class RGeo::CoordSys::SRSDatabase::UrlReader

A spatial reference database implementation that fetches data from internet URLs.

Public Class Methods

new(opts_={}) click to toggle source

Create a URL-based spatial reference database.

Options:

:cache: If set to true, lookup results are cached so if the same URL is requested again, the result is served from cache rather than issuing another HTTP request. Default is false.

# File lib/rgeo/coord_sys/srs_database/url_reader.rb, line 62
def initialize(opts_={})
  @cache = opts_[:cache] ? {} : nil
end

Public Instance Methods

clear_cache() click to toggle source

Clear the cache if one is present.

# File lib/rgeo/coord_sys/srs_database/url_reader.rb, line 96
def clear_cache
  @cache.clear if @cache
end

get(ident_) click to toggle source

Retrieve the given URL and return an Entry. Returns nil if the URL cannot be read as an OGC WKT or Proj4 coordinate system

# File lib/rgeo/coord_sys/srs_database/url_reader.rb, line 71
def get(ident_)
  ident_ = ident_.to_s
  return @cache[ident_] if @cache && @cache.include?(ident_)
  uri_ = ::URI.parse(ident_)
  result_ = nil
  ::Net::HTTP.start(uri_.host, uri_.port) do |http_|
    request_ = uri_.path
    request_ = "#{request_}?#{uri_.query}" if uri_.query
    response_ = http_.request_get(request_)
    if response_.kind_of?(::Net::HTTPSuccess)
      response_ = response_.body.strip
      if response_[0,1] == '+'
        result_ = Entry.new(ident_, :proj4 => response_)
      else
        result_ = Entry.new(ident_, :coord_sys => response_)
      end
    end
  end
  @cache[ident_] = result_ if @cache
  result_
end