Skip to content

The generic worker

Guide: Using ProcessingRunner

The ProcessingRunner method is a generic utility for running QGIS processing algorithms in Q-ETL worflows. It is part of the Worker.Generic class and is designed to simplify the execution of QGIS algorithms by handling progress feedback and logging automatically.

How to Use

  1. Import the Worker class: Ensure you have imported the Worker class from your project.

  2. Get the code from QGIS When you want to use a tool from the QGIS Processing toolbox, that has not been ported to Q-ETL, you can fill in the dialog en QGIS, and have the code that you need be generated for you.

    Open the tool you want, and fill in the dialog:

    When you have choosen your parameters, select Export to Python Script

    If you paste the code into a text editor, you can see the parameters you have selected :

  3. Parameters:

    • algName (str): The QGIS algorithm ID (e.g., 'native:buffer').
    • parameters (dict): The parameters required by the algorithm. Refer to QGIS documentation for details.

  4. Call ProcessingRunner: Use the method by specifying the algorithm name and a dictionary of parameters.

    You call the worker, at put in your python script - adjusting for input layers to amatch your Q-ETL variables:

  5. Output: The method returns the output layer produced by the algorithm.

Notes

  • The method handles progress bar updates and logging automatically.
  • Errors are logged and will terminate the script if encountered.

Typical Use Cases

This is used, if a tool has not been portet to Q-ETL. Then you can use this tool, to run it anyways.