Smuggle

Is a gem to manage exports and imports with ease, separating the logic from the models, resulting in a much cleaner codebase. Easy to use, with familiar structure.

Smuggle is not dependent on Rails, you can use it on ActiveModel/ActiveRecord models, as well as plain ruby objects and hashes.

Links:

Requirements

Ruby 2.5.0

Installation

To install, run:

gem install smuggle

Or add the following to your Gemfile:

gem "smuggle"

Usage

Exporters

Given the following plain old ruby object:

class User
  attr_accessor :name

  def initialize(name)
    @name = name
  end
end

An exporter can be defined by inheriting from Smuggle::Exporter::Base and defining the attributes to export:

class UserExporter < Smuggle::Exporter::Base
  attributes :name
end

Extra logic can be establish inside the exporter file, using the same name as the attribute:

class UserExporter < Smuggle::Exporter::Base
  attributes :name

  def name
    super + " - exported"
  end
end

If there are no attributes defined in the exporter and you are using ActiveModel or ActiveRecord, all the attributes of the record will be included. If it is a hash, then all values will be included.

To generate the csv data simply call:

users = [User.new("Rick Sanchez"), User.new("Morty Smith")]
Smuggle::Services::Export.call(scope: users, exporter: UserExporter)
# => "Full name,Full name\nRick Sanchez,Rick Sanchez\nMorty Smith,Morty Smith\n"

Or if you are using ActiveRecord, the exporter class will be automatically resolved from the scope:

Smuggle::Services::Export.call(scope: User.all)

To add labels for your attributes (to show in the header instead of the raw attribute keys) you can add attribute_labels to your exporter:

class UserExporter < Smuggle::Exporter::Base
  attributes :name
  attribute_labels name: "Full name"
end

users = [User.new("Rick Sanchez"), User.new("Morty Smith")]

Smuggle::Services::Export.call(scope: users, exporter: UserExporter)
# => "Full name\nRick Sanchez\nMorty Smith\n"

Importers

Given the following plain old ruby object:

class User
  attr_accessor :name

  def initialize(name)
    @name = name
  end
end

An importer can be defined by inheriting from Smuggle::Importer::Base and defining the attributes to export:

class UserImporter < Smuggle::Importer::Base
  # If no attributes are defined, the importer will infer them from the model's .attribute_names
  # If any attributes are explicitly defined, all other entries in the CSV are ignored
  attributes :name

  # Computed attributes from the row data
  def name
    [row[:first_name], row[:last_name]].join(" ")
  end

  def persist
    # Create your instance here
    model.new(to_h)
    # The result is collected by the Import service

    # If you want to persist your data, you can do so here. This is an example using ActiveRecord
    # model.create(to_h)
  end
end

For example:

Given the following users.csv file:

"first_name","last_name"
"Rick","Sanchez"
"Morty","Smith"

Just run:

Smuggle::Services::Import.call(model: User, filepath: "users.csv")
# => [#<User name: "Rick Sanchez">, #<User name: "Morty Smith">]

The importer class will be resolved from the model name, otherwise you could explicitely set the importer like this:

Smuggle::Services::Import.call(model: User, filepath: "users.csv", importer: UserImporter)

Generators

If you are using rails you can use the following generators:

$ rails g smuggle:install
create app/exporters/application_exporter.rb
create app/importers/application_importer.rb

To generate an exporter, you can run the following command:

$ rails g smuggle:exporter user
create app/exporters/user_exporter.rb

You can also include the attributes you wish to export by running:

$ rails g smuggle:exporter user email username created_at
create app/exporters/user_exporter.rb

And to generate an importer, just run:

$ rails g smuggle:importer user email username full_name
create app/importers/user_importer.rb

Tests

To test, run:

bundle exec rspec spec/

Versioning

Read Semantic Versioning for details. Briefly, it means:

Major (X.y.z) - Incremented for any backwards incompatible public API changes.
Minor (x.Y.z) - Incremented for new, backwards compatible, public API enhancements/fixes.
Patch (x.y.Z) - Incremented for small, backwards compatible, bug fixes.