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!')
}
}
Related
Is this instance lifecycle hooks diagram also valid(the same) for a vue.js single file component or a global component(vue.componnet())? or is it only used for a Vue instance(new Vue)??
thanks.
Yes, these lifecycle hooks are there for all vue instances: SFCs, global components, explicit new Vue, vue-test-utils wrappers, and so on.
The only thing that SFC do are to write the .render method for you because it's way simpler to write it with an html-like syntax rather than write the render function manually.
In an SFC, you'd tap into them as such:
<script>
export default {
created() {
// do something on created
}
}
</script>
In an explicit new Vue, like this:
new Vue({
created() {
// do something on created
}
});
You get the point.
When I search for something I came across this post
Here, something, I believe it is component, is defined as below.
export default {
name: 'app',
methods: {
testFunction: function (event) {
console.log('test clicked')
}
},
components: {
Test
}
}
As per the documentation, I came across this
import BaseButton from './BaseButton.vue'
import BaseIcon from './BaseIcon.vue'
import BaseInput from './BaseInput.vue'
export default {
components: {
BaseButton,
BaseIcon,
BaseInput
}
}
I really not sure, whether app is a component which contains Test. Is it the component definition in export? How do we understand that is a component from vue code?
Is it only by the below ways?
Vue.component
components in Vue instance
Not sure - the export default way?
I understand that I sound different because it is Javascript. Could someone help me with this?
There are conventionally, three different types of components in Vue JS.
Root Component
View Component
Normal Component
In a conventional structure the Root component is named 'app' and is passed to the Vue instance when initializing the App for the first time. This component can not be imported and reused inside other components as it will cause a recursive effect. For example this App.vue file is a Root component. It is used inside this main.js file and passed to the Vue instance using new Vue.
The View components are dynamically added or removed from the Root component based on the route. They are written and act as normal component and are only used for Vue router component property. For example the Home and Comments components inside this Router index file are known as View components. They are passed inside the route objects as components inside individual routes. When the app navigates to that particular route, the <router-view> template inside the App.vue file gets replace with the template of the corresponding View component.
Normal components can be used anywhere and are imported by other components. They can be imported inside the View components as well as the Root components. For example, in root component App.vue we see the component Navbar is used. In View component Comments.vue the Replies component is used.
All these components are identical in declaration and behavior but differ in usage.
In order to use a dynamically-defined single page component, we use the component tag, thusly:
<component v-bind:is="componentName" :prop="someProperty"/>
...
import DynamicComponent from '#/components/DynamicComponent.vue';
...
components: {
DynamicComponent
},
props: {
componentName: String,
someProperty: null,
}
The problem is, this isn't really very dynamic at all, since every component we could ever possibly want to use here needs to be not only imported statically, but also registered in components.
We tried doing this, in order at least to avoid the need to import everything:
created() {
import(`#/components/${this.componentName}.vue`);
},
but of course this fails, as it seems that DynamicComponent must be defined before reaching created().
How can we use a component that is truly dynamic, i.e. imported and registered at runtime, given only its name?
From the documentation: Emphasis mine
<!-- Component changes when currentTabComponent changes -->
<component v-bind:is="currentTabComponent"></component>
In the example above, currentTabComponent can contain either:
the name of a registered component,
or a component’s options object
If currentTabComponent is a data property of your component you can simply import the component definition and directly pass it to the component tag without having to define it on the current template.
Here is an example where the component content will change if you click on the Vue logo.
Like this:
<component :is="dynamic" />
...
setComponentName() {
this.dynamic = () => import(`#/components/${this.componentName}.vue`);
},
Solution for Nuxt only
As of now its possible to auto-import components in Nuxt (nuxt/components). If you do so, you have a bunch of components ready to be registered whenever you use them in your vue template e.g.:
<MyComponent some-property="some-value" />
If you want to have truly dynamic components combined with nuxt/components you can make use of the way Nuxt prepares the components automagically. I created a package which enables dynamic components for auto-imported components (you can check it out here: #blokwise/dynamic).
Long story short: with the package you are able to dynamically import your components like this:
<NuxtDynamic :name="componentName" some-property="some-value" />
Where componentName might be 'MyComponent'. The name can either be statically stored in a variable or even be dynamically created through some API call to your backend / CMS.
If you are interested in how the underlying magic works you can checkout this article: Crank up auto import for dynamic Nuxt.js components
According to the official Documentation: Starting from v2.13, Nuxt can auto import your components when used in your templates, to activate this feature, set components: true in your configuration
you are talking about async components. You simply need to use the following syntax to return the component definition with a promise.
Vue.component('componentName', function (resolve, reject) {
requestTemplate().then(function (response) {
// Pass the component definition to the resolve callback
resolve({
template: response
})
});
})
Usually I use a js code with functions to run on some events.
Now I am using nuxt.js and I wonder where to put this file or how to create a global method to use these functions in every component.
I could write the methods that I need inside every a specific component but after it wouldn't be usable outsite of it.
How to do that in vue/nuxt?
So one way to do it in vue.js is by using mixins, in nuxt you can also use mixins, then you should register them as plugins, but first:
Non global mixins
Create an extra folder for your mixins. For example in a /mixins/myMixin.js
export default {
methods: {
commonMethod() {
console.log('Hello')
}
}
}
Then import in a layout, page or component and add it via the mixins object:
<script>
import myMixin from '~/mixins/myMixin.js'
export default {
mixins: [myMixin]
}
</script>
Global mixins
For example in a new file plugins/mixinCommon.js:
import Vue from 'vue'
Vue.mixin({
methods: {
commonMethod() {}
}
})
Include the file in nuxt.config.js like that:
plugins: ['~/plugins/mixinCommon']
After that you would have the method everywhere available and call it there with this.commonMethod(). But here an advice from the vue.js docs:
Use global mixins sparsely and carefully, because it affects every
single Vue instance created, including third party components. In most
cases, you should only use it for custom option handling like
demonstrated in the example above. It’s also a good idea to ship them
as Plugins to avoid duplicate application.
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 ....
}