form组件的总结

1、form组件（******）
                  局部钩子
                  全局钩子
                   '''
                    实例化时:

                        self.fields={
                            "username":"字段规则对象",
                            "password":"字段规则对象",
                        }

                    is_valid时:
                        self._errors = {}
                        self.cleaned_data = {}

                        #局部钩子:

                        for name, field in self.fields.items():
                              try:

                                    value = field.clean(value)
                                    self.cleaned_data[name] = value
                                    if hasattr(self, 'clean_%s' % name):
                                        value = getattr(self, 'clean_%s' % name)()
                                        self.cleaned_data[name] = value
                              except ValidationError as e:
                                    self.add_error(name, e)

                        # 全局钩子:

                        self.clean()               # def self.clean():return self.cleaned_data

                        return  not self.errors    # True或者False
                    '''
                    使用组件：

                            form.py

                                  class LoginForm(forms.Form):
                                       username=forms.CharField()

                            views.py:

                                  def login(request):
                                       if request.is_ajax():
                                            loginform=LoginForm(request.POST)

                                            loginResponse={"user":None,"error_msg":None}
                                            if loginform.is_valid():
                                                loginResponse["user"]=username
                                                # session操作

                                                                                        else:
                                                loginResponse["error_msg"]loginform.errors

                                            return Httpresponse(json.dumps(loginResponse))

                                       loginform=LoginForm()

                                       return(request,"login.html",{"loginform":loginform})               

                            login.html:
                                    <form>
                                           {{loginform.username}}
                                            <input type="button" value="submit" id="subBtn">
                                                                         </form>

                                                                            <script>
                                              $("#subBtn").click(function(){

                                                     $.ajax({
                                                        url:"/login/",
                                                        type:"POST",
                                                        data:{},
                                                        success:function(data){
                                                               // data    loginResponse

                                                        }
                                                     })
                                              })

                                    </script>