5.9. Admin Form

5.9.1. Example

from django import forms
from django.contrib import admin
from django.utils.html import format_html
from django.utils.safestring import mark_safe
from shop.models import Customer


class MessageRenderer(forms.Textarea):
    def render(self, name, value, attrs=None, renderer=None):
        if not value:
            return super().render(name, value, attrs, renderer)
        else:
            html = '{}' + forms.HiddenInput().render(name, value)
            value = self.format_value(value).replace('\n', '<br>')
            return format_html(html, mark_safe(value))


class MyForm(forms.ModelForm):
    class Meta:
        model = Customer
        fields = ['author', 'body']
        widgets = {
            'body': MessageRenderer(attrs={'cols': '80', 'rows': '15'}),
        }


@admin.register(Customer)
class CustomerAdmin(admin.ModelAdmin):
    form = MyForm