GIS_Day_2016

INTRO:WEB GISWITH
GEODJANGO AND
LEAFLETJS
GIS DAY 2016 PRESENTATION
BY JOSEPH KARIUKI
Theme: GIS For Sustainable Development

PREAMBLE
• Why FOSS?
• Embracing FOSS role in GIS/GIT and education domains.
• Sustainable Development Goals (SDGs) and Geospatial technology.
joehene@gmail.com GIS Day 2016

PREREQUISITES
• Python with pip or easy_install.
• PostgreSQL with PostGIS support.
• Django, django-leaflet, django-geojson, psycopg2, gdal (installed into virtual environment
using pip or easy_install).
• Code editor (Notepad++ or SublimeText preferred)

WHAT IS DJANGO?
• Free an Open Source (FOSS) web application framework, written in Python programming
language.
• Django grew from real-world applications developed in Lawrence, Kansas City in 2003,
growing popular in 2005 and released publicly in 2005.
• 1.0 version released in 2008, current version ==1.10

DJANGO CONCEPT
• HTTP in, HTTP out
HTTP Request HTTP Response
URLs
VIEWS
Models
Templates

DJANGO MVC / MVT ARCHITECTURE
• Django is designed to enhance loose-coupling and strict separation between a web
application constituents promoting easy customization of web application part(s) without
affecting others.
• M – Model
• V –View
• C – Controller / T -Template

WHAT IS LEAFLET?
• LEAFLET is an Open Source JavaScript Library for interactive maps.
• Supports mobile mapping and can be extended through use of plugins.
• It takes advantage of HTML5 and CSS3 on browsers.
• Source code can be obtained from http://github.com/Leaflet/Leaflet
• Leaflet API has ‘Map’ as the central class and is used to create a map on a page and
manipulate it.

APPLICATION ARCHITECTURE
Model
View & Template
Spatial Dataset
Back-End
JavascriptAPI
Basemap
Front-End
django-leaflet
GDAL/OGR

BASIC STEPS
• Downloading Python (version 2.7.12 used in this)
• Installing virtualenv / easy_install
• Creating a virtualenv, activating it and installing required packages (previously listed)
• Starting Django project named ‘webgis’
• Creating ‘onyeshamap’ application within ‘webgis’ project
• Configure webgis project with postGIS support
• Create GIS-enabled Django Models, admin using GDAL LayerMapping

PARENT DIRECTORY
webgis
• onyeshamap
• mywebgis
• db.sqlite (removed)
• manage.py

PROJECT DIRECTORY
webgis/webgis
• __init__.py
• settings.py
• urls.py
• wsgi.py

SETTINGS.PY
• DEBUG is a boolean that turns on/off the debug mode of the project. If set to
True, Django will display detailed error pages when an uncaught exception
is thrown by your application.
• ALLOWED_HOSTS is not applied while debug mode is on or when running tests
• INSTALLED_APPS is a setting you will have to edit in all projects.This setting tells Django which
applications are active for this site. By default, Django includes the following applications:

SETTINGS.PY (CONT…)
• django.contrib.admin:This is an administration site.
• django.contrib.auth:This is an authentication framework.
• django.contrib.contenttypes:This is a framework for content types.
• django.contrib.sessions:This is a session framework.
• django.contrib.messages:This is a messaging framework.
• django.contrib.staticfiles:This is a framework for managing static files.
• leaflet: Allows use of leaflet in our Django project.
• djgeojson: allows (de)serialization (Geo)django objects into GeoJSON.
• onyeshamap: This is application created for purposes of this project.

APPS DIRECTORY
webgis/onyshamap
• __init__.py
• admin.py
• apps.py
• models.py
• tests.py
• urls.py
• views.py

SPATIAL DATABASE
Postgresql with postGIS
• Database Name:
• Owner:
• Host:
• Port: 54…

PROJECT SETTING CONFIGURATION

GDAL (LAYER MAPPING)
• Inspects the given OGR-compatible data source (e.g., a shapefile) and outputs a GeoDjango
model with the given model name. In this example: ./manage.py ogrinspect
onyeshamap/data/CCTV_locations.shp CCTV ---srid=32737 –mapping –multi
• Makes use of positional arguments which are
~ data_source – path to the data source
~ model_name – name of the model to be created
~ SRID – Spatial Reference Identifier
~ mapping - Generate mapping dictionary for use with `LayerMapping`

GDAL (LAYER MAPPING)

DATA IN QGIS

ONYESHAMAP DATA MODELS (BACKEND)

DATAVIEW AS GEOJSON

GEODJANGO WEB APPLICATION (FRONTEND)

DJANGO USERS
• RCMRD apps portal – apps.rcmrd.org/
• Instagram – www.Instagram.com
• Bitbucket – https://bitbucket.org
• NASA Website – www.nasa.gov
• PinterestWebsite – www.pinterest.com
• Eventbrite – www.eventbrite.com

REFERENCE LINKS
• https://docs.djangoproject.com/en/1.10/ref/contrib/gis/
• https://tutorial.djangogirls.org/en/
• https://www.imagespace.com/blog/2011/09/21/geo-django-quickstart
• https://github.com/joehene/djangoleaflet/ - GitHub Repository

DEMO
• Performed in Ubuntu Linux Desktop 14.04LTS operating system
• DataVisualization in Q-GIS
• Django production server start
• Django-Leaflet web application showcase

GIS_Day_2016

Recommended

Recommended

More Related Content

Similar to GIS_Day_2016

Similar to GIS_Day_2016 (20)

GIS_Day_2016