如何以Django模型形式添加自定义字段？ [英] How to add a custom field in django model form?

问题描述

我正在尝试在表单中添加一个只读字段。

I'm trying to add a readonly field in a form.

模型文件夹已注册在其中管理网站。 FolderAdminForm 定义自定义字段统计信息。 文件夹模型中没有 statistcs 字段，我只想在表单上放置一些只读数据。该数据在模板中定义。

The model Folder is registered in admin site. The FolderAdminForm defines the custom field statistics. There isn't statistcs field in the Folder model, I just want to put some readonly data on the form. This data is defined in the template.

但是，只要用户没有编辑权限，我都会收到错误消息。如果用户仅具有查看权限，则会引发此错误：

But I get a error whenever the user doesn't have edit permission. If the user only have the view permission,this error is raised:

AttributeError: Unable to lookup 'statistics' on Folder or FolderAdmin

这是我的代码：

class CustomWidget(forms.Textarea):
    template_name = 'widget.html'


class FolderAdminForm(forms.ModelForm):
    class Meta:
        model = Folder
        fields = ('field1', 'field2', 'field3',)

    statistics = forms.Field(
        widget=CustomWidget,
        label='Estatísticas',
        help_text='Estatísticas da pasta',
    )

推荐答案

仅当我尝试打开没有编辑权限（即具有只读权限）的文件夹实例时，才会发生错误。因此，django将统计信息字段视为只读字段，然后搜索该字段的标签。 Django在Model，ModelAdmin中寻找此标签。由于它们都不具有统计信息属性，因此会引发错误。
因此，这对我有用：

The error only occurred whenever I tried to open a folder instance without edit permission (i.e. with read only permission). Therefore, django consider the statistics field as a read only field and then search for a label for this field. Django look for this label in Model, ModelAdmin. Since none of them has the 'statistics' attribute, the error is raised. So, this worked for me:

 class FolderAdminForm(forms.ModelForm):
    class Meta:
        model = Folder
        fields = ('field1', 'field2', 'field3',)

        labels = {'statistics': 'Estatísticas'}

    statistics = forms.Field(
        widget=CustomWidget,
        label='Estatísticas',
        help_text='Estatísticas da pasta',
    )

因此，每当django查找统计信息标签时，它都会找到该标签并且不会引发错误。我不知道为什么它不能识别作为字段参数传递的标签。

Therefore, whenever django looks for a label for statistics, it finds this label and the error is not raised. I don't know why it doesn't recognize the label passed as a Field parameter.

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