DirModel

Import and export directories with an ORM-like interface.

Installation

Add this line to your application's Gemfile:

gem 'dir_model'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dir_model

Usage

Import

class BasicDirModel
  include DirModel::Model

  file :image, regex: -> { /Zones\/Sector_(?<sector_id>.*)\/Zone_(?<zone_id>.*)\.(?<extension>png|jpg)/i }
end

named matches are available under matches[:sector_id] or directly when you calling sector_id

An implementation possible of Import

class BasicImportDirModel < BasicDirModel
  include DirModel::Import

  protected

  def model
    Project.find(context[:project_id]).sectors.find(sector_id).zones.find(zone_id)
  end
end

You can have access at the file through

BasicImportDirModel.new(source_path, project_id: 42).image

Relation

Has One

A dir_model can have a relation like has_one basically is

class ChildImportDirModel
  include DirModel::Model
  include DirModel::Import
  file :metadata, regex: ->(foreign_value) { "Zones\/(?<sector_name>#{foreign_value})\/Zone_(?<zone_id>.*)\.(?<extension>json)" }
end

class ParentImportDirModel < BasicImportDirModel
  has_one :dependency, ChildImportDirModel, foreign_key: :sector_name

  def sector_name
    "sector_#{sector_id}"
  end
end

parent_instance.dependency # => ChildImportDirModel
child.parent # => parent_instance

Has Many

You can define an has_many relation with another DirModel, is this case syntax is a bit different you have to pass a foreign_key, basically the name of the method should return a value will be replace in the regex in children relationships, like examples below

NOTE regex on child pass explicitly the value

class ZoneDirModel
  include DirModel::Model
  include DirModel::Import
  file :image, regex: ->(foreign_value) { "Zones\/(?<sector_name>#{foreign_value})\/Zone_(?<zone_id>.*)\.(?<extension>png|jpg)" }
end

class SectorDirModel
  include DirModel::Model
  file :image, regex: -> { /Sectors\/Sector_(?<sector_id>.*)\.(?<extension>png|jpg)/i }
end

class SectorImportDirModel < SectorDirModel
  include DirModel::Import

  has_many :dependencies, ZoneDirModel, foreign_key: :sector_name

  def sector_name
    'sector_1'
  end
end

Import Callbacks

DirModel::Import::Dir can be subclassed to access ActiveModel::Callbacks.

next - before, around, or after each change in current_dir_model

and implement the callbacks:

class ImportDir < DirModel::Import::Dir
  before_next :track_progress

  def track_progress
    ...
  end
end

Export

class BasicDirModel
  include DirModel::Model

  file :image, path: -> { "#{dir}/#{sub_dir}" }, name: -> { image_name }
end

path and name can take Proc or String if doesn't have any interpolation.

If you don't know the extension of your image it will be automatically discover, but this works only for image so if you send, for instance, a json file you have to explicitly provide extension on the :name options

class BasicExportDirModel < BasicDirModel
  include DirModel::Export

  def dir
    'Sectors'
  end

  def sub_dir
    source_model.sector_name
  end

  def image_name
    source_model.zone_name
  end

  def image
    source_model.zone
  end

  def image_extension
    '.png'
  end
end

fixture_models = [
  OpenStruct.new({
    id: 42,
    sector_name: 'sector_name',
    zone_name: 'zone_name',
    zone: File.new('spec/fixtures/image.png'),
  })
]

exporter = DirModel::Export::AggregateDir.new

exporter.generate do |dir|
  models.each do |model|
    dir.append_model(BasicExportDirModel, model)
  end
end

exporter.dir_path # => path of generated dir .../Sectors

an skip? method based on the name of file :image is create, this method is named image_skip?

default implementation

def skip?
  image.present?
end

NOTE Safe to override on your Exporter

In fact this is equivalent to

def skip?
  source_model.zone.present?
end

by default Exporter provide a link between source_model and your file like

def image
  source_model.image
end