Introduction to admin file in django

Amrit Panta
May 4, 2023, 5:11 p.m.

In this tutorial we will learn about the admin.py file in django and it's related operation.

#main urls.py
admin.site.site_title=""
admin.site.site_header=""

To render a model in Django admin, we need to modify myapp/admin.py

from django.contrib import admin 
from django.contrib.admin import DateFieldListFilter    
# Register your models here. 
from myapp.models import ConfigCategory,ConfigChoice    
admin.site.register(Blog)


class ChoiceInline(admin.StackedInline):
    model = ConfigChoice
    extra = 0


@admin.register(ConfigCategory)
class ConfigCategoryAdmin(admin.ModelAdmin):
    add_form = CustomUserAddForm
    form = CustomUserChangeForm
    list_display = ["uuid", "name","full_name", "system", "description", "created_at""updated_at","color_name"]
    list_editable=['status']
    list_filter = ["created_at","system__name, ("created_at", DateFieldListFilter)]
    empty_value_display = 'Not Available'
    search_fields = ["name","system__name"]
    fields = ('name', 'begin_datetime') #if you want to show only few field in admin
    exclude = ('end_datetime', )
    inlines = [ChoiceInline]
    readonly_fields = ('created_at', 'updated_at', 'created_by')
    ordering = ('id', )
    prepopulated_fields={"slug":("name","address")}
    list_display_links=['id','title']
    save_on_top=True
    list_per_page=10
    radio_fields={"choices_field_in_model":admin.HORIZONTAL}   

    def color_name(self,obj):
        return format_html(f'<span style="color:red">{obj.name}<span>')
    def clickme(self,obj):
        return format_html(f'<a href="/admin/ajax/student/{obj.id}/change/"> View </a>')
    def photo_tage(self,obj):
        return format_html(f'<img src="/media/{obj.profile}" style="height:50px;width:50px"/>')
    readonly_fields=["photo_tage"] # to show any user define field in detail page , mention here

    """
    The raw_id_fields Input widget should contain a primary key if the field is a ForeignKey or a 
    comma separated list of values if the field is a ManyToManyField. 
    """
    raw_id_fields = ("show",)
    date_hierarchy = "begin_datetime"

    #to show less content
    def less_content(self,obj):
        return obj.description[:30]
    #now you can mention less_content in list-display

    #you can defile custom field also too
    def full_name(self, obj):
        return f"{obj.name} {obj.last_name}"

    #fieldsets control the layout of admin
    fieldsets = (
        ("Some options", {
            'fields': ('name', 'show')
        }),
        ('Date options', {
            'classes': ('collapse',),
            'fields': ('begin_datetime', 'end_datetime'),
        }),
    )
   
    fieldsets = (
        ('User', {'fields': ('uuid', 'username', 'email', 'password', 'created_by')}),
        ('Permissions', {'fields': ('is_active', 'is_superuser', 'is_admin', 'is_staff')}),
        ('Dates', {'fields': ('created_at', 'updated_at', 'last_login',)}),
    )

    add_fieldsets = (
        (None, {
            "classes": ("wide",),
            "fields": ("email", "username", "password", "confirm_password"),
        }),
    )
    #to provide permission
    MAX_OBJECTS=10
    def has_add_permission(self, request):
        if self.model.objects.count() >= MAX_OBJECTS:
            return False
        return super().has_add_permission(request)

Django Admin Interface can be used to graphically implement CRUD (Create, Retrieve, Update, Delete).

Custom Django admin List action

Django Admin List actions are used to perform operations in bulk.

Example Model

from django.db import models

class Ticket(models.Model):
    STATUS = (
        ('P', 'In Process'),
        ('S', 'Success'),
        ('C', 'Cancled'),
    )

    name = models.CharField(max_length=225)
    status = models.CharField(choices=STATUS,
                              max_length=20,
                              help_text="Status of this instance")

admin.py

from django.contrib import admin
from app.models import Ticket, Show

@admin.register(Ticket)
class TickerAdmin(admin.ModelAdmin):
    list_display = ('id', 'status', 'show', 'begin_datetime', 'end_datetime')
    actions = ["cancel_tickets"]

    def cancel_tickets(self, request, queryset):
        for ticket in queryset:
            ticket.status = "C"
            ticket.save()
    
    cancel_tickets.short_description = 'Cancel Selected Tickets'

Django save_model method()

Django Admin save_model is used to create and update model object from Django admin panel

from django.contrib import admin
from app.models import Ticket

@admin.register(Ticket)
class TickerAdmin(admin.ModelAdmin):

    def save_model(self, request, obj, form, change):
        if not change:
            obj.owner = request.user
        elif change:
            obj.updated_by = request.user
        super().save_model(request, obj, form, change)

How to show Image field in django admin panel

There are two possible approach to do that

1. Using mark_safe()

2. Using sorl-thumbnail()

1. Using mark_safe()

model.py

from django.db import models
from django.utils.html import mark_safe


class Post(models.Model):
    title = models.CharField(max_length=255)
    thumbnail = models.ImageField(upload_to='post/thumbnail/%Y/%m/%d/', null=True, blank=True)

    @property
    def thumbnail_preview(self):
        if self.thumbnail:
            return mark_safe('<img src="{}" width="300" height="300" />'.format(self.thumbnail.url))
        return ""

admin.py

from django.contrib import admin
from post.models import Post


class PostAdmin(admin.ModelAdmin):
    list_display = ('id', 'title')
    readonly_fields = ('thumbnail_preview',)

    def thumbnail_preview(self, obj):
        return obj.thumbnail_preview

    thumbnail_preview.short_description = 'Thumbnail Preview'
    thumbnail_preview.allow_tags = True

admin.site.register(Post, PostAdmin)

2. Using sorl-thumbnail()

First we need to install sorl-thumbnail

$ pip install sorl-thumbnail

Then register sorl.thumbnail, in the INSTALLED_APPS section of your project's settings.

INSTALLED_APPS = [
    'django.contrib.auth',
    'django.contrib.admin',
    'django.contrib.sites',
    'django.contrib.comments',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.contenttypes',
    'sorl.thumbnail',
]

Now run migrate command

python manage.py migrate

models.py

from django.db import models
from sorl.thumbnail import get_thumbnail
from django.utils.html import format_html

class Post(models.Model):
    title = models.CharField(max_length=255)
    thumbnail = models.ImageField(upload_to='post/thumbnail/%Y/%m/%d/', null=True, blank=True)

    @property
    def thumbnail_preview(self):
        if self.thumbnail:
            _thumbnail = get_thumbnail(self.thumbnail,
                                   '300x300',
                                   upscale=False,
                                   crop=False,
                                   quality=100)
            return format_html('<img src="{}" width="{}" height="{}">'.format(_thumbnail.url, _thumbnail.width, _thumbnail.height))
        return ""

admin.py

from django.contrib import admin
from post.models import Post


class PostAdmin(admin.ModelAdmin):
    list_display = ('id', 'title')
    readonly_fields = ('thumbnail_preview',)

    def thumbnail_preview(self, obj):
        return obj.thumbnail_preview

    thumbnail_preview.short_description = 'Thumbnail Preview'
    thumbnail_preview.allow_tags = True

admin.site.register(Post, PostAdmin)

You can also show thumbnail preview in admin List by adding thumbnail_preview in list_display

list_display = ('id', 'title', 'thumbnail_preview')

Login with email instead of username in django admin

models.py

from django.contrib.auth.models import AbstractUser

class User(AbstractUser):
    USERNAME_FIELD = 'email'
    email = models.EmailField(max_length=255, unique=True)
    REQUIRED_FIELDS = [] # removes email from REQUIRED_FIELDS

Don’t forget to point AUTH_USER_MODEL to it.

settings.py

AUTH_USER_MODEL = ‘your_app.User’

Now register the model in the app’s admin.py:

admin.py

from django.contrib.auth.admin import UserAdmin
admin.site.register(User, UserAdmin)

How to apply filter on foreignkey in Django admin panel

In order to apply a filter on Foreign Key in Django admin, we need to override formfield_for_foreignkey method admin.py file.

admin.py

class PostAdmin(admin.ModelAdmin):
    list_display = ('id', 'title')

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        if db_field.name == "author":
            kwargs["queryset"] = User.objects.filter(is_author=True)
        return super(PostAdmin, self).formfield_for_foreignkey(db_field, request, **kwargs)

How to apply filter on manytomany key in Django admin panel

Suppose we have to model User and Post.

models.py

from django.db import models


class User(models.Model):
    name = models.CharField(max_length=255)
    is_author = models.BooleanField(default=False)


class Post(models.Model):
    title = models.CharField(max_length=255)
    author = models.ManyToManyField(User, related_name="posts", blank=True)

Now in Post.author we want to show only those uses whose is_author is True.

admin.py

from django.contrib import admin
from post.models import Post, User


class PostAdmin(admin.ModelAdmin):
    list_display = ('id', 'title')

    def formfield_for_manytomany(self, db_field, request, **kwargs):
        if db_field.name == "author":
            kwargs["queryset"] = User.objects.filter(is_author=True)
        return super(PostAdmin, self).formfield_for_manytomany(db_field, request, **kwargs)


class UserAdmin(admin.ModelAdmin):
    list_display = ('id', 'name', 'is_author')


admin.site.register(Post, PostAdmin)
admin.site.register(User, UserAdmin)