It's my first post on stackoverflow, so sorry in advance if I do something incorrectly. My question;
I've setup a VueJS project, and I'm trying to reach data that I put in the App.vue from another component. To do this, I use this.$root.count for example, but it returns undefined.
Main.js:
import Vue from 'vue'
import VueRouter from 'vue-router'
import App from './App'
Vue.use(VueRouter);
const router = new VueRouter({
mode: 'history',
routes: [{
path: '/',
name: 'home',
component: function (resolve) {
require(['./components/Hello.vue'], resolve)
}
}, {
path: '/race-pilot',
name: 'racePilot',
component: function (resolve) {
require(['./components/RacePilot.vue'], resolve)
}
}
});
new Vue({
el: '#app',
router,
template: '<App/>',
components: { App }
});
App.vue:
<template>
<div>
<div class="menu" ref="menu">
<router-link :to="{ name: 'home' }">Home</router-link>
<router-link :to="{ name: 'racePilot' }">Race Pilot</router-link>
</div>
<div id="app">
<router-view></router-view>
</div>
</div>
</template>
<style src="./assets/css/app.scss" lang="scss"></style>
<script>
import Hello from './components/Hello'
export default {
name: 'app',
components: {
Hello
},
data () {
return {
count: '0'
}
}
}
</script>
RacePilot.vue:
<template>
<div class="race-pilot">
</div>
</template>
<script>
export default {
name: 'RacePilot',
mounted() {
console.log(this.$root.count);
}
}
</script>
So the last log returns undefined. However, if I log this.$root, I do get the object. Anybody any idea? Thanks in advance!
Vuex is fine and all, but if you just want to expose a property to all of your views in a router based app, you can set it on the router-view.
<router-view :count="count"></router-view>
Then your view component just needs to accept it as a prop.
export default {
props:["count"],
name: 'RacePilot',
mounted() {
console.log(this.count);
}
}
this.$root references the top level Vue instance (new Vue...) and not the App VueComponent.
it is really hacky, other solutions are preferable, but this could work:
new Vue({
el: '#app',
router,
template: '<App/>',
components: { App },
methods: {
getCount() {
return this.$children[0].count
}
},
});
and using getCount() in RacePilot.vue:
export default {
name: 'RacePilot',
mounted() {
console.log(this.$root.getCount());
}
}
You are trying to access data which is stored in App.vue but this data will be local to the component and not accessible globally.
App.vue is not the root instance (referred to by $root), instead it is the first component within the root instance which is actually created at main.js. It is during this creation time, you need to pass the data which will then be exposed for all child components via $root.
Here is the relevant portion of main.js, modified accordingly :-
new Vue({
el: '#app',
data: { count: 0 },
router,
template: '<App/>',
components: { App }
});
Tip : To confirm that App.vue is indeed the first child of root instance, try comparing the references of this.$root with this.$parent. It should returntrue which means that root instance is the parent of App.vue.
References :-
https://v2.vuejs.org/v2/guide/instance.html
https://v2.vuejs.org/v2/api/#vm-root
https://v2.vuejs.org/v2/guide/components-edge-cases.html#Accessing-the-Root-Instance
It should had worked as it is, as it is working here.
However a better way to manage global variables, which are available across components should be solved by state machine. Vue has Vuex for that purpose as stated here.
You should not do it like that.
Definitely you should not try to access other components like that.
To share data between components you can either use props (one-way binding) or Vuex to make data accessible and editable from all components through store.
You can use global $store or $router if you will start your Vue app this way:
new Vue({
el: '#q-app',
router,
store
render: h => h(require('./App'))
})
Then you can access store (for state change or access state (do not mutate state this way)) - this.$store.state.yourStaneName
You can also make the App component the actual root by passing the component directly to the Vue instance, which would look something like this:
new Vue(App).$mount('#app')
You'll probably have to move the router to App.vue, but this will make sure that this.$root will resolve to your App component directly.
Related
I'm having trouble understanding how to get a computed property all the way out through the router to my template. Here's a basic idea of what I'm doing:
const Home = {
template: '<router-link to="/level/1">Level 1</router-link>'
}
const Level = {
template: '<template>|{{ id }}|{{ message }}|</template>',
props: ['id','message']
}
const router = new VueRouter({
routes: [
{ path: '/', component: Home, props: true },
{ path: '/level/:id', component: Level, props: true }
]
})
const vm = new Vue({
el: '#app',
router,
template: '<router-view></router-view>',
computed: {
message() {
return 'HELLO';
}
}
})
When I click the "Level 1" link, the result I expect to see is:
|1|HELLO|
The result I actually see is:
|1||
The final usage will be a bit more functional than this, but hopefully that's enough to expose whatever it is that I'm not understanding about props, or routing, or computed properties.
There are 2 issues:
1) There's an error:
Cannot use <template> as component root element because it may contain multiple nodes.
So change that to a div. When using the Vue CLI, templates are wrapped in <template> but there still needs to be a different root element inside of it.
2) The Level component has a prop called message but it isn't passed. The Home route passes id but not message. Home can't pass message at the moment, because it's in the root component, and Home didn't receive it.
You could:
Use Vuex to solve this most cleanly
Define message in Home instead of the root and pass it to Level
Pass the message from root to Home and then again from Home to Level
Hi Guys i'm trying to create a look something like Bootstrap Nav Tabs but with Vuejs and Vue Router i also want to change the url in browser
here is my code for VueRouter
it is working fine but the Parent component(UserProfile) get re-render every time i switch between UserProfilePosts or UserDetails because i know my code going to be larger and this is not a good user experience,Thanks
{
path:'/:id',
component:UserProfile,
children: [
{ path: '', component: UserProfilePosts },
{ path: 'details', component: UserDetails },
],
meta:{
requiresAuth:true
}
}
Main Component(UserProfile):
<template>
<div class="container-fluid">
<h1>UserProfile</h1>
<router-link to="/username">Post's</router-link>
<router-link to="/username/details">Details</router-link>
<router-view></router-view>
</div>
<script>
export default{
created(){
console.log('created');
}
}</script>
You can try using Vuex with vex-persist. Vue refresh and reload the html each time it is asked. I am new to vue and this was how I implemented it, though it may not be the best solution.
VueX is the one central source of truth that your components can look for information. It will be easier passing down as prop and all the components just head to the 'store' for information
This stores the information as a local / session storage. For more information check out : https://github.com/championswimmer/vuex-persistuex-persist
import Vue from 'vue'
import Vuex from 'vuex'
import VuexPersistence from 'vuex-persist'
const vuexLocal = new VuexPersistence({
storage: window.sessionStorage
})
Vue.use(Vuex)
export default new Vuex.Store({
plugins: [vuexLocal.plugin],
state: {
database: []
},
mutations: {
pushToDatabase: (state, val) => {
state.database.push (val}
}
},
getters: {
getData: state => {
return state.database
}
}
})
Im using Vue Router. In my code I used to have:
<div v-bind:is="page.component_name" v-bind:page="page"></div>
Which worked, and the page data was passed to the component. But how do I do the same with a router-view? This doesn't seem to work:
<router-view v-bind:page="page"></router-view>
js:
var vm = new Vue({
...,
router : new VueRouter({
routes : [
{ path: '/foo', component: { template: '<div>foo</div>', created:function(){alert(1);} } },
//{ path: '/bar', component: { template: '<div>bar</div>', created:function(){alert(2);} } },
{ path: '/bar', component: Vue.component("ti-page-report") }
]
}),
...
});
vue-router has a dedicated page in docs on how to pass props to router-view.
Passing Props to Route Components
Example snippet from docs:
const router = new VueRouter({
routes: [
{ path: '/user/:id', component: User, props: true },
// for routes with named views, you have to define the `props` option for each named view:
{
path: '/user/:id',
components: { default: User, sidebar: Sidebar },
props: { default: true, sidebar: false }
}
]
})
If you are looking for simplified usage, props can still be passed the same way they are passed to any component. But component that is used for rendering the route (the one that is specified in route definition) should expect to receive the props.
Here is simple usage example of passing props to router-view:
I personally decided to use provide/inject feature: preserving reactivity with minimal overhead.
The component ("ti-page-report") that needs to access the props being sent just needs to add it:
<template>
<div>
<h1>Now you can access page: {{ page }}</h1>
</div>
</template>
export default {
name: "TiPageReport",
props: ['page'], // can now be accessed with this.page
...
};
See https://v2.vuejs.org/v2/guide/components-props.html for how to use props properly.
main.js:
import Vue from 'vue'
import App from './app.vue'
let vm = new Vue({
el: '.layers-container',
render: h => h(App),
})
//This doesn't work, layers undefined
console.log(vm.layers);
//This doesn't work either
vm.layers.push({'name': 'image2'})
app.vue using vue-loader:
<template>
<div>
<div v-for="item in layers>
<a :href="item.name"></a>
</div>
</div>
</template>
<script>
export default {
name: 'app',
data() {
return {
layers: [{'name': 'image1'}]
}
}
}
</script>
I have objects from a canvas that are treated as layers I want to add to this list, so I'm trying to take the instance of Vue and push objects onto it so it then updates the data in the template. But, it seems that I can't actually do that outside of the component itself, and I don't know if I'm just doing it wrong, or if I really have to put the rest of my code into the components.
How would I push the data as exampled above, to the layers array in app.vue?
I'm learning Vue router. And I want to made programmatic navigation without using <router-link> in templates file.
My router and view:
router = new VueRouter({
routes: [
{path : '/videos', name: 'allVideos', component: Videos },
{path : '/videos/:id/edit', name: 'editVideo', component: VideoEdit },
]
});
new Vue({
el: "#app",
router,
created: function(){
if(!localStorage.hasOwnProperty('auth_token')) {
window.location.replace('/account/login');
}
router.push({ name: 'allVideos' })
}
})
So by default I push to 'allVideos' route and inside that component I have a button and method for redirecting to ''editVideo'
button:
<button class="btn btn-sm btn-warning" #click="editVideo(video)">Edit</button>
method:
editVideo(video) {router.push({ name: 'editVideo', params: { id: video.id } })},
It works fine. But when I try to get id inside a VideoEdit component using $route.params.id I got error Uncaught ReferenceError: $route is not defined
Maybe it's because I'm not using npm for now just a cdn version of Vue and Vuerouter. Any solutions? Thanks!
Updated: btw in Vue dev tool I see $route instance inside the component
Updated:
var VideoEdit = Vue.component('VideoEdit', {
template: ` <div class="panel-heading">
<h3 class="panel-title">Edit {{vieo.name}}</h3>
</div>`,
data() {
return {
error: '',
video: {},
}
},
created: function () {
console.log($route.params.id);
},
})
Thanks to Sandeep Rajoria
we found solution, need to use this.$route except $route inside a component
For those who getting the error after adding this
TypeError: Cannot read property '$route' of undefined
We need to use a regular function instead of ES6 arrow functions
data: function() {
return {
usertype: this.$route.params.type
};
},
This worked for me.
import Vue from 'vue'
import Router from 'vue-router';
Vue.use(Router)
const router = new VueRouter({
routes: [
{path : '/videos', name: 'allVideos', component: Videos },
{path : '/videos/:id/edit', name: 'editVideo', component: VideoEdit },
]
});
new Vue({
el: "#app",
router,
created: function(){
if(!localStorage.hasOwnProperty('auth_token')) {
window.location.replace('/account/login');
}
this.$router.push({ name: 'allVideos' });
}
})
If you're using vue v2 & vue-router v2 then in vue-cli generated boilerplate way to access router e.g. from component is to import router (exported in router/index.js)
<script>
import Router from '../router';
then in your code you can use router functions like:
Router.push('/contacts'); // go to contacts page
For those attempting to use es6 arrow functions, another alternative to #Kishan Vaghela is:
methods: {
gotoRegister() {
this.$router.push('register')
}
}
as explained in the first answer of Methods in ES6 objects: using arrow functions
In my case these previous solutions don't work for me so
i did the following
<script>
import Router from '../router';
then in your code you can use this one
this.$router.push('/contacts');