timoxley / apply-changes

Apply Array/Object.observe format changesets to an object.

apply-changes

Take a changes array in the format produced by Object.observe and Array.observe, and apply those changes to another object.

There's many 'changeset' formats floating around, might as well conform to a format built into JavaScript itself.

Example

var apply = require('apply-changes')

var localUser = {
  name: 'Original'
}

var remoteUser = {
  name: 'Original'
}

Object.observe(localUser, function(changes) {
  apply(remoteUser, changes)
  console.log(remoteUser.name) // 'Updated' 
  console.log(localUser.name === remoteUser.name) // true
})

localUser.name = 'Updated'

Why

Say you have an environment where Object.observe is implemented (e.g. node 0.11.x), and you want to easily replicate changes to another environment perhaps one without Object.observe (e.g. vintage 2013 web browser). In this scenario, you could send a raw stream of changes directly from Object.observe callback to observe-apply to have changes applied in the other environment.

Caveats

The recipient of the changes must be treated as read-only. apply-changes does not verify the state of recieving object matches the state of source object. Updates are likely to corrupt data if you change the recipient object.

Licence

MIT

apply-changes's Issues

add comments *

/** @todo: add comments **/