pouchdb

PouchDB (Portable CouchDB JavaScript implementation)

The PouchDB Website is at: http://pouchdb.com/

PouchDB is a JavaScript library that allows you to store and query data for web applications that need to work offline, and sync with an online database when you are online.

The Browser Database that Syncs

Based on the work of Apache CouchDB, PouchDB provides a simple API in which to store and retrieve JSON objects, due to the similiar API, and CouchDB's HTTP API it is possible to sync data that is stored in your local PouchDB to an online CouchDB as well as syncing data from CouchDB down to PouchDB (you can even sync between 2 PouchDB databases).

Getting started

Download pouch.js and include in your HTML.

API Documentation

Most of the Pouch API is exposed as fun(arg, [options], [callback]) Where both the options and the callback are optional. Callbacks are in the node.js idiom of function(err, data) Where the first argument will be undefined unless there is an error, further arguments specify the result.

API Methods

• Create a database
• Delete a database
• Create a document
• Update a document
• Create a batch of documents
• Fetch a document
• Fetch documents
• Query the database
• Delete a document
• Get database information
• Listen to database changes
• Replicate a database

Create a database

Pouch('idb://dbname', [options], [callback])

This method gets an existing database if one exists or creates a new one if one does not exist. The protocol field denotes which backend you want to use (currently only http and indexeddb are supported)

Pouch('idb://test', function(err, db) {
  // Use db to call further functions
})

Delete a database

Pouch.destroy(name, [callback])

Delete database with given name

Pouch.destroy('idb://test', function(err, info) {
  // database deleted
})

Create a document

db.post(doc, [options], [callback])

Create a new document. Only use db.post if you want PouchDB to generate an ID for your document, otherwise use (db.put)[#update-a-document]

db.post({ title: 'Cony Island Baby' }, function(err, response) {
  // Response:
  // {
  //   "ok": true,
  //   "id": "0B3358C1-BA4B-4186-8795-9024203EB7DD",
  //   "rev": "1-5782E71F1E4BF698FA3793D9D5A96393"
  // }
})

Update a document

db.put(doc, [options], [callback])

Create a new document or update an existing document. If the document already exists you must specify its revision (_rev), otherwise a conflict will occur.

db.put({ _id: 'mydoc', title: 'Rock and Roll Heart' }, function(err, response) {
  // Response:
  // {
  //   "ok": true,
  //   "id": "mydoc",
  //   "rev": "1-A6157A5EA545C99B00FF904EEF05FD9F"
  // }
})

Save an attachment to a document

 db.putAttachment(id, rev, doc, type, [callback])

Create an attachment in an existing document.

db.put({ _id: 'otherdoc', title: 'Legendary Hearts' }, function(err, response) {
  var doc = 'Legendary hearts, tear us all apart\nMake our emotions bleed, crying out in need';
  db.putAttachment('otherdoc/text', response.rev, doc, 'text/plain', function(err, res) {
    // Response:
    // {
    //   "ok": true,
    //   "id": "otherdoc",
    //   "rev": "2-068E73F5B44FEC987B51354DFC772891"
    // }
  })
})

Create a batch of documents

db.bulkDocs(docs, [options], [callback])

Modify, create or delete multiple documents.

db.bulkDocs({ docs: [{ title: 'Lisa Says' }] }, function(err, response) {
  // Response array:
  // [
  //   {
  //     "ok": true,
  //     "id": "828124B9-3973-4AF3-9DFD-A94CE4544005",
  //     "rev": "1-A8BC08745E62E58830CA066D99E5F457"
  //   }
  // ]
})

Fetch a document

db.get(docid, [options], [callback])

Getrieves a document, specified by docid.

• options.revs: Include revision history of the document
• options.revs_info: Include a list of revisions of the document, and their availability

db.get('mydoc', function(err, doc) {
  // Document:
  // {
  //   "title": "Rock and Roll Heart",
  //   "_id": "mydoc",
  //   "_rev": "1-A6157A5EA545C99B00FF904EEF05FD9F"
  // }
})

Fetch documents

db.allDocs([options], [callback])

Fetch multiple documents.

• options.include_docs: Include the associated document with each change
• options.conflicts: Include conflicts
• options.startkey & options.endkey: Get documents with keys in a certain range
• options.descending: Reverse the order of the output table

db.allDocs(function(err, response) {
  // Document rows:
  // {
  //   "total_rows": 4,
  //   "rows": [
  //     {
  //       "id": "0B3358C1-BA4B-4186-8795-9024203EB7DD",
  //       "key": "0B3358C1-BA4B-4186-8795-9024203EB7DD",
  //       "value": {
  //         "rev": "1-5782E71F1E4BF698FA3793D9D5A96393"
  //       }
  //     },
  //     {
  //       "id": "828124B9-3973-4AF3-9DFD-A94CE4544005",
  //       "key": "828124B9-3973-4AF3-9DFD-A94CE4544005",
  //       "value": {
  //         "rev": "1-A8BC08745E62E58830CA066D99E5F457"
  //       }
  //     },
  //     {
  //       "id": "mydoc",
  //       "key": "mydoc",
  //       "value": {
  //         "rev": "1-A6157A5EA545C99B00FF904EEF05FD9F"
  //       }
  //     },
  //     {
  //       "id": "otherdoc",
  //       "key": "otherdoc",
  //       "value": {
  //         "rev": "1-3753476B70A49EA4D8C9039E7B04254C"
  //       }
  //     }
  //   ]
  // }
})

Query the database

db.query(fun, [options], [callback])

Retrieve a view.

• fun: Name of a view function or function
• options.reduce: To reduce or not. The default is to reduce if there is a reduce function

function map(doc) {
  if(doc.title) {
    emit(doc.title, null);
  }
}
db.query({map: map}, {reduce: false}, function(err, response) {
  // View rows:
  // {
  //   "rows": [
  //     {
  //       "id": "0B3358C1-BA4B-4186-8795-9024203EB7DD",
  //       "key": "Cony Island Baby",
  //       "value": null
  //     },
  //     {
  //       "id": "otherdoc",
  //       "key": "Legendary Hearts",
  //       "value": null
  //     },
  //     {
  //       "id": "828124B9-3973-4AF3-9DFD-A94CE4544005",
  //       "key": "Lisa Says",
  //       "value": null
  //     },
  //     {
  //       "id": "mydoc",
  //       "key": "Rock and Roll Heart",
  //       "value": null
  //     }
  //   ]
  // }
})

Delete a document

db.remove(doc, [options], [callback])

Delete a document.

db.get('mydoc', function(err, doc) {
  db.remove(doc, function(err, response) {
    // Response:
    // {
    //   "ok": true,
    //   "id": "mydoc",
    //   "rev": "2-9AF304BE281790604D1D8A4B0F4C9ADB"
    // }
  })
})

Get database information

db.info(callback)

Get information about a database.

db.info(function(err, info) {
  // Database information:
  // {
  //   "db_name": "test",
  //   "doc_count": 4,
  //   "update_seq": 0
  // }
})

Listen to database changes

db.changes(options)

A list of changes made to documents in the database, in the order they were made.

• options.include_docs: Include the associated document with each change
• options.continuous: Use longpoll feed
• options.conflicts: Include conflicts
• options.descending: Reverse the order of the output table
• options.filter: Reference a filter function from a design document to selectively get updates
• options.since: Start the results from the change immediately after the given sequence number

db.changes(function(err, response) {
  // Changes list:
  // {
  //   "results": [
  //     {
  //       "id": "0B3358C1-BA4B-4186-8795-9024203EB7DD",
  //       "seq": 1,
  //       "changes": [
  //         {
  //           "rev": "1-5782E71F1E4BF698FA3793D9D5A96393"
  //         }
  //       ]
  //     },
  //     {
  //       "id": "mydoc",
  //       "seq": 2,
  //       "changes": [
  //         {
  //           "rev": "1-A6157A5EA545C99B00FF904EEF05FD9F"
  //         }
  //       ]
  //     },
  //     {
  //       "id": "otherdoc",
  //       "seq": 3,
  //       "changes": [
  //         {
  //           "rev": "1-3753476B70A49EA4D8C9039E7B04254C"
  //         }
  //       ]
  //     },
  //     {
  //       "id": "828124B9-3973-4AF3-9DFD-A94CE4544005",
  //       "seq": 4,
  //       "changes": [
  //         {
  //           "rev": "1-A8BC08745E62E58830CA066D99E5F457"
  //         }
  //       ]
  //     }
  //   ]
  // }
})

Replicate a database

Pouch.replicate(from, to, [callback])

Pouch.replicate('idb://mydb', 'http://localhost:5984/mydb', function(err, changes) {
  //
})

Node.js

PouchDB has experimental support for node.js, with leveldb-backed storage and support for syncing with CouchDB. Get the latest version from git, or install via npm:

npm install pouchdb

Open issues on github for bugs you find in your experimenting.

The node-leveldb adapter exposes the same API as documented above, so you can use it just like you would in a browser. Instead of idb:// use ldb:// or http:// in the protocol field of the url.

var Pouch = require('pouchdb')

# leveldb-backed pouch
Pouch("ldb://my-db", function(err, db) {
  // use db.put, db.get, db.replicate, etc.
});

# couchdb-backed pouch
Pouch("http://localhost:5984", function(err, db) {
  // use db.put, db.get, db.replicate, etc.
})

To run the tests under node, install node-qunit and run the proxy server and a local CouchDB in admin-party mode, as described below.

npm install qunit
node_modules/.bin/qunit \
    -d ./src/pouch.js \
    -c ./src/adapters/pouch.leveldb.js \
    -t ./tests/test.basics.js # space-delimited list of tests to run

Running the tests

To run the full test suite (including replication) you'll need to run a CORS proxy pointing to a CouchDB. The CORS-Proxy is now bundled with this repo. To start it do the following:

cd CORS-Proxy
node server.js

by default this server expects you to be running a local CouchDB instance in admin party mode on http://127.0.0.1:5984, it will proxy requests to CouchDB and provide CORS support (see: https://github.com/daleharvey/pouchdb/issues/25)

The tests themselves also need to be served from a running server and not from the filesystem, the simplest way to do this is:

$ cd $POUCH
$ python -m SimpleHTTPServer

You should now be able to visit http://127.0.0.1:8000/tests/test.html to run the test suite.