Django Admin list_display - 如何使用 list_display 从 JSON 字段中列出字典值

Question

我想在 Django Admin list_display 中显示 JSON 字段中的特定值。

models.py:
class Foo(models.Model):
client = models.ForeignKey(Client, verbose_name="Kunde")

description = models.CharField(verbose_name=u'Titel', max_length=100)
description_file = models.FileField(verbose_name="Vorschau", upload_to='postings', blank=True, help_text=u'Vorschau/Endfassung')
accepted_by_client = models.BooleanField(verbose_name="abgenommen", help_text=u"")
needs_correction = models.BooleanField(verbose_name=u"Korrektur nötig", help_text=u"")
active = models.BooleanField(verbose_name="Publiziert", help_text=u"")
ctime = models.DateTimeField(verbose_name="Angelegt am", blank=True, null=True)
valid_until = models.DateField(verbose_name=u"gültig bis", blank=True, null=True, default = lambda: datetime.datetime.now()+datetime.timedelta(days=28) )
valid_from = models.DateField(verbose_name=u"gültig ab", blank=True, default=datetime.datetime.now ) 
link = models.CharField(verbose_name="Formular", max_length=255, blank=True, help_text="generierter Link zum Formular")
admin_notes = models.TextField(u'Notizen für Mitarbeiter', blank=True, help_text=u"")
client_notes = models.TextField(verbose_name=u"Notizen für Kunde", blank=True, help_text=u"")

context = JsonField()

def __unicode__(self):
    return self.client.company_name + ' : ' + str(self.id)

admin.py:

class FooAdmin(admin.ModelAdmin):
    #list view
    def apis(self, object):
        data = Foo.context['bar']
        return data

    list_display = (
        'id', 
        'client',
        'description', 
        'active', 'ctime', 
        'valid_until',
        'valid_from',
        'clickable_preview_link',
        'clickable_editor_link',
        'apis'
    )

admin.site.register(Foo, FooAdmin)

我的问题是，我无法从 JSON 字段“上下文”访问单个值。我只收到一个空列。

我该怎么做？

提前致谢！

Answer 1

class FooAdmin(admin.ModelAdmin):
    #list view
    def apis(self, object):
        data = Foo.context['bar']
        return data

    list_display = (
        'id', 
        'client',
        'description', 
        'active', 'ctime', 
        'valid_until',
        'valid_from',
        'clickable_preview_link',
        'clickable_editor_link',
        'apis',
        'json_data'
    )

    def json_data(self, obj):
        for key, value in obj.context:
            return "{0}: {1}".format(key, value)
        return ''