Sometimes data comes to you with a headlight out.
Maniuplate hashes from an external source so they work for your database setup. Especially useful when reading data from external api or csv. Instead of writing a messy conversion system, create easily testable Diddler objects to massage the data.
Add this line to your application's Gemfile:
gem 'padiddler'
First, get a sample piece of input that needs diddling. In this example, the first name and last name don't need extra processing but the date of birth should be renamed and turned into a Date object.
input = {
first_name: 'Jeremiah',
last_name: 'Hemphill',
tel_no: '555-1234',
dob_year: '2014',
dob_month: '1',
dob_day: '24'
}
Second, define your Diddler for the input
PersonDiddler < Padiddler::Base
# these instance variables should be made public with no changes
keep :first_name, :last_name
# these instance variable should be renamed in the output
# in this case, the input key 'tel_no' will be called 'phone' in the output.
rename :tel_no => :phone
# this additional output should be added
add :date_of_birth do
Date.parse("#{@dob_year}/#{@dob_month}/#{@dob_day}")
end
end
Third, diddle away
input = get_input_from_csv
input.each_row do |row|
pdiddler = PersonDiddler.new(row)
Person.create(pdiddler.diddle)
end