csv_record

CsvRecord

CSV Record connects Ruby classes to CSV documents in order to establish an almost zero-configuration persistence layer for applications.

Getting Started

Add this line to your application's Gemfile:

gem 'csv_record'

And then execute:

$ bundle

Or install it yourself as:

$ gem install csv_record

And inside your Ruby models just require and include the CSVRecord lib and start using it in the same way as your are used to:

require 'csv_record'

class Jedi
  include CsvRecord::Document

  attr_accessor :name, :age, :midi_chlorians
end

Persistence

To persist the data objects created in your application you can use the following methods:

Jedi.create( # save the new record in its CSV file
  name: 'Luke Skywalker',
  age: 18,
  midi_chlorians: '12k'
)

jedi.save # save the record in its CSV file (either creating or changing)

jedi.update_attribute :age, 29 # update a single field of an object
jedi.update_attributes age: 29, midi_chlorians: '18k' # update multiple fields at the same time

jedi.destroy # removes the record from its CSV file

jedi.new_record? # checks if the record is new

Querying

Records can be queried through the following methods:

Jedi.all # retrieves all saved records

Jedi.find jedi.id # find through its id
Jedi.find jedi # find through the record

Jedi.find_by_age 18 # find dynamically with a property
Jedi.find_by_name_and_age 'Luke Skywalker', 18 # find dynamically with multiple properties

Jedi.where age: 18, name: 'Luke Skywalker', midi_chlorians: '12k' # find with a multiple parameters hash

Jedi.count # returns the amount of records in its CSV file

Jedi.first # retrieves the first record in its CSV file
Jedi.last # retrieves the last record in its CSV file

Lazy querying is the default behavior now Yey!!

query = Jedi.where(age: 37).where(midi_chlorians: '4k')
query # #<CsvRecord::Query:0x007fdff3d31aa0>

query.first # #<Jedi:0x007f9df6cea478>

Associations

Belongs To

A Belongs To association can be declared through the following method:

class JediOrder
  include CsvRecord::Document

  attr_accessor :rank
end

class Jedi
  include CsvRecord::Document

  belongs_to :jedi_order

  attr_accessor :name
end

jedi_order = JediOrder.create rank: 'council'

jedi = Jedi.new name: 'Lukas Alexandre'

jedi.jedi_order = jedi_order
# or
jedi.jedi_order_id = jedi_order.id

jedi.save

jedi.jedi_order # #<JediOrder:0x007f9b249b24d8>

Has Many

Extending the previous example, you can use the has_many method to establish the inverse relationship:

class JediOrder
  include CsvRecord::Document

  attr_accessor :rank

  has_many :jedis
end

jedi_order = JediOrder.create rank: 'council'

jedi.jedi_order = jedi_order
jedi.save

jedi_order.jedis # [#<Jedi:0x007f9b249b24d8>]

Has One

The same as has_many but limited to one associated record.

class jedi
  include CsvRecord::Document

  attr_accessor :name

  has_one :padawan
end

class Padawan
  include CsvRecord::Document

  attr_accessor :name

  belongs_to :jedi
end

padawan = Padawan.create name: 'Lukas Alexandre'

jedi.padawan = padawan

jedi.padawan # #<Padawan:0x007f9b249b24d8>

Callbacks

Overview

Callbacks can be used to execute code on predetermined moments.

Usage

after_create do
  # learn the way of the force
end

self refers to the instance you are in

Available Callbacks

Here is a list with all the available callbacks, listed in the same order in which they will get called during the respective operations:

Finding an Object

• after_initialize
• after_find

Creating an Object

• after_initialize
• before_validation
• after_validation
• before_save
• before_create
• after_create
• after_save

Updating an Object

• before_validation
• after_validation
• before_save
• before_update
• after_update
• after_save

Destroying an Object

• before_destroy
• after_destroy

Validations

Helpers available:

validates_presence_of: Ensures if the specified attribute(s) were filled

validates_uniqueness_of: Ensures that the specified attribute(s) are unique within its CSV file

validate: Uses custom method(s) to validate the model

class Jedi
  include CsvRecord::Document

  attr_accessor :name

  validates_presence_of :name
  validates_uniqueness_of :name

  validate :my_custom_validator_method

  validate do
    self.errors.add :attribute if self.using_dark_force?
  end

  def my_custom_validator_method
    self.errors.add :attribute if self.attacking_instead_of_defending?
  end
end

jedi = Jedi.new

jedi.valid? # => false
jedi.invalid? # => true
jedi.save # => false

Customizations

Someday you might want to go "out of the rail" that we propose. Here is what you can do now:

Changing the table_name

store_as :wierd_table_name

Changing the field column name

mapping :name => :wierd_field

Bug reports

If you discover a problem with CSV_Record, we would like to know about it. Please let us know on the project issues page.

Contributing

We hope that you will consider contributing to CSV_Record. Please read this short overview for some information about how to get started:

https://github.com/lukelex/csv_record/wiki/Contributing

You will usually want to write tests for your changes. To run the test suite, go into CSV_Record's top-level directory and run "bundle install" and "rake". For the tests to pass.

Precautions

CsvRecord creates a db folder in the root of your application. Be sure that it has permission to do so.