Beginners Guide To Geo-Django

GeoDjango is a built-in application that is included as a contrib module in Django. It’s actually a complete framework itself that can also be used separately from Django. It provides a toolbox of utilities for building GIS web applications.

Requirements:

• Postgres(Or MySql, MongoDB)
• PostGIS extension needs to be installed on Postgres
• QGIS GeoDjango Dependencies or install Geospatial libraries GEOS, GDAL, and PROJ.4,

Project Setup:

$ mkdir dj_gis && cd dj_gis
$ python3 -m venv env
$ source env/bin/activate
$ pip install django djangorestframework django-leaflet geopy psycopg2-binary 
$ django-admin.py startproject config
$ python manage.py startapp my_geo_app

setting.py

#config/settings.py

INSTALLED_APPS = [
    "django.contrib.gis",
    "my_geo_app",
    "rest_framework",
]

urls.py

#config/urls.py

from django.contrib import admin
from django.urls import path
from django.urls.conf import include


urlpatterns = [
    path("admin/", admin.site.urls),
    path("api/v1/", include("my_geo_app.urls")),
]

include url.py file on my_geo_app app

from django.urls import path

urlpatterns = []

Let’s create a model app/models.py

from django.db import models
from django.contrib.gis.db import models # GeoDjango


class Casino(models.Model):
    name = models.CharField(max_length=255)
    address = models.CharField(max_length=255)
    created_at = models.DateTimeField(auto_now_add=True)
    location = models.PointField(null=True) # lat and long point fields

    def __str__(self):
        return self.name

let’s create a serializer and views for our model.

from location.models import Casino
from rest_framework import serializers


class CasinoSerializer(serializers.ModelSerializer):
    class Meta:
        model = Casino

        fields = ("id", "name", "address", "location")

        extra_kwargs = {"location": {"read_only": True}}

my_geo_app/views.py

from location.serializers import CasinoSerializer
from django.shortcuts import render
from rest_framework import generics
from .models import Casino

from django.contrib.gis.geos import Point
from geopy.geocoders import Nominatim

geolocator = Nominatim(user_agent="casino")


class ListCreateGenericViews(generics.ListCreateAPIView):
    queryset = Casino.objects.all()
    serializer_class = CasinoSerializer

    def perform_create(self, serializer):
        address = serializer.initial_data["address"]
        g = geolocator.geocode(address)
        lat = g.latitude
        lng = g.longitude
        pnt = Point(lng, lat)
        print(pnt)
        serializer.save(location=pnt)


class HotelUpdateRetreiveView(generics.RetrieveUpdateDestroyAPIView):
    queryset = Casino.objects.all()
    serializer_class = CasinoSerializer

    def perform_update(self, serializer):
        address = serializer.initial_data["address"]
        g = geolocator.geocode(address)
        lat = g.latitude
        lng = g.longitude
        pnt = Point(lng, lat)
        print(pnt)
        serializer.save(location=pnt)

geopy makes it easy for Python developers to locate the coordinates of addresses, cities, countries, and landmarks across the globe using third-party geocoders and other data sources.

urls.py

from django.urls import path
from .views import CasinoUpdateRetreiveView, ListCreateGenericViews

urlpatterns = [
    path("casinos", ListCreateGenericViews.as_view()),
    path(
        "casinos/<str:pk>",
        CasinoUpdateRetreiveView.as_view(),
    ),
]

Database and leaflet settings

DATABASES = {
    "default": {
        "ENGINE": "django.contrib.gis.db.backends.postgis",
        "NAME": "locator",
        "USER": "locator",
        "PASSWORD": "locator",
        "HOST": "http://127.0.0.1:8000",
        "PORT": "5432",
    }
}

LEAFLET_CONFIG = {
    # "SPATIAL_EXTENT": (5.0, 44.0, 7.5, 46),
    "DEFAULT_CENTER": (13.3888599 52.5170365), #set your corordinate
    "DEFAULT_ZOOM": 16,
    "MIN_ZOOM": 3,
    "MAX_ZOOM": 20,
    "DEFAULT_PRECISION": 6,
    "SCALE": "both",
    "ATTRIBUTION_PREFIX": "anshu is cool",
}

Register a model to admin

from django.contrib import admin
from leaflet.admin import LeafletGeoAdmin

from .models import Casino


@admin.register(Casino)
class HotelAdmin(LeafletGeoAdmin):
    list_display = ("id", "name", "address", "location", "created_at")

Everything is good to go, just make the necessary migrations and run the app

python manage.py makemigrations
python manage.py migrate
python manage.py createsuperuser
python manage.py runserver

Cheers!!!