browser-nano

Browser build of nano driver for CouchDB. Direct nano build with browserify lends 1MB+ file after minification, broser-nano offers 125KB version (77KB for light).

Installation

Available with npm and bower

npm install browser-nano

bower install browser-nano

Versioning

browser-nano's version corresponds to nano's version (in alpha for the moment)

Distribution (full vs light)

• dist/browser-nano.full.js
• dist/browser-nano.full.min.js
• dist/browser-nano.light.js
• dist/browser-nano.light.min.js

light doesn't support follow and followUpdates methods but offers 100KB of size decrease in return.

API

Refer to original documentation

Differences and Specificity

To include browser-nano to your web page add following tag:

<script src="browser-nano.light.min.js"></script>

that will populate global scope with nano variable

Cross-Origin Resource Sharing (CORS)

Unlike NodeJs nano version, we often deal with cross-domain, cross-port, cross-protocol requests in browser. To enable CORS:

var couch = nano({
	url: 'http://api.host.tld',
	cors: true
});

This will tell browser-nano to attach credential headers (CouchDB's AuthSession cookie) to each request.

Note. CORS and cookie authentication should be enabled in CouchDB config:

[couch_httpd_auth]
allow_persistent_cookies = true
require_valid_user = true

[httpd]
enable_cors = true

[cors]
credentials = true
origins = *

HTTP Basic Authorization

To perform requests with basic auth information:

var couch = nano('http://username:[email protected]'); or var couch = nano({url: 'http://username:[email protected]'});

Caveats

OPTIONS Preflight Request

CouchDB with enabled basic auth and session cookie has peculiarity to require valid user (basic auth headers) when accessing session endpoint which actually initiates new session for specified user name and password fields.

Once again, you required to provide basic auth headers to post auth information (form fields) to get a session cookie.

On the server-side situation could be handled with:

require('request').post('http://login:[email protected]/_session', {form: {
	name: login,
	password: password
}}, function (err, response) {
	// parse AuthSession cookie from response
});

But can't be handled from browser if session endpoint is CORS to your current location. Because of OPTIONS preflight request which doesn't pass any credentials for security reasons.

The Workaround

Is to proxy session endpoint request from a server-side using technique above and pass parsed cookie down to the browser. Just don't forget to toss in Access-Control-Allow-Credentials: true header along with Set-Cookie: AuthSession=.... for cookie you've got.

Self-Signed SSL Certificate Issue

When using CouchDB through HTTPS protocol with self-signed certificate need to manually accept it first. This could be done by accessing Couch's web admin-console on https-port manually. Otherwise, will get 'Invalid certificate error', 'NET::ERR_CERT_INVALID' or something similar, depends on browser.

How to enable SSL with CouchDB