rabbitmq-server/deps/rabbitmq_cli/lib/rabbitmq/cli/formatters/json.ex

## The contents of this file are subject to the Mozilla Public License
## Version 1.1 (the "License"); you may not use this file except in
## compliance with the License. You may obtain a copy of the License
## at http://www.mozilla.org/MPL/
##
## Software distributed under the License is distributed on an "AS IS"
## basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
## the License for the specific language governing rights and
## limitations under the License.
##
## The Original Code is RabbitMQ.
##
## The Initial Developer of the Original Code is GoPivotal, Inc.
## Copyright (c) 2007-2016 Pivotal Software, Inc.  All rights reserved.

# Basic JSON formatter. Supports 1-level of
# collection using start/finish_collection.
# Primary purpose is to translate stream from CTL,
# so there is no need for multiple collection levels

defmodule RabbitMQ.CLI.Formatters.Json do
  @behaviour RabbitMQ.CLI.Formatters.FormatterBehaviour

  def format_output(output, _) do
    {:ok, json} = JSON.encode(output)
    json
  end

  def format_stream(stream, options) do
    elements = Stream.scan(stream, :empty,
                           fn
                           ({:error, msg}, _) ->
                             {:error, msg};
                           (element, previous) ->
                             separator = case previous do
                               :empty -> "";
                               _      -> ","
                             end
                             format_element(element, separator, options)
                           end)
    Stream.concat([["["], elements, ["]"]])
  end

  def format_element(val, separator, options) do
    separator <> format_output(val, options)
  end
end