Question

我有一个带有字段和选择字段的多值字段。我需要将选项传递给choicefield构造函数，但是当我尝试将其传递到我的自定义多值字段时，我得到一个错误__init__()得到了一个意外的关键字参数'choices'。

我知道代码的其余部分有效，因为当我从__init__和super中删除choices关键字参数时，多值字段显示正确，但没有任何选择。

这就是我设置自定义多值字段的方法：

class InputAndChoice(object):
    def __init__(self, text_val='', choice_val=''):
        self.text_val=text_val
        self.choice_val=choice_val

class InputAndChoiceWidget(widgets.MultiWidget):
    def __init__(self, attrs=None):
        widget = (widgets.TextInput(),
                  widgets.Select()
                 )
        super(InputAndChoiceWidget, self).__init__(widget, attrs=attrs)

    def decompress(self,value):
        if value:
            return [value.text_val, value.choice_val]
        return [None, None]


class InputAndChoiceField(forms.MultiValueField):
    widget = InputAndChoiceWidget

    def __init__(self, required=True, widget=None, label=None, initial=None,
                 help_text=None, choices=None):
        field = (
                 fields.CharField(),
                 fields.ChoiceField(choices=choices),
                 )
        super(InputAndChoiceField, self).__init__(fields=field, widget=widget, 
              label=label, initial=initial, help_text=help_text, choices=choices)

我称之为：

input_and_choice = InputAndChoiceField(choices=[(1,'first'),(2,'second')])

那么如何将选择传递给我的ChoiceField字段？

编辑：

我已经尝试过stefanw的建议，但仍然没有运气。我已经使用logging.debug在init的末尾打印出InputAndChoiceField的内容，self.fields [1] .choices包含正确的值，但是它没有在浏览器中显示任何选项。

Answer 1

我遇到了同样的问题并解决了这个问题：

class InputAndChoiceWidget(widgets.MultiWidget):
    def __init__(self,*args,**kwargs):
        myChoices = kwargs.pop("choices")
        widgets = (
            widgets.TextInput(),
            widgets.Select(choices=myChoices)
        )
        super(InputAndChoiceWidget, self).__init__(widgets,*args,**kwargs)

class InputAndChoiceField(forms.MultiValueField):
    widget = InputAndChoiceWidget

    def __init__(self,*args,**kwargs):
        # you could also use some fn to return the choices;
        # the point is, they get set dynamically 
        myChoices = kwargs.pop("choices",[("default","default choice")])
        fields = (
            fields.CharField(),
            fields.ChoiceField(choices=myChoices),
        )
        super(InputAndChoiceField,self).__init__(fields,*args,**kwargs)
        # here's where the choices get set:
        self.widget = InputAndChoiceWidget(choices=myChoices)

在widget的构造函数中添加一个“choices”kwarg。然后在创建字段后显式调用构造函数。

Answer 2

查看__init__的{{1}}来源：

forms.MultiValueField

所以我会像这样覆盖def __init__(self, fields=(), *args, **kwargs): super(MultiValueField, self).__init__(*args, **kwargs) # Set 'required' to False on the individual fields, because the # required validation will be handled by MultiValueField, not by those # individual fields. for f in fields: f.required = False self.fields = fields：

__init__

您甚至可能希望def __init__(self, *args, **kwargs): choices = kwargs.pop("choices",[]) super(InputAndChoiceField, self).__init__(*args, **kwargs) self.fields = ( fields.CharField(), fields.ChoiceField(choices=choices), )代替super(MultiValueField, self).__init__(*args, **kwargs)，因为您自己设置字段而不是通过参数获取字段。

Answer 3

传递小部件中的选项为我解决了这个问题

class InputAndChoiceWidget(widgets.MultiWidget):
    def __init__(self, attrs=None):
        choices = [('a', 1), ('b', 2)]
        widget = (widgets.TextInput(),
                  widgets.Select(choices=choices)
                 )
        super(InputAndChoiceWidget, self).__init__(widget, attrs=attrs)

Answer 4

ModelChoiceField is technically a ChoiceField，但它实际上并没有使用任何ChoiceField的实现。所以，这就是我如何使用它。

class ChoiceInputMultiWidget(MultiWidget):
    """Kindly provide the choices dynamically"""
    def __init__(self, attrs=None):
        _widget = (
            Select(attrs=attrs),
            TextInput(attrs=attrs)
        )
        super().__init__(_widget, attrs)

class ModelChoiceInputField(MultiValueField):
    widget = ChoiceInputMultiWidget

    def __init__(self, *args, **kwargs):

        _fields = (
            ModelChoiceField(queryset=Type.objects.all()),
            CharField()
        )
        super().__init__(_fields, *args, **kwargs)

        # Use the auto-generated widget.choices by the ModelChoiceField
        self.widget.widgets[0].choices = self.fields[0].widget.choices

Answer 5

class HTML5DateInput(DateInput):

    input_type = 'date'


class CustomSelectRangeWidget(forms.MultiWidget):

    def __init__(self, attrs=None, choices = ()):
        widgets = (Select(attrs=attrs, choices=choices), HTML5DateInput(attrs=attrs), HTML5DateInput(attrs=attrs))
        super(CustomSelectRangeWidget, self).__init__(widgets, attrs)

    def decompress(self, value):
        if value:
            return [value.field, value.start, value.stop]
        return [None, None, None]

    def format_output(self, rendered_widgets):
        return '-'.join(rendered_widgets)

class CustomSelectRangeField(forms.MultiValueField):

    widget = CustomSelectRangeWidget

    def __init__(self, *args, **kwargs):
        if kwargs.has_key('choices') :
            choices = kwargs.pop('choices')
        else:
            choices = ()
        fields = (
            forms.ChoiceField(choices=choices),  #field with choices,
                                             # so that clean can be passed
            forms.DateField(),
            forms.DateField(),
            )
        super(CustomSelectRangeField, self).__init__(fields=fields, *args, **kwargs)
        #initialize widget with choices.
        self.widget = CustomSelectRangeWidget(choices=choices)

    def compress(self, data_list):
        if data_list:
           #check if datalist has 3 not null values
           if len([v for v in data_list if v not in [None, '']]) == 3:
               out_dict = {'field':data_list[0], 'start':data_list[1], 'stop':data_list[2]}
               return out_dict
       return None

Django MultiValueField - 如何将选择传递给ChoiceField？

5 个答案: