Module: Mongo::Conversions

Included in:
Cursor, Support
Defined in:
lib/mongo/util/conversions.rb

Overview

Utility module to include when needing to convert certain types of objects to mongo-friendly parameters.

Constant Summary collapse

ASCENDING_CONVERSION = 
["ascending", "asc", "1"]
DESCENDING_CONVERSION = 
["descending", "desc", "-1"]

Instance Method Summary collapse

Instance Method Details

#array_as_sort_parameters(value) ⇒ Object

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:

array_as_sort_parameters([["field1", :asc], ["field2", :desc]]) => { "field1" => 1, "field2" => -1}



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# File 'lib/mongo/util/conversions.rb', line 41

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

#hash_as_sort_parameters(value) ⇒ Object

Allows sort parameters to be defined as a Hash. Does not allow usage of un-ordered hashes, therefore Ruby 1.8.x users must use BSON::OrderedHash.

Example:

hash_as_sort_parameters({:field1 => :asc, "field2" => :desc}) => { "field1" => 1, "field2" => -1}



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# File 'lib/mongo/util/conversions.rb', line 18

def hash_as_sort_parameters(value)
  if RUBY_VERSION < '1.9' && !value.is_a?(BSON::OrderedHash)
    raise InvalidSortValueError.new(
      "Hashes used to supply sort order must maintain ordering." +
      "Use BSON::OrderedHash."
    )
  else
    order_by = value.inject({}) do |memo, (key, direction)|
      memo[key.to_s] = sort_value(direction.to_s.downcase)
      memo
    end
  end
  order_by
end

#sort_value(value) ⇒ Object

Converts the String, Symbol, or Integer to the corresponding sort value in MongoDB.

Valid conversions (case-insensitive):

ascending, asc, :ascending, :asc, 1 => 1 descending, desc, :descending, :desc, -1 => -1

If the value is invalid then an error will be raised.

Raises:



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# File 'lib/mongo/util/conversions.rb', line 85

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: " +
    "Mongo::ASCENDING, 'ascending', 'asc', :ascending, :asc, 1, Mongo::DESCENDING, " +
    "'descending', 'desc', :descending, :desc, -1.")
end

#string_as_sort_parameters(value) ⇒ Object

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

string_as_sort_parameters("field") => { "field" => 1 } string_as_sort_parameters("") => {}



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# File 'lib/mongo/util/conversions.rb', line 71

def string_as_sort_parameters(value)
  return {} if (str = value.to_s).empty?
  { str => 1 }
end