grischard/lurefproxy.py

## lurefproxy.py
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from flask import Flask
from flask import request
from flask import Response
import json
from pyproj import Proj
from pyproj import transform
import requests

app = Flask(__name__)
LUREF = Proj("+init=EPSG:2169")
WGS84 = Proj(proj='latlong', datum='WGS84')


def __reproject(_p):
    ll = transform(LUREF, WGS84, _p[0], _p[1])
    return [round(ll[0], 7), round(ll[1], 7)]  # 7 decimals


def reproject(target_url):
    geojson_object = requests.get(target_url).json()
    geojson_object.pop("crs", None)  # drop crs object
    for f in geojson_object['features']:
        f.pop("bbox", None)  # drop bbox object
        if f["geometry"]["type"] == "Point":
            if f["geometry"]["coordinates"][0] < 1000:
                continue  # Probably not LUREF
            p = f["geometry"]["coordinates"]
            p = __reproject(p)
        elif f["geometry"]["type"] == "Polygon":
            if f["geometry"]["coordinates"][0][0][0] < 1000:
                continue  # Probably not LUREF
            for r in f["geometry"]["coordinates"]:
                for p in r:
                    p = __reproject(p)
        else:
            if f["geometry"]["coordinates"][0][0] < 1000:
                continue  # Probably not LUREF
            for p in f["geometry"]["coordinates"]:
                p = __reproject(p)
    return geojson_object


@app.route('/<path:path>')
def catch_all(path):
    # Target URL is everything after the url root
    target_url = request.url[len(request.url_root):]
    resp = Response(response=json.dumps(reproject(target_url)),
                    status=200, mimetype="application/json")
    resp.headers.add('Access-Control-Allow-Origin', '*')
    return resp


@app.route('/favicon.ico')
def favicon():
    return Response(response="404 not found", status=404)


@app.route('/')
def hello():
    vdl = "http://opendata.vdl.lu/odaweb/"
    catalogjson = requests.get(vdl + "?describe=1").json()
    catalog = [
        '<li><a href="/{vdl}?cat={id}">{name}</a></li>'
        .format(vdl, id=item["id"], name=item["i18n"]["fr"]["name"])
        for item in sorted(
            catalogjson["data"], key=lambda k: k['i18n']['fr']['name']
        )
    ]
    return """<!doctype html><html><head>
                  <title>LUREF to WGS84 GeoJSON converter</title>
              </head><body>
              <h2>LUREF to WGS84 GeoJSON converter microservice</h2>
              <p>Translates GeoJSON URL from LUREF to WGS84.</p>
              <h4>What do I do with this?</h4>
              <pThe output is valid WGS84 geojson, which you can easily
              <a href="http://leafletjs.com/examples/geojson.html">
                  display on a map</a></p>
              <h4>Extra features</h4>
              <ul><li>Deletes redundant VdL 'crs' and 'bbox' objects</li>
              <li>Sanity check, if X < 1000 it's probably not LUREF because
              that point is way outside of Luxembourg, and we won't convert it.
              <h4>Examples to try</h4>
              <p>The <a
              href="https://data.public.lu/en/organizations/ville-de-luxembourg">
              City of Luxembourg</a> publishes data in LUREF:</p>
              <p><ul>{}</ul></p>
              <p><emph>Mat <span style="color:red">♥</span> codéiert. Hat tip:
                  <a href="https://twitter.com/jaykayone">@jaykayone</a>.
              </emph></p>
              </body></html>""".format(''.join(catalog))

if __name__ == '__main__':
    app.run()
	#!/usr/bin/env python
	# -- coding: utf-8 --
	from flask import Flask
	from flask import request
	from flask import Response
	import json
	from pyproj import Proj
	from pyproj import transform
	import requests

	app = Flask(__name__)
	LUREF = Proj("+init=EPSG:2169")
	WGS84 = Proj(proj='latlong', datum='WGS84')


	def __reproject(_p):
	ll = transform(LUREF, WGS84, _p[0], _p[1])
	return [round(ll[0], 7), round(ll[1], 7)] # 7 decimals


	def reproject(target_url):
	geojson_object = requests.get(target_url).json()
	geojson_object.pop("crs", None) # drop crs object
	for f in geojson_object['features']:
	f.pop("bbox", None) # drop bbox object
	if f["geometry"]["type"] == "Point":
	if f["geometry"]["coordinates"][0] < 1000:
	continue # Probably not LUREF
	p = f["geometry"]["coordinates"]
	p = __reproject(p)
	elif f["geometry"]["type"] == "Polygon":
	if f["geometry"]["coordinates"][0][0][0] < 1000:
	continue # Probably not LUREF
	for r in f["geometry"]["coordinates"]:
	for p in r:
	p = __reproject(p)
	else:
	if f["geometry"]["coordinates"][0][0] < 1000:
	continue # Probably not LUREF
	for p in f["geometry"]["coordinates"]:
	p = __reproject(p)
	return geojson_object


	@app.route('/<path:path>')
	def catch_all(path):
	# Target URL is everything after the url root
	target_url = request.url[len(request.url_root):]
	resp = Response(response=json.dumps(reproject(target_url)),
	status=200, mimetype="application/json")
	resp.headers.add('Access-Control-Allow-Origin', '*')
	return resp


	@app.route('/favicon.ico')
	def favicon():
	return Response(response="404 not found", status=404)


	@app.route('/')
	def hello():
	vdl = "http://opendata.vdl.lu/odaweb/"
	catalogjson = requests.get(vdl + "?describe=1").json()
	catalog = [
	'<li><a href="/{vdl}?cat={id}">{name}</a></li>'
	.format(vdl, id=item["id"], name=item["i18n"]["fr"]["name"])
	for item in sorted(
	catalogjson["data"], key=lambda k: k['i18n']['fr']['name']
	)
	]
	return """<!doctype html><html><head>
	<title>LUREF to WGS84 GeoJSON converter</title>
	</head><body>
	<h2>LUREF to WGS84 GeoJSON converter microservice</h2>
	<p>Translates GeoJSON URL from LUREF to WGS84.</p>
	<h4>What do I do with this?</h4>
	<pThe output is valid WGS84 geojson, which you can easily
	<a href="http://leafletjs.com/examples/geojson.html">
	display on a map</a></p>
	<h4>Extra features</h4>
	<ul><li>Deletes redundant VdL 'crs' and 'bbox' objects</li>
	<li>Sanity check, if X < 1000 it's probably not LUREF because
	that point is way outside of Luxembourg, and we won't convert it.
	<h4>Examples to try</h4>
	<p>The <a
	href="https://data.public.lu/en/organizations/ville-de-luxembourg">
	City of Luxembourg</a> publishes data in LUREF:</p>
	<p><ul>{}</ul></p>
	<p><emph>Mat <span style="color:red">♥</span> codéiert. Hat tip:
	<a href="https://twitter.com/jaykayone">@jaykayone</a>.
	</emph></p>
	</body></html>""".format(''.join(catalog))

	if __name__ == '__main__':
	app.run()