Troubleshooting: Issue with Vue component template iteration

What is causing the issue with iterating inside the component template in the code above?

<!DOCTYPE html>
<html>
<head>
  <title>Exploring Vue components</title>
  <script src="https://cdn.jsdelivr.net/npm/vue"></script>
  <style>
  </style>
</head>
<body>
    <div id="blog-post-demo">
      <blog-post :posts="posts"></blog-post>
    </div>
  <script>
    
Vue.component('blog-post', {
  props: ['posts'],
  template: `
    <div class="blog-post" v-for="post in posts">
      <h3> {{ post.title }}</h3>
      <button>Enlarge text</button>
      <div v-html="post.content"></div>
    </div>`,
})
new Vue({
  el   : '#blog-post-demo',
  data : {
    posts : [
      {id: 1, title : 'My Journey to Africa',    content : 'I am the post'},
      {id: 2, title : 'My Journey to America',   content : 'I am the post'},
      {id: 3, title : 'My Journey to Antartica', content : 'I am the post'},
      {id: 4, title : 'My Journey to Asia',      content : 'I am the post'},
    ],
  }
})
  </script>
</body>
</html>

The second code snippet above is functioning correctly, but it is unclear why the first one is not working as expected. Can anyone provide insight into this issue?

<!DOCTYPE html>
<html>
<head>
  <title>Exploring Vue components</title>
  <script src="https://cdn.jsdelivr.net/npm/vue"></script>
</head>
<body>
    <div id="blog-post-demo">
      <blog-post v-for="post in posts" :post="post"></blog-post>
    </div>
  <script>
    
Vue.component('blog-post', {
  props: ['post'],
  template: `
    <div class="blog-post">
      <h3> {{ post.title }}</h3>
      <button>Enlarge text</button>
      <div v-html="post.content"></div>
    </div>`,
})
new Vue({
  el   : '#blog-post-demo',
  data : {
    posts : [
      {id: 1, title : 'My Journey to Africa',    content : 'I am the post'},
      {id: 2, title : 'My Journey to America',   content : 'I am the post'},
      {id: 3, title : 'My Journey to Antartica', content : 'I am the post'},
      {id: 4, title : 'My Journey to Asia',      content : 'I am the post'},
    ],
  }
})
  </script>
</body>
</html>

Answer №1

Here's a straightforward explanation:

"You cannot use v-for on the root element of a stateful component because it results in rendering multiple elements."

A template in Vue can only contain a single root element. If necessary, you can wrap your component in a DIV tag. However, in this scenario, it might be better to go with the second example as it appears more elegant and aligns with the single responsibility principle for that component.

For more detailed information, refer to the VueJS official documentation: https://v2.vuejs.org/v2/guide/components.html#A-Single-Root-Element

Answer №2

The issue arises when attempting to use a repetitive element as the main template root.

When utilizing a Vue.js development version, an error message may appear...

[Vue warn]: Template compilation error:

Attempting to apply v-for to a stateful component root element will result in rendering multiple elements.

To resolve this, adjust the component's template to:

template: `<div><div v-for="post in posts" :key="post.id">...</div></div>`

Demo

Vue.component('blog-post', {
  props: ['posts'],
  template: `<div>
    <div class="blog-post" v-for="post in posts" :key="post.id">
      <h3> {{ post.title }}</h3>
      <button>Enlarge text</button>
      <div v-html="post.content"></div>
    </div>
  </div>`,
})
new Vue({
  el   : '#blog-post-demo',
  data : {
    posts : [
      {id: 1, title : 'My Journey to Africa',    content : 'I am the post'},
      {id: 2, title : 'My Journey to America',   content : 'I am the post'},
      {id: 3, title : 'My Journey to Antartica', content : 'I am the post'},
      {id: 4, title : 'My Journey to Asia',      content : 'I am the post'},
    ],
  }
})
<script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="cfb9baaa8ffde1f9e1feff">[email protected]</a>/dist/vue.min.js"></script>
<div id="blog-post-demo">
  <blog-post :posts="posts"></blog-post>
</div>

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Error encountered: The Bootstrap modal() function is showing as undefined when using npm modules

Every time I attempt to call $("#myDiv").modal(), an error occurs. The error message reads: Uncaught TypeError: undefined is not a function This error has popped up in different scenarios, with various parameters being passed to modal(). Many solutions o ...

Exploring a one-dimensional nested array in order to make updates to the higher level nodes

I have a 1D nested array: nestedArr: [ { id: 1, parentId: null, taskCode: '12', taskName: 'Parent', duration: 0, assignee: '', crewCount: 0, startDate: null, endDate: null, dependencies: []}, { id: 2, parentId: 1, taskCo ...

Each time a page loads, the react useContext feature is causing the web socket connection to reset

I have integrated websockets into various parts of my nextJS application and need to make sure they are accessible everywhere without resetting the socket connection. Whenever the connection is reset, it loses all the rooms it was connected to, causing iss ...

Having trouble sending a POST request from my React frontend to the Node.js backend

My node.js portfolio page features a simple contact form that sends emails using the Sendgrid API. The details for the API request are stored in sendgridObj, which is then sent to my server at server.js via a POST request when the contact form is submitted ...

What are the best practices for running node in VSCode?

$ node test.js internal/modules/cjs/loader.js:883 throw err; ^ I have exhausted all possible solutions, including checking the PATH route for Node.js, restarting, and using different files. Despite the fact that I am able to retrieve the version when ...

Is it more suitable for a library used by getStaticProps to be classified as a normal dependency or a dev

When working with NextJS's getStaticProps, I am implementing a library that is only utilized during build time. Should this library be categorized as a regular or development dependency in my package.json? ...

Converting Ajax to JSON with Jquery offline and Manifest for enhanced offline web applications

Looking to create an offline web application, I'm in the process of transitioning from Ajax to JSON using JQuery offline. Here is the initial Ajax code: $.ajax({ url: contentpage, data: contentpagedata, cache: false }).done(function( html ) { ...

The Ionic tab is already finished displaying even before the data has completed loading

Creating a favorites section for a vouchers app has proven to be slightly challenging. When attempting to retrieve the current user's favorite vouchers and display them using ngFor in the HTML, I encountered an issue. The very first time I open the fa ...

Guide to emitting a value using the composition API

I'm currently working with a datepicker component that is part of a form in my Vue3 app using the composition API. My challenge is how to pass a value from the datepicker component back up to the form component. Unfortunately, I've encountered ...

Progress Indicator on my online platform

I've been attempting to remove a loading bar from my website, but I can't seem to locate it in the site files. I even tried using Google Chrome's inspection tool, but I couldn't pinpoint the loader. Can someone please assist me? Visit ...

Can props.children be given a ref without any existing ref?

Consider this scenario... MainComponent.js <Wrapper> <p ref={React.createRef()}>{state.item1}</p> <p>{state.item2}</p> <p>{state.item3}</p> <p>{state.item4}</p> </Wr ...

Filtering a table with a customized set of strings and their specific order using pure JavaScript

Recently, I've been diving into APIs and managed to create a table using pure vanilla javascript along with a long list of sorting commands that can filter the table based on strings. My goal is to establish an object containing strings in a specific ...

React Material Table - issue with data filtering accuracy

Currently in my React project, I am utilizing Material Table. While everything appears to be rendering correctly, the filtering and searching functionalities are not working as expected. To provide more context, below is a sample of the code: ht ...

javascript href clears Internet Explorer webpage

I noticed a strange issue with my HTML page. In Internet Explorer, when I click on the link, it displays the return value on a blank page. However, in Chrome, it simply executes the function without affecting the page appearance. Is there a way to make I ...

Ensure that any modifications made to an Angular service are reflected across all components that rely on that service

I am currently in the process of replicating a platform known as Kualitee.com, which serves as a test-management tool utilized by QA Engineers. Within Kualitee, users can access multiple projects, each containing various test cases and team members. The ab ...

Tables that respond to changes in screen size, allowing nested table cells to inherit widths

I am currently working on a responsive table with unique content in each row and a concertina feature for expanding rows. When the concertina is activated, it adds another row to the table below the current row, using a td element with a colspan attribute ...

What is the best way to organize divs in a grid layout that adapts to different screen sizes, similar to the style

Is there a way to align multiple elements of varying heights against the top of a container, similar to what is seen on Wolfram's homepage? I noticed that they used a lot of JavaScript and absolute positioning in their code, but I'm wondering if ...

What are the challenges associated with using replaceChild?

function getLatestVideos(url) { var http = new XMLHttpRequest(); http.open("GET", url, false); // false for synchronous request http.send(null); return http.responseText; } var videosText = getLatestVideos("https://www.googleapis.com/youtube/v3/se ...

Should I refrain from storing user files on my server?

Greetings! I am currently working on an Express js + React js application and using MySQL for database management. I have successfully stored user information like email, hashed passwords, and user IDs in the database. However, now I want to create ...

What is the reason behind console.log() displaying an array, while typeof returning 'object'?

This question pertains to the outcome of a mongoose find() operation. After running the code console.log('apparently this is an ' + typeof campaign.advertGroups, campaign.advertGroups); The resulting output is as follows: apparently this is an ...