Method: Trailblazer::Macro.Each

Defined in:
lib/trailblazer/macro/each.rb

.Each(block_activity = nil, dataset_from: nil, item_key: :item, id: Macro.id_for(block_activity, macro: :Each, hint: dataset_from), collect: false, **dsl_options_for_iterated, &block) ⇒ Object 



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# File 'lib/trailblazer/macro/each.rb', line 85

def self.Each(block_activity=nil, dataset_from: nil, item_key: :item, id: Macro.id_for(block_activity, macro: :Each, hint: dataset_from), collect: false, **dsl_options_for_iterated, &block)
  dsl_options_for_iterated = block_activity if block_activity.is_a?(Hash) # Ruby 2.5 and 2.6

  block_activity, outputs_from_block_activity = Macro.block_activity_for(block_activity, &block)

  collect_options       = options_for_collect(collect: collect)
  dataset_from_options  = options_for_dataset_from(dataset_from: dataset_from)

  wrap_static_for_block_activity = task_wrap_for_iterated(
    {Activity::Railway.Out() => []}. # per default, don't let anything out.
    merge(collect_options).
    merge(dsl_options_for_iterated)
  )

  # This activity is passed into the {Runner} for each iteration of {block_activity}.
  container_activity = Activity::TaskWrap.container_activity_for(
    block_activity,
    id:        "invoke_block_activity",
    # merged into {:config}:
      each:        true, # mark this activity for {compute_runtime_id}.
  ).merge(
    outputs: outputs_from_block_activity,
  )

  # FIXME: we can't pass {wrap_static: wrap_static_for_block_activity} into {#container_activity_for}
  #        because when patching, the container_activity is not recompiled, so we need the Hash here
  #        with defaulting.
  # FIXME: this "hack" is only here to satify patching.
  config = container_activity[:config].merge(wrap_static: Hash.new(wrap_static_for_block_activity))
  container_activity.merge!(config: config)

  # DISCUSS: move to Wrap.
  termini_from_block_activity =
    outputs_from_block_activity.
      # DISCUSS: End.success needs to be the last here, so it's directly behind {Start.default}.
      sort { |a,b| a.semantic == :success ? 1 : -1 }.
      collect { |output|
        [output.signal, id: "End.#{output.semantic}", magnetic_to: output.semantic, append_to: "Start.default"]
      }

  state = Declarative::State(
    block_activity:   [block_activity, {copy: Trailblazer::Declarative::State.method(:subclass)}], # DISCUSS: move to Macro::Strategy.
    item_key:         [item_key, {}], # DISCUSS: we could even allow the wrap_handler to be patchable.
    failing_semantic: [[:failure, :fail_fast], {}],
    activity:         [container_activity, {}],
    success_signal:   [termini_from_block_activity[-1][0], {}] # FIXME: when subclassing (e.g. patching) this must be recomputed.
  )

  # |-- Each/composers_for_each
  # |   |-- Start.default
  # |   |-- Each.iterate.block            This is Class.new(Each), outputs_from_block_activity
  # |   |   |-- invoke_block_activity.0      step :invoke_block_activity.0
  # |   |   |   |-- Start.default
  # |   |   |   |-- notify_composers
  # |   |   |   `-- End.success
  # |   |   `-- invoke_block_activity.1      step "invoke_block_activity.1"
  # |   |       |-- Start.default
  # |   |       |-- notify_composers
  iterate_strategy = Class.new(Each) do
    extend Macro::Strategy::State # now, the Wrap subclass can inherit its state and copy the {block_activity}.
    initialize!(state)
  end

  each_activity = Activity::FastTrack(termini: termini_from_block_activity) # DISCUSS: what base class should we be using?
  each_activity.extend Each::Transitive

  # {Subprocess} with {strict: true} will automatically wire all {block_activity}'s termini to the corresponding termini
  # of {each_activity} as they have the same semantics (both termini sets are identical).
  each_activity.step Activity::Railway.Subprocess(iterate_strategy, strict: true),
    id: "Each.iterate.#{block ? :block : block_activity}" # FIXME: test :id.

  Activity::Railway.Subprocess(each_activity).
    merge(id: id).
    merge(dataset_from_options) # FIXME: provide that service via Subprocess.
end