The v-model mandate may be a two-way information official mandate in Vue.js, which ties the esteem of a shape input component to a component information property. It allows changes made by the client within the input field to be consequently reflected within the component information and bad habit versa.
Here’s an example of using v-model to bind an input element to a component data property:
Enter your name:</label>
<input type="text" id="name" v-model="userName">
<p>Hello, {{ userName }}!</p>
</div>
</template>
<script>
export default {
data() {
return {
userName: ''
}
}
}
</script>
When text is added into the input box, Vue.js updates the component’s userName property, which causes a fresh rendering of the component with the updated name shown.
All things considered, the v-model is a potent directive that makes it easier to create two-way data bindings between form elements and component data attributes in Vue.js applications.
Vue CSS Authoritative
Vue provides several ways to bind CSS styles and classes dynamically to HTML elements based on the component’s data. The primary way to bind CSS styles is through the v-bind directive or its shorthand.
Here’s an example of binding a CSS style to a component data property:
<template>
<div :style="{ backgroundColor: bgColor }">
<h1>Welcome to my website!</h1>
</div>
</template>
<script>
export default {
data() {
return {
bgColor: '#ffffff'
}
},
mounted() {
// Change the background color after a delay
setTimeout(() => {
this.bgColor = '#f5f5f5';
}, 2000);
}
}
</script>
In this example, the v-bind directive or : shorthand is used to bind the backgroundColor style to the bgColor data property. Initially, the bgColor property is set to #ffffff, resulting in a white background. After 2 seconds, the bgColor property is updated to #f5f5f5, causing the background color to change to a light grey.
We can also bind CSS classes using the v-bind directive or: shorthand. Here’s an example of binding a class to a component data property:
<template>
<div :class="{ 'is-active': isActive }">
<h2>My Account</h2>
</div>
</template>
<script>
export default {
data() {
return {
isActive: true
}
}
}
</script>
<style>
.is-active {
background-color: #f5f5f5;
color: #333;
}
</style>
In this example, the v-bind directive or : shorthand is used to bind the is-active class to the isActive data property. When isActive is true, the is-active class is applied to the
element, resulting in a grey background and dark text.
Computed Properties by Vue
When other data properties are changed, computed properties in Vue.js are immediately updated. These properties are calculated depending on other data properties. In a Vue.js component, computed properties may be used to do computations, filter data, and alter data.
Here’s an example of a computed property in a Vue.js component:
<template>
<div>
<p>{{ message }}</p>
<button @click="reverseMessage">Reverse Message</button>
</div>
</template>
<script>
export default {
data() {
return {
text: 'Hello World'
}
},
computed: {
message() {
return this.text.split('').reverse().join('');
}
},
methods: {
reverseMessage() {
this.text = this.text.split('').reverse().join('');
}
}
}
</script>
The message computed property in the following example is computed using the text data property. Using the split(), reverse(), and join() methods, the message property returns the text property’s inverse. The inverted message is then shown using the calculated property in the template.
When the text property is updated by clicking the “Reverse Message” button, the message computed property is automatically updated, triggering a re-render of the component and updating the displayed message.
In general, computed properties in Vue.js provide a useful method to do calculations and data transformations based on other data properties in a component, allowing developers to write clean and understandable code.
Watchers of Vue
When a data property in a component changes, the watcher function in Vue.js is invoked. Watchers are helpful for carrying out asynchronous activities, changing data before it is rendered, or updating other components of the component in response to data changes.
Here’s an example of a watcher in a Vue.js component:
<template>
<div>
<p>{{ message }}</p>
<button @click="reverseMessage">Reverse Message</button>
</div>
</template>
<script>
export default {
data() {
return {
text: 'Hello World'
}
},
computed: {
message() {
return this.text.split('').reverse().join('');
}
},
watch: {
text(newText, oldText) {
console.log(`text changed from ${oldText} to ${newText}`);
}
},
methods: {
reverseMessage() {
this.text = this.text.split('').reverse().join('');
}
}
}
</script>
In this example, the watch property is used to define a watcher for the text data property. The watcher function receives two arguments: the new value of the text property and the old value. In this case, the watcher function simply logs a message to the console when the text property changes.
The watcher function is activated when the “Reverse Message” button is pressed, updating the text property. The previous and updated values of the text property are recorded in a message that the watcher function logs to the console.
Templates for vue
In Vue.js, a template is a section of code that defines how the component should be rendered in the DOM. A Vue template can include HTML, CSS, and JavaScript code, and can also include Vue-specific syntax such as directives, expressions, and computed properties.
A Vue template is seen here:
<template>
<div class="container">
<h1>{{ title }}</h1>
<ul>
<li v-for="item in items" :key="item.id">{{ item.text }}</li>
</ul>
</div>
</template>
<script>
export default {
data() {
return {
title: 'My List',
items: [
{ id: 1, text: 'Item 1' },
{ id: 2, text: 'Item 2' },
{ id: 3, text: 'Item 3' }
]
}
}
}
</script>
<style>
.container {
background-color: #fff;
padding: 20px;
border: 1px solid #ccc;
}
</style>
In this example, the Vue template defines a container div element with a title and a list of item. The title and items data properties are defined in the component’s data() function and are used in the template using Vue expressions ({{ }}) and directives (v-for).
The template also includes some CSS styles defined in the style block, which are applied to the container div element..