Vue - vue-storage-watcher

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vue-storage-watcher

the real reactive watcher for localStorage.
I search a few days for a lib to watch the ls, but failed.

you can use this tiny ls wrapper which works well with vue.js.

you can use this as persistent data layer even instead of vuex.

  • familiar usage just like bus.
  • reactive
  • type supported
  • small size

Install

npm install vue-storage-watcher –save

Sample

import lsWatcher from "vue-storage-watcher"

Vue.use(lsWatcher, { prefix: "myproject_" })

storage type

  • localStorage
  • sessionStorage

Options

  • prefix => default is “”
  • storage => default is “local” which means window.localStorage will be used as Storage Object. Another alternative is “session”

Methods

this.\$ls or this.\$ss in Component context for localStorage/sessionStorage
Vue.\$ls or Vue.\$ss in global.

I will list basic api just with ls.

set

this.$ls.set("token", "abccc")

the value will be saved in storage with the prefix + key
and emit the changes to all the subscribers.

you also can give the key an expire duration with the unit of ms

this.$ls.set("token", "abccc", 3000)

the key will be expried in 3s, you will get null after that.

ttl

ttl will return -1 if one of the following scenarios happen:

  • the key is non-exist
  • the key is already expired
  • the key has no expire time

else return the remaining lifetime with ms as the unit

this.$ls.ttl("token")

get

this.$ls.get("token", "default")

get the value with a default return value if it’s not existed

subscribe the key

this.$ls.on("token", callback)

subscribe the key in the storage, will trigger the callback function if any changes happen.

the return value is the handler need to be used to unsubscribe

tricky
there is an immediate options as a third args which will trigger cb immediate if set true

this.$ls.on("token", callback, true)

unsubscribe the key

const handler = this.$ls.on("token", cb)
this.$ls.off("token", handler)

please make sure you unsubscribe beforeDestroy the component

remove

this.$ls.remove("token")

remove will delete the key in storage and emit all the subscribers with null value

clear

this.$ls.clear()

delete all the keys with your prefix. and all the subscribers will not receive changes any more

init

this.$ls.init()

init will set all your current localStorge keys into the plugins

  • add prefix for all the keys

and then you can use get and on mehtod to make them reactive

FAQ

  • if you want to using localStorage and sessionStorage at same page, pls use the plugin as following
import lsWatcher from "vue-storage-watcher"

Vue.use({ ...lsWatcher }, { prefix: "myproject_" })

Vue.use({ ...lsWatcher }, { prefix: "myproject_ss_", storage: "session" })
  • possibly polyfill
// wather polyfill for IE 11
import "core-js/fn/symbol"
import "core-js/fn/map"