minimalistic couchdb driver for node.js
nano
features:
nano
.npm install nano
to use nano
you need to connect it to your couchdb install, to do that:
var nano = require('nano')('http://localhost:5984');
to create a new database:
nano.db.create('alice');
and to use it:
var alice = nano.db.use('alice');
in this examples we didn't specify a callback
function, the absence of a callback means “do this, ignore what happens”. in nano
the callback function receives always three arguments:
err
- the error, if anybody
- the http response body from couchdb, if no error. json parsed body, binary for non json responsesheader
- the http response header from couchdb, if no errora simple but complete example using callbacks is:
var nano = require('nano')('http://localhost:5984'); // clean up the database we created previously nano.db.destroy('alice', function() { // create a new database nano.db.create('alice', function() { // specify the database we are going to use var alice = nano.use('alice'); // and insert a document in it alice.insert({ crazy: true }, 'rabbit', function(err, body, header) { if (err) { console.log('[alice.insert] ', err.message); return; } console.log('you have inserted the rabbit.') console.log(body); }); }); });
if you run this example(after starting couchdb) you will see:
you have inserted the rabbit. { ok: true, id: 'rabbit', rev: '1-6e4cb465d49c0368ac3946506d26335d' }
you can also see your document in futon.
configuring nano to use your database server is as simple as:
var nano = require('nano')('http://localhost:5984') , db = nano.use('foo') ;
however if you don't need to instrument database objects you can simply:
// nano parses the url and knows this is a database var db = require('nano')('http://localhost:5984/foo');
you can also pass options to the require:
// nano parses the url and knows this is a database var db = require('nano')('http://localhost:5984/foo');
to specify further configuration options you can pass an object literal instead:
// nano parses the url and knows this is a database var db = require('nano')( { "url" : "http://localhost:5984/foo" , "requestDefaults" : { "proxy" : "http://someproxy" } , "log" : function (id, args) { console.log(id, args); } });
Please check request for more information on the defaults. They support features like cookie jar, proxies, ssl, etc.
You can tell nano to not parse the url (maybe the server is behind a proxy, is accessed through a rewrite rule or other):
// nano does not parse the url and return the server api // "http://localhost:5984/prefix" is the CouchDB server root var couch = require('nano')( { "url" : "http://localhost:5984/prefix" "parseUrl" : false }); var db = couch.use('foo');
a very important configuration parameter if you have a high traffic website and are using nano is setting up the pool.size
. by default, the node.js http global agent (client) has a certain size of active connections that can run simultaneously, while others are kept in a queue. pooling can be disabled by setting the agent
property in requestDefaults
to false, or adjust the global pool size using:
http.globalAgent.maxSockets = 20;
you can also increase the size in your calling context using requestDefaults
if this is problematic. refer to the request documentation and examples for further clarification.
here's an example explicitly using the keep alive agent (installed using npm install agentkeepalive
), especially useful to limit your open sockets when doing high-volume access to couchdb on localhost:
var agentkeepalive = require('agentkeepalive'); var myagent = new agentkeepalive({ maxSockets: 50 , maxKeepAliveRequests: 0 , maxKeepAliveTime: 30000 }); var db = require('nano')( { "url" : "http://localhost:5984/foo" , "requestDefaults" : { "agent" : myagent } });
creates a couchdb database with the given name
.
nano.db.create('alice', function(err, body) { if (!err) { console.log('database alice created!'); } });
get informations about name
.
nano.db.get('alice', function(err, body) { if (!err) { console.log(body); } });
destroys name
.
nano.db.destroy('alice');
even though this examples looks sync it is an async function.
lists all the databases in couchdb
nano.db.list(function(err, body) { // body is an array body.forEach(function(db) { console.log(db); }); });
compacts name
, if designname
is specified also compacts its views.
replicates source
on target
with options opts
. target
has to exist, add create_target:true
to opts
to create it prior to replication.
nano.db.replicate('alice', 'http://admin:password@otherhost.com:5984/alice', { create_target:true }, function(err, body) { if (!err) console.log(body); });
asks for the changes feed of name
, params
contains additions to the query string.
nano.db.changes('alice', function(err, body) { if (!err) { console.log(body); } });
Uses Follow to create a solid changes feed. please consult follow documentation for more information as this is a very complete API on it's own.
var feed = db.follow({since: "now"}); feed.on('change', function (change) { console.log("change: ", change); }); feed.follow(); process.nextTick(function () { db.insert({"bar": "baz"}, "bar"); });
gets database information.
nano.db.info(function(err, body) { if (!err) { console.log(‘got database info’', body); } });
creates a scope where you operate inside name
.
var alice = nano.use('alice'); alice.insert({ crazy: true }, 'rabbit', function(err, body) { // do something });
alias for nano.use
alias for nano.use
alias for nano.use
makes a request to couchdb, the available opts
are:
opts.db
– the database nameopts.method
– the http method, defaults to get
opts.path
– the full path of the request, overrides opts.doc
and opts.att
opts.doc
– the document nameopts.att
– the attachment nameopts.qs
– query string parameters, appended after any existing opts.path
, opts.doc
, or opts.att
opts.content_type
– the content type of the request, default to json
opts.headers
– additional http headers, overrides existing onesopts.body
– the document or attachment bodyopts.encoding
– the encoding for attachmentsopts.multipart
– array of objects for multipart requestalias for nano.request
alias for nano.request
_ / '_) WAT U SAY! _.----._/ / / / _/ ( | ( | /__.-|_|--|_l
an object containing the nano configurations, possible keys are:
url
- the couchdb urldb
- the database namelisten to db updates, the available params
are:
params.feed
– Type of feed. Can be one oflongpoll
: Closes the connection after the first event.continuous
: Send a line of JSON per event. Keeps the socket open until timeout.eventsource
: Like, continuous, but sends the events in EventSource format.params.timeout
– Number of seconds until CouchDB closes the connection. Default is 60.params.heartbeat
– Whether CouchDB will send a newline character (\n) on timeout. Default is true.** changed in version 6 **
Use Follow to create a solid _db_updates
feed. Please consult follow documentation for more information as this is a very complete api on it's own
var feed = nano.followUpdates({since: "now"}); feed.on('change', function (change) { console.log("change: ", change); }); feed.follow(); process.nextTick(function () { nano.db.create('alice'); });
inserts doc
in the database with optional params
. if params is a string, its assumed as the intended document name. if params is an object, its passed as query string parameters and docName
is checked for defining the document name.
var alice = nano.use('alice'); alice.insert({ crazy: true }, 'rabbit', function(err, body) { if (!err) console.log(body); });
The insert
function can also be used with the method signature db.insert(doc,[callback])
, where the doc
contains the _id
field e.g.
var alice = nano.use('alice') alice.insert({ _id: 'myid', crazy: true }, function(err, body) { if (!err) console.log(body) })
and also used to update an existing document, by including the _rev
token in the document being saved:
var alice = nano.use('alice') alice.insert({ _id: 'myid', _rev: '1-23202479633c2b380f79507a776743d5', crazy: false }, function(err, body) { if (!err) console.log(body) })
removes revision rev
of docname
from couchdb.
alice.destroy('rabbit', '3-66c01cdf99e84c83a9b3fe65b88db8c0', function(err, body) { if (!err) console.log(body); });
gets docname
from the database with optional query string additions params
.
alice.get('rabbit', { revs_info: true }, function(err, body) { if (!err) console.log(body); });
same as get
but lightweight version that returns headers only.
alice.head('rabbit', function(err, _, headers) { if (!err) console.log(headers); });
copy
the contents (and attachments) of a document to a new document, or overwrite an existing target document
alice.copy('rabbit', 'rabbit2', { overwrite: true }, function(err, _, headers) { if (!err) console.log(headers); });
bulk operations(update/delete/insert) on the database, refer to the couchdb doc.
list all the docs in the database with optional query string additions params
. This is useful for searching.
alice.list({startkey:'cat', limit:3}, function(err, body) { if (!err) { body.rows.forEach(function(doc) { console.log(doc); }); } });
For a full list of params, see couchdb doc.
bulk fetch of the database documents, docnames
are specified as per couchdb doc. additional query string params
can be specified, include_docs
is always set to true
.
** changed in version 6 **
bulk fetch of the revisions of the database documents, docnames
are specified as per couchdb doc. additional query string params
can be specified, this is the same method as fetch but include_docs
is not automatically set to true
.
inserts a doc
together with attachments
and params
. if params is a string, its assumed as the intended document name. if params is an object, its passed as query string parameters and docName
is checked for defining the document name. refer to the doc for more details. attachments
must be an array of objects with name
, data
and content_type
properties.
var fs = require('fs'); fs.readFile('rabbit.png', function(err, data) { if (!err) { alice.multipart.insert({ foo: 'bar' }, [{name: 'rabbit.png', data: data, content_type: 'image/png'}], 'mydoc', function(err, body) { if (!err) console.log(body); }); } });
get docname
together with its attachments via multipart/related
request with optional query string additions params
. refer to the doc for more details. the multipart response body is a Buffer
.
alice.multipart.get('rabbit', function(err, buffer) { if (!err) console.log(buffer.toString()); });
inserts an attachment attname
to docname
, in most cases params.rev
is required. refer to the doc for more details.
var fs = require('fs'); fs.readFile('rabbit.png', function(err, data) { if (!err) { alice.attachment.insert('rabbit', 'rabbit.png', data, 'image/png', { rev: '12-150985a725ec88be471921a54ce91452' }, function(err, body) { if (!err) console.log(body); }); } });
or using pipe
:
var fs = require('fs'); fs.createReadStream('rabbit.png').pipe( alice.attachment.insert('new', 'rab.png', null, 'image/png') );
get docname
's attachment attname
with optional query string additions params
.
var fs = require('fs'); alice.attachment.get('rabbit', 'rabbit.png', function(err, body) { if (!err) { fs.writeFile('rabbit.png', body); } });
or using pipe
:
var fs = require('fs'); alice.attachment.get('rabbit', 'rabbit.png').pipe(fs.createWriteStream('rabbit.png'));
changed in version 6
destroy attachment attname
of docname
's revision rev
.
alice.attachment.destroy('rabbit', 'rabbit.png', {rev: '1-4701d73a08ce5c2f2983bf7c9ffd3320'}, function(err, body) { if (!err) console.log(body); });
calls a view of the specified design with optional query string additions params
. if you're looking to filter the view results by key(s) pass an array of keys, e.g { keys: ['key1', 'key2', 'key_n'] }
, as params
.
alice.view('characters', 'crazy_ones', function(err, body) { if (!err) { body.rows.forEach(function(doc) { console.log(doc.value); }); } });
calls a list function feeded by the given view of the specified design document.
alice.viewWithList('characters', 'crazy_ones', 'my_list', function(err, body) { if (!err) { console.log(body); } });
calls a show function of the specified design for the document specified by doc_id with optional query string additions params
.
alice.show('characters', 'format_doc', '3621898430', function(err, doc) { if (!err) { console.log(doc); } });
take a look at the couchdb wiki for possible query paramaters and more information on show functions.
calls the design's update function with the specified doc in input.
db.atomic("update", "inplace", "foobar", {field: "foo", value: "bar"}, function (error, response) { assert.equal(error, undefined, "failed to update"); assert.equal(response.foo, "bar", "update worked"); });
Note that the data is sent in the body of the request. An example update handler follows:
"updates": { "in-place" : "function(doc, req) { var field = req.body.field; var value = req.body.value; var message = 'set '+field+' to '+value; doc[field] = value; return [doc, message]; }"
calls a view of the specified design with optional query string additions params
.
alice.search('characters', 'crazy_ones', { q: 'cat' }, function(err, doc) { if (!err) { console.log(doc); } });
check out the tests for a fully functioning example.
nano supports making requests using couchdb‘s cookie authentication functionality. there’s a example in coffeescript, but essentially you just:
var nano = require('nano')('http://localhost:5984') , username = 'user' , userpass = 'pass' , callback = console.log // this would normally be some callback , cookies = {} // store cookies, normally redis or something ; nano.auth(username, userpass, function (err, body, headers) { if (err) { return callback(err); } if (headers && headers['set-cookie']) { cookies[user] = headers['set-cookie']; } callback(null, "it worked"); });
reusing a cookie:
var auth = "some stored cookie" , callback = console.log // this would normally be some callback , alice = require('nano')( { url : 'http://localhost:5984/alice', cookie: 'AuthSession=' + auth }); ; alice.insert(doc, function (err, body, headers) { if (err) { return callback(err); } // change the cookie if couchdb tells us to if (headers && headers['set-cookie']) { auth = headers['set-cookie']; } callback(null, "it worked"); });
getting current session:
var nano = require('nano')({url: 'http://localhost:5984', cookie: 'AuthSession=' + auth}); nano.session(function(err, session) { if (err) { return console.log('oh noes!') } console.log('user is %s and has these roles: %j', session.userCtx.name, session.userCtx.roles); });
nano is minimalistic but you can add your own features with nano.request(opts, callback)
for example, to create a function to retrieve a specific revision of the rabbit
document:
function getrabbitrev(rev, callback) { nano.request({ db: 'alice', doc: 'rabbit', method: 'get', params: { rev: rev } }, callback); } getrabbitrev('4-2e6cdc4c7e26b745c2881a24e0eeece2', function(err, body) { if (!err) { console.log(body); } });
you can pipe in nano like in any other stream. for example if our rabbit
document has an attachment with name picture.png
(with a picture of our white rabbit, of course!) you can pipe it to a writable stream
var fs = require('fs'), nano = require('nano')('http://127.0.0.1:5984/'); var alice = nano.use('alice'); alice.attachment.get('rabbit', 'picture.png').pipe(fs.createWriteStream('/tmp/rabbit.png'));
then open /tmp/rabbit.png
and you will see the rabbit picture.
check issues
to run (and configure) the test suite simply:
cd nano
npm install
npm test
after adding a new test you can run it individually (with verbose output) using:
nano_env=testing node tests/doc/list.js list_doc_params
where list_doc_params
is the test name.
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git clone git://github.com/dscape/nano.git
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licensed under the apache license, version 2.0 (the “license”); you may not use this file except in compliance with the license. you may obtain a copy of the license at
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