immutable-with-cursors v0.0.1

Immutable Data Collections With Cursors

This is a simple wrapper around Facebooks immutable data collection library, adding Om-style cursors.

Cursors are a way of passing around smaller parts of a larger data structure, that will call back to the parent data structure when updated. This is very useful in component-based web libraries (e.g. React), where sub components only should be passed the subset of data that they need, yet must be able to pass updates back up the tree.

Usage example with React.

API

coll.watch(watcher)

Register a watcher to be triggered when the collection is updated.

coll.unwatch(watcher)

Remove a registered watcher.

coll.triggerWatchers(value)

Calls all registered watchers with the passed value, then returns the value.

coll.cursor(keypath, callback, notFoundValue

Creates a cursor at the given keypath and returns it. When the cursor is updated, tha callback is called with the parent collection.