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danny
dannypolygonParser
eCFR geospatial data extraction utility
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polygonParser
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README.md

eCFR §202.1401 Polygon Converter

This app parses government-related location data from eCFR §202.1401 and converts it to polygons for download as GeoJSON or Shapefile. It features a modern web UI with map preview and supports both URL scraping and pasted tabular data.

Features

  • URL Scraping: Paste eCFR URLs to automatically extract coordinate data
  • Direct Input: Paste raw tabular coordinate data directly
  • Interactive Map: Preview polygons on a Leaflet map with zoom and pan
  • Multiple Export Formats: Download as GeoJSON or Shapefile
  • Data Inspection: Collapsible GeoJSON text view for inspection
  • Modern UI: Clean, responsive interface with TailwindCSS

Usage

  1. Input Data: Either paste an eCFR URL or raw coordinate data
  2. Parse: Click "Parse Data" to extract polygons
  3. Preview: View polygons on the interactive map
  4. Download: Export as GeoJSON or Shapefile format

Supported Input Formats

eCFR URLs

  • Example: https://www.ecfr.gov/api/renderer/v1/content/enhanced/2025-09-10/title-28?chapter=I&part=202&subpart=N&section=202.1401

Raw Coordinate Data

  • Area ID followed by coordinate pairs
  • Tab-separated format with area ID and coordinate pairs
  • Supports various coordinate formats (lat,lon or lon,lat)

Technical Stack

  • Backend: Hono.js API framework
  • Frontend: React with TypeScript
  • Mapping: Leaflet.js
  • Styling: TailwindCSS
  • Storage: Val Town SQLite for caching