Django test-app snippet

admin.py

from django.contrib import admin

# Register your models here.

from .models import Item, Feature, RequiredMaterial, DevelopmentProject


class ItemAdmin(admin.ModelAdmin):
	model = Item

admin.site.register(Item, ItemAdmin)



class FeatureAdmin(admin.ModelAdmin):
	model = Feature

admin.site.register(Feature, FeatureAdmin)



class RequiredMaterialInline(admin.TabularInline):
	model = RequiredMaterial
	extra = 1

class DevelopmentProjectAdmin(admin.ModelAdmin):
	inlines = (RequiredMaterialInline,)
	list_display = ("development_project", "was", "becomes", "types_of_materials_needed")

admin.site.register(DevelopmentProject, DevelopmentProjectAdmin)

models.py

from django.db import models
from django.core.exceptions import ValidationError

# Create your models here.



class Item(models.Model):
	name = models.CharField(max_length=255)
#	illustration = models.ImageField(upload_to=)

	def __str__(self):
		return self.name



class Feature(models.Model):
	# A feature is what occupies a slot, it can be a man-made constuct or natural terrain.
	name = models.CharField(max_length=255)
	description = models.TextField(max_length=255)
#	illustration = models.ImageField(upload_to=)

	def __str__(self):
		return self.name



class DevelopmentProject(models.Model):
	# Development projects can be applied to features in order to improve them.
	was = models.ForeignKey(Feature, related_name='Project Source')
	becomes = models.ForeignKey(Feature, related_name='Project Result')
	materials_needed = models.ManyToManyField(Item, through='RequiredMaterial')
#	illustration = models.ImageField(upload_to=)

	def development_project(self):
		return ("[%s] ⇒ [%s]" % (str(self.was), str(self.becomes)))

	def types_of_materials_needed(self):
		return ",\n".join([r.name for r in self.materials_needed.all()])



def validate_material_quantity(talue):
	if value % 10 != 0:
		raise ValidationError('Please input a multiple of 10.')

class RequiredMaterial(models.Model):
	project = models.ForeignKey(DevelopmentProject)
	item = models.ForeignKey(Item)
	quantity = models.PositiveSmallIntegerField(default=0, validators=[validate_material_quantity])

	def __str__(self):
		quantity_of_items = str(self.item) + ', ' + str(self.quantity)
		return quantity_of_items