+
+ # Construct a random token of a given length
+ def self.make_token(length = 30)
+ chars = 'abcdefghijklmnopqrtuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
+ token = ''
+
+ length.times do
+ token += chars[(rand * chars.length).to_i].chr
+ end
+
+ return token
+ end
+
+ # Return an encrypted version of a password
+ def self.encrypt_password(password, salt)
+ return Digest::MD5.hexdigest(password) if salt.nil?
+ return Digest::MD5.hexdigest(salt + password)
+ end
+
+ # Return an SQL fragment to select a given area of the globe
+ def self.sql_for_area(minlat, minlon, maxlat, maxlon, prefix = nil)
+ tilesql = QuadTile.sql_for_area(minlat, minlon, maxlat, maxlon, prefix)
+ minlat = (minlat * 10000000).round
+ minlon = (minlon * 10000000).round
+ maxlat = (maxlat * 10000000).round
+ maxlon = (maxlon * 10000000).round
+
+ return "#{tilesql} AND #{prefix}latitude BETWEEN #{minlat} AND #{maxlat} AND #{prefix}longitude BETWEEN #{minlon} AND #{maxlon}"
+ end
+
+