Understanding Directives in Vue.js

Hello students! Welcome to lesson 1 of module 2: Vue.js Directives. Today, we will learn what directives are and how to use them in our Vue.js applications.

What are Directives?

Directives are elements that allow adding additional functionality to the DOM. They are prefixed with v-.

Vue.js directives can be divided into two categories:

• Attribute Directives: These directives add or modify attributes of the DOM.
• Event Directives: These directives add or modify events of the DOM.

Attribute Directives

Attribute directives are the most common. They are used to add or modify attributes of the DOM.

For example, the v-bind directive binds data from your application to the DOM.

Example

Let’s see an example of using the v-bind directive to bind the name property of an object to the title attribute of an h1 element.

<h1 v-bind:title="name">Hello, world!</h1>

In the above example, the value of the name property of the object will be bound to the title attribute of the h1 element.

Other Common Attribute Directives

In addition to the v-bind directive, there are other common attribute directives, such as:

• v-on: Adds an event listener to an element.
• v-model: Binds an input element to the state of a component.
• v-for: Iterates over a list.

Event Directives

Event directives are used to add or modify events of the DOM.

For example, the v-on:click directive adds a click event listener to an element.

Example

Let’s see an example of using the v-on:click directive to add a click event listener to a button element.

<button v-on:click="showMessage">Click here</button>

In the above example, the showMessage() method will be called when the user clicks the button element.

Other Common Event Directives

In addition to the v-on:click directive, there are other common event directives, such as:

• v-on:keyup: Adds a keyup event listener to an element.
• v-on:submit: Adds a submit event listener to an element.
• v-on:change: Adds a change event listener to an element.

Conclusion

In this lesson, we learned what directives are and how to use them in our Vue.js applications.

Directives are a powerful tool that can be used to add additional functionality to our applications.

In the next few lessons, we will learn about the most common Vue.js directives, including v-bind, v-if, v-show, and v-for.

Challenge

Here’s a challenge for you:

• Create a Vue.js application that displays the user’s name.
• Use the v-bind directive to bind the user’s name to an h1 element.

Good luck!