needle-retry-x

Needle-Retry

The leanest and most handsome HTTP client in the Nodelands.

var needle = require('needle');

needle.get('http://www.google.com', function(error, response) {
  if (!error && response.statusCode == 200)
    console.log(response.body);
});

Callbacks not floating your boat? Needle got your back.

var data = {
  file: '/home/johnlennon/walrus.png',
  content_type: 'image/png'
};

needle
  .post('https://my.server.com/foo', data, { multipart: true })
  .on('readable', function() { /* eat your chunks */ })
  .on('end', function() {
    console.log('Ready-o, friend-o.');
  })

With only one single dependency, Needle supports:

• HTTP/HTTPS requests, with the usual verbs you would expect
• All of Node's native TLS options, such as 'rejectUnauthorized' (see below)
• Basic & Digest authentication
• Multipart form-data (e.g. file uploads)
• HTTP Proxy forwarding, optionally with authentication
• Streaming gzip or deflate decompression
• Automatic XML & JSON parsing
• 301/302/303 redirect following, with fine-grained tuning, and
• Streaming non-UTF-8 charset decoding, via iconv-lite

And yes, Mr. Wayne, it does come with the latest streams2 support.

This makes Needle an ideal alternative for performing quick HTTP requests in Node, either for API interaction, downloading or uploading streams of data, and so on. If you need OAuth, AWS support or anything fancier, you should check out mikeal's request module.

Install

$ npm install needle-retry

Usage

// using callback
needle.get('ifconfig.me/all.json', function(error, response) {
  if (!error)
    console.log(response.body.ip_addr); // JSON decoding magic. :)
});

// using streams
var out = fs.createWriteStream('logo.png');
needle.get('https://google.com/images/logo.png').pipe(out);

As you can see, you can call Needle with a callback or without it. When passed, the response body will be buffered and written to response.body, and the callback will be fired when all of the data has been collected and processed (e.g. decompressed, decoded and/or parsed).

When no callback is passed, the buffering logic will be skipped but the response stream will still go through Needle's processing pipeline, so you get all the benefits of post-processing while keeping the streamishness we all love from Node.

Response pipeline

Depending on the response's Content-Type, Needle will either attempt to parse JSON or XML streams, or, if a text response was received, will ensure that the final encoding you get is UTF-8. For XML decoding to work, though, you'll need to install the xml2js package as we don't enforce unneeded dependencies unless strictly needed.

You can also request a gzip/deflated response, which, if sent by the server, will be processed before parsing or decoding is performed.

needle.get('http://stackoverflow.com/feeds', { compressed: true }, function(err, resp) {
  console.log(resp.body); // this little guy won't be a Gzipped binary blob
                          // but a nice object containing all the latest entries
});

Or in anti-callback mode, using a few other options:

var options = {
  compressed         : true, // sets 'Accept-Encoding' to 'gzip,deflate'
  follow_max         : 5,    // follow up to five redirects
  rejectUnauthorized : true  // verify SSL certificate
}

var stream = needle.get('https://backend.server.com/everything.html', options);

stream.on('readable', function() {
  while (data = this.read()) {
    console.log(data.toString());
  }
})

API

All of Needle's request methods return a Readable stream, and both options and callback are optional. If passed, the callback will return three arguments: error, response and body, which is basically an alias for response.body.

needle.head(url, [options,] callback)

var options = {
  open_timeout: 5000 // if we don't get our response headers in 5 seconds, boom.
}

needle.head('https://my.backend.server.com', function(err, resp) {
  if (err)
    console.log('Shoot! Something is wrong: ' + err.message)
  else
    console.log('Yup, still alive.')
})

needle.get(url, [options,] callback)

needle.get('google.com/search?q=syd+barrett', function(err, resp) {
  // if no http:// is found, Needle will automagically prepend it.
});

needle.post(url, data, [options,] callback)

var options = {
  headers: { 'X-Custom-Header': 'Bumbaway atuna' }
}

needle.post('https://my.app.com/endpoint', 'foo=bar', options, function(err, resp) {
  // you can pass params as a string or as an object.
});

needle.put(url, data, [options,] callback)

var nested = {
  params: {
    are: {
      also: 'supported'
    }
  }
}

needle.put('https://api.app.com/v2', nested, function(err, resp) {
  console.log('Got ' + resp.bytes + ' bytes.') // another nice treat from this handsome fella.
});

needle.patch(url, data, [options,] callback)

Same behaviour as PUT.

needle.delete(url, data, [options,] callback)

var options = {
  username: 'fidelio',
  password: 'x'
}

needle.delete('https://api.app.com/messages/123', null, options, function(err, resp) {
  // in this case, data may be null, but you need to explicity pass it.
});

needle.request(method, url, data, [options,] callback)

Generic request. This not only allows for flexibility, but also lets you perform a GET request with data, in which case will be appended to the request as a query string.

var data = {
  q      : 'a very smart query',
  page   : 2,
  format : 'json'
}

needle.request('get', 'forum.com/search', data, function(err, resp) {
  if (!err && resp.statusCode == 200)
    console.log(resp.body); // here you go, mister.
});

More examples after this short break.

Request options

For information about options that've changed, there's always the changelog.

• open_timeout: (or timeout) Returns error if connection takes longer than X milisecs to establish. Defaults to 10000 (10 secs). 0 means no timeout.
• read_timeout: Returns error if data transfer takes longer than X milisecs, after connection is established. Defaults to 0 (no timeout).
• follow_max : (or follow) Number of redirects to follow. Defaults to 0. See below for more redirect options.
• multipart : Enables multipart/form-data encoding. Defaults to false. Use it when uploading files.
• proxy : Forwards request through HTTP(s) proxy. Eg. proxy: 'http://user:[e-mail]:3128'.
• agent : Uses an http.Agent of your choice, instead of the global, default one.
• headers : Object containing custom HTTP headers for request. Overrides defaults described below.
• auth : Determines what to do with provided username/password. Options are auto, digest or basic (default). auto will detect the type of authentication depending on the response headers.
• json : When true, sets content type to application/json and sends request body as JSON string, instead of a query string.

Response options

• decode_response : (or decode) Whether to decode the text responses to UTF-8, if Content-Type header shows a different charset. Defaults to true.
• parse_response : (or parse) Whether to parse XML or JSON response bodies automagically. Defaults to true. You can also set this to 'xml' or 'json' in which case Needle will only parse the response if the content type matches.
• output : Dump response output to file. This occurs after parsing and charset decoding is done.

Note: To stay light on dependencies, Needle doesn't include the xml2js module used for XML parsing. To enable it, simply do npm install xml2js.

HTTP Header options

These are basically shortcuts to the headers option described above.

• cookies : Sets a {key: 'val'} object as a 'Cookie' header.
• compressed: If true, sets 'Accept-Encoding' header to 'gzip,deflate', and inflates content if zipped. Defaults to false.
• username : For HTTP basic auth.
• password : For HTTP basic auth. Requires username to be passed, but is optional.
• accept : Sets 'Accept' HTTP header. Defaults to */*.
• connection: Sets 'Connection' HTTP header. Defaults to close.
• user_agent: Sets the 'User-Agent' HTTP header. Defaults to Needle/{version} (Node.js {node_version}).

Node.js TLS Options

These options are passed directly to https.request if present. Taken from the original documentation:

• pfx : Certificate, Private key and CA certificates to use for SSL.
• key : Private key to use for SSL.
• passphrase : A string of passphrase for the private key or pfx.
• cert : Public x509 certificate to use.
• ca : An authority certificate or array of authority certificates to check the remote host against.
• ciphers : A string describing the ciphers to use or exclude.
• rejectUnauthorized : If true, the server certificate is verified against the list of supplied CAs. An 'error' event is emitted if verification fails. Verification happens at the connection level, before the HTTP request is sent.
• secureProtocol : The SSL method to use, e.g. SSLv3_method to force SSL version 3.

Redirect options

These options only apply if the follow_max (or follow) option is higher than 0.

• follow_set_cookies : Sends the cookies received in the set-cookie header as part of the following request. false by default.
• follow_set_referer : Sets the 'Referer' header to the requested URI when following a redirect. false by default.
• follow_keep_method : If enabled, resends the request using the original verb instead of being rewritten to get with no data. false by default.
• follow_if_same_host : When true, Needle will only follow redirects that point to the same host as the original request. false by default.
• follow_if_same_protocol : When true, Needle will only follow redirects that point to the same protocol as the original request. false by default.

Overriding Defaults

Yes sir, we have it. Needle includes a defaults() method, that lets you override some of the defaults for all future requests. Like this:

needle.defaults({
  open_timeout: 60000,
  user_agent: 'MyApp/1.2.3',
  parse_response: false });

This will override Needle's default user agent and 10-second timeout, and disable response parsing, so you don't need to pass those options in every other request.

Examples Galore

HTTPS GET with Basic Auth

needle.get('https://api.server.com', { username: 'you', password: 'secret' },
  function(err, resp) {
    // used HTTP auth
});

Or use RFC-1738 basic auth URL syntax:

needle.get('https://username:[e-mail]', function(err, resp) {
    // used HTTP auth from URL
});

Digest Auth

needle.get('other.server.com', { username: 'you', password: 'secret', auth: 'digest' },
  function(err, resp, body) {
    // needle prepends 'http://' to your URL, if missing
});

Custom Accept header, deflate

var options = {
  compressed : true,
  follow     : 10,
  accept     : 'application/vnd.github.full+json'
}

needle.get('api.github.com/users/tomas', options, function(err, resp, body) {
  // body will contain a JSON.parse(d) object
  // if parsing fails, you'll simply get the original body
});

GET XML object

needle.get('https://news.ycombinator.com/rss', function(err, resp, body) {
  // if xml2js is installed, you'll get a nice object containing the nodes in the RSS
});

GET binary, output to file

needle.get('http://upload.server.com/tux.png', { output: '/tmp/tux.png' }, function(err, resp, body) {
  // you can dump any response to a file, not only binaries.
});

GET through proxy

needle.get('http://search.npmjs.org', { proxy: 'http://localhost:1234' }, function(err, resp, body) {
  // request passed through proxy
});

GET a very large document in a stream (from 0.7+)

var stream = needle.get('http://www.as35662.net/100.log');

stream.on('readable', function() {
  var chunk;
  while (chunk = this.read()) {
    console.log('got data: ', chunk);
  }
});

GET JSON object in a stream (from 0.7+)

var stream = needle.get('http://jsonplaceholder.typicode.com/db', { parse: true });

stream.on('readable', function() {
  var node;

  // our stream will only emit a single JSON root node.
  while (node = this.read()) {
    console.log('got data: ', node);
  }
});

GET JSONStream flexible parser with search query (from 0.7+)

 // The 'data' element of this stream will be the string representation
 // of the titles of all posts.

needle.get('http://jsonplaceholder.typicode.com/db', { parse: true })
      .pipe(new JSONStream.parse('posts.*.title'));
      .on('data', function (obj) {
        console.log('got post title: %s', obj);
      });

File upload using multipart, passing file path

var data = {
  foo: 'bar',
  image: { file: '/home/tomas/linux.png', content_type: 'image/png' }
}

needle.post('http://my.other.app.com', data, { multipart: true }, function(err, resp, body) {
  // needle will read the file and include it in the form-data as binary
});

Stream upload, PUT or POST

needle.put('https://api.app.com/v2', fs.createReadStream('myfile.txt'), function(err, resp, body) {
  // stream content is uploaded verbatim
});

Multipart POST, passing data buffer

var buffer = fs.readFileSync('/path/to/package.zip');

var data = {
  zip_file: {
    buffer       : buffer,
    filename     : 'mypackage.zip',
    content_type : 'application/octet-stream'
  }
}

needle.post('http://somewhere.com/over/the/rainbow', data, { multipart: true }, function(err, resp, body) {
  // if you see, when using buffers we need to pass the filename for the multipart body.
  // you can also pass a filename when using the file path method, in case you want to override
  // the default filename to be received on the other end.
});

Multipart with custom Content-Type

var data = {
  token: 'verysecret',
  payload: {
    value: JSON.stringify({ title: 'test', version: 1 }),
    content_type: 'application/json'
  }
}

needle.post('http://test.com/', data, { timeout: 5000, multipart: true }, function(err, resp, body) {
  // in this case, if the request takes more than 5 seconds
  // the callback will return a [Socket closed] error
});

For even more examples, check out the examples directory in the repo.

Testing

To run tests, you need to generate a self-signed SSL certificate in the test directory. After cloning the repository, run the following commands:

$ mkdir -p test/keys
$ openssl genrsa -out test/keys/ssl.key 2048
$ openssl req -new -key test/keys/ssl.key -x509 -days 999 -out test/keys/ssl.cert

Then you should be able to run npm test once you have the dependencies in place.

Credits

Written by Tomás Pollak, with the help of contributors.

Copyright

(c) Fork Ltd. Licensed under the MIT license.