Django - 我如何才能使管理 *changelist* 界面中的表格中的单元格只有在它为空时才可编辑?

Django - how can I make a cell in a table in the admin *changelist* interface editable only if it is null?(Django - 我如何才能使管理 *changelist* 界面中的表格中的单元格只有在它为空时才可编辑?)

问题描述

我希望我的数据在 Django 管理页面中是可编辑的.但是，我只希望每行中的某些字段列是可编辑的.这些列将随每一行而改变.基本上，如果某个单元格中的值为空，我希望显示一个下拉选项.如果它不为空，那么我不希望它是可编辑的并且希望它是只读的.

I would like my data to be editable inline in the Django admin page. However, I only want some fields columns in each row to be editable. These columns will change for each row. Basically, I want a dropdown choice to be displayed if the value in a certain cell is null. If it is not null, then I don't want it to be editable and would like it to be readonly.

models.py:

class Size(models.Model):
    size = models.CharField(max_length=20, primary_key=True)

class Book(models.Model):
    title = models.CharField(max_length=100, primary_key=True)
    size = models.ForeignKey(Size, null=False)

class Pamphlet(models.Model):
    title = models.CharField(max_length=100, primary_key=True)
    size = models.ForeignKey(Size, null=True)
    book = models.ForeignKey(Book, null=True)

admin.py:

class PamphletAdmin(admin.ModelAdmin):
    model = Pamphlet
    list_editable = ('size','book')
    list_display = ('title', 'size', 'book',)

    def get_changelist_form(self, request, **kwargs):
        return PamphletChangeListForm

forms.py:

class PamphletChangeListForm(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        super(PamphletChangeListForm, self).__init__(*args, **kwargs)
        instance = kwargs.get('instance')
        if instance:
            self.fields['book'].queryset = Book.objects.filter(
                size=instance.size
            )
            if instance.size is not None:
                self.fields['size'].widget.attrs['readonly'] = 'readonly'

此设置不适用于我.size 在更改列表表单中显示为可编辑，即使它不为空.还有 - 我有什么不明白的?

This setup is not working for me. The size shows as editable in the changelist form even when it is not null. Also - what have I failed to understand?

推荐答案

如果您的字段使用 input 元素，例如 TextField，请添加 readonly 属性到更改列表表单的 __init__ 方法中的字段小部件的 attrs dict.像这样的:

If your field uses an input element, such as a TextField, add the readonly attribute to the field's widget's attrs dict in the changelist form's __init__ method. Something like this:

class PamphletChangeListForm(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        super(PamphletChangeListForm, self).__init__(*args, **kwargs)
        instance = kwargs.get('instance')
        if instance:
            self.fields['book'].queryset = Book.objects.filter(
                size=instance.size
            )
            if instance.size is not None:
                self.fields['size'].widget.attrs['readonly'] = 'readonly'

这不会保护您免受恶意用户伪造帖子数据的侵害 - 因为您需要进一步自定义您的管理员.但是，如果您的管理员中有恶意用户，您的问题就更大了.

That won't protect you against a malicious user faking post data - for that you'd need to customize your admin further. But if you have malicious users on your admin you have bigger problems.

如果您的字段使用 select 元素，则必须对其进行更多更改 - select 属性没有 readonly 作为受支持的属性.相反，您需要一个具有不变值的隐藏输入和一个文本表示，以便用户可以看到设置是什么.Django 不包含这样的小部件，但您可以定义自己的:

If your field uses a select element, you have to change it more - select attributes don't have readonly as a supported attribute. Instead, you'll want a hidden input with the unchanging value, and a text representation so the user can see what the setting is. Django does not include such a widget, but you can define your own:

class LabeledHiddenInput(forms.widgets.HiddenInput):
    def render(self, name, value, attrs=None):
        base_output = super(LabeledHiddenInput, self).render(name, value, attrs)
        if value:
            return base_output + unicode(value)
        else:
            return base_output

您可能需要更小心的转义甚至一些 HTML 格式，这只是一个简单的示例.如果您需要更多示例，请查看内置小部件的源代码.

You might need more careful escaping or even some HTML formatting, this is just a quick example. Check the source code for the built in widgets if you need more examples.

然后您可以使用该小部件而不是默认选择:

Then you can use that widget instead of the default select:

        if instance.size is not None:
            self.fields['size'].widget = LabeledHiddenInput()

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