Module: Candy::Collection

Includes:
Enumerable
Defined in:
lib/candy/collection.rb

Overview

Handles Mongo queries for cursors upon a particular Mongo collection.

Defined Under Namespace

Modules: ClassMethods

Constant Summary collapse

FIND_OPTIONS = 
[:fields, :skip, :limit, :sort, :hint, :snapshot, :timeout]
UP_SORTS = 
[Mongo::ASCENDING, 'ascending', 'asc', :ascending, :asc, 1, :up]
DOWN_SORTS = 
[Mongo::DESCENDING, 'descending', 'desc', :descending, :desc, -1, :down]

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args, &block) ⇒ Object 



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# File 'lib/candy/collection.rb', line 71

def method_missing(name, *args, &block)
  if @_candy_cursor.respond_to?(name)
    @_candy_cursor.send(name, *args, &block)
  elsif FIND_OPTIONS.include?(name)
    @_candy_options[name] = args.shift
    refresh_cursor
    self
  else
    @_candy_query[name] = args.shift
    @_candy_query.merge!(args) if args.is_a?(Hash)
    refresh_cursor
    self
  end
end

Instance Method Details

#each ⇒ Object

Makes our collection enumerable. This relies heavily on Mongo::Cursor methods – we only reimplement it so that the objects we return can be Candy objects.



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# File 'lib/candy/collection.rb', line 89

def each
  while this = @_candy_cursor.next_document
    yield self.class._candy_piece.new(this)
  end
end

#initialize(*args, &block) ⇒ Object

Here endeth the ClassMethods module



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# File 'lib/candy/collection.rb', line 58

def initialize(*args, &block)
  conditions = args.pop || {}
  super
  @_candy_query = {}
  if conditions.is_a?(Hash)
    @_candy_options = {:fields => '_id'}.merge(extract_options(conditions))
    @_candy_query.merge!(conditions)
  else
    @_candy_options = {:fields => '_id'}
  end
  refresh_cursor
end

#next ⇒ Object

Get our next document as a Candy object, if there is one.



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# File 'lib/candy/collection.rb', line 96

def next
  if this = @_candy_cursor.next_document
    self.class._candy_piece.new(this)
  end
end

#sort(*fields) ⇒ Object

Determines the sort order for this collection, with somewhat simpler semantics than the MongoDB options. Each value is either a field name (which defaults to ascending sort) or a direction (which modifies the field name immediately prior) or a two-element array of same. Direction can be :up or :down in addition to Mongo’s accepted values of :ascending, ‘asc’, 1, etc.

As an added bonus, sorts can also be chained. If you call #sort more than once then all sorts will be applied in the order in which you called them.



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# File 'lib/candy/collection.rb', line 110

def sort(*fields)
  @_candy_sort ||= []
  temp_sort = []
  until fields.flatten.empty?
    this = fields.pop  # We're going backwards so that we can test for modifiers
    if UP_SORTS.include?(this)
      temp_sort.unshift [fields.pop, Mongo::ASCENDING]
    elsif DOWN_SORTS.include?(this)
      temp_sort.unshift [fields.pop, Mongo::DESCENDING]
    else
      temp_sort.unshift [this, Mongo::ASCENDING]
    end
  end
  @_candy_sort += temp_sort
  @_candy_cursor.sort(@_candy_sort)
  self
end