lib/volt/models/buffer.rb
require 'volt/reactive/reactive_accessors'
module Volt
module Buffer
# Save saves the contents of a buffer to the save_to location. If the buffer is new, it will create a new
# model to save to. Otherwise it will be an existing model. Save returns a promise that may fail with
# validation errors from the server (or the client). You can also pass a block as a shortcut to calling
# ```.save!.then do```
def save!(&block)
# TODO: this shouldn't need to be run, but if no attributes are assigned, then
# if needs to be run. Maybe there's a better way to handle it.
validate!.then do
# Get errors from validate
errors = self.errors.to_h
result = nil
if errors.size == 0
# cache save_to in a local
save_to = self.save_to
if save_to
if save_to.is_a?(ArrayModel)
# Add to the collection
promise = save_to.create(attributes)
else
# We have a saved model
promise = save_to.assign_attributes(attributes)
end
result = promise.then do |new_model|
# The main model saved, so mark the buffer as not new
@new = false
if new_model
# Mark the model as loaded
new_model.change_state_to(:loaded_state, :loaded)
# Set the buffer's id to track the main model's id
self.save_to = new_model
end
# Copy attributes back from save_to model
@attributes = new_model.attributes
# Remove tracked changes
clear_tracked_changes!
new_model
end.fail do |errors|
if errors.is_a?(Hash)
server_errors.replace(errors)
# Merge the server errors into the main errors
self.errors.merge!(server_errors.to_h)
end
promise_for_errors(errors)
end
else
fail 'Model is not a buffer, can not be saved, modifications should be persisted as they are made.'
end
else
# Some errors, mark all fields
result = promise_for_errors(errors)
end
# If passed a block, call then on it with the block.
result = result.then(&block) if block
result
end
end
# When errors come in, we mark all fields and return a rejected promise.
def promise_for_errors(errors)
mark_all_fields!
# Wrap in an Errors class unless it already is one
errors = errors.is_a?(Errors) ? errors : Errors.new(errors)
Promise.new.reject(errors)
end
def buffer?
options[:buffer] || false
end
# Returns a buffered version of the model
def buffer
model_path = options[:path]
model_klass = self.class
new_options = options.merge(path: model_path, save_to: self, buffer: true).reject { |k, _| k.to_sym == :persistor }
model = nil
Volt::Model.no_validate do
model = model_klass.new(attributes, new_options, :loaded)
model.instance_variable_set('@new', @new)
end
model
end
def self.included(base)
base.include ReactiveAccessors
base.reactive_accessor :__save_to
end
def save_to
val = __save_to
unless val
# Lazy load the save_to
self.save_to = options[:save_to]
return __save_to
end
val
end
def save_to=(val)
self.__save_to = val
end
def saved_state
if buffer?
# cache save_to in local
lsave_to = self.save_to
lsave_to.try(:saved_state) || :not_saved
else
super
end
end
def saved?
saved_state == :saved
end
end
end