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# encoding: UTF-8
# --
# Copyright (C) 2008-2010 10gen Inc.
#
# Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ++
module EM::Mongo #:nodoc:
# Utility module to include when needing to convert certain types of
# objects to mongo-friendly parameters.
module Conversions
ASCENDING_CONVERSION = ["ascending", "asc", "1"]
DESCENDING_CONVERSION = ["descending", "desc", "-1"]
# Converts the supplied +Array+ to a +Hash+ to pass to mongo as
# sorting parameters. The returned +Hash+ will vary depending
# on whether the passed +Array+ is one or two dimensional.
#
# Example:
#
# <tt>array_as_sort_parameters([["field1", :asc], ["field2", :desc]])</tt> =>
# <tt>{ "field1" => 1, "field2" => -1}</tt>
def array_as_sort_parameters(value)
order_by = BSON::OrderedHash.new
if value.first.is_a? Array
value.each do |param|
if (param.class.name == "String")
order_by[param] = 1
else
order_by[param[0]] = sort_value(param[1]) unless param[1].nil?
end
end
elsif !value.empty?
if order_by.size == 1
order_by[value.first] = 1
else
order_by[value.first] = sort_value(value[1])
end
end
order_by
end
# Converts the supplied +String+ or +Symbol+ to a +Hash+ to pass to mongo as
# a sorting parameter with ascending order. If the +String+
# is empty then an empty +Hash+ will be returned.
#
# Example:
#
# *DEPRECATED
#
# <tt>string_as_sort_parameters("field")</tt> => <tt>{ "field" => 1 }</tt>
# <tt>string_as_sort_parameters("")</tt> => <tt>{}</tt>
def string_as_sort_parameters(value)
return {} if (str = value.to_s).empty?
{ str => 1 }
end
# Converts the +String+, +Symbol+, or +Integer+ to the
# corresponding sort value in MongoDB.
#
# Valid conversions (case-insensitive):
#
# <tt>ascending, asc, :ascending, :asc, 1</tt> => <tt>1</tt>
# <tt>descending, desc, :descending, :desc, -1</tt> => <tt>-1</tt>
#
# If the value is invalid then an error will be raised.
def sort_value(value)
val = value.to_s.downcase
return 1 if ASCENDING_CONVERSION.include?(val)
return -1 if DESCENDING_CONVERSION.include?(val)
raise InvalidSortValueError.new(
"#{self} was supplied as a sort direction when acceptable values are: " +
"EM::Mongo::ASCENDING, 'ascending', 'asc', :ascending, :asc, 1, EM::Mongo::DESCENDING, " +
"'descending', 'desc', :descending, :desc, -1.")
end
end
end
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