JS-YAML - YAML 1.1 parser for JavaScript

Online Demo

This is a native port of PyYAML, the most advanced YAML parser. Now you can use all modern YAML feature right in JavaScript. Originally snapshoted version - PyYAML 3.10 (2011-05-30).

npm install js-yaml

If you want to inspect your YAML files from CLI, install js-yaml.bin.

<script src="js-yaml.min.js"></script>
<script type="text/javascript">
var doc = jsyaml.load('greeting: hello\nname: world');
</script>

Browser support is still buggy, and mostly done to run online demo. If you can help to improve browser compatibility and AMD support - rise pull request.

JS-YAML automatically registers handlers for .yml and .yaml files. You can load them just with require. That's mostly equivalent to calling loadAll() on file handler ang gathering all documents into array. Just with one string!

require('js-yaml');

// Get array of documents, or throw exception on error
var docs = require('/home/ixti/examples.yml');

console.log(docs);

If you are sure, that file has only one document, chained shift() will help to exclude array wrapper:

require('js-yaml');

// Get array of documents, or throw exception on error
var singleDoc = require('/home/ixti/examples.yml').shift();

console.log(singleDoc);

Parses source as single YAML document. Returns JS object or throws exception on error.

This function does NOT understands multi-doc sources, it throws exception on those.

var yaml = require('js-yaml');

// pass the string
fs.readFile('/home/ixti/example.yml', 'utf8', function (err, data) {
  if (err) {
    // handle error
    return;
  }
  try {
    console.log( yaml.load(data) );
  } catch(e) {
    console.log(e);
  }
});

Same as Load, but understands multi-doc sources and apply iterator to each document.

var yaml = require('js-yaml');

// pass the string
fs.readFile('/home/ixti/example.yml', 'utf8', function (err, data) {
  if (err) {
    // handle error
    return;
  }

  try {
    yaml.loadAll(data, function (doc) {
      console.log(doc);
    });
  } catch(e) {
    console.log(e);
  }
});

Same as load() but uses safe schema - only recommended tags of YAML specification (no JavaScript-specific tags, e.g. !!js/regexp).

Same as loadAll() but uses safe schema - only recommended tags of YAML specification (no JavaScript-specific tags, e.g. !!js/regexp).

The list of standard YAML tags and corresponding JavaScipt types. See also YAML Tag Discussion and Yaml Types.

!!null ''                   # null
!!bool 'yes'                # bool
!!int '3...'                # number
!!float '3.14...'           # number
!!binary '...base64...'     # buffer
!!timestamp 'YYYY-...'      # date
!!omap [ ... ]              # array of key-value pairs
!!pairs [ ... ]             # array or array pairs
!!set { ... }               # array of objects with given keys and null values
!!str '...'                 # string
!!seq [ ... ]               # array
!!map { ... }               # object

JavaScript-specific tags

!!js/regexp /pattern/gim            # RegExp
!!js/undefined ''                   # Undefined
!!js/function 'function () {...}'   # Function

Note, that you use arrays or objects as key in JS-YAML. JS do not allows objects or array as keys, and stringifies them at the moment of adding them.

---
? [ foo, bar ]
: - baz
? { foo: bar }
: - baz
  - baz

=>

{ "": ["baz"], "[object Object]": ["baz", "baz"] }

View the LICENSE file (MIT).