Introduction ¶

The piece addresses automating report generation to capture current data states. A practical use case mentioned involves “capturing spatial data into a PostGIS database and want a snapshot of that every few hours expressed as a pdf report.”

Core Concept ¶

The tutorial demonstrates generating PDFs by leveraging a QGIS project file (.qgs) combined with a QGIS layout template (.qpt file).

Code Implementation ¶

The author provides a Python script that:

• Initializes a QGIS application instance
• Loads a project from a specified path
• Reads template content from a .qpt file
• Creates a QgsComposition object from the template
• Implements string substitution mapping (e.g., replacing [DATE_TIME_START] with actual values)
• Sets map canvas and legend items
• Exports the composed layout as PDF

Key setup variables include project_path = 'project.qgs' and template_path = 'template.qpt'.

Execution ¶

The script runs via command line:

python generate_pdf.py

Benefit: This approach enables “all kinds of useful outputs without ever needing to open QGIS each time you generate the report.”

Additional Resources ¶

The author references a Gist repository for potential future updates to the example code.