ExJsonPath is an Elixir library which allows to query maps (JSON objects) and lists (JSON arrays), using JSONPath expressions.
ExJsonPath is not limited to JSON, but allows to query nearly any kind of map or list, with just one main restriction: keys have to be strings.
- Add
ExJsonPath
dependency to your project'smix.exs
:
def deps do
[
{:exjsonpath, "~> 0.1"}
]
end
- Run
mix deps.get
iex(1)> ExJSONPath.eval([%{"v" => 1}, %{"v" => 2}, %{"v" => 3}], "$[?(@.v > 1)].v")
{:ok, [2, 3]}
iex(1)> {:ok, json} = File.read("store.json")
iex(2)> {:ok, store} = Jason.decode(json)
iex(3)> ExJSONPath.eval(store, "$.store.book[?(@.price > 20)].title")
{:ok, ["The Lord of the Rings"]}
Full documentation can be found at hexdocs.pm/exjsonpath.
Expressions with no leading selector ($
or @
) default to current item, however they are a
common extension to JSONPath that should be avoided for compatibility reasons.
This project has been created in order to provide support to JSONPath to Astarte Flow. We are open to any contribution and we encourage adoption of this library to anyone looking for a maps and lists query language.