how to pass props to root App component in vuejs v3?

Question

How can i pass some variable from the main div folder:

<div 
      id="app" 
      someVariable='some value'
></div>

and to have it as a prop in the main App component in VueJS v3.0:

    name: "App",
    components: {
    },
    props: {
        someVariable: {
            type: String,
            default: "-"
        
    }
}

Answer 1

You could not access that using props, but you could get the value of that attribute using some Vanilla js DOM like document.getElementById("app").getAttribute("someVariable")

const {
  createApp
} = Vue;
const App = {
  props: ["someVariable"],
  data() {
    return {

    }
  },
  mounted() {
    console.log(document.getElementById("app").getAttribute("someVariable"))
  }
}
const app = createApp(App)
app.mount('#app')

<script src="https://unpkg.com/[email protected]/dist/vue.global.prod.js"></script>

<div id="app" someVariable='some value'>
  Vue 3 app
</div>