+ def search_osm_nominatim_reverse
+ # get query parameters
+ zoom = params[:zoom]
+
+ # create result array
+ @results = []
+
+ # ask nominatim
+ response = fetch_xml(nominatim_reverse_url(:format => "xml"))
+
+ # parse the response
+ response.elements.each("reversegeocode/result") do |result|
+ lat = result.attributes["lat"]
+ lon = result.attributes["lon"]
+ object_type = result.attributes["osm_type"]
+ object_id = result.attributes["osm_id"]
+ description = result.text
+
+ @results.push(:lat => lat, :lon => lon,
+ :zoom => zoom,
+ :name => description,
+ :type => object_type, :id => object_id)
+ end
+
+ render :action => "results"
+ rescue StandardError => e
+ host = URI(Settings.nominatim_url).host
+ @error = "Error contacting #{host}: #{e}"
+ render :action => "error"
+ end
+
+ private
+
+ def nominatim_url(format: nil)
+ # get query parameters
+ query = params[:query]
+ minlon = params[:minlon]
+ minlat = params[:minlat]
+ maxlon = params[:maxlon]
+ maxlat = params[:maxlat]
+
+ # get view box
+ viewbox = "&viewbox=#{minlon},#{maxlat},#{maxlon},#{minlat}" if minlon && minlat && maxlon && maxlat
+
+ # get objects to excude
+ exclude = "&exclude_place_ids=#{params[:exclude]}" if params[:exclude]
+
+ # build url
+ "#{Settings.nominatim_url}search?format=#{format}&extratags=1&q=#{escape_query(query)}#{viewbox}#{exclude}&accept-language=#{http_accept_language.user_preferred_languages.join(',')}"
+ end
+
+ def nominatim_reverse_url(format: nil)
+ # get query parameters
+ lat = params[:lat]
+ lon = params[:lon]
+ zoom = params[:zoom]
+
+ # build url
+ "#{Settings.nominatim_url}reverse?format=#{format}&lat=#{lat}&lon=#{lon}&zoom=#{zoom}&accept-language=#{http_accept_language.user_preferred_languages.join(',')}"
+ end
+
+ def fetch_text(url)
+ response = OSM.http_client.get(URI.parse(url))
+
+ if response.success?
+ response.body
+ else
+ raise response.status.to_s
+ end
+ end
+
+ def fetch_xml(url)
+ REXML::Document.new(fetch_text(url))
+ end
+
+ def escape_query(query)
+ CGI.escape(query)
+ end
+
+ def normalize_params
+ if query = params[:query]
+ query.strip!
+
+ if latlon = query.match(/^(?<ns>[NS])\s*#{dms_regexp('ns')}\W*(?<ew>[EW])\s*#{dms_regexp('ew')}$/) ||
+ query.match(/^#{dms_regexp('ns')}\s*(?<ns>[NS])\W*#{dms_regexp('ew')}\s*(?<ew>[EW])$/)
+ params.merge!(to_decdeg(latlon.named_captures.compact)).delete(:query)
+
+ elsif latlon = query.match(%r{^(?<lat>[+-]?\d+(?:\.\d+)?)(?:\s+|\s*[,/]\s*)(?<lon>[+-]?\d+(?:\.\d+)?)$})
+ params.merge!(:lat => latlon["lat"], :lon => latlon["lon"]).delete(:query)
+
+ params[:latlon_digits] = true
+ end
+ end
+
+ params.permit(:query, :lat, :lon, :latlon_digits, :zoom, :minlat, :minlon, :maxlat, :maxlon)
+ end
+
+ def dms_regexp(name_prefix)
+ /
+ (?: (?<#{name_prefix}d>\d{1,3}(?:\.\d+)?)°? ) |
+ (?: (?<#{name_prefix}d>\d{1,3})°?\s*(?<#{name_prefix}m>\d{1,2}(?:\.\d+)?)['′]? ) |
+ (?: (?<#{name_prefix}d>\d{1,3})°?\s*(?<#{name_prefix}m>\d{1,2})['′]?\s*(?<#{name_prefix}s>\d{1,2}(?:\.\d+)?)["″]? )
+ /x
+ end
+
+ def to_decdeg(captures)
+ ns = captures.fetch("ns").casecmp?("s") ? -1 : 1
+ nsd = BigDecimal(captures.fetch("nsd", "0"))
+ nsm = BigDecimal(captures.fetch("nsm", "0"))
+ nss = BigDecimal(captures.fetch("nss", "0"))
+
+ ew = captures.fetch("ew").casecmp?("w") ? -1 : 1
+ ewd = BigDecimal(captures.fetch("ewd", "0"))
+ ewm = BigDecimal(captures.fetch("ewm", "0"))
+ ews = BigDecimal(captures.fetch("ews", "0"))
+
+ lat = ns * (nsd + (nsm / 60) + (nss / 3600))
+ lon = ew * (ewd + (ewm / 60) + (ews / 3600))