Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
rawStream.pipe(JSONStream.parse()).pipe(streamOfObjects)
JavaScript

Fetching latest commit…

Cannot retrieve the latest commit at this time

Failed to load latest commit information.
examples
test
.gitignore
.npmignore
.travis.yml
LICENSE.APACHE2
LICENSE.MIT
index.js
package.json
readme.markdown

readme.markdown

JSONStream

streaming JSON.parse and stringify

example

var request = require('request')
  , JSONStream = require('JSONStream')
  , es = require('event-stream')

var parser = JSONStream.parse(['rows', true])
  , req = request({url: 'http://isaacs.couchone.com/registry/_all_docs'})
  , logger = es.mapSync(function (data) {
      console.error(data)
      return data
    })

in node 0.4.x

req.pipe(parser)
parser.pipe(logger)

in node v0.5.x

req.pipe(parser).pipe(logger)

JSONStream.parse(path)

usally, a json API will return a list of objects.

path should be an array of property names, RegExps, booleans, and/or functions. any object that matches the path will be emitted as 'data' (and piped down stream)

if path is empty or null, or if no matches are made:
JSONStream.parse will only one 'data': the root object.

(this is useful when there is an error, because the error will probably not match your path)

example

query a couchdb view:

curl -sS localhost:5984/tests/_all_docs&include_docs=true

you will get something like this:

{"total_rows":129,"offset":0,"rows":[
  { "id":"change1_0.6995461115147918"
  , "key":"change1_0.6995461115147918"
  , "value":{"rev":"1-e240bae28c7bb3667f02760f6398d508"}
  , "doc":{
      "_id":  "change1_0.6995461115147918"
    , "_rev": "1-e240bae28c7bb3667f02760f6398d508","hello":1}
  },
  { "id":"change2_0.6995461115147918"
  , "key":"change2_0.6995461115147918"
  , "value":{"rev":"1-13677d36b98c0c075145bb8975105153"}
  , "doc":{
      "_id":"change2_0.6995461115147918"
    , "_rev":"1-13677d36b98c0c075145bb8975105153"
    , "hello":2
    }
  },
]}

we are probably most interested in the rows.*.docs

create a Stream that parses the documents from the feed like this:

JSONStream.parse(['rows', true, 'doc']) //rows, ANYTHING, doc

awesome!

JSONStream.stringify(open, sep, close)

Create a writable stream.

you may pass in custom open, close, and seperator strings.
But, by default, JSONStream.stringify() will create an array,
(with default options open='[\n', sep='\n,\n', close='\n]\n')

If you call JSONStream.stringify(false)
the elements will only be seperated by a newline.

If you only write one item this will be valid JSON.

If you write many items,
you can use a RegExp to split it into valid chunks.

JSONStream.stringifyObject(open, sep, close)

Very much like JSONStream.stringify, but creates a writable stream for objects instead of arrays.

Accordingly, open='{\n', sep='\n,\n', close='\n}\n'.

When you .write() to the stream you must supply an array with [ key, data ] as the first argument.

numbers

There are occasional problems parsing and unparsing very precise numbers.

I have opened an issue here:

https://github.com/creationix/jsonparse/issues/2

+1

Acknowlegements

this module depends on https://github.com/creationix/jsonparse
by Tim Caswell
and also thanks to Florent Jaby for teaching me about parsing with: https://github.com/Floby/node-json-streams

license

MIT / APACHE2

Something went wrong with that request. Please try again.