dom-ot

dom-ot

The DOM changes. You can capture those changes and sync multiple documents in real-time using this library to transform the changes for automagic conflict resolution.

Sounds awesome? It is. To learn more about operational transformation, go to wikipedia or check out this guide to textual ot. Also, check out gulf-contenteditable for a ready-made wrapper.

Install

npm install dom-ot

API

domOT

The object you get from require('dom-ot') is a full-featured shareJS ottype. This allows you to use dom-ot together with shareJS or the more unixy gulf. The shareJS interface will deal only with edits. An edit is essentially an array of operations.

new domOT.Move(fromPath, toPath, [serializedNode])

This operation allows you to move a node from one path to another. Set fromPath to null to insert a node into the tree (which should be passed as serializedNode, serialized with vdom-serialize). Set toPath to null, to remove a node from the tree (you should also pass serializedNode here to enable inversion of the operation).

new domOT.Manipulate(path, attribute, value, oldValue=null)

This operation allows you to set an attribute named attribute of a given node at path to a specific value. Set value to null to remove the attribute.

new domOT.ManipulateText(path, diff)

This operation allows you to modify the nodeValue of a text node, by specifying a diff (which should be a packed changeset).

Operation#transformAgainst(op, [left])

Transforms this operation in-place against another one, so that it assumes the changes of the other one have already happened. Use left to break ties.

Operation#invert()

Inverts the operation in-place.

Operation#apply(rootNode, [index])

Apply an operation on a document, specified by rootNode. Optionally, you may set index to true, to automatically index nodes for importing MutationSummaries (see the mutationSummary adapter).

domOT.adapters

Usually you will not create these operations by hand: Fortunately there's a handy adapter that will turn MutationObserver summaries into dom-ot edits. Currently there's only an import method available that allows you to convert mutation summaries into dom-ot edits, but not the other way around. I simply couldn't find a use case for that, so that's it.

domOT.adapters.mutationSummary

domOT.adapters.mutationSummary.import(summary, rootNode)

• summary is a summary object as returned by MutationSummary
• rootNode is the rootNode that was observed Before installing a MutationObserver with MutationSummary and importing the changes with this function, you will need to run an indexing function on the rootNode, so that the adapter can figure out where the nodes were before. Also, you need to continuously index newly inserted or moved nodes. You can set the optional index param of <Operation>#apply to true, to do this automatically and efficiently.

domOT.adapters.mutationSummary.createIndex(rootNode)

Creates an index for all children of rootNode which is necessary for import() to work.

Tests

Run browserify test/tests.js > bundle.js, then open test/index.html in the browser of your choice.

Changelog

v3.0.0

• Implement operation inversion

Legal

(c) 2015 by Marcel Klehr

Licensed under the terms of the LGPL. See LICENSE.txt in the root directory of this project.