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How To Build Location-Based App with Geo🌎Django
by lymaaJune 15th, 2021
Too Long; Didn't Read
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. The GeoGis extension needs to be installed on postgres or install Geospatial libraries GEOS, GDAL, and PROJ.4, or geopy psycopg2-binary. Here we are getting co-ordinates(Longitude, Latitude) of location by inputting names of country and city.Company Mentioned
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.
Purpose of this tutorial
Nothing much fancy, here we are getting co-ordinates(Longitude, Latitude) of location by inputting names of country and city.
Requirements :
- Postgrespostgis extension needs to be installed on postgres
- QGIS GeoDjango Dependencies or install Geospatial libraries GEOS, GDAL, and PROJ.4 ,
Note: above requirements need to be installed on your machine separately before continuing
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 location
config/settings.py
#config/settings.py
INSTALLED_APPS = [
"django.contrib.gis",
"location",
"rest_framework",
]
config/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("location.urls")),
]
include url.py file on location app
#location/urls.py
from django.urls import path
urlpatterns = []So we finished basic setups
Let's create a model location/models.py
from django.db import models
from django.contrib.gis.db import models # GeoDjango Model API
class Hotel(models.Model):
name = models.CharField(max_length=255)
address = models.CharField(max_length=255)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
location = models.PointField(null=True) # Spatial Field Types
def __str__(self) -> str:
return self.namehere, we include a pointfield spatial field of geo django model api.
let's create a serializer and views for our model.
# location/serializers.py
from location.models import Hotel
from rest_framework import serializers
class HotelSerializer(serializers.ModelSerializer):
class Meta:
model = Hotel
fields = ("id", "name", "address", "location")
extra_kwargs = {"location": {"read_only": True}}
location/views.py
from rest_framework import generics
from .models import Hotel
from django.contrib.gis.geos import Point
from geopy.geocoders import Nominatim
geolocator = Nominatim(user_agent="location")
class ListCreateGenericViews(generics.ListCreateAPIView):
queryset = Hotel.objects.all()
serializer_class = HotelSerializer
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 = Hotel.objects.all()
serializer_class = HotelSerializer
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)Note: above view can be further refactor using viewsets or your desired ones.
so, geopy library comes in handy, which is is a Python client for several popular geocoding web services. 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.
let's update our urls:
#location/urls.py
from django.urls import path
from .views import HotelUpdateRetreiveView, ListCreateGenericViews
urlpatterns = [
path("hotels", ListCreateGenericViews.as_view()),
path(
"hotels/<str:pk>",
HotelUpdateRetreiveView.as_view(),
),
]Creating a Database:
sudo -u postgres psql
CREATE DATABASE locator;
CREATE USER locator WITH PASSWORD 'locator';
CREATE EXTENSION postgis;
ALTER ROLE locator SET client_encoding TO 'utf8';
ALTER ROLE locator SET default_transaction_isolation TO 'read committed';
ALTER ROLE locator SET timezone TO 'UTC';
ALTER ROLE locator SUPERUSER;
GRANT ALL PRIVILEGES ON DATABASE locator TO locator;let's make some changes on our settings.py
INSTALLED_APPS = [
"django.contrib.admin",
"django.contrib.auth",
"django.contrib.contenttypes",
"django.contrib.sessions",
"django.contrib.messages",
"django.contrib.staticfiles",
"django.contrib.gis",
"location",
"rest_framework",
"leaflet",
]
DATABASES = {
"default": {
"ENGINE": "django.contrib.gis.db.backends.postgis",
"NAME": "locator",
"USER": "locator",
"PASSWORD": "locator",
"HOST": "localhost",
"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": "powered by me",
}
Registering model on admin
from django.contrib import admin
from leaflet.admin import LeafletGeoAdmin
from .models import Hotel
@admin.register(Hotel)
class HotelAdmin(LeafletGeoAdmin):
list_display = ("id", "name", "address", "location", "created_at", "updated_at")so, we have added leaflet, leaflet_config and database. For more about Leaflet you can visit Read the docs
let's run our app:
python manage.py makemigrations
python manage.py migrate
python manage.py createsuperuser
python manage.py runserverhere, what you get on the admin panel.
Let's add some data using browsable api or you can use postman too.
Try it out yourself for update and delete
You can find the code in github repo.
L O A D I N G
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