PyQGIS

Develop your QGIS plugin

Licencia (CC BY-SA 3.0)

III QGIS User Conference
7 August 2017 - Nødebo

Luigi Pirelli

luipir@gmail.com

lpirelli@boundlessgeo.com

@Ginetto

http://slides.com/luigipirelli/developqgisplugins-nodebo2017

Who am I

15 years working on Satellite Ground Segments for

Landsat, Cryosat, MODIS, Sentinel...

Since 2006 in QGIS/GRASS

QGIS Plugin y Core developer

Since 2015 part of Boundless Desktop Team

Commercial solution base on QGIS (and more)

Founder of GFOSS.it

Italian OSGEO Local Chapter

Coautor of "Mastering QGIS"

https://www.packtpub.com/big-data-and-business-intelligence/mastering-qgis-second-edition

Reviewer

QGIS Python Programming Cookbook

https://www.packtpub.com/application-development/qgis-python-programming-cookbook

More PyQGIS books

Beginner

Advanced

http://qgis.org/es/site/

Download

http://qgis.org/es/site/forusers/download.html

docker pull kartoza/qgis-desktop

docker pull kartoza/qgis-server

Example data: http://qgis.org/downloads/data/

QGIS

Free as Freedom - mainly GPL2

Open - Anyone can participate

Trasparent - PSC coordination list is also open

How to Participate

Issues - http://hub.qgis.org/issues

Helps - In ML o en freenode #qgis channel

Bug fix: https://github.com/qgis/QGIS/pulls

Translates - http://qgis.org/en/site/getinvolved/translate.html

other languages e.g QGIS-es: http://lists.osgeo.org/cgi-bin/mailman/listinfo/qgis-es

but best part is particpating to...

When your user group?

Having right vote on using QGIS funds... and more

QGIS is wrote in:

C++ (almos all)

Python (some core plugins)

Javascript (some parts in Plugin Manager)

www.openhub.net/p/qgis

C++ - http://qgis.org/api/

Python - http://qgis-python.kartoza.com/docs/

http://geoapis.sourcepole.com/qgispyapi/

https://webgeodatavore.github.io/pyqgis-samples/

Lenguages

Ask and give online help

• Mailing lists
  • Devs: lists.osgeo.org/mailman/listinfo/qgis-developer
  • Users: lists.osgeo.org/mailman/listinfo/qgis-user
• IRC
  • #qgis on www.freenode.net
  • WebIRC: webchat.freenode.net/?channels=#qgis
  • Gitter: https://gitter.im/qgis/QGIS​
• StackExchange

  • http://gis.stackexchange.com/?tags=qgis

Ask help to the QGIS

The core Python console

or

IPython Console plugin

by A.Pasotti

• Exploring commands
  • help(...)
  • dir(...)
• To test command
• To test code

Help each other

>>>> https://goo.gl/GdaqY8 <<<<

Ice break

coding in python console

Plugins

95% of C++ API can be accessed by Python thanks to SIP wrappers

https://wiki.python.org/moin/SIP

PyQGIS Cookbook

http://docs.qgis.org/2.18/en/docs/pyqgis_developer_cookbook/

http://docs.qgis.org/testing/en/docs/pyqgis_developer_cookbook/

The better school is to install end read plugins code

Let's build a plugin

with QGIS Plugin Builder (versión 2.16)

What we need

• Python editor (vi, Atom, Eric4, Eclipse, PyCharm,...)
• Optional: if we need Graphical User Interface (GUI)
  • *.ui file editors (Qt Creator, Qt Designer)
  • Resource builder pyrcc4 (pyqt4-dev-tools)
• Optional:
  • ​project builder "make" (build-essential)

Steps

• Import plugin code project

• Plugin structure

• add instruction in self.run()

• Do debug

A simple run() code

tnx to Fran Raga: http://slides.com/franciscojoseragalopez/pyqgis/fullscreen#/12

Plugins for QGIS2 and QGIS3

• Python part:
  • https://docs.python.org/3/howto/pyporting.html
  • http://python-future.org/
  • http://python-future.org/compatible_idioms.html
• QGIS part
  • https://github.com/qgis/QGIS/blob/master/scripts/2to3
  • QT4 and QT5 abstraction
    • from qgis.PyQt import (QtGui, QtCore,...)
      • instead of:
        • from PyQT4 import (QtGui, QtCore,...)
        • from PyQT5 import (QtGui, QtCore,...)
  • New qgis APIs for QGIS3:
    • https://qgis.org/api/api_break.html

Luigi Pirelli

luipir@gmail.com

lpirelli@boundlessgeo.com

@ginetto

github.com/luipir 

www.linkedin.com/in/luigipirelli

gis.stackexchange.com/users/19667/luigi-pirelli

Licence: (CC BY-SA 3.0)