JSONPath

Analyse, transform, and selectively extract data from JSON documents (and JavaScript objects).

Install

npm install JSONPath

Usage

In node.js:

var JSONPath = require('JSONPath');
JSONPath({json: obj, path: path});

For browser usage you can directly include lib/jsonpath.js, no browserify magic necessary:

<script src="lib/jsonpath.js"></script>
<script>
    JSONPath({json: obj, path: path});
</script>

An alternative syntax is available as:

JSONPath(options, obj, path);

The following format is now deprecated:

jsonPath.eval(options, obj, path);

Other properties that can be supplied for options (the first argument) include:

• autostart (default: true) - If this is supplied as false, one may call the evaluate method manually as needed.
• flatten (default: false) - Whether the returned array of results will be flattened to a single dimension array.
• resultType (default: "value") - Can be case-insensitive form of "value" or "path" to determine whether to return results as the values of the found items or as their absolute paths.
• sandbox (**default: An empty object **) - Key-value map of variables to be available to code evaluations such as filtering expressions. (Note that the current path and value will also be available; see the Syntax section for details.)
• wrap (default: true) - Whether or not to wrap the results in an array. If wrap is set to false, and no results are found, false will be returned (as opposed to an empty array). If wrap is set to false and a single result is found, that result will be the only item returned. An array will still be returned if multiple results are found, however.

Syntax with examples

Given the following JSON, taken from http://goessner.net/articles/JsonPath/ :

{
  "store": {
    "book": [
      {
        "category": "reference",
        "author": "Nigel Rees",
        "title": "Sayings of the Century",
        "price": 8.95
      },
      {
        "category": "fiction",
        "author": "Evelyn Waugh",
        "title": "Sword of Honour",
        "price": 12.99
      },
      {
        "category": "fiction",
        "author": "Herman Melville",
        "title": "Moby Dick",
        "isbn": "0-553-21311-3",
        "price": 8.99
      },
      {
        "category": "fiction",
        "author": "J. R. R. Tolkien",
        "title": "The Lord of the Rings",
        "isbn": "0-395-19395-8",
        "price": 22.99
      }
    ],
    "bicycle": {
      "color": "red",
      "price": 19.95
    }
  }
}

XPath	JSONPath	Result	Notes
/store/book/author	$.store.book[*].author	the authors of all books in the store
//author	$..author	all authors
/store/*	$.store.*	all things in store, which are some books and a red bicycle.
/store//price	$.store..price	the price of everything in the store.
//book[3]	$..book[2]	the third book
//book[last()]	$..book[(@.length-1)] $..book[-1:]	the last book in order.
//book[position()<3]	$..book[0,1] $..book[:2]	the first two books
//book/*[self::category|self::author] or //book/(category,author) in XPath 2.0	$..book[category,author]	the categories and authors of all books
//book[isbn]	$..book[?(@.isbn)]	filter all books with isbn number
//book[price<10]	$..book[?(@.price<10)]	filter all books cheapier than 10
//*[price>19]/..	$..[?(@.price>19)]^	categories with things more expensive than 19	Parent (caret) not present in original spec
//*	$..*	all Elements in XML document. All members of JSON structure.
/store/book/[position()!=1]	$.store.book[?(@path !== "$['store']['book'][0]")]	All books besides that at the path pointing to the first	@path not present in original spec

Any additional variables supplied as properties on the optional "sandbox" object option are also available to (parenthetical-based) evaluations.

Development

Running the tests on node: npm test. For in-browser tests:

• Ensure that nodeunit is browser-compiled: cd node_modules/nodeunit; make browser;
• Serve the js/html files:

    node -e "require('http').createServer(function(req,res) { \
        var s = require('fs').createReadStream('.' + req.url); \
        s.pipe(res); s.on('error', function() {}); }).listen(8082);"

• To run the tests visit http://localhost:8082/test/test.html.

License

MIT License.