Add PipelineML conversion utility

README.md

@@ -23,3 +23,24 @@ npm run dev
 Then visit: http://localhost:3000
 
 
+
+## Python utilities
+
+A helper script is provided in `scripts/pipeline_ml.py` to convert GeoJSON or
+shapefiles to a simplified PipelineML XML representation and back. It also
+demonstrates downloading the hydrogen pipeline layer from the EU Transparency
+Platform and displaying the result on an OpenStreetMap basemap using Folium.
+
+### Usage
+
+1. Install Python dependencies (requires `geopandas`, `requests`, `shapely`, and
+   `folium`).
+2. Run the script:
+
+```bash
+python scripts/pipeline_ml.py
+```
+
+This will download the EU pipeline layer, write `eu_pipeline.geojson`, convert it
+to `eu_pipeline.xml`, load it back, and create `map.html` showing the pipelines
+as an overlay.

scripts/pipeline_ml.py

@@ -0,0 +1,81 @@
+import geopandas as gpd
+import requests
+import xml.etree.ElementTree as ET
+from shapely.geometry import LineString
+import folium
+
+
+def fetch_arcgis_geojson(url: str, out_path: str) -> gpd.GeoDataFrame:
+    """Download a GeoJSON layer from an ArcGIS REST endpoint."""
+    r = requests.get(url)
+    r.raise_for_status()
+    with open(out_path, 'w', encoding='utf-8') as f:
+        f.write(r.text)
+    return gpd.read_file(out_path)
+
+
+def xlsx_to_geojson(xlsx_path: str, out_path: str) -> gpd.GeoDataFrame:
+    """Load an XLSX table with WKT geometry and export to GeoJSON."""
+    df = gpd.read_file(xlsx_path)
+    if df.crs is None:
+        df.set_crs(4326, inplace=True)
+    df.to_file(out_path, driver='GeoJSON')
+    return df
+
+
+def geodataframe_to_pipelinexml(gdf: gpd.GeoDataFrame, out_path: str) -> None:
+    """Convert a GeoDataFrame of LineString geometries to a simple PipelineML XML."""
+    root = ET.Element('PipelineML')
+    segments = ET.SubElement(root, 'PipelineSegments')
+
+    for idx, row in gdf.iterrows():
+        seg = ET.SubElement(segments, 'PipelineSegment', id=str(idx))
+        geom = ET.SubElement(seg, 'Geometry')
+        if isinstance(row.geometry, LineString):
+            for x, y in row.geometry.coords:
+                ET.SubElement(geom, 'pos').text = f"{x},{y}"
+        for col, val in row.items():
+            if col != 'geometry' and val is not None:
+                ET.SubElement(seg, col).text = str(val)
+
+    tree = ET.ElementTree(root)
+    tree.write(out_path, encoding='utf-8', xml_declaration=True)
+
+
+def pipelinexml_to_geodataframe(xml_path: str) -> gpd.GeoDataFrame:
+    """Parse a simplified PipelineML XML back into a GeoDataFrame."""
+    tree = ET.parse(xml_path)
+    root = tree.getroot()
+    features = []
+    for seg in root.findall('.//PipelineSegment'):
+        coords = []
+        for pos in seg.find('Geometry').findall('pos'):
+            x, y = map(float, pos.text.split(','))
+            coords.append((x, y))
+        props = {child.tag: child.text for child in seg if child.tag != 'Geometry'}
+        features.append({'geometry': LineString(coords), **props})
+    gdf = gpd.GeoDataFrame(features, geometry='geometry', crs='EPSG:4326')
+    return gdf
+
+
+def display_on_map(gdf: gpd.GeoDataFrame, out_html: str = 'map.html') -> None:
+    """Create a Leaflet map using Folium with the GeoDataFrame layer."""
+    center = gdf.geometry.unary_union.centroid
+    m = folium.Map(location=[center.y, center.x], zoom_start=5)
+    folium.GeoJson(gdf.__geo_interface__).add_to(m)
+    m.save(out_html)
+    print(f"Map saved to {out_html}")
+
+
+if __name__ == '__main__':
+    # Example workflow using the EU Transparency Platform pipeline layer
+    url = (
+        'https://webgate.ec.europa.eu/getis/rest/services/Energy/TP_HYDROGEN/MapServer/5/query'
+        '?where=OBJECTID>=0&outFields=*&returnGeometry=true&f=geojson'
+    )
+    geojson_path = 'eu_pipeline.geojson'
+    xml_path = 'eu_pipeline.xml'
+    gdf = fetch_arcgis_geojson(url, geojson_path)
+    geodataframe_to_pipelinexml(gdf, xml_path)
+    restored = pipelinexml_to_geodataframe(xml_path)
+    display_on_map(restored)