Mounting component instance to $root from plugin - vue.js

I'm creating a plugin, where there will be a single instance of ModalsContainer per $root.
Because of that - I want to create the instance manually, rather than having people add <v-modalscontainer/> to their app.
Code below does just that, it loads components and registers them for Vue to use, then creates an instance of the container and mounts it - the issue is, it's mounted nowhere - the method mounted() of component has console.log() in it and clearly it gets executed without an issue - but it's not mounted in any of $roots.
import Modal from './components/Modal.vue'
import ModalContainer from './components/ModalsContainer.vue'
const plugin =
{
install(Vue, options = {})
{
Vue.component('v-modal', Modal)
Vue.component('v-modalscontainer', ModalContainer)
var instance = new (Vue.extend(ModalContainer))
instance.$mount()
}
}
export default plugin

Related

Using the mitt-library in Vue with Webpack hot-reload causes problems?

In my Vue3 app, I'm using the mitt eventbus library to emit and receive events between components.
I put this in onMounted of a list component that needs to refresh:
mitt.on("list_refresh", (evt) => {
refresh();
});
In another component that contains the list-component as a child (or grandchild), I do this in a method:
mitt.emit("list_refresh", {});
This works ok, but while developing with hot-reload on, the events seem to be emitted multiple times, as if they're created extra each time the app reloads, instead of overwriting the old ones.
When I reload the entire page in the browser, it works fine again.
Any idea to prevent this?
It looks like your component is missing a corresponding off() call to remove the event listener. During hot reload, the current component instances unmount, and new ones mount; so if you're not removing current event listeners, you'll just pile on new event listeners. To resolve the issue, use the onUnmounted hook to remove the event listener when the component is removed from the DOM.
Also, make sure to pass cached function references (instead of inline functions) to mitt.on() and mitt.off() to ensure the given event listener lookup succeeds in mitt.off():
// mitt.on('list_refresh', () => refresh()) ❌
mitt.on('list_refresh', refresh) ✅
mitt.off('list_refresh', refresh)
Your setup() should look similar to this:
import { onMounted, onUnmounted } from 'vue'
export default {
setup() {
const refresh = () => { /*...*/ }
onMounted(() => mitt.on('list_refresh', refresh))
onUnmounted(() => mitt.off('list_refresh', refresh)) 👈
}
}

Dynamically listen to custom event on parent component

In my custom library I have several components which run ajax requests, and when a given request fails the component emits an error event.
Then, in my main component I want to listen to all error events emmited and run the method handleErrors, but for that I have to go on every component and add #error="handleErrors".
Is there a way to configure my main component to catch error events dynamically and call handleErrors without going on each component and adding it? Preferrably changes to the main component only.
You can use the EventBus system in Vue instance. Actually EventBus is a different Vue instance your Main Vue instance. You make your own Event bus system.$emit, $on and $off events.
event-bus.js
import Vue from 'vue';
export const EventBus = new Vue();
and now you are ready to use.
some-component.vue
// Import the EventBus.
import { EventBus } from './event-bus.js';
// Send the event on a channel (eventName) with a payload (the click count.)
EventBus.$emit('eventName', this.clickCount);
other-component.vue
// Import the EventBus.
import { EventBus } from './event-bus.js';
// Listen for the eventName event and its payload.
EventBus.$on('eventName', clickCount => {
console.log(clickCount)
});
// Stop listening.
EventBus.$off('eventName');
more information and example
https://alligator.io/vuejs/global-event-bus/
Figured a way to do it without refactoring the individual components: just injected the listener in every component using a mixin.
The result:
// Before starting up the main instance:
Vue.mixin({
created: function() {
this.$on('error', function(error) {
// Then I handled the errors here.
);
}
});

How to access Vuex from Vue Plugin?

How can I access my store from my plugin? Console returns undefined.
import store from './store';
export default {
install(vue, opts){
Vue.myGlobalFunction = function(){
console.log(store);
}
}
}
I recently had to do this too to make a pouchDb plugin, and came up with a new way.
When you create your first Vue object, you can do this.
import PouchDb from '#/pouch_db/PouchDbPlugin'
let DefaultVue = Vue.extend({
components: {App},
store,
created () {
Vue.use(PouchDb, this.$store) // Create it by passing in the store you want to use
}
})
My plugin adds an additional store, and it's own mutations and getters.
export default {
install (Vue, store) {
store.registerModule('PouchDb', pds)
const pouchDb = new PouchDb(store)
Vue.pouchDb = pouchDb
Vue.prototype.$pouchDb = pouchDb
}
}
Inside the constructor, I store the store
class PouchDb {
constructor (store) {
this.store = store
// ... etc.
}
// ... more functions
}
And then use it in other functions
class PouchDb {
// ... constructor and other functions
async addSync (docId) {
this.store.dispatch('PouchDb/addSync', docId)
}
}
It's a bit of a cheat to pass in the store, but seems to work nicely. It's usable throughout the app like this
// Inside vuex store
Vue.pouchDb.addSync(// ...etc)
// inside component
this.$pouchDb.removeSync(// ...etc)
See official guide here where it states
A Vue.js plugin should expose an install method. The method will be called with the Vue constructor as the first argument, along with possible options:
So you can do this, very easily.
Vue.use( {
install(Vue){
Vue.prototype.$something = function (){
this.$store...etc
}
}
} )
To use, simply do this.$something() in a components methods/computed etc, or directly in the component markup as {{$something()}}
This will remove the plugin needing to know where the store actually resides, while still allowing you to utilize the store within the plugin.
This is because it will inherit the scope of whatever component utilizes it, thus providing access to all of the components instance properties, including things like $store, $router as well any of it's local properties such as computed properties, parents etc. Essentially the plugin functions as if it is directly a part of the component (eg if you used it as a mixin).
For Vue 3
Incase if you wonder, how to do it in Vue 3, You can use the following.
plugin.js
export default {
install(app) { // app instance
console.log(app.config.globalProperties.$store)
}
}
main.js
import store from './pathtostore'
import plugin from './plugin'
createApp(...).use(store).use(plugin)
When app starts, you import your store and "append" it to Vue, globally.
Now, if you use() your plugin, the first parameter of install() is always Vue itself, and in this moment Vue already has access to the store, in the install method you can simply start
install(vue, opts) {
... here your can acces to vue.$store ....
}

How to call mounted or created within a Vue plugin?

I am trying to create some plugins according to this article:
https://alligator.io/vuejs/creating-custom-plugins/
I have a plugin that needs to run something when the root Vue instance mounts or is created. So far I can only see a way to inject something into all components which is not what I would want.
I simply need to do something when the main Vue instance mounts. How can I do this with a plugin?
The install method from the plugin does not seem to do the trick because this seems to happen before the actual created method.
It's possible to have multiple root Vue components. A "root component" is just a component created with the new syntax and no parent component, so you can detect this as follows:
Vue.mixin({
created() {
if (!this.$parent) {
// This is either the root component or a component
// created with `new` and no parent
}
}
})
It's actually easy to include mixins for just a particular component!
In your component that you want to add the mixin to, just import it like you would anything else, and include an array in your component called mixins like so:
import myMixin from 'src/mixin/myMixin'
export default {
mixins: [myMixin]
}
Then your myMixin code would look like this (don't use Vue.mixin, which is global):
export default {
beforeMount () {
console.log('Your component is about to be mounted!')
}
}

Vuejs - require is not defined

I am just playing around with vuejs router and try to load a component.
I used the sample code and changed foo
// Define some components
var Foo = Vue.extend({
template: require('./components/test.vue')
});
var Bar = Vue.extend({
template: '<p>This is bar!</p>'
});
// The router needs a root component to render.
// For demo purposes, we will just use an empty one
// because we are using the HTML as the app template.
var App = Vue.extend({})
// Create a router instance.
// You can pass in additional options here, but let's
// keep it simple for now.
var router = new VueRouter()
// Define some routes.
// Each route should map to a component. The "component" can
// either be an actual component constructor created via
// Vue.extend(), or just a component options object.
// We'll talk about nested routes later.
router.map({
'/foo': {
component: Foo
},
'/bar': {
component: Bar
}
})
// Now we can start the app!
// The router will create an instance of App and mount to
// the element matching the selector #app.
router.start(App, '#app')
I also tested it with
Vue.component('Foo', {
template: require('./components/test.vue')
})
In my test.vue i have
<template>
<h2>Test</h2>
</template>
But not as soon as i use require i get everytime the error Required is not defined in my dev tools.
What do i wrong here?
require is a builtin in the NodeJS environment and used in Grunt build environments.
If you also want to use it in a browser environment you can integrate this version of it: http://requirejs.org
(Author) This is outdated:
Use Browserify or Webpack as there is active support in the Vue community
http://vuejs.org/guide/application.html#Deploying_for_Production (dead link)
I personally used this repo of the Vue GitHub-org to get started quickly.
Edit:
This has moved on a bit in early 2018.
Deployment guide: https://v2.vuejs.org/v2/guide/deployment.html
'getting started' type repo: https://github.com/vuejs/vue-loader