GitLocker: The Coding Marketplace

Description:

djangoadmindisplay 1.3.0

django-admin-display

Simplifies the use of function attributes (eg. short_description) for the django admin and makes mypy happy :)
Requirements

Python 3.6.1 or newer
Django >= 1.11

Usage
If you want to change the behaviour of how Django displays a read-only value in the admin interface,
you can add some special attributes to the corresponding method.
Supported values are
short_description
Customize the column’s title of the callable.
empty_value_display
Show this value instead, if the value of a field is None, an empty string, or an iterable without elements.
admin_order_field
Indicate that the value is represented by a certain database field.
boolean
Display a pretty “on” or “off” icon if the method returns a boolean.
allow_tags (deprecated since Django 1.9)
Disable auto-escaping.
The following example shows, how you normally apply these attributes to an AdminModel or a Model method.
class Company(models.Model):
...

def owner(self) -> bool:
return self.owner.last_name
owner.short_description = "Company owner"
owner.admin_order_field = 'owner__last_name'

This module replaces the way of defining these attributes by providing a handy decorator.
from django_admin_display import admin_display

class Company(models.Model):
...

@admin_display(
short_description="Company owner",
admin_order_field='owner__last_name',
)
def owner(self) -> bool:
return self.owner.last_name

Why?
There are mainly two reasons why this module exists.
Usage with @property
It is quite common that a calculated model property is displayed in the admin interface:
class Company(models.Model):
...

@property
def created_on(self) -> datetime.date:
return self.created_at.date()

In order to add special attributes, you have to create a protected method,
attach the attributes and wrap that method using property():
class Company(models.Model):
...

def _created_on(self) -> datetime.date:
return self.created_at.date()
_created_on.short_description = "Created on"
created_on = property(_created_on)

This is quite cumbersome, hard to read and most people don't know that this is even possible.
To overcome these downsides you can achieve the same result using the @admin_display decorator:
from django_admin_display import admin_display

class Company(models.Model):
...

@property
@admin_display(
short_description = "Created on",
)
def created_on(self) -> datetime.date:
return self.created_at.date()

mypy
If you are using mypy, you have probably stumbled over an error similar to this one

"Callable[[Any, Any], Any]" has no attribute "short_description"

A common solution is to ignore the type checking by adding # type: ignore to the end of the line:
class CompanyAdmin(admin.ModelAdmin):
...

def created_on(self, company: models.Company) -> datetime.date:
return company.created_at.date()
created_on.short_description = "Created on" # type: ignore

The issue is already known and heavily discussed on github.
This decorator solves the issue by internally using # type: ignore and providing a well-defined signature for setting the attributes.
It is not an optimal solution but works well until the issue has been resolved.
Development
This project uses poetry for packaging and
managing all dependencies and pre-commit to run
flake8, isort,
mypy and black.
Clone this repository and run
poetry install
poetry run pre-commit install

to create a virtual enviroment containing all dependencies.
Afterwards, you can run the test suite using
poetry run pytest

This repository follows the Conventional Commits
style.
Cookiecutter template
This project was created using cruft and the
cookiecutter-pyproject template.
In order to update this repository to the latest template version run
cruft update

in the root of this repository.