Class: Dommy::Internal::MutationCoordinator

Inherits:
Object
  • Object
show all
Defined in:
lib/dommy/internal/mutation_coordinator.rb

Overview

Coordinates mutation notification to observers and custom element lifecycle callbacks. Isolates mutation observation and custom element logic from Document’s public API.

Instance Method Summary collapse

Constructor Details

#initialize(document, observer_manager) ⇒ MutationCoordinator

Returns a new instance of MutationCoordinator.



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 8

def initialize(document, observer_manager)
  @document = document
  @observer_manager = observer_manager
end

Instance Method Details

#notify_attribute_changed(element, name, old_value, new_value) ⇒ Object 



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 63

def notify_attribute_changed(element, name, old_value, new_value)
  return unless element&.respond_to?(:attribute_changed_callback)

  klass = element.class
  return unless klass.respond_to?(:observed_attributes)
  return unless klass.observed_attributes.include?(name.to_s.downcase)

  element.attribute_changed_callback(name, old_value, new_value)
rescue StandardError
  nil
end

#notify_attribute_mutation(target_node:, attribute_name:, old_value:) ⇒ Object

Fire MutationObserver attribute records



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 120

def notify_attribute_mutation(target_node:, attribute_name:, old_value:)
  target = @document.wrap_node(target_node)
  return nil unless target

  attr = attribute_name.to_s.downcase
  new_value = target_node[attr]

  # Custom Element attributeChangedCallback (synchronous)
  notify_attribute_changed(target, attr, old_value, new_value)

  @observer_manager.observers_matching(target).each do |observer|
    entry = observer.find_matching_entry(target)
    next unless entry && entry[:attributes]

    filter = entry[:attribute_filter]
    next if filter && !filter.include?(attr)

    observer.enqueue(
      MutationRecord.new(
        type: "attributes",
        target: target,
        attribute_name: attr,
        old_value: entry[:attribute_old_value] ? old_value : nil
      )
    )
  end

  nil
end

#notify_character_data_mutation(target_node:, old_value:) ⇒ Object

Fire MutationObserver characterData records



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 151

def notify_character_data_mutation(target_node:, old_value:)
  target = @document.wrap_node(target_node)
  return nil unless target

  @observer_manager.observers_matching(target).each do |observer|
    entry = observer.find_matching_entry(target)
    next unless entry && entry[:character_data]

    observer.enqueue(
      MutationRecord.new(
        type: "characterData",
        target: target,
        old_value: entry[:character_data_old_value] ? old_value : nil
      )
    )
  end

  nil
end

#notify_child_list_mutation(target_node:, added_nodes:, removed_nodes:, previous_sibling: nil, next_sibling: nil) ⇒ Object

Fire MutationObserver childList records



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 76

def notify_child_list_mutation(
  target_node:,
  added_nodes:,
  removed_nodes:,
  previous_sibling: nil,
  next_sibling: nil
)
  target = @document.wrap_node(target_node)
  return nil unless target
  return nil if added_nodes.empty? && removed_nodes.empty?

  wrapped_added = added_nodes.map { |node| @document.wrap_node(node) }.compact
  wrapped_removed = removed_nodes.map { |node| @document.wrap_node(node) }.compact

  # Fire Custom Element lifecycle callbacks (synchronous, before MutationObserver microtask)
  added_nodes.each { |nk| notify_connected_subtree(nk) }
  removed_nodes.each { |nk| notify_disconnected_subtree(nk) }

  # Capture previousSibling / nextSibling (the position within target)
  prev_w = previous_sibling
  next_w = next_sibling
  if (prev_w.nil? && next_w.nil?) && !added_nodes.empty?
    first_nk = added_nodes.first
    last_nk = added_nodes.last
    prev_w ||= @document.wrap_node(first_nk.previous) if first_nk.respond_to?(:previous)
    next_w ||= @document.wrap_node(last_nk.next) if last_nk.respond_to?(:next)
  end

  record = MutationRecord.new(
    type: "childList",
    target: target,
    added_nodes: wrapped_added,
    removed_nodes: wrapped_removed,
    previous_sibling: prev_w,
    next_sibling: next_w
  )
  @observer_manager.observers_matching(target).each do |observer|
    observer.enqueue(record)
  end

  nil
end

#notify_connected(element) ⇒ Object

Fire CustomElement lifecycle: connected (synchronous, before mutation delivery)



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 24

def notify_connected(element)
  return unless element&.respond_to?(:connected_callback)

  element.connected_callback
rescue StandardError
  nil
end

#notify_connected_subtree(nk) ⇒ Object

Walk a subtree and fire connected/disconnected callbacks for all elements



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 41

def notify_connected_subtree(nk)
  return unless nk.respond_to?(:element?)

  if nk.element?
    wrapped = @document.wrap_node(nk)
    notify_connected(wrapped) if wrapped
  end

  nk.children.each { |c| notify_connected_subtree(c) } if nk.respond_to?(:children)
end

#notify_disconnected(element) ⇒ Object 



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 32

def notify_disconnected(element)
  return unless element&.respond_to?(:disconnected_callback)

  element.disconnected_callback
rescue StandardError
  nil
end

#notify_disconnected_subtree(nk) ⇒ Object 



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 52

def notify_disconnected_subtree(nk)
  return unless nk.respond_to?(:element?)

  if nk.element?
    wrapped = @document.wrap_node(nk)
    notify_disconnected(wrapped) if wrapped
  end

  nk.children.each { |c| notify_disconnected_subtree(c) } if nk.respond_to?(:children)
end

#register_observer(observer) ⇒ Object 



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 13

def register_observer(observer)
  @observer_manager.register(observer)
  nil
end

#unregister_observer(observer) ⇒ Object 



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# File 'lib/dommy/internal/mutation_coordinator.rb', line 18

def unregister_observer(observer)
  @observer_manager.unregister(observer)
  nil
end