HappyMapper::Differ

In the unlikely scenario you use HappyMapper and you need to find differences between two documents, this could be a solution.

Ok, your probably won’t use or need this. But since I enjoy writing to myself here is how to use it.

Note: this library is wildly memory inefficient

````ruby def left %Q Car Box

end

def right %Q Car Red Box Cup

end

require ‘happymapper_differ’

class Person include HappyMapper

tag ‘person’ attribute :name, String has_many :items, “Item” end

class Item include HappyMapper has_one :name, String end

result = HappyMapper::Differ.new(Person.parse(left), Person.parse(right)).diff

result.changed? #=> true

result.changes #=> “items”=>[#<Item:0x007ffd2d8d5a68 @name=”Red Box”>, #<Item:0x007ffd2d8d5630 @name=”Cup”>]

result.name.changed? #=> true

result.name.was #=> “Carl”

result.items[0].changed? #=> false result.items[1].changes? #=> Box” result.items[2].changed? #=> true result.items[2] #=> nil result.items[2].was #=> #<Item:0x007fde2c045ee0 @name=”Cup”> ````

Extended methods

HappyMapper::Differ extends each HappyMapper instance and element with the following methods:

method	purpose
changed?	returns true if this element, or a child has changed
changes	returns a hash with each element or attribute which changed, and changed value
was	returns the prior object from the right. If there is no change this will be the current value.

Contributing

1. Fork it ( https://github.com/pharos-ie/happymapper-differ/fork )
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 a new Pull Request