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Delta Pouch

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A PouchDB plugin for partial updates that uses the every-doc-is-a-delta storage pattern. You can use delta pouch to enable conflict-free collaborative editing of the same docs.


var db = new PouchDB('pages');
// Create a new page{ url: '', views: 0 }).then(function (doc) {
  // Update only the views attribute{
    $id: doc.$id, // Set the id 
    views: 1 });

Note: if you tried something similar with the db.put() built into pouchdb, the url attribute would be blanked out.

Live Demo: Profile

Profile Demo

Live Demo: Websites

Websites Demo


To use this plugin, include it after pouchdb.js in your HTML page:

<script src="pouchdb.js"></script>
<script src=""></script>

Or to use it in Node.js, just npm install it:

npm install delta-pouch

And then attach it to the PouchDB object:

var PouchDB = require('pouchdb');

More Examples:

Create doc{ url: '', views: 0 }).then(function (doc) {
  // doc.$id is the id of the created doc 

Update doc{
    $id: doc.$id, // id from creation 
    views: 1
}).then(function (item) {
  // item.$id is the id of the updated doc, i.e. item.$id = doc.$id 

Delete doc

db.delete(doc.$id).then(function (item) {
  // item.$id is the id of the deleted doc 

Fetch all docs

db.all().then(function (docs) {
  // docs is an "associate array" of docs 


db.cleanup().then(function () {
  // clean up has completed 

Delta pouch stores every change as a doc. The cleanup() function removes any changes that are no longer needed and should probably be run via a periodic background process like a node cron job. It is not necessary to use the cleanup() function, but it is advisable as it reduces unneeded syncing and data storage.

Listen for events

  .on('create', function (doc) {
    // e.g. doc = { $id: 123, url: '', views: 0  } 
  .on('update', function (changes) {
    // e.g. changes = { $id: 123, views: 1  } 
  .on('delete', function (id) {
    // e.g. id = 123 

Save changes

var oldDoc = { $id: 123, url: '', views: 0 };
var newDoc = { url: '', views: 1 };
db.saveChanges(oldDoc, newDoc).then(function (changes) {
  // changes = { $id: 123, views: 1 }; 

Running the included examples

Note: you must have couchdb installed and Admin Party enabled

npm install
npm run dev

Visit the target example in your browser, e.g.

Using Delta Pouch with angularjs

Check out factoryng, an all-in-one angularjs adapter that has great support for Delta Pouch!


Interested in contributing?


Checkout DeltaDB an offline-first database written in JS.