#--
# Copyright (c) 2005-2012, John Mettraux, jmettraux@gmail.com
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
# Made in Japan.
#++


module Ruote::Exp

  #
  # Reads the content of a local file or a file reachable over http and places
  # the content in a [process] variable or a [workitem] field.
  #
  # Always attempts to parse the content as JSON. If the parsing fails, simply
  # considers as plain text.
  #
  #   Ruote.process_definition do
  #     read 'http://defs.example.org/filters/filter1.json', :to => 'x'
  #     read 'http://defs.example.org/filters/filter1.json', :to => 'f:x'
  #     read 'http://defs.example.org/filters/filter2.json', :to => 'v:y'
  #     read 'filters/filter3.json', :to => 'f:y'
  #     read 'texts/greetings${f:greeting_index}.txt', :to => 'f:greetings'
  #     # ...
  #   end
  #
  class ReadExpression < FlowExpression

    names :read

    def apply

      to = attribute('to')
      from = attribute('from') || attribute_text

      content = open(from).read rescue nil
        # should this happen in the worker loop ? thread out ?

      content = Rufus::Json.decode(content) rescue content

      set_vf(to, content)

      reply_to_parent(h.applied_workitem)
    end

    def reply(workitem)

      # empty, never called
    end
  end
end