class Planter::Seeder
Class that seeders should inherit from. Seeders should be in db/seeds
, and named TABLE_seeder.rb
, where TABLE
is the name of the table being seeded (I.E. users_seeder.rb
). If your seeder is named differently than the table, you'll need to specify the table with the model
option. The seeder's class name should be the same as the file name, but camelized. So, UsersSeeder
. The directory where the seeder files are located can be changed via an initializer.
The most basic way to seed is to have a CSV file with the same name as the table in db/seed_files/
. So, users.csv
. This CSV should have the table's column names as header. To seed using this method, your class should look like the following. Note that :csv_name
and :model
are only required if your seeder or csv are named differently than the table being seeded. The directory where the seed files are kept can be changed via an initializer.
# db/seeds/users_seeder.rb require 'planter' class UsersSeeder < Planter::Seeder seeding_method :csv, csv_name: :users, model: 'User' end
Another way to seed is to create records from a data array. To do this, your class must implement a data
attribute or method, which is an array of hashes. Note that this class already provides the attr_reader
for this attribute, so the most you have to do is create instance variables in your constructor. If if you want your data to be different for each new record (via Faker, +Array#sample+, etc.), you'll probably want to supply a method called data that returns an array of new data each time.
require 'planter' class UsersSeeder < Planter::Seeder seeding_method :data_array def data [{foo: 'bar', baz: 'bar'}] end end
In both of the above methods, you can specify a parent
association, which is the belongs_to
association name in your model, which, when specified, records will be created for each record in the parent table. For example, if we're seeding the users table, and the model is User
, which belongs to Person
, then doing the following will create a user record for each record in the Person table. Note that nothing is automatically done to prevent any validation errors; you must do this on your own, mostly likely using Faker
or a similar library.
require 'planter' class UsersSeeder < Planter::Seeder seeding_method :data_array, parent: :person def data [{foo: 'bar', baz: 'bar'}] end end
You can also set number_of_records
to determine how many times each record in the data
array will get created. The default is 1. Note that if this attribute is set alongside parent
, number_of_records
will be how many records will be created for each record in the parent table.
require 'planter' class UsersSeeder < Planter::Seeder seeding_method :data_array, number_of_records: 5 def data [{foo: 'bar', baz: 'bar'}] end end
By default, all fields are used to look up the record. If it already exists, it is not re-created. If you have specific fields that a record should be looked-up by, you can pass the unique_columns
option. This will attempt to look up the record by those fields only, and if one doesn't exist, one will be created with the rest of the attributes. An example of when this would be useful is with Devise; you can't pass password
in the create method, so specifying unique_columns
on everything except password
allows it to be passed as an attribute to the first_or_create
call.
require 'planter' class UsersSeeder < Planter::Seeder seeding_method :data_array, unique_columns: %i[username email] def data [{username: 'foo', email: 'bar', password: 'Example'}] end end
If you need to seed a different way, put your own custom seed
method in your seeder class and do whatever needs to be done.
Constants
- SEEDING_METHODS
The allowed seeding methods.
@return [Array]
Attributes
Array of hashes used to create records. Your class must set this attribute when using data_array
seeding method, although it's probably more likely that you'll want to define a method that returns a new set of data each time (via Faker
, +Array#sample+, etc.). When using csv
, data
will be set to the data within the csv. You can override this.
@return [Array]
A hash of user-defined column names and procs to be run on values. This is most useful for when seeding from csv, and you need to transform, say, 'true' (String) into true (Boolean). The user may define this as an instance variable, or define a method that returns the hash.
When defining a Proc/Lambda, you can make it accept 0, 1, or 2 arguments.
-
When 0, the value is replaced by the result of the Lambda.
-
When 1, the value is passed to the Lambda, and is subsequently replaced by the result of the Lambda.
-
When 2, the value is the first argument, and the entire row, as a Hash, is the second argument. This allows for more complicated transformations that can be dependent on other fields and values in the record.
@return [Hash, nil]
@example
class UsersSeeder < Planter::Seeder seeding_method :csv def transformations { admin: ->(v) { v == 'true' }, last_name: ->(value, row) { "#{value} #{row[:suffix]}".squish } } end end
Public Class Methods
If your class is going to use the inherited seed
method, you must tell it which seeding_method
to use. The argument to this method must be included in the SEEDING_METHODS
array.
@param [Symbol] seed_method
@kwarg [Integer] number_of_records
@kwarg [String] model
@kwarg [Symbol, String] parent
@kwarg [Symbol, String] csv_name
@kwarg [Symbol, String] unique_columns
@kwarg [String] erb_trim_mode
@example
require 'planter' class UsersSeeder < Planter::Seeder seeding_method :csv, number_of_records: 2, model: 'User' parent: :person, csv_name: :awesome_users, unique_columns %i[username email], erb_trim_mode: '<>' end
# File lib/planter/seeder.rb, line 212 def self.seeding_method( seed_method, number_of_records: 1, model: nil, parent: nil, csv_name: nil, unique_columns: nil, erb_trim_mode: nil ) unless SEEDING_METHODS.include?(seed_method.intern) raise ArgumentError, "Method must be: #{SEEDING_METHODS.join(', ')}" end self.seed_method = seed_method self.number_of_records = number_of_records self.model = model || to_s.delete_suffix('Seeder').singularize self.parent = parent self.csv_name = csv_name || to_s.delete_suffix('Seeder').underscore self.erb_trim_mode = erb_trim_mode || Planter.config.erb_trim_mode self.unique_columns = case unique_columns when String, Symbol then [unique_columns.intern] when Array then unique_columns.map(&:intern) end end
Public Instance Methods
The csv file corresponding to the model.
@return [String]
# File lib/planter/seeder.rb, line 174 class_attribute :csv_name
What trim mode should ERB use?
@return [String]
# File lib/planter/seeder.rb, line 138 class_attribute :erb_trim_mode
The model for the table being seeded. If the model name you need is different, change via seeding_method
.
@return [String]
# File lib/planter/seeder.rb, line 152 class_attribute :model
The number of records to create from each record in the data
array. If nil, defaults to 1, but you can override this in your class via seeding_method
.
@return [Integer]
# File lib/planter/seeder.rb, line 168 class_attribute :number_of_records
The model of the parent. When provided with association
, records in the data
array, will be created for each record in the parent table. Your class must set this attribute via seeding_method
.
@return [String]
# File lib/planter/seeder.rb, line 160 class_attribute :parent
The default seed method. To use this method, your class must provide a valid seeding_method
, and not implement its own seed
method.
# File lib/planter/seeder.rb, line 241 def seed validate_attributes extract_data_from_csv if seed_method == :csv parent ? create_records_from_parent : create_records end
The seeding method specified.
@return [Symbol]
# File lib/planter/seeder.rb, line 180 class_attribute :seed_method
When creating a record, the fields that will be used to look up the record. If it already exists, a new one will not be created.
@return [Array]
# File lib/planter/seeder.rb, line 145 class_attribute :unique_columns