Created
October 10, 2015 10:29
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effector
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'use strict' | |
import { | |
EventEmitter | |
} from 'events' | |
const keyRegExp = /\{(\w+)\}/g | |
const sep = '.' | |
function resolveParam(keyPath, payload){ | |
return keyPath | |
.replace( | |
keyRegExp | |
, (_,$1) => payload[$1] | |
) | |
.split(sep) | |
} | |
function walk(cur, tiers, lvl = 0){ | |
if(tiers.length === 0){ | |
return cur | |
} | |
let prop = cur[tiers[0]] | |
let tails = tiers.slice(1) | |
if(tails.length === 0){ | |
return prop | |
}else if(prop === undefined || prop === null){ | |
throw new Error(` {lvl} `) | |
}else{ | |
return walk(prop, tails, lvl + 1) | |
} | |
} | |
const evName = 'change' | |
function deepMerge(tiers, source, patch){ | |
//FIXME Immutable! | |
let target = source | |
let locationTiers = tiers.slice(0,tiers.length - 1) | |
let patchKey = tiers[tiers.length - 1] | |
walk(target, locationTiers)[patchKey] = patch | |
return target | |
} | |
export default function Effector(initialState = {}){ | |
let currentState = initialState | |
let broadcastMap = {} | |
const emitter = new EventEmitter() | |
const getState = () => currentState | |
const subscribe = (fn) => { | |
let cb = (nextState) => fn(nextState) | |
emitter.addListener(evName, cb) | |
return () => emitter.removeListener(evName, cb) | |
} | |
const createAction = (keyPath, fn, deps = []) => { | |
let action = (payload, options = {}) => { | |
let tiers = resolveParam(keyPath, payload) | |
let source = walk(currentState, tiers) | |
let args = [payload, source].concat(deps.map((dp) => { | |
return walk(currentState, resolveParam(dp, payload)) | |
})) | |
args.push(function resolve(target){ | |
currentState = deepMerge(tiers, currentState, target) | |
Object.keys(broadcastMap).forEach((path) => { | |
if(keyPath.indexOf(path) > 0){ | |
broadcastMap[path].forEach((subcriber) => { | |
subcriber(payload, {trigger:false}) | |
}) | |
} | |
}) | |
if(options.trigger !== false){ | |
emitter.emit(evName, currentState) | |
} | |
}) | |
return fn.apply(null, args) | |
} | |
action.listenTo = (path) => { | |
var subcribers; | |
if(!broadcastMap[path]){ | |
subcribers = broadcastMap[path] = [action] | |
}else{ | |
subcribers = broadcastMap[path] | |
} | |
return action | |
} | |
return action | |
} | |
return { | |
createAction, | |
subscribe, | |
getState | |
} | |
} |
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