Get Vue component object (class) from component instance - vue.js

Question
Given I am in component context, how do I get the component object? By component object I mean the object you get when you import Component from 'Component.vue'.
Current progress
Here's one possibility I found.
const component = {
methods: {
getComponent: () => this,
displayItem () {
console.log('this.getComponent()', this.getComponent()) // undefined
console.log('this', this) // component instance
console.log('component', component) // what I need (component object)
},
},
}
export default component
The downside though is that it kills IDE support.
I also checked this manually.
Ideal solution
The approximation to syntax I'd like to see: this.$component.
What's the point?
Instantiate components via :is="component".
Perform instance of check.

The closer you got is vm.$options:
Vue.component('some-comp', {
template: '<p>{{ message }}</p>',
props: {name: String},
data() {
return {
message: 'Open the console!'
}
},
computed: {
example() {
return this.message.toUpperCase();
}
},
watch: {
message() {
console.log('watcher triggered');
}
},
mounted() {
console.log(this.$options);
console.dir(this.$options.__proto__);
}
});
new Vue({
el: '#app'
})
<script src="https://unpkg.com/vue"></script>
<div id="app">
<some-comp :name="'Alice'"></some-comp>
</div>
But it seems what you want is constructor:
Vue.component('aaa-aaa', {
template: '<div>AAA component</div>'
})
Vue.component('bbb-bbb', {
template: '<div>BBB component</div>'
})
new Vue({
el: '#app',
mounted() {
console.log(this.$refs.a1);
console.log(this.$refs.a1.constructor);
console.log(this.$refs.b1);
console.log(this.$refs.b1.constructor);
console.log('a1 a2', this.$refs.a1.constructor === this.$refs.a2.constructor)
console.log('a1 b1', this.$refs.a1.constructor === this.$refs.b1.constructor)
console.log('b1 b2', this.$refs.b1.constructor === this.$refs.b2.constructor)
console.log('b2 a2', this.$refs.b2.constructor === this.$refs.a2.constructor)
}
})
<script src="https://unpkg.com/vue"></script>
<div id="app">
<aaa-aaa ref="a1"></aaa-aaa>
<aaa-aaa ref="a2"></aaa-aaa>
<bbb-bbb ref="b1"></bbb-bbb>
<bbb-bbb ref="b2"></bbb-bbb>
</div>

Related

Vue 3: Wait until parent is done with data fetching to fetch child data and show loader

I'm looking for a reusable way to display a full page loader (Sidebar always visible but the loader should cover the content part of the page) till all necessary api fetches has been done.
I've got a parent component LaunchDetails wrapped in a PageLoader component
LaunchDetails.vue
<template>
<PageLoader>
<router-link :to="{ name: 'launches' }"> Back to launches </router-link>
<h1>{{ name }}</h1>
<section>
<TabMenu :links="menuLinks" />
</section>
<section>
<router-view />
</section>
</PageLoader>
</template>
<script>
import TabMenu from "#/components/general/TabMenu";
export default {
data() {
return {
menuLinks: [
{ to: { name: "launchOverview" }, display_name: "Overview" },
{ to: { name: "launchRocket" }, display_name: "Rocket" },
],
};
},
components: {
TabMenu,
},
created() {
this.$store.dispatch("launches/fetchLaunch", this.$route.params.launch_id);
},
computed: {
name() {
return this.$store.getters["launches/name"];
},
},
};
</script>
PageLoader.vue
<template>
<Spinner v-if="isLoading" full size="medium" />
<slot v-else></slot>
</template>
<script>
import Spinner from "#/components/general/Spinner.vue";
export default {
components: {
Spinner,
},
computed: {
isLoading() {
return this.$store.getters["loader/isLoading"];
},
},
};
</script>
The LaunchDetails template has another router-view. In these child pages new fetch requests are made based on data from the LaunchDetails requests.
RocketDetails.vue
<template>
<PageLoader>
<h2>Launch rocket details</h2>
<RocketCard v-if="rocket" :rocket="rocket" />
</PageLoader>
</template>
<script>
import LaunchService from "#/services/LaunchService";
import RocketCard from "#/components/rocket/RocketCard.vue";
export default {
components: {
RocketCard,
},
mounted() {
this.loadRocket();
},
data() {
return {
rocket: null,
};
},
methods: {
async loadRocket() {
const rocket_id = this.$store.getters["launches/getRocketId"];
if (rocket_id) {
const response = await LaunchService.getRocket(rocket_id);
this.rocket = response.data;
}
},
},
};
</script>
What I need is a way to fetch data in the parent component (LaunchDetails). If this data is stored in the vuex store, the child component (LaunchRocket) is getting the necessary store data and executes the fetch requests. While this is done I would like to have a full page loader or a full page loader while the parent component is loading and a loader containing the nested canvas.
At this point the vuex store is keeping track of an isLoading property, handled with axios interceptors.
All code is visible in this sandbox
(Note: In this example I could get the rocket_id from the url but this will not be the case in my project so I'm really looking for a way to get this data from the vuex store)
Im introduce your savior Suspense, this feature has been added in vue v3 but still is an experimental feature. Basically how its work you create one suspense in parent component and you can show a loading when all component in any depth of your application is resolved. Note that your components should be an async component means that it should either lazily loaded or made your setup function (composition api) an async function so it will return an async component, with this way you can fetch you data in child component and in parent show a fallback if necessary.
More info: https://vuejs.org/guide/built-ins/suspense.html#suspense
You could use Events:
var Child = Vue.component('child', {
data() {
return {
isLoading: true
}
},
template: `<div>
<span v-if="isLoading">Loading …</span>
<span v-else>Child</span>
</div>`,
created() {
this.$parent.$on('loaded', this.setLoaded);
},
methods: {
setLoaded() {
this.isLoading = false
}
}
});
var Parent = Vue.component('parent', {
components: { Child },
data() {
return {
isLoading: true
}
},
template: `<div>
Parent
<Child />
</div>`,
mounted() {
let request1 = new Promise((resolve, reject) => {
setTimeout(resolve, 1000);
});
let request2 = new Promise((resolve, reject) => {
setTimeout(resolve, 2000);
});
Promise.all([ request1, request2 ]).then(() => this.$emit('loaded'))
}
});
new Vue({
components: { Parent },
el: '#app',
template: `<Parent />`
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app"></div>
This may be considered an anti-pattern since it couples the parent with the child and events are considered to be sent the other way round. If you don't want to use events for that, a watched property works just fine, too. The non-parent-child event emitting was removed in Vue 3 but can be implemented using external libraries.

How to fix Vue 3 template compilation error : v-model value must be a valid JavaScript member expression?

I am working on a vue project and the vue version is 3.0
And recently I can see these many warnings for some reason.
Template compilation error: v-model value must be a valid JavaScript member expression
I guess it is because I am using long v-model variable name like this.
<textarea v-model="firstVariable.subVariable.subVariableKey" readonly></textarea>
Please let me know if any idea.
Thanks in advance
This is the component and template code.
var myTemplate = Vue.defineComponent({
template: '#myTemplate',
data() {
return {
firstVariable: {}
}
},
mounted() {
loadData();
},
methods:{
loadData() {
axios.get(MY_ROUTES).then(res => {
// let's suppose res.data is going to be {subVariable: {subVariableKey: "val"}}
this.firstVariable = res.data;
})
}
}
});
// template.html
<script type="text/template" id="myTemplate">
<div class="container">
<textarea v-model="firstVariable.subVariable?.subVariableKey"></textarea>
</div>
</script>
In order that your property go reactive you've to define its full schema :
data() {
return {
firstVariable: {
subVariable: {
subVariableKey: ''
}
}
}
},
and use it directly without optional chaining
v-model="firstVariable.subVariable.subVariableKey"
because v-model="firstVariable.subVariable?.subVariableKey" malformed expression like v-model="a+b" like this test
Example
var comp1 = Vue.defineComponent({
name: 'comp1',
template: '#myTemplate',
data() {
return {
firstVariable: {
subVariable: {
subVariableKey: ''
}
}
}
},
mounted() {
this.loadData();
},
methods: {
loadData() {
}
}
});
const {
createApp
} = Vue;
const App = {
components: {
comp1
},
data() {
return {
}
},
mounted() {
}
}
const app = createApp(App)
app.mount('#app')
<script src="https://unpkg.com/vue#3.0.0-rc.11/dist/vue.global.prod.js"></script>
<div id="app" >
vue 3 app
<comp1 />
</div>
<script type="text/template" id="myTemplate">
<div class="container">
<textarea v-model="firstVariable.subVariable.subVariableKey"></textarea>
<div>
{{firstVariable.subVariable.subVariableKey}}
</div>
</div>
</script>
You are adding a new property to an object which is not reactive.
Vue cannot detect property addition or deletion. Since Vue performs
the getter/setter conversion process during instance initialization, a
property must be present in the data object in order for Vue to
convert it and make it reactive. For example:
Source
Instead of
this.firstVariable = res.data;
Use
this.$set(this.firstVariable, 'subVariable', res.data.subVariable);

How do I make reactive global property in vuejs plugin?

I put $testCounter in a plugin to make it global :
Vue.use({
install(Vue) {
Vue.prototype.$testCounter = 0;
Vue.prototype.$incrementCounter = () => {
Vue.prototype.$testCounter++;
};
});
I want to output it in some component. I also need its value to be updated globally, and reactively :
<template>
<p>{{ $testCounter }}</p>
</template>
<script>
mounted() {
let comp = this;
comp.watcherId = setInterval(() => {
comp.$incrementCounter();
// I want to remove this line and still be reactive :
comp.$forceUpdate();
}, 1000);
}
</script>
I need the property to be reactive, I tried a multiple solution as watchers, computed props, vm.$set(...), but I can't find the right way to do this.
Solution 1: use Vuex
Solution 2: set the global reactive data in root component and use it by calling this.$root
demo: https://jsfiddle.net/jacobgoh101/mdt4673d/2/
HTML
<div id="app">
<test1>
{{$root.testCounter}}
</test1>
</div>
Javascript
Vue.component('test1', {
template: `
<div>
test1
<slot></slot>
</div>
`,
mounted() {
setInterval(() => {
this.$root.incrementCounter();
}, 1000)
}
});
new Vue({
el: "#app",
data: {
testCounter: 1
},
methods: {
incrementCounter: function() {
this.testCounter++;
}
}
})

Access dynamic child component

How do I access my subcomponent? For example my parent component has the following 'dynamic' component (the component changes all the time at runtime).
<template>
<!-- The below component count be Component1 or Component2, etc. -->
<component id="my-cmp" v-if="templateComponent" :is="templateComponent"></component>
</template>
How can I access myCmp to call a function...this.myCmp.doSomething() doesn't work. Please note using emit here isn't a solution because emit will call doSomething() on all 'dynamic' components not just the current one.
Below is an example of my usage:
<template>
<!-- The below component count be Component1 or Component2, etc. -->
<component id="my-cmp" v-if="templateComponent" :is="templateComponent"></component>
</template>
<script type="text/javascript">
export default {
components: {
'cmp1': Component1,
'cmp2': Component1,
},
computed: {
templateComponent() {
// ...some logic that will determine if to use/chage to Component1 or Component2
return 'cmp1'
},
},
methods: {
someTrigger() {
// how can I reference #my-cmp?
// For the purpose of; myCmp.doSomething()
// I have tried the below technique BUT this will call doSomething
// on BOTH components not just the current/visible one
this.$emit('doSomethingNow') // Component1 and Component2 register using this.$parent.$on('doSomethingNow', this.doSomething)
}
}
}
</script>
use ref property,give you an example:
Vue.component('com1',{
template: '<div>component com1</div>',
methods: {
fn () {
alert('method called')
}
}
})
var app = new Vue({
el: '#app',
data () {
},
computed: {
whichCom () {
return 'com1'
}
},
methods: {
btnClick () {
this.$refs.myCom.fn()
}
}
})
<script src="https://cdn.jsdelivr.net/npm/vue#2.5.16/dist/vue.js"></script>
<div id="app">
<component ref="myCom" v-if="whichCom" :is="whichCom"></component>
<button #click="btnClick">call method of com1</button>
</div>

VueJs how to get data from Vue.component

I want to know how to get data from Vue.component and send to
this >>var app = new Vue({ })<<
this is my code
Vue.component('my-form', {
template: '#my-form',
props:['ddTechtemp'],
data: function () {
return {
isCores: app.testCorres,
activeClass: 'isCorrespon',
errorClass: 'isTech',
tempData : {cell1 : "",
cell2 : "",
cell3 : "",
cell4 : "",
cell5 : "",
cell6 : ""
},
}
},
watch:{
tempData:{
handler:function(newVal,oldVal){
app.ddTechtemp = newVal;
},
deep:true,
}
},
methods:{
}});
I want to get data from above code and send to this code var app = new Vue({ data: Vue.component.data})
Anyone understand me please help.Thank you
In Vue.js parent-child relationship is run by
1) passing props from parent to child
2) emitting custom events from child to parent
So, if you need to pass some data from child to parent - use this.$emit to emit a custom event with your data, and listen for this event in parent component with v-on:myevent or #myevent shorthand. The data you pass with event is found in $event variable.
Example: https://jsfiddle.net/wostex/63t082p2/51/
<div id="app">
<myform #newdata="handleData($event)"></myform>
<p>name: {{ user.name }}</p>
<p>age: {{ user.age }}</p>
</div>
new Vue({
el: '#app',
data: {
user: { name: '', age: 0 }
},
methods: {
handleData: function(e) {
[this.user.name, this.user.age] = e;
}
},
components: {
'myform': {
template: `
<div>
<input type="text" v-model="formData.name" placeholder="Your name">
<input type="number" v-model.number="formData.age">
</div>`,
data: function() {
return { formData: { name: '', age: 0 } }
},
watch: {
formData: {
handler: function() {
this.$emit('newdata', [this.formData.name, this.formData.age]);
},
deep: true
}
}
}
}
});
Another way would be to work with advanced things like a Vuex store for ''state management'' but for simple implementations one additional reactive component would work as well.
in src/store/index.js
import { reactive } from 'vue';
export const store = reactive({
some_id : 0,
});
And in a component src/component/SelectComponent.vue
<script setup>
import { store } from "#/store";
</script>
<script>
export default {
name: "SelectComponent",
// rest of the component source here
}
</script>
<template>
<select v-model="store.some_id">
<option v-for="itm in list" :key=itm.id" :value="itm.id">{{ itm.text }}</option>
</select>
</template>
Using the component in src/views/SomeView.vue
<script setup>
import { store } from "#/store";
import SelectComponent from "#/components/SelectComponent"
</script>
<script>
//... use store.some_id in some method
</script>
You can store all your global variables in the store/index.js file and keep reactive. You might want to add watchers to observe the store variable(s).
WARNING: this is discouraged for large, complex Vue applications
NOTE: this is an easy approach for simple state management not requrring Vuex with all the actions and mutations, states and contexts - plumbing.