrftoken = getCookie('csrftoken');
      
      var form = new FormData();
      form.append("f_id", $("#f_id").val());
      form.append("image_path", $("#image_path")[0].files[0]);
      $.ajax({
          headers: {'X-CSRFToken': csrftoken},
          url: "{% url 'add_data' %}",
          type: "POST",
          data: form,
          
          processData: false,
          contentType: false,
          cache: false,
          
          success: function (result) {
              if (result.code === 200) {
                  alert_message(JSON.stringify(result.message));
                      } else {
                          console.log("success", result);
                          alert_message(JSON.stringify(result.message));
                      }
                  },
                  fail: function (result) {
                      console.log("fail",);
                      alert_message(result.info);
                  },
                  error: function (result) {
                      alert_message(result.status + ": " + result.statusText);
                  }
              });
  
          }
  

三、关于MEDIA的相关设定

• settings.py

  ...
  MEDIA_URL = '/media/'
  MEDIA_ROOT = os.path.join(BASE_DIR,'media')
  ...
  

• urls.py

  ...
  from django.conf import settings
  from django.conf.urls.static import static
  urlpatterns = [
      ...
  ] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)
  ...