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.

Installing

$ gem install jamespath

Or with Bundler:

gem 'jamespath', '~> 1.0'

Usage

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'

Expression Syntax

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

License & Acknowledgements

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.