I'm new in Vue and would like assistance on how to access and use variables created in Mounted() in my methods.
I have this code
Template
<select class="controls" #change="getCatval()">
Script
mounted() {
var allcards = this.$refs.allcards;
var mixer = mixitup(allcards);
},
methods: {
getCatval() {
var category = event.target.value;
// I want to access mixer here;
}
}
I can't find a solution anywhere besides this example where I could call a method x from mounted() and pass mixer to it then use it inside my getCatval()
Is there an easier way to access those variables?
I will first suggest you to stop using var, and use the latest, let and const to declare variable
You have to first declare a variable in data():
data(){
return {
allcards: "",
mixer: ""
}
}
and then in your mounted():
mounted() {
this.allcards = this.$refs.allcards;
this.mixer = mixitup(this.allcards);
},
methods: {
getCatval() {
let category = event.target.value;
this.mixer
}
}
like Ninth Autumn said : object returned by the data function and props of your components are defined as attributes of the component, like your methods defined in the method attribute of a component, it's in this so you can use it everywhere in your component !
Here an example:
data() {
return {
yourVar: 'hello',
};
},
mounted() { this.sayHello(); },
method: {
sayHello() { console.log(this.yourVar); },
},
Update
you cannot pass any value outside if it's in block scope - Either you need to get it from a common place or set any common value
As I can see, var mixer = mixitup(allcards); is in the end acting as a function which does some operation with allcards passed to it and then returns a value.
1 - Place it to different helper file if mixitup is totally independent and not using any vue props used by your component
In your helper.js
const mixitup = cards => {
// Do some operation with cards
let modifiedCards = 'Hey I get returned by your function'
return modifiedCards
}
export default {
mixitup
}
And then in your vue file just import it and use it is as a method.
In yourVue.vue
import Helpers from '...path../helpers'
const mixitup = Helpers.mixitup
export default {
name: 'YourVue',
data: ...,
computed: ...,
mounted() {
const mixer = mixitup(allcards)
},
methods: {
mixitup, // this will make it as `vue` method and accessible through
this
getCatval() {
var category = event.target.value;
this.mixitup(allcards)
}
}
}
2- Use it as mixins if your mixitup dependent to your vue and have access to vue properties
In your yourVueMixins.js:
export default {
methods: {
mixitup(cards) {
// Do some operation with cards
let modifiedCards = 'Hey I get returned by your function'
return modifiedCards
}
}
}
And import it in your vue file:
import YourVueMixins from '...mixins../YourVueMixins'
const mixitup = Helpers.mixitup
export default {
name: 'YourVue',
mixins: [YourVueMixins] // this will have that function as vue property
data: ...,
computed: ...,
mounted() {
const mixer = this.mixitup(allcards)
},
methods: {
getCatval() {
var category = event.target.value;
this.mixitup(allcards)
}
}
}
Related
In vue 2+ I can easily get the instance of this as a result I can write something like this,
// main.js
app.use(ElMessage)
// home.vue
this.$message({
showClose: true,
message: 'Success Message',
type: 'success',
})
What should I do for vue 3 as,
Inside setup(), this won't be a reference to the current active
instance Since setup() is called before other component options are
resolved, this inside setup() will behave quite differently from this
in other options. This might cause confusions when using setup() along
other Options API. - vue 3 doc.
Using ElMessage directly
ElementPlus supports using ElMessage the same way as $message(), as seen in this example:
import { ElMessage } from 'element-plus'
export default {
setup() {
const open1 = () => {
ElMessage('this is a message.')
}
const open2 = () => {
ElMessage({
message: 'Congrats, this is a success message.',
type: 'success',
})
}
return {
open1,
open2,
}
}
}
Using $message()
Vue 3 provides getCurrentInstance() (an internal API) inside the setup() hook. That instance allows access to global properties (installed from plugins) via appContext.config.globalProperties:
import { getCurrentInstance } from "vue";
export default {
setup() {
const globals = getCurrentInstance().appContext.config.globalProperties;
return {
sayHi() {
globals.$message({ message: "hello world" });
},
};
},
};
demo
Note: Being an internal API, getCurrentInstance() could potentially be removed/renamed in a future release. Use with caution.
Providing a different method where the idea is to set a globally scoped variable to the _component property of the viewmodel/app or component:
pageVM = Vue.createApp({
data: function () {
return {
renderComponent: true,
envInfo: [],
dependencies: [],
userGroups: []
}
},
mounted: function () {
//Vue version 3 made it harder to access the viewmodel's properties.
pageVM_props = pageVM._component;
this.init();
},
I tried to provide my data from a parent element like below.
data(){
return{
allData:null,
ingCollection:null,
selectedDish:[]
}
},
mounted(){
Promise.all([
d3.json('data.json'),
d3.json('ingredientsonly.json')
]).then((data)=>{
this.allData=data[0];
this.ingCollection=data[1];
})
},
components:{sidePanel,centerPiece},
methods: {
// receiveIngredients(selected){
// let selections = this.allData.filter(d=>{
// d.ingredients.includes(selected)
// });
// }
},
provide() {
return{
allData:this.allData,
ingCollection:this.ingCollection,
selectedDish:this.selectedDish,
receiveIngredients:this.receiveIngredients
}
}
However, after mounted lifecycle hook was run,
data is updated while provide elements were not updated.
Why is it?
Thank you
provide() is only called once at initialization, and not when there's a change to the references within.
Instead, you can provide an object (e.g., named root), and then update a property of that object in mounted():
export default {
provide() {
return {
root: {
allData: null,
ingCollection: null,
}
}
},
mounted() {
Promise.all([
d3.json('data.json'),
d3.json('ingredientsonly.json')
]).then((data)=>{
this.root.allData = data[0];
this.root.ingCollection = data[1];
})
}
}
We are building a web application using Vue JS and PHP, we are new to Vue JS. The server-side execution is fine, the API is able to fetch data as JSON. While trying out a static array display before making the API call, we find that the function in imported "app.js" is not getting called and the table displayed is empty. Please let us know what we might be doing wrong. Appreciate your help.
import Vue from 'vue';
export const MY_CONST = 'Vue.js';
export let memberList = new Vue({
el: '#members',
data: {
members: []
},
mounted: function () {
this.getAllMembers();
},
methods: {
getAllMembers: function () {
/*
axios.get("https://xxxxxx.com/services/api.php")
.then(function (response) {
memberList.members = response.data.members;
});
*/
memberList.members = [{ "empname": "Dinesh Dassss" },
{ "empname": "Kapil Koranne" }];
}
}
});
This is the Vue component. The members object is empty.
<script>
import * as mykey from './app.js'
export default {
name: 'Home',
props: {
msg: String
},
data() {
return {
message: `Hello ${mykey.MY_CONST}!`,
members: mykey.memberList.members
}
}
};
</script>
You can also use this reference for current instance reference:
getAllMembers: function () {
var me = this;
/*
axios.get("https://xxxxxx.com/services/api.php")
.then(function (response) {
// direct this not works here but we have
//saved this in another variable and scope of a var is there
me.members = response.data.members;
});
*/
// this reference works fine here.
this.members = [{ "empname": "Dinesh Dassss" },
{ "empname": "Kapil Koranne" }];
}
When I get data from the server, like
[{methodName:mothodValue},{methodName:mothodValue}]
then I want dynamic generation method, like
methods: {
functionArray.forEach(function (item) {
item.functionName:function () {
item.functionValue;
}
})
}
so this is my code
var componentName = Vue.component(componentName, {
data: function () {
return {
value: value
}
},
template: componentTemplate,
methods:{
functionArray.forEach(function (item) {
item.functionName:function () {
item.functionValue;
}
})
}
})
the old code was
methods:{
getValue : function(){
getValue(this.value);
}
}
Is that possible?
If the data from the server is returned before the creation of the Vue component (I'm not sure if you can add methods after the creation of a Vue component), then you can create a methods object like so:
var methods = {};
functionArray.forEach(function (item) {
methods[item.functionName] = item.functionValue;
});
You can't populate an object literal with code, but you can populate an empty object literal afterwards with code like so.
Then you can put it into your component like so:
var componentName = Vue.component(componentName, {
// ..
methods: methods
});
How to pass a variable from a function in the component in Vue?
This is my code:
export default {
name: 'app',
data: function () {
return{
city1: '',
city2: '',
metr: 0
}
},
created () {
ymaps.ready(init);
function init() {
$data.city1 = 'sdf'; // ?this to data of component?
Because you created an new function, the this inside it will be not point to the Vue component, but to the this of the function itself.
You can use an arrow function, or save the reference of the this, then use it later.
created() {
const self = this;
ymaps.init(init);
function init() {
self.city1 = 'sdf';
}
}
Or (better):
created() {
const init = () => {
this.city1 = 'sdf';
}
ymaps.init(init);
}