Powerful geographic web framework GeoDjango

1. Powerful geographic web
framework GeoDjango
07/11/2018
Mitsuki Sugiya
Plone Conf 2018 Tokyo

2. Who am I
2
● Mitsuki Sugiya @equal_001
● Backend Engineer at Retty, Inc.

3. Powerful geographic web
framework GeoDjango
07/11/2018
Mitsuki Sugiya
Plone Conf 2018 Tokyo

4. Agenda
● Overview GeoDjango
● What is geospatial information?
● Way to start the project and how to use features
● What a Can you Do with GeoDjango

5. Overview GeoDjango

6. GeoDjango
● GeoDjango is an included module for
geospatial data.
● It provides to make it as easy and simple as
possible to create geographic Web
applications, like location-based services.

7. What is geospatial
information

8. Geospatial information
■ It is a data and information having an implicit or explicit
association with a location relative to the Earth

9. Why we use
GeoDjango?

10. Problems
■ Many data formats
✓ shp, geojson, GeoTIFF, PNG…
■ Representation of geospatial information on the model
✓ POINT, LINESTRING, POLYGON...

11. Problems
■ Many data formats
✓ shp, geojson, GeoTIFF, PNG…
■ Representation of geospatial information on the model
✓ POINT, LINESTRING, POLYGON...
< Hey, I have those features!

12. GeoDjango
Main Feature

13. Main Features
■ Django model fields for ORG geometries and raster data
■ Extensions to ORM for querying and manipulating spatial data
■ Loosely-coupled, high-level Python interfaces for GIS geometry
and raster operations and data manipulation in different formats
■ Editing geometry fields from the admin

14. Spatial Fields support
■ GeometryField
■ PointField
■ LineStringFiled
■ PolygonField
■ MultiPointField
■ MultiLineStringField
■ MultiPolygonField
■ GemetryCollectionField
■ RsterField

15. Ex Defining a Geographic Model

16. GeoDjango installation
■ Python and Django
■ Geospatial backends
✓ PostgreSQL, PostGIS
■ Geospatial libraries
✓ install GEOS, GDAL, PROJ4

17. Spatial Backends

18. Spatial Backends

19. PostGIS 2+
A spatial database extender for PstgreSQL object-relational database.
It is the de facto standard of geospatial database.
■ Add GEOMETRY type to database
■ Many Vector and raster data functions included
■ Network Topology support
https://postgis.net/features/

20. Importing spatial data (model definition)
$ python manage.py ogrinspect world/data/TM_WORLD_BORDERS-0.3.shp
WorldBorder --srid=4326 --mapping --multi
# This is an auto-generated Django model module created by ogrinspect.
from django.contrib.gis.db import models
class WorldBorder(models.Model):
fips = models.CharField(max_length=2)
iso2 = models.CharField(max_length=2)
:
geom = models.MultiPolygonField(srid=4326)

21. Importing spatial data (layer mapping)
$ python manage.py ogrinspect world/data/TM_WORLD_BORDERS-0.3.shp
WorldBorder --srid=4326 --mapping --multi
# Auto-generated `LayerMapping` dictionary for WorldBorder model
worldborder_mapping = {
'fips': 'FIPS',
'iso2': 'ISO2',
:
'geom': 'MULTIPOLYGON',
}

22. Importing spatial data (layer mapping)
$python manage.py shell
>>> from world import load
>>> load.run() # load fiished
>>>

23. Geographic admin

24. Geographic admin

25. Conclusion
■ Geodjango is handy module for handring geospatial data
✓ Building into the same Django you can already know
✓ Supported GEOMETRY type
✓ Extensions to ORM for querying and manipulating spatial data
✓ manage.py for geodjango: simple spatial data definition and
import function
✓ Editing geometry fields from the admin

26. Thank you!

27. Quick start

28. Setting up database configuration