Class: ReactiveBlock

Inherits:
Object show all
Includes:
ReactiveTags
Defined in:
lib/volt/reactive/reactive_block.rb

Instance Method Summary collapse

Methods included from ReactiveTags

included, #reactive_method_tag

Constructor Details

#initialize(source, check_block, run_block) ⇒ ReactiveBlock

Returns a new instance of ReactiveBlock.



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# File 'lib/volt/reactive/reactive_block.rb', line 8

def initialize(source, check_block, run_block)
  @source = ReactiveValue.new(source)
  @check_block = check_block
  @run_block = run_block
end

Instance Method Details

#change_cell_count(size) ⇒ Object

We need to make sure we’re listening on the result from each cell, that way we can trigger when the value changes.



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# File 'lib/volt/reactive/reactive_block.rb', line 39

def change_cell_count(size)
  current_size = @cell_trackers.size

  if current_size < size
    # Add trackers

    current_size.upto(size-1) do |index|
      # Get the reactive value for the index
      val = @source[index]

      result = @check_block.call(val)

      @cell_trackers << result.on('changed') do
        puts "RESULT CHANGED: #{index} - #{self.object_id}"
        trigger!('changed')
      end
    end
  elsif current_size > size
    (current_size-1).downto(size) do |index|
      @cell_trackers[index].remove
      @cell_trackers.delete_at(index)
    end
  end
end

#cur ⇒ Object 



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# File 'lib/volt/reactive/reactive_block.rb', line 14

def cur
  val = @run_block.call(@source)

  return val
end

#event_added(event, scope_provider, first, first_for_event) ⇒ Object 



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# File 'lib/volt/reactive/reactive_block.rb', line 77

def event_added(event, scope_provider, first, first_for_event)
  setup_listeners if first
end

#event_removed(event, last, last_for_event) ⇒ Object 



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# File 'lib/volt/reactive/reactive_block.rb', line 81

def event_removed(event, last, last_for_event)
  teardown_listeners if last
end

#inspect ⇒ Object 



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# File 'lib/volt/reactive/reactive_block.rb', line 85

def inspect
  "@#{cur}"
end

#reactive? ⇒ Boolean

Returns:



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# File 'lib/volt/reactive/reactive_block.rb', line 4

def reactive?
  true
end

#setup_listeners ⇒ Object 



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# File 'lib/volt/reactive/reactive_block.rb', line 20

def setup_listeners
  @cell_trackers = []
  @setup = false
  @added_tracker = @source.on('added') do |_, index|
    change_cell_count(@source.size.cur)
  end

  @removed_tracker = @source.on('removed') do |_, index|
    change_cell_count(@source.size.cur)
  end

  @setup = true

  # Initial cell tracking
  change_cell_count(@source.size.cur)
end

#teardown_listeners ⇒ Object 



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# File 'lib/volt/reactive/reactive_block.rb', line 65

def teardown_listeners
  @added_tracker.remove
  @added_tracker = nil

  @removed_tracker.remove
  @removed_tracker = nil

  change_cell_count(0)

  @cell_trackers = nil
end