Module: DocumentHydrator::HydrationProc::Mongo

Defined in:
lib/document_hydrator/hydration_proc/mongo.rb

Class Method Summary collapse

Class Method Details

.collection(coll, options = {}) ⇒ Object

Create a hydration proc that fetches subdocuments by ID from the provided collection.

coll - The Mongo::Collection containing the subdocuments options - (Optional) hash of options to pass to MongoDB::Collection#find.

Defaults to {}.

Returns a Proc that maps IDs to their corresponding subdocuments within the collection.



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# File 'lib/document_hydrator/hydration_proc/mongo.rb', line 14

def collection(coll, options = {})
  Proc.new do |ids|
    if options[:fields]
      # We need to _id key in order to assemble the results hash.
      # If the caller has requested that it be omitted from the
      # result, re-enable it and then strip later.
      field_selectors = options[:fields]
      id_key = field_selectors.keys.detect { |k| k.to_s == '_id' }
      if id_key && field_selectors[id_key] == 0
        field_selectors.delete(id_key)
        strip_id = true
      end
    end
    subdocuments = coll.find({ '_id' => { '$in' => ids } }, options)
    subdocuments.inject({}) do |hash, subdocument|
      hash[subdocument['_id']] = subdocument
      subdocument.delete('_id') if strip_id
      hash
    end
  end
end