OpenMensa parser for STW Potsdam after canteen website redesign

stw_potsdam/views.py

@@ -0,0 +1,56 @@
+# -*- encoding: utf-8 -*-
+
+from flask import Flask, make_response
+from werkzeug.contrib.cache import SimpleCache
+
+import feed
+from config import read_canteen_config
+from canteen_api import MenuParams, download_menu
+
+CACHE_TIMEOUT = 45 * 60
+
+app = Flask(__name__)
+
+cache = SimpleCache()
+
+
+def canteen_not_found(config, canteen_name):
+    app.logger.warn('Canteen %s not found', canteen_name)
+    configured = ', '.join("'{}'".format(c) for c in config.keys())
+    message = "Canteen '{canteen}' not found, available: {configured}".format(canteen=canteen_name,
+                                                                              configured=configured)
+    return make_response(message, 404)
+
+
+def get_menu_cached(canteen):
+    params = MenuParams(canteen_id=canteen.id, chash=canteen.chash)
+    menu = cache.get(params)
+    if menu:
+        app.logger.info('Using cached menu for %s', canteen)
+    return menu or get_menu(canteen, params)
+
+
+def get_menu(canteen, params):
+    app.logger.info('Downloading menu for %s', canteen)
+    menu = download_menu(params)
+    cache.set(params, menu, timeout=CACHE_TIMEOUT)
+    return menu
+
+
+def canteen_feed_xml(canteen, menu):
+    xml = feed.render(canteen, menu)
+    response = make_response(xml)
+    response.mimetype = 'text/xml'
+    return response
+
+
+@app.route('/canteen/<canteen_name>')
+def canteen_feed(canteen_name):
+    config = read_canteen_config()
+
+    if canteen_name not in config:
+        return canteen_not_found(config, canteen_name)
+
+    canteen = config[canteen_name]
+    menu = get_menu_cached(canteen)
+    return canteen_feed_xml(canteen, menu)