python - Django-parler:类型对象 'BookImage' 没有属性 '_parler_meta'

Question

当我尝试使用 django 管理界面添加新的 Book 时，django-parler 引发此错误。

models.py

from django.db import models
from django.urls import reverse
from isbn_field import ISBNField
from django.core.validators import MinValueValidator
from parler.models import TranslatableModel, TranslatedFields


class Genre(TranslatableModel):
    translations = TranslatedFields(
        title=models.CharField(max_length=200,
                               db_index=True),
        slug=models.SlugField(max_length=200,
                              db_index=True,
                              unique=True,
                              help_text='Unique value for book page URL, created from name.'),
        description=models.TextField(blank=True, db_index=True),

    )

    class Meta:
        db_table = 'genres'
        verbose_name_plural = 'Genres'

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse('bookstore:book_list_by_genre',
                       args=[self.slug])


class Book(TranslatableModel):
    translations = TranslatedFields(
        title=models.CharField(max_length=200,
                               db_index=True),
        slug=models.SlugField(max_length=200,
                              db_index=True,
                              unique=True),
        author=models.CharField(max_length=100,
                                db_index=True,
                                blank=True,
                                null=True,
                                default=None),
        edition_language=models.CharField(max_length=100,
                                          db_index=True,
                                          blank=True,
                                          null=True,
                                          default=None),
        description=models.TextField(blank=True,
                                     db_index=True),
        binding=models.CharField(max_length=100,
                                 db_index=True,
                                 blank=True,
                                 null=True,
                                 default=None),
    )

    genres = models.ManyToManyField(Genre, related_name='books',
                                    default=None,
                                    blank=True)
    isbn = ISBNField(unique=True,
                     blank=True,
                     null=True,
                     help_text='ISBN is a ten or thirteen digit number used to '
                               'identify books and book-like resources.')

    price = models.DecimalField(max_digits=9, decimal_places=2, default=0.00, validators=[MinValueValidator(0.00)])
    old_price = models.DecimalField(max_digits=9, decimal_places=2, default=0.00, validators=[MinValueValidator(0.00)])
    discount = models.DecimalField(max_digits=4, decimal_places=2, default=0, max_length=4)
    quantity = models.PositiveIntegerField(validators=[MinValueValidator(1)])
    publisher = models.CharField(max_length=100, blank=True, null=True, default=None)
    pub_year = models.CharField(max_length=4, blank=True, null=True, default=None)
    bestseller = models.BooleanField(default=False)
    available = models.BooleanField(default=True)
    created = models.DateTimeField(auto_now_add=True)
    updated = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = 'books'
        ordering = ['-created']

    def __str__(self):
        return self.title

    def save(self, *args, **kwargs):
        if self.discount == 0 and self.old_price >= self.price:
            self.price = self.old_price

        if self.discount != 0:
            self.old_price = self.price
            # calculate discount
            self.price = self.price * (100 - self.discount) / 100

        super(Book, self).save(*args, **kwargs)

    def get_absolute_url(self):
        return reverse('bookstore:book_detail',
                       args=[self.id, self.slug])


class BookImage(models.Model):
    book = models.OneToOneField(Book, on_delete=models.CASCADE, blank=True, null=True, default=None)
    image = models.ImageField(upload_to='img/books/%Y/%m/%d', blank=True, null=True, default=None, unique=True)
    created = models.DateTimeField(auto_now_add=True, auto_now=False)
    updated = models.DateTimeField(auto_now_add=False, auto_now=True)

    def __str__(self):
        return str(self.id)

    class Meta:
        db_table = 'images'
        verbose_name = 'Book Image'
        verbose_name_plural = 'Book Images'

admin.py

from django.contrib import admin
from .models import *
from parler.admin import TranslatableAdmin, TranslatableStackedInline


class BookImageInline(TranslatableStackedInline):
    model = BookImage
    max_num = 1
    # set limit for extra entries
    extra = 0


@admin.register(Genre)
class GenreAdmin(TranslatableAdmin):
    # set up fields ordering
    list_display = ['title', 'slug']
    # set up admin search fields
    search_fields = ['title', 'description']

    def get_prepopulated_fields(self, request, obj=None):
        return {'slug': ('title',)}


@admin.register(Book)
class BookAdmin(TranslatableAdmin):
    list_display = ['title', 'slug', 'price',
                    'available', 'created', 'updated']
    list_filter = ['available', 'created', 'updated']
    list_editable = ['price', 'available']
    inlines = [BookImageInline]

    def get_prepopulated_fields(self, request, obj=None):
        return {'slug': ('title',)}


@admin.register(BookImage)
class BookImageAdmin(admin.ModelAdmin):
    list_display = ('book', 'created', 'updated',)
    list_filter = ('book',)

    class Meta:
        model = BookImage

Answer 1

BookImageInline 不得翻译，因为底层模型 BookImage 不可翻译:

class BookImageInline(StackedInline):  # not TranslatableStackedInline
    # ...

集成此Inline的模型(在您的情况下为Book)是否可翻译，与内联类型的选择无关。