Class: Model

Inherits:
Object show all
Includes:
ModelHashBehaviour, ModelHelpers, ModelState, ModelWrapper, Validations
Defined in:
lib/volt/models/model.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from ModelState

#change_state_to, #loaded?, #state

Methods included from Validations

#errors, included, #mark_field!, #marked_errors, #marked_fields

Methods included from ModelHashBehaviour

#clear, #delete, #false?, #nil?, #to_h, #true?

Methods included from ModelHelpers

#class_at_path, #deep_unwrap, #event_added, #event_removed

Methods included from ModelWrapper

#wrap_value, #wrap_values

Constructor Details

#initialize(attributes = {}, options = {}, initial_state = nil) ⇒ Model

Returns a new instance of Model.



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# File 'lib/volt/models/model.rb', line 23

def initialize(attributes={}, options={}, initial_state=nil)
  @deps = HashDependency.new
  self.options = options

  self.send(:attributes=, attributes, true)

  @cache = {}

  # Models start in a loaded state since they are normally setup from an
  # ArrayModel, which will have the data when they get added.
  @state = :loaded

  @persistor.loaded(initial_state) if @persistor
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name, *args, &block) ⇒ Object 



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# File 'lib/volt/models/model.rb', line 84

def method_missing(method_name, *args, &block)
  if method_name[0] == '_'
    if method_name[-1] == '='
      # Assigning an attribute with =
      assign_attribute(method_name, *args, &block)
    else
      read_attribute(method_name)
    end
  else
    # Call method directly on attributes.  (since they are
    # not using _ )
    attributes.send(method_name, *args, &block)
  end
end

Instance Attribute Details

#attributes ⇒ Object

Returns the value of attribute attributes.



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# File 'lib/volt/models/model.rb', line 20

def attributes
  @attributes
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/volt/models/model.rb', line 21

def options
  @options
end

#parent ⇒ Object (readonly)

Returns the value of attribute parent.



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# File 'lib/volt/models/model.rb', line 21

def parent
  @parent
end

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/volt/models/model.rb', line 21

def path
  @path
end

#persistor ⇒ Object (readonly)

Returns the value of attribute persistor.



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# File 'lib/volt/models/model.rb', line 21

def persistor
  @persistor
end

Instance Method Details

#! ⇒ Object

Pass through needed



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# File 'lib/volt/models/model.rb', line 79

def !
  !attributes
end

#<<(value) ⇒ Object

Initialize an empty array and append to it



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# File 'lib/volt/models/model.rb', line 226

def <<(value)
  if @parent
    @parent.expand!
  else
    raise "Model data should be stored in sub collections."
  end

  # Grab the last section of the path, so we can do the assign on the parent
  path = @path.last
  result = @parent.send(path)

  if result.nil?
    # If this isn't a model yet, instantiate it
    @parent.send(:"#{path}=", new_array_model([], @options))
    result = @parent.send(path)
  end

  # Add the new item
  result << value

  return nil
end

#==(val) ⇒ Object

Pass the comparison through



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# File 'lib/volt/models/model.rb', line 68

def ==(val)
  if val.is_a?(Model)
    # Use normal comparison for a model
    return super
  else
    # Compare to attributes otherwise
    return attributes == val
  end
end

#assign_attribute(method_name, *args, &block) ⇒ Object

Do the assignment to a model and trigger a changed event



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# File 'lib/volt/models/model.rb', line 100

def assign_attribute(method_name, *args, &block)
  # Free any cached value
  free(method_name)

  self.expand!
  # Assign, without the =
  attribute_name = method_name[0..-2].to_sym

  value = args[0]

  attributes[attribute_name] = wrap_value(value, [attribute_name])
  @deps.changed!(attribute_name)

  # Let the persistor know something changed
  @persistor.changed(attribute_name) if @persistor
end

#buffer ⇒ Object

Returns a buffered version of the model



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# File 'lib/volt/models/model.rb', line 295

def buffer
  model_path = options[:path]

  # When we grab a buffer off of a plual class (subcollection), we get it as a model.
  if model_path.last.plural? && model_path[-1] != :[]
    model_klass = class_at_path(model_path + [:[]])
  else
    model_klass = class_at_path(model_path)
  end

  new_options = options.merge(path: model_path, save_to: self).reject {|k,_| k.to_sym == :persistor }
  model = model_klass.new({}, new_options, :loading)

  if state == :loaded
    setup_buffer(model)
  else
    self.parent.then do
      setup_buffer(model)
    end
  end

  return model
end

#expand! ⇒ Object

If this model is nil, it makes it into a hash model, then sets it up to track from the parent.



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# File 'lib/volt/models/model.rb', line 214

def expand!
  if attributes.nil?
    @attributes = {}
    if @parent
      @parent.expand!

      @parent.send(:"#{@path.last}=", self)
    end
  end
end

#free(name) ⇒ Object

Removes an item from the cache



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# File 'lib/volt/models/model.rb', line 208

def free(name)
  @cache.delete(name)
end

#inspect ⇒ Object 



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# File 'lib/volt/models/model.rb', line 249

def inspect
  str = nil
  Computation.run_without_tracking do
    str = "<#{self.class.to_s}:#{object_id} #{attributes.inspect}>"
  end

  return str
end

#new_array_model(attributes, options) ⇒ Object 



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# File 'lib/volt/models/model.rb', line 186

def new_array_model(attributes, options)
  # Start with an empty query
  options = options.dup
  options[:query] = {}

  ArrayModel.new(attributes, options)
end

#new_model(attributes, options) ⇒ Object 



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# File 'lib/volt/models/model.rb', line 182

def new_model(attributes, options)
  class_at_path(options[:path]).new(attributes, options)
end

#read_attribute(method_name) ⇒ Object

When reading an attribute, we need to handle reading on: 1) a nil model, which returns a wrapped error 2) reading directly from attributes 3) trying to read a key that doesn’t exist.



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# File 'lib/volt/models/model.rb', line 121

def read_attribute(method_name)
  # Reading an attribute, we may get back a nil model.
  method_name = method_name.to_sym

  if method_name[0] != '_' && attributes == nil
    # The method we are calling is on a nil model, return a wrapped
    # exception.
    return return_undefined_method(method_name)
  else
    # See if the value is in attributes
    value = (attributes && attributes[method_name])

    # Also check @cache
    value ||= (@cache && @cache[method_name])

    # Track dependency
    @deps.depend(method_name)

    if value
      # key was in attributes or cache
      return value
    else
      # Cache the value, will be removed when expanded or something
      # is assigned over it.
      # TODO: implement a timed out cache flusing
      new_model = read_new_model(method_name)
      @cache[method_name] = new_model

      return new_model
    end
  end
end

#read_new_model(method_name) ⇒ Object

Get a new model, make it easy to override



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# File 'lib/volt/models/model.rb', line 155

def read_new_model(method_name)
  if @persistor && @persistor.respond_to?(:read_new_model)
    return @persistor.read_new_model(method_name)
  else
    opts = @options.merge(parent: self, path: path + [method_name])
    if method_name.plural?
      return new_array_model([], opts)
    else
      return new_model(nil, opts)
    end
  end
end

#return_undefined_method(method_name) ⇒ Object 



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# File 'lib/volt/models/model.rb', line 168

def return_undefined_method(method_name)
  # Methods called on nil capture an error so the user can know where
  # their nil calls are.  This error can be re-raised at a later point.
  begin
    raise NilMethodCall.new("undefined method `#{method_name}' for #{self.to_s}")
  rescue => e
    result = e

    # Cleanup backtrace
    # TODO: this could be better
    result.backtrace.reject! {|line| line['lib/models/model.rb'] || line['lib/models/live_value.rb'] }
  end
end

#save! ⇒ Object 



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# File 'lib/volt/models/model.rb', line 258

def save!
  # Compute the erros once
  errors = self.errors

  if errors.size == 0
    save_to = options[:save_to]
    if save_to
      if save_to.is_a?(ArrayModel)
        # Add to the collection
        new_model = save_to.append(self.attributes)

        # Set the buffer's id to track the main model's id
        self.attributes[:_id] = new_model._id
        options[:save_to] = new_model

        # TODO: return a promise that resolves if the append works
      else
        # We have a saved model
        return save_to.assign_attributes(self.attributes)
      end
    else
      raise "Model is not a buffer, can not be saved, modifications should be persisted as they are made."
    end

    return Promise.new.resolve({})
  else
    # Some errors, mark all fields
    self.class.validations.keys.each do |key|
      mark_field!(key.to_sym)
    end

    return Promise.new.reject(errors)
  end
end

#trigger_by_attribute!(event_name, attribute, *passed_args) ⇒ Object 



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# File 'lib/volt/models/model.rb', line 194

def trigger_by_attribute!(event_name, attribute, *passed_args)
  trigger_by_scope!(event_name, *passed_args) do |scope|
    method_name, *args, block = scope

    # TODO: Opal bug
    args ||= []

    # Any methods without _ are not directly related to one attribute, so
    # they should all trigger
    !method_name || method_name[0] != '_' || (method_name == attribute.to_sym && args.size == 0)
  end
end