I am learning Vue and messing around with examples in their guide. I am trying to register a sub-component locally inside a root vue component as described here. But it does not appear on my page. What am I missing ? app.components also returns undefined.
console.log('Loading my script');
var componentX = {
template: `<h3>Hello</h3>`
}
var app = new Vue({
el: '#vue-div',
template: `<div>Vue is working</div>`,
components: {
'component-x': componentX
}
})
console.log(app.components);
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
</head>
<body>
<div id="vue-div">
<component-x></component-x>
</div>
<script src="https://cdn.jsdelivr.net/npm/vue#2.6.12"></script>
<script src="./js/test.js"></script>
</body>
</html>
The issue is, your main Vue has a template - this replaces any HTML inside the target element
So, you can either add the component-x inside the new Vue constructor template:
console.log('Loading my script');
var componentX = {
template: `<h3>Hello</h3>`
}
var app = new Vue({
el: '#vue-div',
template: `<div>Vue is working<component-x></component-x></div>`,
components: {
'component-x': componentX
}
})
console.log(app.$options.components);
<div id="vue-div"></div>
<script src="https://cdn.jsdelivr.net/npm/vue#2.6.12"></script>
<script src="./js/test.js"></script>
Or you can remove the template: from the new Vie constructor and the existing content of the target element will be used
console.log('Loading my script');
var componentX = {
template: `<h3>Hello</h3>`
}
var app = new Vue({
el: '#vue-div',
components: {
'component-x': componentX
}
})
console.log(app.$options.components);
<div id="vue-div">
Vue is working
<component-x></component-x>
</div>
<script src="https://cdn.jsdelivr.net/npm/vue#2.6.12"></script>
Related
I have a simple index.html file. It includes the Vue JS application and has the following code.
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Test</title>
<script>
const foo = {
bar: 100
};
</script>
<script src="main.js"></script>
</head>
<body>
<div id="app"></div>
</body>
</html>
Here's how the Vue JS app looks like.
main.js
import Vue from "vue"
import App from "./App.vue"
Vue.config.productionTip = false
new Vue({
render: h => h(App)
}).$mount("#app")
App.vue
<template>
<div>
{{ config.bar }}
</div>
</template>
<script>
export default {
props: {
config: {
type: Object,
default: () => {},
},
}
}
</script>
I simply want to pass the const foo variable into the App.vue file. I already tried to pass it as a prop to the <div id="app" :config="foo"></div>, however it did throw an undefined error in App.vue.
How can I pass a JS variable from HTML into a Vue Application and to the component?
Suppose I have a simple Vue component like this:
Vue.component('blog-post', {
props: ['title'],
template: '<h3>{{ title }}</h3>'
})
I don't want to render the component. I just want to pass the title somehow into blog-post component inside my script code, and get the DOM accordingly. For example, if I pass the title value Hello, then I expected the full DOM as <h3>Hello</h3>. I'll assign the DOM into a variable for using later.
One solution is to create a new Vue instance with only the target component, $mount it, and then get the outerHTML of its $el (root element):
Vue 2
<script src="https://unpkg.com/vue#2.6.12/dist/vue.min.js"></script>
<script>
Vue.component('blog-post', {
props: ['title'],
template: '<h3>{{ title }}</h3>'
})
const app = new Vue({
template: `<blog-post title="Hello world" />`
}).$mount()
console.log(app.$el.outerHTML)
</script>
Vue 3
In Vue 3, create an app instance, and call its mount() on a newly created <div>. The return value of mount() is the root component, which contains $el:
<script src="https://unpkg.com/vue#3.2.39/dist/vue.global.prod.js"></script>
<script>
const app = Vue.createApp({
template: `<blog-post title="Hello world" />`
})
app.component('blog-post', {
props: ['title'],
template: '<h3>{{ title }}</h3>'
})
const comp = app.mount(document.createElement('div'))
console.log(comp.$el.outerHTML)
</script>
If you want to get HTML of your component, you must to use ref attribute of parent element.
Try something like that:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<div id="app">
<div>
<button #click="logComponentBlogPost">Log Component</button>
</div>
<div v-show="false" ref="BlogPost">
<blog-post title="Hello Word"></blog-post>
</div>
</div>
<script>
let BlogPost = Vue.component('BlogPost', {
props: ['title'],
template: '<h3>{{ title }}</h3>',
});
new Vue({
el: '#app',
components: { BlogPost },
methods: {
logComponentBlogPost() {
console.log(this.$refs.BlogPost.innerHTML);
},
},
});
</script>
</body>
</html>
I'm a Vue newbie and I'm experimenting with vue-router and dynamic loading of components without using any additional libraries (so no webpack or similar).
I have created an index page and set up a router. When I first load the page I can see that subpage.js has not been loaded, and when I click the <router-link> I can see that the subpage.js file is loaded. However, the URL does not change, nor does the component appear.
This is what I have so far:
index.html
<html>
<head>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
<script src="https://unpkg.com/vue-router/dist/vue-router.js"></script>
</head>
<body>
<div id="app">
<h1>Hello App!</h1>
<router-link to="/subpage">To subpage</router-link>
<router-view></router-view>
</div>
<script src="main.js"></script>
</body>
</html>
main.js
const router = new VueRouter({
routes: [
{ path: '/subpage', component: () => import('./subpage.js') }
]
})
const app = new Vue({
router
}).$mount('#app');
subpage.js
export default {
name: 'SubPage',
template: '<div>SubPage path: {{msg}}</div>'
data: function() {
return {
msg: this.$route.path
}
}
};
So the question boils down to: How can I dynamically load a component?
How can I dynamically load a component?
Try this:
App.vue
<template>
<div id="app">
<router-link to="/">Home</router-link>
<router-link to="/about">About</router-link>
<hr/>
<router-view></router-view>
</div>
</template>
<script>
export default {
name: 'app',
components: {}
};
</script>
main.js
import Vue from 'vue';
import VueRouter from 'vue-router';
import App from './App.vue';
Vue.use(VueRouter);
Vue.config.productionTip = false;
const Home = () => import('./components/Home.vue');
const About = () => import('./components/About.vue');
const router = new VueRouter({
mode: 'history',
routes:[
{path:'/', component: Home},
{path:'/about',component: About}
]
})
new Vue({
router,
render: h => h(App)
}).$mount('#app');
Home.vue
<template>
<div>
<h2>Home</h2>
</div>
</template>
<script>
export default {
name: 'Home'
};
</script>
About.vue
<template>
<div>
<h2>About</h2>
</div>
</template>
<script>
export default {
name: 'About'
};
</script>
This way, the component Home will be automatically loaded.
This is the demo: https://codesandbox.io/s/48qw3x8mvx
I share your wishes for "as lean as possible" codebase and therefore made this simple example code below (also accessible at https://codesandbox.io/embed/64j8pypr4k).
I am no Vue poweruser either, but when researching I have thought about three possibilities;
dynamic imports,
requirejs,
old school JS generated <script src /> include.
It looks like the last is the easiest and takes least effort too :D Probably not best practice and probably obsolete soon (at least affter dynamic import support).
NB: This example is friendly to more recent browsers (with native Promises, Fetch, Arrow functions...). So - use latest Chrome or Firefox to test :) Supporting older browsers may be done with some polyfills and refactoring etc. But it will add a lot to codebase...
So - dynamically loading components, on demand (and not included before):
index.html
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="x-ua-compatible" content="ie=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Vue lazyload test</title>
<style>
html,body{
margin:5px;
padding:0;
font-family: sans-serif;
}
nav a{
display:block;
margin: 5px 0;
}
nav, main{
border:1px solid;
padding: 10px;
margin-top:5px;
}
.output {
font-weight: bold;
}
</style>
</head>
<body>
<div id="app">
<nav>
<router-link to="/">Home</router-link>
<router-link to="/simple">Simple component</router-link>
<router-link to="/complex">Not sooo simple component</router-link>
</nav>
<main>
<router-view></router-view>
</main>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.0.3/vue.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue-router/2.0.1/vue-router.min.js"></script>
<script>
function loadComponent(componentName, path) {
return new Promise(function(resolve, reject) {
var script = document.createElement('script');
script.src = path;
script.async = true;
script.onload = function() {
var component = Vue.component(componentName);
if (component) {
resolve(component);
} else {
reject();
}
};
script.onerror = reject;
document.body.appendChild(script);
});
}
var router = new VueRouter({
mode: 'history',
routes: [
{
path: '/',
component: {
template: '<div>Home page</div>'
},
},
{
path: '/simple',
component: function(resolve, reject) {
loadComponent('simple', 'simple.js').then(resolve, reject);
}
},
{ path: '/complex', component: function(resolve, reject) { loadComponent('complex', 'complex.js').then(resolve, reject); }
}
]
});
var app = new Vue({
el: '#app',
router: router,
});
</script>
</body>
</html>
simple.js:
Vue.component("simple", {
template: "<div>Simple template page loaded from external file</div>"
});
complex.js:
Vue.component("complex", {
template:
"<div class='complex-content'>Complex template page loaded from external file<br /><br />SubPage path: <i>{{path}}</i><hr /><b>Externally loaded data with some delay:</b><br /> <span class='output' v-html='msg'></span></div>",
data: function() {
return {
path: this.$route.path,
msg: '<p style="color: yellow;">Please wait...</p>'
};
},
methods: {
fetchData() {
var that = this;
setTimeout(() => {
/* a bit delay to simulate latency :D */
fetch("https://jsonplaceholder.typicode.com/todos/1")
.then(response => response.json())
.then(json => {
console.log(json);
that.msg =
'<p style="color: green;">' + JSON.stringify(json) + "</p>";
})
.catch(error => {
console.log(error);
that.msg =
'<p style="color: red;">Error fetching: ' + error + "</p>";
});
}, 2000);
}
},
created() {
this.fetchData();
}
});
As you can see - function loadComponent() does the "magic" thing of loading components here.
So it works, but it is probably not the best solution, with regards to the (at least) following:
inserting tags with JS can be treated as a security problem
in the near future,
performance - synchronously loading files block the thread (this can
be a major no-no later in app's life),
I did not test caching etc. Can be a real problem in production,
You loose the beauty of (Vue) components - like scoped css, html and
JS that can be automatically bundled with Webpack or something,
You loose the Babel compilation/transpilation,
Hot Module Replacement (and state persistance etc) - gone, I believe,
I probably forgot about other problems that are obvious for
senior-seniors :D
Hope I helped you though :D
I wanted to see how usefull are "new" dynamic imports today (https://developers.google.com/web/updates/2017/11/dynamic-import), so I did some experiments with it. They do make async imports way easier and below is my example code (no Webpack / Babel / just pure Chrome-friendly JS).
I will keep my old answer (How to dynamically load components in routes) for potential reference - loading scripts that way works in more browsers than dynamic imports do (https://caniuse.com/#feat=es6-module-dynamic-import).
So at the end I noticed that you were actually very, very, very close with your work - it was actually just a syntax error when exporting imported JS module (missing comma).
Example below was also working for me (unfortunately Codesandbox's (es)lint does not allow the syntax, but I have checked it locally and it worked (in Chrome, even Firefox does not like the syntax yet: (SyntaxError: the import keyword may only appear in a module) ));
index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Page Title</title>
</head>
<body>
<div id="app">
<h1>Hello App!</h1>
<router-link to="/temp">To temp</router-link>
<router-link to="/module">To module</router-link>
<router-view></router-view>
</div>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
<script src="https://unpkg.com/vue-router/dist/vue-router.js"></script>
<script src="main.js"></script>
</body>
</html>
main.js:
'use strict';
const LazyRouteComponent = {
template: '<div>Route:{{msg}}</div>',
data: function() {
return {
msg: this.$route.path
}
}
}
const router = new VueRouter({
routes: [
{
path: '/temp',
component: {
template: '<div>Hello temp: {{msg}}</div>',
data: function() {
return {
msg: this.$route.path
}
}
}
},
{ path: '/module', name: 'module', component: () => import('./module.js')},
{ path: '*', component: LazyRouteComponent }
]
})
const app = new Vue({
router
}).$mount('#app');
and the key difference, module.js:
export default {
name: 'module',
template: '<div>Test Module loaded ASYNC this.$route.path:{{msg}}</div>',
data: function () {
return {
msg: this.$route.path
}
},
mounted: function () {
this.$nextTick(function () {
console.log("entire view has been rendered after module loaded Async");
})
}
}
So - allmost exactly like your code - but with all the commas;
subpage.js
export default {
name: 'SubPage',
template: '<div>SubPage path: {{msg}}</div>',
data: function() {
return {
msg: this.$route.path
}
}
};
So - your code works (i tested it by copy pasting) - you were actually just missing a comma after template: '<div>SubPage path: {{msg}}</div>'.
Nevertheless this only seems to work in:
Chrome >= v63
Chrome for Android >= v69
Safari >= v11.1
IOS Safari >= v11.2
(https://caniuse.com/#feat=es6-module-dynamic-import)...
The code below just show the title in curly braces, what is wrong with the VueJs setup?
<!DOCTYPE html>
<html lang="en">
<head>
<script src="https://unpkg.com/vue#2.5.13/dist/vue.js"></script>
</head>
<body>
<div id='app'>
<p>{{ title }}</p>
</div>
<script>
new Vue({
el: '#app',
data: {
title: 'A Title'
}
});
</script>
</body>
</html>
#Web Dev It works fine but you need to do this in script tag
var app = new Vue({
el: '#app',
data: {
title: 'A Title'
}
});
And now if you load the page and you will see a title and then you can open the console and change title by typing app.title = 'My new title'
I'm trying a demo on vuejs. Now I want the html title to bind a vm field.
The below is what I tried:
index.html
<!DOCTYPE html>
<html id="html">
<head>
<title>{{ hello }}</title>
<script src="lib/requirejs/require.min.js" data-main="app"></script>
</head>
<body>
{{ hello }}
<input v-model="hello" title="hello" />
</body>
</html>
app.js
define([
'jquery', 'vue'
], function ($, Vue) {
var vm = new Vue({
el: 'html',
data: {
hello: 'Hello world'
}
});
});
But the title seemed not bounded, how to make it work?
There are essentially two ways to solve it.
Use an existing Package
For example, vue-meta:
<template>
<div id="app">
<router-view></router-view>
</div>
</template>
<script>
export default {
name: 'App',
metaInfo: {
// if no subcomponents specify a metaInfo.title, this title will be used
title: 'Default Title',
// all titles will be injected into this template
titleTemplate: '%s | My Awesome Webapp'
}
}
</script>
Create your own Component
Create a vue file containing:
<script>
export default {
name: 'vue-title',
props: ['title'],
watch: {
title: {
immediate: true,
handler() {
document.title = this.title;
}
}
},
render () {
},
}
</script>
Register the component using
import titleComponent from './title.component.vue';
Vue.component('vue-title', titleComponent);
Then you can use it in your templates, e.g.
<vue-title title="Static Title"></vue-title>
<vue-title :title="dynamic.something + ' - Static'"></vue-title>
You can do it with 1 line in the App.vue file, like this:
<script>
export default {
name: 'app',
created () {
document.title = "Look Ma!";
}
}
</script>
Or change the <title> tag content in public/index.html
<!DOCTYPE html>
<html>
<head>
<title>Look Ma!</title> <!- ------ Here ->
</head>
...
This answer is for vue 1.x
using requirejs.
define([
'https://cdn.jsdelivr.net/vue/latest/vue.js'
], function(Vue) {
var vm = new Vue({
el: 'html',
data: {
hello: 'Hello world'
}
});
});
<!DOCTYPE html>
<html id="html">
<head>
<title>{{ hello }}</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.2.0/require.js" data-main="app"></script>
</head>
<body>
{{ hello }}
<input v-model="hello" title="hello" />
</body>
</html>
you can do it like this using the ready function to set the initial value and watch to update when the data changes.
<html>
<head>
<title>Replace Me</title>
</head>
<body>
<script src="https://cdn.jsdelivr.net/vue/latest/vue.js"></script>
<div id="app">
<input v-model="title">
</div>
<script>
new Vue({
el: '#app',
ready: function () {
document.title = this.title
},
data: {
title: 'My Title'
},
watch: {
title: function (val, old) {
document.title = val
}
}
})
</script>
</body>
</html>
also i tried this based on your original code and it works
<html>
<head>
<title>{{ title }}</title>
</head>
<body>
<script src="https://cdn.jsdelivr.net/vue/latest/vue.js"></script>
<div id="app">
<input v-model="title">
</div>
<script>
new Vue({
el: 'html',
data: {
title: 'My Title'
}
})
</script>
</body>
</html>
Just to chime in here. I have read that VueJS wants nothing to do with the meta stuff so I would do such things outside of the "VueJS" realm.
Basically make a plain vanilla js service like below. Here you could add all the functions to handle the meta data stuff such as the Open Graph data.
meta.js
export setTitle(title) {
document.title = title
}
Now we can import the service in main and then provide it to any component in the app who wants it. I could even use my meta service in other projects too which use different frameworks like React or Angular. Portability is super cool!
main.js
import meta from './meta'
new Vue({
router,
render: h => h(App),
provide: {
meta: meta
}
}).$mount('#app')
Here the component injects the meta service it wants to use.
someView.vue
export default {
name: 'someView',
inject: ['meta'],
data: function() {
returns {
title: 'Cool title'
}
},
created: function() {
this.meta.setTitle(this.title);
}
}
This way the meta service is decoupled from the app because different parent components can provide different versions of the meta service. Now you can implement various strategies to see which one is right for you or even different strategies per component.
Basically the inject walks up the component hierarchy and takes the meta service from the first parent who provides it. As long as the meta service follows a proper interface, you're golden.
Decoupling with DI is super cool 😃
Title and meta tags can be edited and updated asynchronously.
You can use state management, create a store for SEO using vuex and update each part accordingly.
Or you can update the element by yourself easily
created: function() {
ajax().then(function(data){
document.title = data.title
document.head.querySelector('meta[name=description]').content = data.description
})
}
If you are using Vuex and want <title> to be part of your application state, then:
create a pageTitle state variable in Vuex
map the state to the template using mapState()
watch it in template, probably add immediate: true to trigger the watcher right away
in watcher, document.title = pageTitle
This will allow you to manage title with Vuex and keep them in sync. I found it useful for SPAs.
By doing this you don't have to mess with your original HTML template, as most of the time Vue root template resides inside <body>.
This is for Vue 2.x.
router.beforeEach((to, from, next) => {
let mohican = to.path; if (mohican == '/') mohican = 'Home'
document.title = mohican.replace('/','');
next();
return;
});
I have an application toolbar component which is common for all pages of my SPA website and is nested in App.vue. In every page I update my common toolbar title in the created hook of the page using Vuex store:
//in every page.vue
created() {
this.$store.commit('toolBar', { pageTitle: this.pageTitle, ... })
},
To automatically update the website title (along with the toolbar title) I use this mutation in the store:
//store.js
toolBar(state,val){
document.title = val.pageTitle
state.toolBar = val
},
Similarly, I use the same mechanism to update e.g. SEO metadata
just pass
:title="data.name"