Class: Api::Base

Inherits:
Object
  • Object
show all
Defined in:
app/models/api/base.rb

Overview

Note:

Originally the warehouse was built nightly by calls the the v0.5 API. When the warehouse was switched to a queue based system the same JSON exposed via the API was used to form the message payload.

Base class for API v0.5, now used for Warehouse message rendering, the actual api is no longer exposed.

Class Method Summary collapse

Class Method Details

.attributes_from_json(params) ⇒ Object


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# File 'app/models/api/base.rb', line 244

def attributes_from_json(params)
  convert_json_attributes_to_attributes(params[model_class.name.underscore])
end

.convert_json_attributes_to_attributes(json_attributes) ⇒ Object

rubocop:todo Metrics/MethodLength


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# File 'app/models/api/base.rb', line 249

def convert_json_attributes_to_attributes(json_attributes) # rubocop:todo Metrics/AbcSize
  return {} if json_attributes.blank?

  attributes = {}
  attribute_to_json_attribute_mappings.each do |attribute, json_attribute|
    attributes[attribute] = json_attributes[json_attribute] if json_attributes.key?(json_attribute)
  end
  associations.each do |association, helper|
    if helper.performs_lookup?
      helper.lookup_associated_record_from(json_attributes) do |associated_record|
        attributes[:"#{association}_id"] = associated_record.try(:id)
      end
    else
      association_attributes = helper.convert_json_attributes_to_attributes(json_attributes)
      attributes[:"#{association}_attributes"] = association_attributes unless association_attributes.empty?
    end
  end
  attributes
end

.create!(params) ⇒ Object


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# File 'app/models/api/base.rb', line 21

def create!(params)
  model_class.create!(attributes_from_json(params))
end

.default_objectObject

Returns the default object to use (by default this is 'nil') and can be overridden by passing ':if_nil_use => :some_function_that_returns_default_object' to with_association.


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# File 'app/models/api/base.rb', line 170

def self.default_object
  nil
end

.extra_json_attributes(&block) ⇒ Object


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# File 'app/models/api/base.rb', line 238

def self.extra_json_attributes(&block)
  self.extra_json_attribute_handlers = Array.new if extra_json_attribute_handlers.empty?
  extra_json_attribute_handlers.push(block)
end

.json_attribute_for_attribute(attribute_or_association, *rest) ⇒ Object

rubocop:todo Metrics/MethodLength


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# File 'app/models/api/base.rb', line 272

def json_attribute_for_attribute(attribute_or_association, *rest) # rubocop:todo Metrics/AbcSize
  json_attribute = attribute_to_json_attribute_mappings[attribute_or_association.to_sym]
  if json_attribute.blank?
    # If we have reached the end of the line, and the attribute_or_association is for what looks like
    # an association, then we'll look it up without the '_id' and return that value.
    if attribute_or_association.to_s =~ (/_id$/) && rest.empty?
      association = associations[attribute_or_association.to_s.sub(/_id$/, '').to_sym]
      raise StandardError, "Unexpected association #{attribute_or_association.inspect}" if association.nil?

      return association.json_attribute_for_attribute(:name)
    end
    json_attribute = associations[attribute_or_association.to_sym].json_attribute_for_attribute(*rest)
  end
  if json_attribute.blank?
    raise StandardError, "Unexpected attribute #{attribute_or_association.inspect} does not appear to be mapped"
  end

  json_attribute
end

.lookup_associated_record_from(json_attributes) {|association.to_s.classify.constantize.find_by(search_parameters)| ... } ⇒ Object

Yields:

  • (association.to_s.classify.constantize.find_by(search_parameters))

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# File 'app/models/api/base.rb', line 215

def self.lookup_associated_record_from(json_attributes)
  attributes = convert_json_attributes_to_attributes(json_attributes)
  return unless attributes.key?(lookup_by)

  search_parameters = { lookup_by => attributes[lookup_by] }
  yield(association.to_s.classify.constantize.find_by(search_parameters))
end

.map_attribute_to_json_attribute(attribute, json_attribute = attribute) ⇒ Object

TODO: Need to warn about 'id' not being 'internal_id'


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# File 'app/models/api/base.rb', line 138

def self.map_attribute_to_json_attribute(attribute, json_attribute = attribute)
  self.attribute_to_json_attribute_mappings =
    attribute_to_json_attribute_mappings.merge(attribute.to_sym => json_attribute.to_s)
end

.map_attribute_to_json_attribute_in_errors(attribute_errors) ⇒ Object

Maps the attribute names in the errors to their JSON counterparts, so that the end user gets the correct information.


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# File 'app/models/api/base.rb', line 31

def map_attribute_to_json_attribute_in_errors(attribute_errors)
  attribute_errors.transform_keys { |a| json_attribute_for_attribute(*a.to_s.split('.')) }
end

.newer_than(object, timestamp) {|timestamp| ... } ⇒ Object

rubocop:todo Metrics/PerceivedComplexity, Metrics/AbcSize

Yields:

  • (timestamp)

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# File 'app/models/api/base.rb', line 152

def self.newer_than(object, timestamp) # rubocop:todo Metrics/CyclomaticComplexity
  return if object.nil? || timestamp.nil?

  modified, object_timestamp = false, ((object.respond_to?(:updated_at) ? object.updated_at : timestamp) || timestamp)
  timestamp, modified = object_timestamp, true if object_timestamp > timestamp
  associations.each do |_association, helper|
    helper.newer_than(helper.target(object), timestamp) { |t| timestamp, modified = t, true }
  end
  nested_has_many_associations.each do |_association, helper|
    helper.target(object).each { |child| helper.newer_than(child, timestamp) { |t| timestamp, modified = t, true } }
  end
  yield(timestamp) if modified
end

.performs_lookup?Boolean

rubocop:enable Metrics/MethodLength

Returns:

  • (Boolean)

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# File 'app/models/api/base.rb', line 211

def self.performs_lookup?
  !!lookup_by
end

.render_class_for_model(model) ⇒ Object

The default behaviour for any model I/O is to write out all of the columns as they appear. Some of the columns are ignored, a few manipulated, but mostly it's a direct copy. rubocop:todo Metrics/MethodLength, Metrics/AbcSize


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# File 'app/models/api/base.rb', line 98

def render_class_for_model(model) # rubocop:todo Metrics/CyclomaticComplexity
  render_class = Class.new(self)

  # NOTE: It's quite annoying that you don't have any access to the inheritable class attributes from
  # within the Class.new block above, so we have to do a separate instance_eval to get it to work.
  render_class.instance_eval do
    self.model_class = model
    model.column_names.each { |column| map_attribute_to_json_attribute(column, column) }

    # TODO[xxx]: It's better that some of these are decided at generation, rather than execution, time.
    extra_json_attributes do |object, json_attributes|
      json_attributes['uuid'] = object.uuid if object.respond_to?(:uuid)

      # Users and roles
      json_attributes['user'] = object.user.nil? ? 'unknown' : object.user. if object.respond_to?(:user)
      if object.respond_to?(:roles)
        object.roles.each do |role|
          json_attributes[role.name.underscore] =
            role.users.map { |user| { login: user., email: user.email, name: user.name } }
        end
      end
    end
  end
  render_class
end

.renders_model(model) ⇒ Object


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# File 'app/models/api/base.rb', line 129

def self.renders_model(model)
  self.model_class = model
end

.to_hash(object) ⇒ Object

rubocop:todo Metrics/PerceivedComplexity, Metrics/MethodLength, Metrics/AbcSize


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# File 'app/models/api/base.rb', line 42

def to_hash(object) # rubocop:todo Metrics/CyclomaticComplexity
  # If the object is nil we get a chance to use the 'default' object that was specified.  By
  # default the "default" object is nil, but you can override it for associations through the
  # with_association(:name, :if_nil_use => :some_method).
  object ||= default_object
  return {} if object.nil?

  json_attributes = {}
  json_attributes['deleted_at'] = Time.zone.now if object.destroyed?

  attribute_to_json_attribute_mappings.each do |attribute, json_attribute|
    json_attributes[json_attribute] = object.send(attribute)
  end
  associations.each do |_association, helper|
    value = helper.target(object)
    json_attributes.update(helper.to_hash(value))
    helper.newer_than(value, json_attributes['updated_at']) do |timestamp|
      json_attributes['updated_at'] = timestamp
    end
  end
  nested_has_many_associations.each do |_association, helper|
    values = helper.target(object)
    all_targets =
      values.map do |value|
        helper.newer_than(value, json_attributes['updated_at']) do |timestamp|
          json_attributes['updated_at'] = timestamp
        end
        helper.to_hash(value)
      end
    json_attributes.update(helper.alias.to_s => all_targets)
  end
  extra_json_attribute_handlers.each { |handler| handler.call(object, json_attributes) }
  json_attributes
end

.to_hash_for_list(object) ⇒ Object

rubocop:enable Metrics/AbcSize, Metrics/MethodLength, Metrics/PerceivedComplexity

Raises:

  • (StandardError)

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# File 'app/models/api/base.rb', line 79

def to_hash_for_list(object)
  raise StandardError, 'The object is nil, which is highly unexpected!' if object.nil?

  json_attributes = {}
  attribute_to_json_attribute_mappings_for_list.each do |attribute, json_attribute|
    json_attributes[json_attribute] = object.send(attribute)
  end
  json_attributes
end

.update!(object, params) ⇒ Object


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# File 'app/models/api/base.rb', line 25

def update!(object, params)
  object.update!(attributes_from_json(params))
end

.with_association(association, options = {}, &block) ⇒ Object

rubocop:todo Metrics/MethodLength


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# File 'app/models/api/base.rb', line 175

def self.with_association(association, options = {}, &block) # rubocop:todo Metrics/AbcSize
  association_helper = Class.new(Api::Base)
  association_helper.class_eval(&block)
  association_helper.singleton_class.class_eval do
    alias_method(:default_object, options[:if_nil_use]) if options.key?(:if_nil_use)
    define_method(:lookup_by) { options[:lookup_by] }
    define_method(:association) { association }
    define_method(:target) do |parent|
      target_object = parent.send(association)
      options[:decorator] && target_object ? options[:decorator].new(target_object) : target_object
    end
  end
  self.associations = Hash.new if associations.empty?
  associations[association.to_sym] = association_helper
end

.with_nested_has_many_association(association, options = {}, &block) ⇒ Object

rubocop:todo Metrics/MethodLength


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# File 'app/models/api/base.rb', line 194

def self.with_nested_has_many_association(association, options = {}, &block) # rubocop:todo Metrics/AbcSize
  association_helper = Class.new(Api::Base)
  association_helper.class_eval(&block)
  association_helper.singleton_class.class_eval do
    define_method(:association) { association }
    define_method(:alias) { options[:as] || association }
    define_method(:target) do |parent|
      target_object = parent.send(association)
      options[:decorator] && target_object ? options[:decorator].new(target_object) : target_object
    end
  end
  self.nested_has_many_associations = Hash.new if nested_has_many_associations.empty?
  nested_has_many_associations[association.to_sym] = association_helper
end