Having seen how to create and export a series of graphs with Data Plotly, let’s move on to the next step: integrating these graphs into a QGIS atlas or automated report. This method can be used to produce customized PDF reports or thematic sheets, one per range, commune, site or entity.
Objective
- Create a dynamic PDF report by entity (e.g.: one sheet per beach);
- Insert graphs generated with Data Plotly into each atlas page;
- Use QGIS Atlas functions and a little automation.
Use case example
You have a releves_dechets layer and a beaches (or communes) layer. You want to create a report for each beach, containing :
- The name of the beach
- A zoomed-in map of the area
- A PNG graphic representing the waste collected (created with Data Plotly)
- Some dynamic statistics (sum, average…)
Step 1: Prepare graphics for each range
Use the Python script described above to generate one PNG image per range:
- graph_Anse_Mourouk.png, graph_Pointe_Coton.png, etc.
- Make sure the image name corresponds exactly to the value of the range field in the main layer.
Step 2: Create the layout in the Layout Composer
- Go to Project > Layout > New layout
- Add :
- A map frame (linked to the beach layer)
- A dynamic text field (e.g.: [% “beach” %])
- An image frame: click on the “Add image” icon
- Activate the Atlas :
- Cover object = layer (e.g. beaches)
- Sorting (optional): you can choose a field for page order (e.g. name)
- Filter entities with an expression (optional)
- Automatic zoom on entity
- Click on your main map in the layout (the map to be automatically centered)
- In the Object Properties panel, Atlas Attributes section, check :
- ✅ Controlled by atlas
- ✅ Fit to entity
Step 3: Dynamically insert PNG graphics
In the image frame, check “Image path from data”
Then enter an expression like:
'file:///C:/temp/export_graphiques/graph_' || "plage" || '.png'This will automatically display the image corresponding to each entity.
Tip: you can use replace(“plage”, ‘ ’, ‘_’) if file names don’t have spaces.
Step 4: Export the atlas
- Click on “Export Atlas as PDF” ;
- Choose an output folder;
- Each page will contain: the map, the beach name, the graph, and associated info.
Bonus: add dynamic statistics
Add text fields with QGIS expressions such as :
aggregate(‘releves_dechets’, ‘sum’, “quantite”, filter := “plage” = attribute(@atlas_feature, ‘plage’))This provides automatic totals or averages for each record.
To summarize
| Step | Function |
|---|---|
| Graphics generation | With Data Plotly + Python |
| Customized layout | QGIS composer |
| Automatic insertion | Dynamic fields + path to PNG |
| Export multi-page PDF | Atlas function |
Use case ideas
- Observation sheets by commune (fauna, flora, waste)
- Environmental reports by site
- Census maps + graphics
- Site or project monitoring
Coming soon…
In the next article, we’ll go a step further and show you how to create a dynamic dashboard in QGIS itself, without leaving the GIS environment: combine Data Plotly, expressions, widgets and panels to build a real-time analysis interface.
