PrintIn this section and the next, we are going to demonstrate how to create plugins for QGIS and then turn the Bus Track Analyzer code from the previous walkthrough into a plugin that adds new layers to the current QGIS project and displays the analysis progress live on the map canvas. However, if this lesson has been your first contact with writing classes and your head is swimming a bit with all the new concepts introduced or you are simply running out of time, we suggest that you just briefly skim through these sections and then watch the video from Section 4.12.7 showing the final Bus Track Analyzer for QGIS plugin. While creating a QGIS plugin yourself is one option that would give you full over&above points in this lesson's homework assignment, the content of these two sections is not required for the assignment and the quiz. You can always come back to these sections if you have time left at the end of the lesson or after the end of the class.
In Section 4.5, you already got an idea of how to write Python code that uses the qgis package, and we also made use of this in the walkthrough from the previous section to produce the final output data sets. In this section, we will teach you how to create plugins for QGIS that show up in the plugin manager and can be integrated into the main QGIS GUI.
Instead of programming QGIS plugins from scratch, we will use the Plugin Builder 3 plugin to create the main files needed for us, and then we will modify and complement these to implement the functionality of our plugin. In this section, we will show you the general workflow of creating a plugin using a simple “Random number generator” plugin with only very little actual functionality. In the walkthrough that follows in the next section, we will then apply this approach to create a plugin version of our Bus Track Analyzer tool from the first walkthrough of the lesson.