rawStream.pipe(JSONStream.parse()).pipe(streamOfObjects)
JavaScript
Switch branches/tags
Nothing to show
Clone or download
Pull request Compare This branch is 208 commits behind dominictarr:master.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Failed to load latest commit information.
examples
test
.gitignore
index.js
package.json
readme.markdown

readme.markdown

JSONStream

streaming JSON.parse and stringify

example

in node v0.4.x

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

var parser = JSONStream.parse(['rows', /./]) //emit parts that match this path (any element of the rows array)
  , req = request({url: 'http://isaacs.couchone.com/registry/_all_docs'})

in node 0.4.x

req.pipe(parser)
parser.pipe(es.log(''))

in node v0.5.x

req.pipe(parser).pipe(es.log(''))

JSONStream.parse(path)

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

path should be an array of property names and/or RedExps. any object that matches the path will be emitted as 'data' (and pipe()d down stream)

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

for example, couchdb returns views like this:

curl -sS localhost:5984/tests/_all_docs

returns 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 interested in the rows.*.docs

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

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

awesome!

todo

  • JSONStream.stringify()

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