Vue 3 passing array warning: Extraneous non-props attributes were passed to component but could not be automatically inherited

Question

please, I'm learning a VueJS 3 and I have probably begineer problem. I have warn in browser developer console like this one:

The Message is:

[Vue warn]: Extraneous non-props attributes (class) were passed to component but could not be automatically inherited because component renders fragment or text root nodes.

I'm passing array of objects to the child Component. In my parent views/Home.vue compoment I have this implemenation:

<template>
  <div class="wrapper">
    <section v-for="(item, index) in items" :key="index" class="box">
      <ItemProperties class="infobox-item-properties" :info="item.properties" />
    </section>
  </div>
</template>
<script>
import { ref } from 'vue'
import { data } from '@/data.js'
import ItemProperties from '@/components/ItemProperties.vue'

export default {
  components: {
    ItemDescription,
  },
  setup() {
    const items = ref(data)

    return {
      items,
    }
  },
</script>

In child compoment components/ItemProperties.vue I have this code:

<template>
  <div class="infobox-item-property" v-for="(object, index) in info" :key="index">
    <span class="infobox-item-title">{{ object.name }}:</span>
    <span v-if="object.type === 'rating'">
      <span v-for="(v, k) in object.value" :key="k">{{ object.icon }}</span>
    </span>
    <span v-else>
      <span>{{ object.value }}</span>
    </span>
  </div>
</template>

<script>
export default {
  props: {
    info: {
      type: Array,
      required: false,
      default: () => [
        {
          name: '',
          value: '',
          type: 'string',
          icon: '',
        },
      ],
    },
  },
}
</script>

It doesn't matter if I have default() function or not. Also doesn't matter if I have v-if condition or not. If I have cycle in the Array, I got this warning

Data are in data.js file. The part of file is here:

export const data = [
  {
    title: 'White shirt',
    properties: [
      { name: 'Material', value: 'Cotton', type: 'string', icon: '' },
      { name: 'Size', value: 'M', type: 'string', icon: '' },
      { name: 'Count', value: 4, type: 'number', icon: '' },
      { name: 'Absorption', value: 4, type: 'rating', icon: '💧' },
      { name: 'Rating', value: 2, type: 'rating', icon: '⭐️' },
      { name: 'Confort', value: 2, type: 'rating', icon: '🛏' },
      { name: 'Sleeves', value: 'Short', type: 'string', icon: '' },
      { name: 'Color', value: 'White', type: 'string', icon: '' },
    ],
  },
]

PS: Application works but I'm afraid about that warning. What can I do please like right way?

I will be glad for any advice. Thank you very much.

Answer 1

The ItemProperties component has multiple root nodes because it renders a list in the root with v-for.

Based on the class name (infobox-item-properties), I think you want the class to be applied to a container element, so a simple solution is to just add that element (e.g., a div) in your component at the root:

// ItemProperties.vue
<template>
  <div>
    <section v-for="(item, index) in items" :key="index" class="box">
    ...
    </section>
  </div>
</template>

demo

Answer 2

You could also prevent passing down attributes in child components by doing this:

export default defineComponent({
  name: "ChildComponentName",
  inheritAttrs: false // This..
})

Source: https://vuejs.org/guide/components/attrs.html