vue mounted with code examples 2

Vue is one of the most popular JavaScript frameworks that is used today. It allows developers to create rich, interactive user interfaces with ease. One of the key features of Vue is its lifecycle hooks, and the mounted hook is one of the most important of these. In this article, we'll explore how Vue's mounted hook works, how to use it, and some code examples to help you get started.

The mounted hook is a lifecycle hook that is called when a Vue instance is mounted to the DOM. At this stage, all other lifecycle hooks have been called, including the created hook. This means that mounted is the perfect place to access the DOM, set up event listeners, and start data fetching. When the mounted hook is called, the Vue instance has fully rendered and is ready to be interacted with.

The following code example shows how to use the mounted hook to access the DOM:

<template>
  <div ref="myDiv">Hello World</div>
</template>

<script>
export default {
  mounted() {
    console.log(this.$refs.myDiv.innerText);
  }
}
</script>

In this example, we are using the ref attribute to give the div element a reference name of "myDiv". We then use the $refs property to access the element and log its innerText to the console. This is a simple example, but it demonstrates how easy it is to access the DOM using Vue's mounted hook.

The mounted hook can also be used to set up event listeners. In the following code example, we will set up a click event listener on a button element:

<template>
  <button ref="myButton">Click Me!</button>
</template>

<script>
export default {
  mounted() {
    this.$refs.myButton.addEventListener('click', () => {
      console.log('Button clicked!');
    });
  }
}
</script>

In this example, we are using the ref attribute again to give the button element a reference name of "myButton". We then use the addEventListener() method to set up a click event listener on the button. When the button is clicked, we log a message to the console. Again, this is a simple example, but it demonstrates how easy it is to set up event listeners using Vue's mounted hook.

Finally, the mounted hook can also be used to start data fetching. In the following code example, we will use the axios library to fetch data from an API when the component is mounted:

<template>
  <div>
    <h1>{{ title }}</h1>
    <ul>
      <li v-for="post in posts" :key="post.id">{{ post.title }}</li>
    </ul>
  </div>
</template>

<script>
import axios from 'axios';

export default {
  data() {
    return {
      title: '',
      posts: []
    }
  },
  mounted() {
    axios.get('https://jsonplaceholder.typicode.com/posts')
      .then(response => {
        this.title = 'Posts';
        this.posts = response.data;
      });
  }
}
</script>

In this example, we are using the axios library to make a GET request to an API that returns a list of posts. We then use the response to set the title property and the posts property in the component's data object. When the component is mounted, the axios request is made and the response is used to update the component's data. This is a powerful example of how Vue's mounted hook can be used to start data fetching.

In conclusion, the mounted hook is a fundamental part of Vue's lifecycle hooks. It provides a way to access the DOM, set up event listeners, and start data fetching. We have explored several code examples that demonstrate how to use the mounted hook in these different ways. By mastering the mounted hook, you can create powerful Vue components that interact with the user and external data sources.

let's delve a bit deeper into some of the topics we covered in the previous article.

First, let's talk about accessing the DOM in Vue using the mounted hook. In Vue, we typically use the ref attribute to give an element a reference name. We can then use the $refs property to access that element in the mounted hook. This makes it very easy to manipulate the DOM in Vue.

Here's a slightly more complex example that demonstrates how to use refs to access multiple elements in the DOM:

<template>
  <div>
    <input ref="input1" type="text">
    <input ref="input2" type="text">
    <button @click="combineText">Combine Text</button>
  </div>
</template>

<script>
export default {
  methods: {
    combineText() {
      const text1 = this.$refs.input1.value;
      const text2 = this.$refs.input2.value;
      const combinedText = `${text1} ${text2}`;
      alert(combinedText);
    }
  }
}
</script>

In this example, we are using two input elements and a button. We give each input element a reference name using the ref attribute. In the combineText method, we access the values of both inputs using their reference names and then combine them. When the button is clicked, an alert is shown with the combined text.

Next, let's talk about setting up event listeners in Vue using the mounted hook. When you need to set up an event listener in Vue, you can use the addEventListener method just like you would in vanilla JavaScript. Here's an example that demonstrates how to set up a click event listener:

<template>
  <button ref="myButton">Click Me!</button>
</template>

<script>
export default {
  mounted() {
    this.$refs.myButton.addEventListener('click', () => {
      alert('Button clicked!');
    });
  }
}
</script>

In this example, we are using a button element with a reference name of "myButton". In the mounted hook, we use the addEventListener method to set up a click event listener on the button. When the button is clicked, an alert is shown with the message "Button clicked!".

Finally, let's talk about starting data fetching using the mounted hook in Vue. This is a common scenario, as many Vue applications need to fetch data from an API or other external source. There are several ways to fetch data in Vue, but one common library used is axios.

Here's an example that demonstrates how to use axios to fetch data from an API and display it in a Vue component:

<template>
  <div>
    <h1>{{ title }}</h1>
    <ul>
      <li v-for="post in posts" :key="post.id">{{ post.title }}</li>
    </ul>
  </div>
</template>

<script>
import axios from 'axios';

export default {
  data() {
    return {
      title: '',
      posts: []
    }
  },
  mounted() {
    axios.get('https://jsonplaceholder.typicode.com/posts')
      .then(response => {
        this.title = 'Posts';
        this.posts = response.data;
      });
  }
}
</script>

In this example, we're using the axios library to make a GET request to an API that returns a list of posts. Inside the mounted hook, we call axios.get to make the request and then update the component's data with the response data using the then method. Once the data has been fetched and stored, the component will re-render with the updated data.

Overall, the mounted hook is a crucial part of Vue's lifecycle hooks. It's used to access the DOM, set up event listeners, and start data fetching. By mastering the mounted hook, you can build powerful, interactive Vue components that respond to user input and external data sources.

Popular questions

  1. What is the mounted hook in Vue?
    Answer: The mounted hook in Vue is a lifecycle hook that is called when a Vue instance is mounted to the DOM. It's a fundamental part of Vue's lifecycle hooks and is used to access the DOM, set up event listeners, and start data fetching.

  2. How can we access the DOM in Vue using the mounted hook?
    Answer: We can use the ref attribute to give an element a reference name and then use the $refs property to access that element in the mounted hook. This makes it easy to manipulate the DOM in Vue, and we can access multiple elements by giving them unique reference names.

  3. How do we set up event listeners in Vue using the mounted hook?
    Answer: We can use the addEventListener method just like we would in vanilla JavaScript. We can select the relevant element using its reference name and then use addEventListener to set up the required event listener.

  4. What is axios and how can we use it to fetch data in Vue using the mounted hook?
    Answer: Axios is a popular JavaScript library used for making HTTP requests. We can use axios to fetch data from an API in Vue by using the get method and providing the URL of the API endpoint. Once the data is fetched, we can store it in the component's data object and use it to update the component's template.

  5. What are some of the benefits of using the mounted hook in Vue?
    Answer: Some of the benefits of using the mounted hook in Vue include: easy access to the DOM, the ability to set up event listeners, and the ability to fetch data from an external source. By using the mounted hook effectively, we can create dynamic and interactive Vue components that respond to user input and data changes.

Tag

Vuemountedex2

Throughout my career, I have held positions ranging from Associate Software Engineer to Principal Engineer and have excelled in high-pressure environments. My passion and enthusiasm for my work drive me to get things done efficiently and effectively. I have a balanced mindset towards software development and testing, with a focus on design and underlying technologies. My experience in software development spans all aspects, including requirements gathering, design, coding, testing, and infrastructure. I specialize in developing distributed systems, web services, high-volume web applications, and ensuring scalability and availability using Amazon Web Services (EC2, ELBs, autoscaling, SimpleDB, SNS, SQS). Currently, I am focused on honing my skills in algorithms, data structures, and fast prototyping to develop and implement proof of concepts. Additionally, I possess good knowledge of analytics and have experience in implementing SiteCatalyst. As an open-source contributor, I am dedicated to contributing to the community and staying up-to-date with the latest technologies and industry trends.
Posts created 3223

Leave a Reply

Your email address will not be published. Required fields are marked *

Related Posts

Begin typing your search term above and press enter to search. Press ESC to cancel.

Back To Top