akkoma-fe/src/lib/persisted_state.js

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import merge from 'lodash.merge'
import objectPath from 'object-path'
const defaultReducer = (state, paths) => (
paths.length === 0 ? state : paths.reduce((substate, path) => {
objectPath.set(substate, path, objectPath.get(state, path))
return substate
}, {})
)
const defaultStorage = (() => {
const hasLocalStorage = typeof window !== 'undefined' && window.localStorage
if (hasLocalStorage) {
return window.localStorage
}
class InternalStorage {
setItem (key, item) {
this[key] = item
return item
}
getItem (key) {
return this[key]
}
removeItem (key) {
delete this[key]
}
clear () {
Object.keys(this).forEach(key => delete this[key])
}
}
return new InternalStorage()
})()
export default function createPersistedState ({
key = 'vuex',
paths = [],
getState = (key, storage) => {
const value = storage.getItem(key)
return value && value !== 'undefined' ? JSON.parse(value) : undefined
},
setState = (key, state, storage) => storage.setItem(key, JSON.stringify(state)),
reducer = defaultReducer,
storage = defaultStorage,
subscriber = store => handler => store.subscribe(handler)
} = {}) {
return store => {
const savedState = getState(key, storage)
if (typeof savedState === 'object') {
store.replaceState(
merge({}, store.state, savedState)
)
}
subscriber(store)((mutation, state) => {
try {
setState(key, reducer(state, paths), storage)
} catch (e) {
console.log("Couldn't persist state:")
console.log(e)
}
})
}
}