yajl

Binding for libyajl

npm install yajl
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YAJL (Yet Another JSON Library) binding for Node.js

YAJL is a low-level sax-like JSON parser developed and maintained by Lloyd Hilaiel.

Node-yajl provides a glue that brings YAJL into Node.js ecosystem. Main feature of this project is a stream JSON parser allowing you to parse data without explicitly delimitting data stream into valid-value chunks.

Node-yajl is forked from yajl-js originally developed by Nikhil Marathe and seems to be no longer maintained.

Synopsis

var yajl = require('yajl');

var h = new yajl.Handle();
h.on( 'error',      function (_) { console.debug(_)     });

h.on( 'startMap',   function ( ) { console.debug('{')   });
h.on( 'endMap',     function ( ) { console.debug('}')   });
h.on( 'startArray', function ( ) { console.debug('[')   });
h.on( 'endArray',   function ( ) { console.debug(']')   });
h.on( 'mapKey',     function (_) { console.debug(_+':') });
h.on( 'null',       function (_) { console.debug('null')});
h.on( 'boolean',    function (_) { console.debug(_)     });
h.on( 'string',     function (_) { console.debug(_)     });
h.on( 'integer',    function (_) { console.debug(_)     });
h.on( 'double',     function (_) { console.debug(_)     });

var data = [
    '{"some"',
    ':["JSON',
    '"],"data',
    '":[-3.5]}'
];

for ( var i in data ) {
    h.parse( data[i] );
}

h.completeParse();

Build & install

Easy mode:

npm install yajl

Build and install manually:

node-waf configure build
node ./test.js
npm install .

Note that this package requires C++ building environment and 'libyajl' at least of version 2 and its dev headers to be installed on target system.

See yajl homepage for details about building and installing 'libyajl'.

API

yajl.Handle(opts)

Handle object constructor. Class Handle itself is a subclass of events.EventEmitter.

Optional argument opts can be passed to constructor. When opts is ommited or null, these defaults are used:

{
    allowComments         : false,
    dontValidateStrings   : false,
    allowTrailingGarbage  : false,
    allowMultipleValues   : false,
    allowPartialValues    : false
}

handle.parse(string)

Parse a data chunk possibly raising number of events.

handle.parseComplete()

Parse any ramaining buffered data.

Because of yajl's stream nature it can't sometimes determine when the recently parsed data contains a valid JSON value or there need more data (e.g. when parsing numeric values). So it's a good idea to call this method every time you reach the end of data stream.

handle.getBytesConsumed()

Get the amount of data consumed from the last chunk passed to handle.

In the case of a successful parse this can help you understand if the entire buffer was consumed or not.

Events

  • 'startMap'
  • 'endMap'
  • 'startArray'
  • 'endArray'
  • 'mapKey'
  • 'null'
  • 'boolean'
  • 'integer'
  • 'double'
  • 'number'
  • 'string'

yajl.Tree(string)

Tree object constructor.

Parses string into an in-memory JSON-tree. Throws SyntaxError in case when string contains bad data.

Resulting object can be retrieved using get method.

tree.get()

Returns parsed JSON value.

License

Modified BSD Lincense. See 'LICENSE' file for details.

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