Vue js with simple JavaScript Vue is undefined - javascript

I am trying to understand how vue works. To do that I simplify it as much as possible, hence no webpack no CDNs or any other packages (unless its a necessity).
So, Came up with this but trying to inject a simple a variable into html gives vue is undefined error.
*vue.js file is taken from npm vue package.
<html>
<head>
<script src="vue.js"></script>
<script>
new vue({
data: 'This must be injected'
}).$mount('#app');
</script>
</head>
<body>
<div id="app">
<p> {{ data }} </p>
</div>
<h1>This is a sample header</h1>
</body>
</html>

You need to have Vue load after the Dom is ready so it can find the element to attach itself to — don't put it in the head. Also it's upper-case Vue. And Data can't just be a naked property it should be a function that returns an object with your properties (it can also be an an object, but it's not recommended once the app starts getting bigger).
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<p> {{ data }} </p>
</div>
<h1>This is a sample header</h1>
<script>
Vue.config.productionTip = false
new Vue({
data(){ return {
data: 'This must be injected'
}
}
}).$mount('#app');
</script>

There are a few problems in your code.
vue should be Vue
data should be an Object or Function - https://v2.vuejs.org/v2/api/#data
<html>
<head>
</head>
<body>
<div id="app">
<p> {{ myText }} </p>
</div>
<h1>This is a sample header</h1>
<script src="vue.js"></script>
<script>
new Vue({
data: {
myText: 'This must be injected'
}
}).$mount('#app');
</script>
</body>
</html>

I think the data must have an object as it's value.
<html>
<head>
<script src="vue.js"></script>
<script>
new Vue({
data: {
txt: 'This must be injected'
}
}).$mount('#app');
</script>
</head>
<body>
<div id="app">
<p> {{ txt }} </p>
</div>
<h1>This is a sample header</h1>
</body>
</html>

Related

Uncaught SyntaxError: The requested module does not provide an export named

i've got this error in my console
Uncaught SyntaxError: The requested module './components/tileHeader/controller.js' does not provide an export named 'tileHeader'
this is my code
components/tileHeader/controller.js:
Vue.component('tileHeader',{
template: '#tileHeader',
data(){
return{
count:0
}
},
})
components/tileHeader/view.html:
<script type="text/x-template" id="tileHeader">
<div class="container">
<div class="row">
<div class="col">
<!--<div v-show="item.label != null || item.label == undefined"
class="label">{{item.label}}</div>
<img v-show="item.image != null" src="item.image"/>-->
<p>This is a Test</p>
</div>
</div>
</div>
</script>
main.js:
import Vue from './vue.js';
import { tileHeader } from './components/tileHeader/controller.js';
new Vue({
el: '#app',
components: {
'tileHeader': tileHeader
},
})
index.html:
<!DOCTYPE html>
<html>
<head>
<title>Vue X-Templates</title>
</head>
<body>
<div id="#app"></div>
<script type="module" src="main.js"></script>
</body>
</html>
i'm working with x-templates.
this is my project structure:
structure
Could you try something like this ?
Create a single file that will contain your html / css and js.
tileHeader.vue :
<template>
<!-- Your view.html -->
</template>
<script>
export default {
name: 'tileHeader',
}
</script>
<style scoped>
</style>
Since the file has a export default, you'll be able to import it in another file
Add to main.js :
import tileHeader from "./components/tileHeader.vue";

Writing javascript code in a component using vue

I am trying to make a component using Vue for my javascript code but it does not work.
My main goal is to create a component with vue or Vue3
<head>
<title></title>
<script src="https://cdn.jsdelivr.net/npm/vue#2/dist/vue.js"></script>
</head
<body>
<div id="app">
<myelement name="ibrahim" age="12"></myelement>
</div>
</body>
<script>
Vue.component("myelement",{
props:["name","age"], // for arguments
template:`
<h1> welcome to my vue component,<br> name :{{name }} and age : {{age}}</h1>
`// template where my code template should be
})
var vm = new Vue({ // creating an object from Vue
el:"#app" // bind my created code to the id "app"
})
</script>
This code is working, but when I put a Javascript code in instead of html code. I got an error
this code I am using for my Javascript code, but the vue is not calling my javascript code . It is just calling my html code
<head>
<title></title>
<script src="https://cdn.jsdelivr.net/npm/vue#2/dist/vue.js"></script>
</head
<body>
<h3>this page works</h3>
<div id="app">
<myelement ></myelement >
</div>
</body>
<script>
document.write("<h1>Header from document.write()</h1>");
var temp = "<h1>Hello from vue veriable</h1>"
Vue.component("myelement ",{
template:`
<script>
alert(1);
document.write("<h1>Header from document.write()</h1>");
</script>
`// template where my code template should be
})
var vm = new Vue({ // creating an object from Vue
el:"#app" // bind my created code to the id "app"
})
</script>
what I want to do is, when I create the tag in the page then the alert(1) will show up.
In vue, you cannot use script tag in template of components and you get below error:
[Vue warn]: Error compiling template: Templates should only be responsible for mapping the state to the UI. Avoid placing tags with side-effects in your templates, such as <script>, as they will not be parsed.
Instead you can put your javascript codes in created lifecycle hook. This hook is called when your component create:
<head>
<title></title>
<script src="https://cdn.jsdelivr.net/npm/vue#2/dist/vue.js"></script>
</head>
<body>
<h3>this page works</h3>
<div id="app">
<myelement></myelement>
</div>
</body>
<script>
Vue.component("myelement", {
template: `<h2>Hello</h2>`,
});
var vm = new Vue({
el: "#app",
created() {
alert(1);
document.write("<h1>Header from document.write()</h1>");
},
});
</script>
I'm not sure but I think this code will work correctly:
<head>
<title></title>
<script src="https://cdn.jsdelivr.net/npm/vue#2/dist/vue.js"></script>
</head>
<body>
<h3>this page works</h3>
<div id="app">
<myelement :message="variableAtParent"></myelement>
</div>
</body>
<script>
Vue.component("myelement", {
props: ['message'],
template: '<p>At child-comp, using props in the template: {{ message }}</p>',,
});
var vm = new Vue({
el: "#app",
data: {
variableAtParent: 'DATA FROM PARENT!'
}
});
</script>

VueJs filters have no effect

Simple code example
<!DOCTYPE html>
<html>
<head>
<title>My first Vue app</title>
<script src="https://cdn.jsdelivr.net/npm/vue#2.6.10/dist/vue.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/axios/0.19.0/axios.min.js"></script>
<style>
</style>
</head>
<body>
<div id="app">
<h1>Bitcoin Price Index</h1>
<div v-for="currency in info">
{{ currency.description }}
<span v-html="currency.symbol"></span>{{ currency.rate_float || currencyToDeciaml }}
</div>
</div>
<script>
const app = new Vue({
el : '#app',
data : {
info : null,
},
filters : {
currencyToDeciaml(val) {console.log(`foo`);
return Number(val).toFixed(2);
}
},
// Dom is ready so now load the data
mounted() {
axios.get(`https://api.coindesk.com/v1/bpi/currentprice.json`)
.then(response => this.info = response.data.bpi);
},
});
</script>
</body>
</html>
I am trying to apply a simple filter currencyToDeciaml but it doesn't even get executed and foo does not display. I cannot seem to figure it out. Any help would be appreciated.
The correct syntax for filters is this:
{{ currency.rate_float | currencyToDeciaml }}
with only one pipe

Refer vue.js data but nothing

1.I am a beginner of vue.js, but when I was trying some examples, I found something uncommon. The first one is when I set id in the body, and write my js code as followed:
<html>
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="./css/semantic.css">
<script type="text/javascript" src="js/vue.js">
</script>
<title></title>
</head>
<body style="background-color:black;" id="app">
<div class="ui container" style="margin:20px;">
<div class="ui segment">
<h1>{{ title }}</h1>
<p>
{{ message }}
</p>
</div>
</div>
<script>
var app = new Vue({
el: "#app",
data: {
message: "Hello, world!",
title: "How about you?"
}
})
</script>
</body>
</html>
And this is my result which does not show me data :
2.And the second problem is when I created an object in the data, and I refer it as followed, it also does not work in the div label.
This is the code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="./css/semantic.css">
<script type="text/javascript" src="js/vue.js">
</script>
<title></title>
</head>
<body style="background-color:black;">
<div class="ui container" style="margin:20px;">
<div class="ui segment" id="app">
<h1>{{ article.title }}</h1>
<p>
{{ article.message }}
</p>
</div>
</div>
<script>
var app = new Vue({
el: "#app",
data: {
article{
message: "Hello, world!",
title: "How about you?"
}
}
})
</script>
</body>
</html>
So I wonder if there some conflicts when I was using semanticUI and vue.js?
As a best practice, you can create a top level div#app, like this:
var app = new Vue({
el: "#app",
data: {
message: "Hello, world!",
title: "How about you?"
}
})
<link href="https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.2.13/semantic.min.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.4.2/vue.min.js"></script>
<body style="background-color:black;">
<div id="app"><!-- just a wrapper for vuejs -->
<div class="ui container" style="margin:20px;">
<div class="ui segment">
<h1>{{ title }}</h1>
<p>
{{ message }}
</p>
</div>
</div>
</div>
</body>

how to use vue.js in simple web application?

I am gonna planning to use vue.js in a web application. but it could not loaded and not fired html in browser. Please look at my below code:
<!DOCTYPE html>
<html>
<head>
<script>
var app = new Vue({
el: '#app',
data: {
message: 'Hello Vue!'
}
});
</script>
</head>
<body>
<div id="app">
{{ message }}
</div>
<script src="https://unpkg.com/vue/dist/vue.js"></script>
</body>
</html>
The problem is you're trying to create Vue instance before vue.js is loaded, so I think if you put your code after vue.js, your application will work fine.
<!DOCTYPE html>
<html>
<head></head>
<body>
<div id="app">
{{ message }}
</div>
<script src="https://unpkg.com/vue/dist/vue.js"></script>
<script>
var app = new Vue({
el: '#app',
data: {
message: 'Hello Vue!'
}
});
</script>
</body>
</html>

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