Ogre

Object Graph Manager

Contents

• Overview
• API
• Todo
• Building
• License

Overview

Weighing in at ~5kb, gzipped, Ogre is pretty svelte. Built with React in mind, Ogre is a simple graph manager that leverages React's own immutability helpers to update objects without changing the surrounding topography.

Although they are called "immutability helpers," Ogre is not about immutability. It is about highly efficient object equality checks:

shouldComponentUpdate( nextProps, _ ) {
    return this.props.item !== nextProps.item
}

Example:

var data= new Ogre({
    idList: [],
    itemMap: {}
})
 
data.onChange( function( changedKeys ){ /* Now you know */ } )
 
var item= { id:'ID1', name:'The First' }
 
// Both of these mutations will only result in a single
// 'onChange' event on the nextTick.
data.set('itemMap.ID1', item)
data.push('idList', item.id )
 
data.get('itemMap.ID1') === item // => true
 

Since the onChange event is accumulated, by default, you could have multiple stores (in a synchronous Flux pattern) all modify a global application state graph (ogre), and only trigger a single render call.

API

new Ogre( initialState={}, options={} )

Options:

name	description	default
maxHistory	Number of old states to remember	1
batchChanges	Batch synchronous mutations into single 'change' event	true
strict	Throw error when mutating non-existing key paths	true

If strict is false, Ogre will automatically create all the missing object paths (Rather like mkdir -p does). It will try to deduce the final leaf container type based on the operation being used. For example if using: ogreData.push( 'new.deeply.nested.leaf') Ogre knows that push is for Arrays, so it'll create the leaf container as an Array. By default any elements in between, if missing, will be objects.

get( path:string, defaultValue:any ):any

set( path:string, value:any ):Ogre

scopeTo( path:string ):Ogre

Returns a lightweight 'cursor' object that has the same API as an Ogre object, but is bound to the specified path as the root. If you subscribe to events on cursors, the callbacks will only be triggered when an element of the graph has changed for this path.

getPrevious( path:string, step=0 ):any

Returns data from history. Step 0 is the previous version. If you set the maxHistory to a higher amount than the default of 1, you can get values up to that many steps back.

Note: Stored revisions of the graph are for the whole tree.

merge( path, object )

push( path, array )

unshift( path, array )

splice( path, start, howMany, ...items) {

map( path, fn )

each( path, fn )

forEach( path, fn )

filter( path, fn )

find( path, fn )

indexOf( path, value )

reduce( path, fn, initialValue )

onChange( handlerFn ):function

Returns a function that, when called, will unsubscribe handlerFn from the event. (Use for supporting anonymous, inline callbacks).

offChange( handlerFn )

isUndefined( path )

isNotUndefined( path )

isDefined( path )

isNull( path )

isNotNull( path )

isEmpty( path )

isNotEmpty( path )

isString( path )

isNotString( path )

isArray( path )

isNotArray( path )

isObject( path )

isNotObject( path )

isNumber( path )

isNotNumber( path )

Todo

• Flesh out API docs.
• More examples.

Building

Compile from src/ to lib/:

npm run build

Compiles for browser to dist/:

npm run dist

Minify browser build:

npm run minify

Run tests:

npm test

The whole shebang:

npm run all

License

The MIT License (MIT)

Copyright (c) 2014-2015 Elucidata unLTD

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.