class ViewModel::TraversalContext

Abstract base for Serialize and DeserializeContexts.

def self.new_child(...)

def self.new_child(...)
  self.allocate.tap { |c| c.initialize_as_child(...) }
end

def self.shared_context_class

def self.shared_context_class
  SharedContext
end

def for_child(parent_viewmodel, association_name:, **rest)

def for_child(parent_viewmodel, association_name:, **rest)
  self.class.new_child(
    shared_context:     shared_context,
    parent_context:     self,
    parent_viewmodel:   parent_viewmodel,
    parent_association: association_name,
    **rest)
end

def for_references

parent)
context (since a shared reference could equally have been reached via any
keep the same shared context, but drop any tree location specific local
Obtain a semi-independent context for descending through a shared reference:

def for_references
  self.class.new(shared_context: shared_context)
end

def initialize(shared_context: nil, **shared_context_params)

def initialize(shared_context: nil, **shared_context_params)
  super()
  @shared_context     = shared_context || self.class.shared_context_class.new(**shared_context_params)
  @parent_context     = nil
  @parent_viewmodel   = nil
  @parent_association = nil
  @root               = true
end

def initialize_as_child(shared_context:, parent_context:, parent_viewmodel:, parent_association:)

override to maintain other node-specific state.
Shared context is the same, ancestry is established, and subclasses can
Overloaded constructor for initialization of descendent node contexts.

def initialize_as_child(shared_context:, parent_context:, parent_viewmodel:, parent_association:)
  @shared_context     = shared_context
  @parent_context     = parent_context
  @parent_viewmodel   = parent_viewmodel
  @parent_association = parent_association
  @root               = false
end

def nearest_root

def nearest_root
  if root?
    self
  else
    parent_context&.nearest_root
  end
end

def nearest_root_viewmodel

def nearest_root_viewmodel
  if root?
    raise RuntimeError.new('Attempted to find nearest root from a root context. This is probably not what you wanted.')
  elsif parent_context.root?
    parent_viewmodel
  else
    parent_context.nearest_root_viewmodel
  end
end

def parent_association(idx = 0)

def parent_association(idx = 0)
  if idx == 0
    @parent_association
  else
    parent_context(idx - 1)&.parent_association
  end
end

def parent_context(idx = 0)

def parent_context(idx = 0)
  if idx == 0
    @parent_context
  else
    @parent_context&.parent_context(idx - 1)
  end
end

def parent_ref(idx = 0)

def parent_ref(idx = 0)
  parent_viewmodel(idx)&.to_reference
end

def parent_viewmodel(idx = 0)

def parent_viewmodel(idx = 0)
  if idx == 0
    @parent_viewmodel
  else
    parent_context(idx - 1)&.parent_viewmodel
  end
end

def root?

def root?
  @root
end

def run_callback(hook, view, **args)

def run_callback(hook, view, **args)
  # Run in-viewmodel callback hooks before context hooks, as they are
  # permitted to alter the model.
  if view.respond_to?(hook.dsl_viewmodel_callback_method)
    view.public_send(hook.dsl_viewmodel_callback_method, hook.context_name => self, **args)
  end
  callbacks.each do |callback|
    callback.run_callback(hook, view, self, **args)
  end
end

Modules

Classes