vue 插件

定义插件,install必须的

MyPlugin.install = function (Vue, options) {
  // 1. add global method or property
  Vue.myGlobalMethod = function () {
    // something logic ...
  }
  // 2. add a global asset
  Vue.directive('my-directive', {
    bind (el, binding, vnode, oldVnode) {
      // something logic ...
    }
    ...
  })
  // 3. inject some component options
  Vue.mixin({
    created: function () {
      // something logic ...
    }
    ...
  })
  // 4. add an instance method
  Vue.prototype.$myMethod = function (options) {
    // something logic ...
  }
}

使用插件Vue.use()

// calls `MyPlugin.install(Vue)`
Vue.use(MyPlugin)
Vue.use(MyPlugin, { someOption: true })

插件只能安装一次，vue会自动判断
官方插件vue-router 会自动调用
有时候在commonJs中需要自己调用

// When using CommonJS via Browserify or Webpack
var Vue = require('vue')
var VueRouter = require('vue-router')

// Don't forget to call this
Vue.use(VueRouter)