Django admin different changeform in add / change。Django Admin新增与修改页面使用不同的Form。

admin.py

@admin.register(m.Holiday)
class HolidayAdmin(admin.ModelAdmin):
    list_display = ('id', 'day', 'category')
    search_fields = ('day',)
    list_filter = ('category',)
    date_hierarchy = 'day'

    def get_form(self, request, obj=None, change=False, **kwargs):
        if not change:
            kwargs['form'] = HolidayForm
            # 如果 self.fields 为空，会再调 get_form() 获取 fields 值，这样造成重复调用，这时再传进来的的 change=False
            self.fields = ['start_day', 'days', 'category']
        else:
            self.fields = ['day', 'category']
        form = super().get_form(request, obj, change, **kwargs)
        return form

    def save_model(self, request, obj, form, change):
        if change:
            super().save_model(request, obj, form, change)
        else:
            # 如果在 form 中的 save 实现，还要考虑 m2m 的情况。麻烦。
            start_day = form.cleaned_data['start_day']
            days = form.cleaned_data['days']
            obj.category = form.cleaned_data['category']
            for i in range(days):
                obj.id = None  # 为 None 的时候会保存一条新记录
                obj.day = start_day + timedelta(days=i)
                obj.save()

forms.py

# coding: utf-8
from datetime import timedelta

from django import forms
from .models import Holiday


class HolidayForm(forms.ModelForm):
    start_day = forms.DateField()
    days = forms.IntegerField(initial=1)

    class Meta:
        model = Holiday
        fields = ['category', 'start_day', 'days']

    def clean(self):
        days = self.cleaned_data['days']
        start_day = self.cleaned_data['start_day']
        for i in range(days):
            day = start_day + timedelta(days=i)
            if Holiday.objects.filter(day=day).exists():
                raise forms.ValidationError("包含的日期重复：%s" % (day.isoformat()))

models.py

class Holiday(models.Model):
    day = models.DateField(unique=True)
    category = models.IntegerField(choices=HOLIDAY_CATEGORY, default=HOLIDAY)

    def __str__(self):
        return self.day.strftime('%Y%m%d')