class Origin::Pipeline
Represents an aggregation pipeline.
@since 2.0.0
Attributes
@attribute [r] aliases The field aliases.
Public Class Methods
Initialize the new pipeline.
@example Initialize the new pipeline.
Origin::Pipeline.new(aliases)
@param [ Hash ] aliases A hash of mappings from aliases to the actual
field names in the database.
@since 2.0.0
# File lib/origin/pipeline.rb, line 51 def initialize(aliases = {}) @aliases = aliases yield(self) if block_given? end
Public Instance Methods
Deep copy the aggregation pipeline. Will clone all the values in the pipeline as well as the pipeline itself.
@example Deep copy the pipeline.
pipeline.__deep_copy__
@return [ Pipeline ] The cloned pipeline.
@since 2.0.0
# File lib/origin/pipeline.rb, line 20 def __deep_copy__ self.class.new(aliases) do |copy| each do |entry| copy.push(entry.__deep_copy__) end end end
Add a group operation to the aggregation pipeline.
@example Add a group operation.
pipeline.group(:count.sum => 1, :max.max => "likes")
@param [ Hash ] entry The group entry.
@return [ Pipeline ] The pipeline.
@since 2.0.0
# File lib/origin/pipeline.rb, line 38 def group(entry) push("$group" => evolve(entry.__expand_complex__)) end
Adds a $project entry to the aggregation pipeline.
@example Add the projection.
pipeline.project(name: 1)
@param [ Hash ] entry The projection.
@return [ Pipeline ] The pipeline.
# File lib/origin/pipeline.rb, line 64 def project(entry) push("$project" => evolve(entry)) end
Add the $unwind entry to the pipeline.
@example Add the unwind.
pipeline.unwind(:field)
@param [ String, Symbol ] field The name of the field.
@return [ Pipeline ] The pipeline.
@since 2.0.0
# File lib/origin/pipeline.rb, line 78 def unwind(field) normalized = field.to_s name = aliases[normalized] || normalized push("$unwind" => name.__mongo_expression__) end
Private Instance Methods
Evolve the entry using the aliases.
@api private
@example Evolve the entry.
pipeline.evolve(name: 1)
@param [ Hash ] entry The entry to evolve.
@return [ Hash ] The evolved entry.
@since 2.0.0
# File lib/origin/pipeline.rb, line 98 def evolve(entry) aggregate = Selector.new(aliases) entry.each_pair do |field, value| aggregate.merge!(field.to_s => value) end aggregate end