How to fix "multiple root element" v-for error - vue.js

I'm new to Vue.js and I'm still learning it. I bumped into this error which I don't know how to solve.
Here is my simple script:
<template>
<div v-for="item in array" :key="item.id">
{{item}}
</div>
</template>
<script>
export default {
data () {
return {
array: ['Lion','Bear','Fish','Bird']
}
}
}
</script>
And here is the error that come up:
Cannot use v-for on stateful component root element because it renders multiple elements.
1 |
2 | <div v-for="item in array" :key="item.id">
| ^^^^^^^^^^^^^^^^^^^^^
3 | {{item}}
4 | </div>
Is there anyone who knows how to fix this error?

Try also renaming variable from array to animalNames similar. And remove id from loop as there is not id element exist, instead you can use index
<template>
<div>
<div v-for="item,index in array" :key="index">
{{item}}
</div>
</div>
</template>

You must have a root tag. Try wrapping your looped div in another div.
<template>
<div>
<div v-for="item in array" :key="item.id">
{{item}}
</div>
</div>
</template>
<script>
export default {
data () {
return {
array: ['Lion','Bear','Fish','Bird']
}
}
}
</script>

Related

Vue.js: Why does $el return a text node

I do have the following code:
<template>
<custom-child></custom-child>
</template>
export default class Custom extends Vue {
mounted() {
console.log(this.$el); // Returns a text node (with an empty content)
console.log(this.$el.nextElementSibling); // Returns a element representing my custom child
}
}
I am quite confused why would I need to use nextElementSibling as I expected $el to return an element directly.
The solution is as follows.
wrong
<template>
<div></div>
<div>
...
</div>
</template>
correct
<template>
<div>
 <div>...</div>
...
</div>
</template>
OR
wrong
<template>
<div></div>
<div>
...
</div>
</template>
correct
<template>
<div>
 <div>...</div>
</router-view>
</div>
</template>
If you do not use a "div" tag just inside the "Template" tag, you will get the same problem.

Has anyone came across this problem? [vue/no-multiple-template-root] The template root disallows 'v-for' directives.eslint-plugin-vue

It is actually a three problems in one:
[vue/no-multiple-template-root]
The template root disallows 'v-for' directives.eslint-plugin-vue
[vue/no-parsing-error]
Parsing error: Expected to be an alias, but got empty.eslint-plugin-vue
[vue/valid-v-for]
Expected 'v-bind:key' directive to use the variables which are defined by the 'v-for' directive.eslint-plugin-vue
Can anyone help me please I am so fed with searching online for it everywhere
enter code
<template>
<div class="post" v-for="post" in posts >
<div><strong>Title</strong>{{post.title}}</div>
<div><strong>Desctiption</strong>{{post.body}}</div>
</div>
</template>
<script>
export default{
data(){
return{
posts:[
{ id: 1, title: 'javascript', body: "the desctiption"},
{ id: 2, title: 'javascript2', body: "the desctiption"},
{ id: 3, title: 'javascript3', body: "the desctiption"},
]
}
}
}
Vue.js must have a single element at the root of the template. If you have av-for directive, when the DOM is populated there will be multiple <div> elements at the root, which Vue does not allow.
So you just need to add another <div> element to surround your v-for div.
Then, move the in posts within your quotes and add a :key
<template>
<div>
<div class="post" v-for="post in posts" :key="post.id">
<div><strong>Title</strong>{{post.title}}</div>
<div><strong>Desctiption</strong>{{post.body}}</div>
</div>
</div>
</template>
In vue two you should one root element, using v-for loop will render multiple elements in the template like :
<div class="post" >
...
</div>
<div class="post" >
...
</div>
to avoid this add an extra div and bind key to the post id :key="post.id":
<template>
<div class="posts">
<div class="post" v-for="post in posts" :key="post.id">
<div><strong>Title</strong>{{post.title}}</div>
<div><strong>Desctiption</strong>{{post.body}}</div>
</div>
</div>
</template>

Show Div When Hover Based on ID in Vue JS

I have a div that when i want hover to it, it will show other div. However, my first div is dynamic, it has an ID. So how will i able to hover to ID based on its ID?
It should be #mouseenter="hoverService{{services.id}} = true" but it causes error. So i made the code below to just static.
Here's my code below:
<template>
<div
class="col-md-3"
v-for="(services, index) in servicesFiltered"
:key="index"
#mouseenter="hoverService = true"
#mouseleave="hoverService = false"
>
<div class="service_background" v-if="hoverService">
<div class="mb-1" v-for="(sub_services, index) in services.menu_items" :key="index">
<router-link
:to="{ path: `/${sub_services.data}`}"
>
<a
href="#"
class="btn btn-outline-primary w-100 services_button"
>{{sub_services.text }}</a>
</router-link>
</div>
</div>
</div>
</template>
<script>
export default {
data() {
return {
hoverService: false
};
}
};
</script>
Try this code
https://codesandbox.io/s/y7p9qyyovz
You need to maintain hover for each item you can not manipulate using single variable for multiple items.

Output html using a Vue template tag, but without having a nested element

My over-arching question is: In Vue, how to output inner html while iterating over a collection but without having to wrap it in an additional div or span.
Specifically: I'm iterating over an array of js objects from within a Vue template. Each object has a "render" method which outputs html.
This works:
template:
`<div id="container">
<template v-for="element in elements">
<span v-html="element.render()"></span>
</template>
</div>
`,
But I would like to do something like below, because I don't want the output to be wrapped in a div or span. This code produces no error but also produces no output:
template:
`<div id="container">
<template v-for="element in elements" v-html="element.render()">
</template>
</div>
`,
In a perfect world, I would do something like this, but mustache format can't output html:
<div id="container">
<template v-for="(element, index) in elements">
{{ element.render() }}
</template>
</div>
The desired output:
<div id="container">
(output of element.render())
(output of element.render())
(output of element.render())
etc.
</div>
Thank you for any guidance,
L
Delete the <template> tag completely and use render function in <script> tag. Something like this, but this code is not tested, demonstrational only.
export default {
...
render (h) {
return h('div', this.elements.map(function (elm) {
return h(elm.render())
})
}
}

vuejs render part of template inside different elements without repeating

I am new to Vuejs. This is what I need to do.
<div v-for="r in records">
<div v-if="r.something">
<div id="x">
{{ r. something}}
more of r here.
</div>
</div>
<div v-else id="x">
same div as in the block above.
</div>
</div>
What I want do is not define div with id x two times as it is huge.
Make your 'div' a component and refer to it in both places.
There are many ways to define your component. This is example shows just one. If you are using WebPack, use a single file component. You can then have your script, html, and css all in one file that gets precompiled. That's the best way to manage your 'huge' div. Then you can continue to refactor and break it up into more components.
const myComponent = {
template: "<div :id='id'>HELLO, my id is {{id}}. r.foo is {{r.foo}} </div>",
props: {
id: String
},
data() {
return {
r: {
foo: 'bar'
}
}
}
}
<div v-for="r in records">
<div v-if="r.something">
<my-component id='x' />
</div>
<div v-else id="x">
<my-component id='x' />
</div>
</div>