Jamespath

Jamespath is a library that lets you select objects from deeply nested structures, arrays, hashes, or JSON objects using a simple expression language.

Think XPath, but for objects.

$ gem install jamespath

Or with Bundler:

gem 'jamespath', '~> 1.0'

To use Jamespath, call the {Jamespath.search} method with an expression and an object ot search:

object = { foo: { bar: ['value1', 'value2', 'value3'] } }
Jamespath.search('foo.bar[0]', object) #=> 'value1'

You can also {Jamespath.compile} an expression if you are performing the same search operation against multiple objects:

object1 = { foo: { bar: ['value1', 'value2', 'value3'] } }
object2 = { foo: { bar: ['value4', 'value5', 'value6'] } }

expr = Jamespath.compile('foo.bar[0]')
expr.search(object1) #=> 'value1'
expr.search(object2) #=> 'value4'

See the JMESpath project for more information on the expression syntax.

This library was written by Loren Segal and Trevor Rowe and is licensed under the MIT license. The implementation is based on the JMESpath library written by James Sayerwinnie for the Python programming language.