Create Your Own Custom QGIS Plugin

Create Your Custom QGIS Plugin 

In this sample tutorial we’re going to create a sample plugin that displays a simple message , the standard  “Hello World”  in the QGIS Interface.

Prerequisites

In this tutorial we needed the following

Software

QGIS Software required (I use version: 2.12.1 Lyon or any other versions current is QGIS 3.8 Zanzibar)

Click the link to download the software appropriate to your platform (https://qgis.org/en/site/forusers/download.html) the software is open source

Platform

Operating System : In this tutorial Windows 7

Steps on Creating Your Custom Quantum (QGIS) Plugin  

1       1. Click on Start Menu ->Click QGIS

         2.   QGIS will then start , Now click on the Plugins Menu , the Plugins menu  dropdown appears.

   3.  Click on Plugin Builder

  4. The QGIS Plugin Builder Appears.

   5. For Class name for the purposes of this tutorial we put HelloWorld (without spaces) for Plugin name we put Hello World .  For the description we put This plugin displays Hello World Message. For module name we put hello_world (without spaces) . Leave the version number and minimum QGIS version as is. Put in your Name for the Author/Company and email address .

    6. Click on Next Button

7. In the about Section put in

 This plugin displays Hello World Message. A simple plugin 

Then click next

8. For the template choose Tool Button with dockwidget what it does is that it creates a section in QGIS interface by which we can display the Hello World Message.

On the text for Menu Item we put in Display Hello World Message , for the Menu , we put in Plugins , this is the portion of the menu where the Menu Item “Display Hello World Message”  is placed

Dockwidget area is Left so where is it? It is placed on the left part of the QGIS Interface , once it is activated later

9. Click on Next ,Leave the next prompt as is, then click next . Click the Checkbox as Flag the plugin as experimental .Click Next , the default directory is displayed

This is where the HelloWorld  class folder you input just a while ago will be placed. Please take note of this directory. This is also the repository of all our future plugin coding modules. Click on Generate .

The plugin builder results appears

10. Click Ok

Now as you see using the Windows Explorer the HelloWorld plugin class has been created in the very same directory as indicated by the Plugin Builder

  We are almost there so what’s next

11. Click on the command OSGeo4W located on the folder of your QGIS

12. Type in cd “put the directory here to where the class Hello World resides and type the plugin name itself”

cd C:\Users\God\.qgis2\python\plugins\HelloWorld

Note: that we can have different usernames , so please take note. Copy the directory to which the HelloWorld resides and type the HelloWorld

13. Then type Make

 Then appears

pyrcc4 -o resources.py resources.qrc

which basically means that we already have all the files needed for the  plugin

14. Now restart QGIS on the Plugin Menu we click on Manage and Install Plugins .Now QGIS is fetching repositories

15. Type in HelloWorld (the class name) in the Search Bar

The HelloWorld Plugin now appears on the search

We can now see the things we put just a while ago in the right portion. The purpose and the brief description of the plugin. Check the plugin then Click Close.

Now click on the Plugins menu again and now we see that it is now available and installed on QGIS

16 .Now click on the Menu Item , Display Hello World Message

We can now see a basic plugin placed in the lower left corner of the QGIS interface.

There you have it .You now have a basic plugin. So that’s it for the first part. On the second part we will be coding using Python to display Warning and Information Messages and we will be tweaking the user interface of the plugin.

Notice that there are texts at the bottom. Just ignore it. It is the default text place on the plugin, we will remove it on the next part of the tutorial