README.md
# SimpleAttributeMapper
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Maps attributes values from one object to another
## Installation
Add this line to your application's Gemfile:
gem 'simple_attribute_mapper'
And then execute:
$ bundle
Or install it yourself as:
$ gem install simple_attribute_mapper
## Usage
```
class Person
include Virtus
attribute :first_name, String
attribute :last_name, String
attribute :email, String
attribute :home_phone, String
attribute :mailing_address, String
end
class User < ActiveRecord::Base
# first_name
# last_name
# user_name
# phone_number
# street
# city
# state
# zip
end
```
first_name and last_name will be automatically mapped
specify additional mappings, i.e. user_name -> email
```
user = User.find(0000)
user.user_name # => "test@example.com"
mapper = SimpleAttributeMapper::Mapper.new({:user_name => :email})
# map returns a new instance of Person
person = mapper.map(user, Person)
person.email # => "test@example.com"
# map_attributes will map onto an existing instance
person = Person.new({email: "foo@bar.com"})
person = mapper.map_attributes(user, person)
person.email # => "test@example.com"
```
Typically you won't create instances of SimpleAttributeMapper::Mapper in your code, instead you will configure all mappings and use `SimpleAttributeMapper.map`, see below
### Configuration
```
# in rails: config/initializers/simple_attribute_mapper_config.rb
SimpleAttributeMapper.configure do |config|
config << SimpleAttributeMapper.from(User).to(Person).with({:user_name => :email}).with({:phone_number => :home_phone})
end
# use later in application to map
user = User.find(0000)
person = SimpleAttributeMapper.map(user, Person)
```
### Mapping options
```
# default, maps all matching attributes
SimpleAttributeMapper.from(User).to(Person)
# map source to target
SimpleAttributeMapper.from(User).to(Person).with({:user_name => :email})
# map nested source to target
# use array; i.e. User#mailing_address -> Address#country -> Country#name
SimpleAttributeMapper.from(User).to(Person).with({[:mailing_address, :country, :name] => :country_name})
# map composite source to target
# use lambda
SimpleAttributeMapper.from(User).to(Person).with({ lambda { |source| "#{source.street}\n#{source.city}, #{source.state}\n#{source.zip}" } => :mailing_address})
```
## Contributing
1. Fork it
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create new Pull Request