First night hacking

.envrc

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+use nix;

.gitignore

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+data/

Makefile

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+.PHONY: all
+all: data/sidewalks.json
+
+data/raw.osm.pbf: data scripts/fetch_osm_data.sh
+	./scripts/fetch_osm_data.sh
+
+data/sidewalks.unmin.json: data/raw.osm.pbf ./scripts/parse_sidewalks.py
+	./scripts/parse_sidewalks.py data/raw.osm.pbf > data/sidewalks.unmin.json
+
+# data/sidewalks.json: data/sidewalks.unmin.json
+# 	<data/sidewalks.unmin.json jq -c >data/sidewalks.json
+
+data/sidewalks.json: data scripts/fetch_sidewalk_data.sh
+	./scripts/fetch_sidewalk_data.sh
+
+data:
+	mkdir -p data

scripts/fetch_osm_data.sh

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+#!/usr/bin/env nix-shell
+#! nix-shell -i bash --pure
+#! nix-shell -p bash curl cacert jq
+
+if [ $# -eq 2 ]; then
+    OUTPUT=$1
+else
+    OUTPUT=data/raw.osm.pbf
+fi
+
+WAY_DATA=$(curl -s https://overpass-api.de/api/interpreter --data-urlencode 'data=[out:json];way["name"="Northern Arizona University"];out geom;')
+
+# Extract coordinates from the response
+COORDINATES=$(echo "$WAY_DATA" | jq '[.elements[] | select(.type == "way") | .geometry[] | [.lon, .lat]]')
+
+echo $COORDINATES
+
+# Ensure we have coordinates
+if [ -z "$COORDINATES" ]; then
+  echo "Error: Could not find coordinates for NAU"
+  exit 1
+fi
+
+# Construct the GeoJSON payload
+PAYLOAD=$(jq -n --argjson coords "$COORDINATES" '{
+  "Name": "none",
+  "RegionType": "geojson",
+  "RegionData": {
+    "type": "Polygon",
+    "coordinates": [$coords]
+  }
+}')
+
+# Send the request to the Slice API
+UUID=$(curl -X POST https://slice.openstreetmap.us/api/ -H "Content-Type: application/json" -d "$PAYLOAD")
+
+while ! [ $(curl https://slice.openstreetmap.us/api/$UUID | jq -r '.Complete') = 'true' ]; do
+    sleep 1
+done
+
+curl https://slice.openstreetmap.us/files/$UUID.osm.pbf -o $OUTPUT

scripts/fetch_sidewalk_data.sh

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+#!/usr/bin/env nix-shell
+#! nix-shell -i bash --pure
+#! nix-shell -p bash curl cacert
+
+# TODO: process out extraneous data
+
+curl -s https://overpass-api.de/api/interpreter --data-urlencode 'data=[out:json];{{geocodeArea:Northern Arizona University}}->.searchArea;(way["highway"="footway"](area.searchArea);way["highway"="cycleway"](area.searchArea););out geom;' -o data/sidewalks.json

scripts/parse_sidewalks.py

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+#!/usr/bin/env nix-shell
+#! nix-shell -i python
+#! nix-shell -p python3 python3Packages.pyosmium python3Packages.requests
+import osmium
+import json
+import sys
+
+class SidewalkHandler(osmium.SimpleHandler):
+    def __init__(self):
+        super(SidewalkHandler, self).__init__()
+        self.sidewalks = []
+
+    def way(self, w):
+        # Convert OSM tags to a normal dict for easier use
+        tags = dict(w.tags)
+        is_sidewalk = False
+
+        # Check for a dedicated footway sidewalk
+        if tags.get('highway') == 'footway':
+            is_sidewalk = True
+        # # Alternatively, check if the 'sidewalk' tag is present and not set to no/none
+        # elif 'sidewalk' in tags and tags['sidewalk'].lower() not in ['no', 'none']:
+        #     is_sidewalk = True
+
+        if is_sidewalk:
+            sidewalk = {
+                "id": w.id,
+                "nodes": [],
+                "tags": tags
+            }
+            # Gather node coordinates if available
+            for n in w.nodes:
+                # Ensure the node location is valid
+                if n.location.valid():
+                    sidewalk["nodes"].append({
+                        "lat": n.location.lat,
+                        "lon": n.location.lon
+                    })
+            self.sidewalks.append(sidewalk)
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2:
+        sys.stderr.write("Usage: python script.py <path-to-osm-pbf-file>\n")
+        sys.exit(1)
+
+    pbf_file = sys.argv[1]
+    handler = SidewalkHandler()
+    # The locations=True flag makes sure node coordinates are available.
+    handler.apply_file(pbf_file, locations=True)
+
+    # Output the results as an indented JSON list
+    print(json.dumps(handler.sidewalks, indent=2))

shell.nix

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+let
+  pkgs = import <nixpkgs> {};
+in
+pkgs.mkShellNoCC {
+  packages = with pkgs; [
+    gnumake
+  ];
+}

test.html

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+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>Leaflet OSM Ways</title>
+  <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css" />
+  <style>
+    #map {
+      height: 100vh;
+      width: 100%;
+    }
+  </style>
+</head>
+<body>
+
+<div id="map"></div>
+
+<script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
+<script>
+  // Initialize the map
+  const map = L.map('map').setView([35.1927479, -111.6538784], 15);
+
+  // Set up the OpenStreetMap tile layer
+  L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
+    attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors'
+  }).addTo(map);
+
+  // Function to generate a random color
+  function getRandomColor() {
+    const letters = '0123456789ABCDEF';
+    let color = '#';
+    for (let i = 0; i < 6; i++) {
+      color += letters[Math.floor(Math.random() * 16)];
+    }
+    return color;
+  }
+
+  // Fetch OSM data
+  fetch('data/sidewalks.min.json')
+    .then(response => response.json())
+    .then(osmData => {
+      
+      // Function to create the polyline and popup for each OSM way
+      osmData.forEach(way => {
+        const latlngs = way.nodes.map(node => [node.lat, node.lon]);
+        const color = getRandomColor(); // Generate a random color
+
+        const polyline = L.polyline(latlngs, {
+          color: color,
+          weight: 5,
+          opacity: 0.7
+        }).addTo(map);
+
+        polyline.on('mouseover', function(e) {
+            e.target.setStyle({
+                weight: 10,
+                opacity: 1,
+            });
+        });
+        polyline.on('mouseout', function(e){
+            e.target.setStyle({
+                weight: 5,
+                opacity: 0.7,
+            });
+        });
+
+        // Create a popup with the tags when clicking on the polyline
+        const tagsContent = Object.entries(way.tags).map(([key, value]) => {
+          return `<b>${key}:</b> ${value}`;
+        }).join('<br>');
+
+        polyline.bindPopup(tagsContent);
+      });
+    })
+    .catch(error => {
+      console.error('Error loading OSM data:', error);
+    });
+</script>
+
+</body>
+</html>