1 files changed, 86 insertions, 0 deletions
diff --git a/exts/importer_base.rb b/exts/importer_base.rb
new file mode 100644
index 0000000..98eb05c
--- /dev/null
+++ b/exts/importer_base.rb
@@ -0,0 +1,86 @@
+#!/usr/bin/env ruby
+#
+# Base class for importers written in Ruby
+#
+# Copyright (C) 2014  Codethink Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+require 'json'
+require 'logger'
+require 'optparse'
+require 'yaml'
+
+module Importer
+  class Base
+    private
+
+    def create_option_parser(banner, description)
+      opts = OptionParser.new
+
+      opts.banner = banner
+
+      opts.on('-?', '--help', 'print this help') do
+        puts opts
+        print "\n", description
+        exit 255
+      end
+    end
+
+    def log
+      @logger ||= create_logger
+    end
+
+    def error(message)
+      log.error(message)
+      STDERR.puts(message)
+    end
+
+    def local_data_path(file)
+      # Return the path to 'file' relative to the currently running program.
+      # Used as a simple mechanism of finding local data files.
+      script_dir = File.dirname(__FILE__)
+      File.join(script_dir, '..', 'data', file)
+    end
+
+    def write_lorry(file, lorry)
+      format_options = { :indent => '    ' }
+      file.puts(JSON.pretty_generate(lorry, format_options))
+    end
+
+    def write_morph(file, morph)
+      file.write(YAML.dump(morph))
+    end
+
+    def write_dependencies(file, dependencies)
+      format_options = { :indent => '    ' }
+      file.puts(JSON.pretty_generate(dependencies, format_options))
+    end
+
+    def create_logger
+      # Use the logger that was passed in from the 'main' import process, if
+      # detected.
+      log_fd = ENV['MORPH_LOG_FD']
+      if log_fd
+        log_stream = IO.new(Integer(log_fd), 'w')
+        logger = Logger.new(log_stream)
+        logger.level = Logger::DEBUG
+        logger.formatter = proc { |severity, datetime, progname, msg| "#{msg}\n" }
+      else
+        logger = Logger.new('/dev/null')
+      end
+      logger
+    end
+  end
+end