i want to pass a String to my child component like this, but previously i want to print it
this is my parent component
{{left.leftA}} // here show me 8
<CustomCard
:left="left.leftA"
export default {
name: 'Parent',
data() {},
setup() {
onMounted(async () => {
const answer = await getData(name)
left.value = answer.response //{leftA:'A', leftB:'B'...}
})
and in my child component i have this declaration
export default {
name: 'CustomCard',
props: {
left: {
type: String,
required: true,
},
i am getting this warning:
[Vue warn]: Invalid prop: type check failed for prop "left". Expected String with
value "undefined", got Undefined
Does it have something to do with how I am loading the data? is it ok to use onMounted?
This is happening because the initial value for value is null. So, on initial render it throws the warning, but upon another render it has the correct prop type (a string) and renders correctly.
You have 3 options. Allow '' as an option on the prop or don’t render the component until you have the correct data or make use of computed Property.
Option-1
{{left.leftA}} // here show me 8
<CustomCard
:left="left.leftA ? left.leftA : ''"
Option-2
{{left.leftA}} // here show me 8
<CustomCard v-if="loaded"
:left="left.leftA"
and in onMounted(}
onMounted(async () => {
const answer = await getData(name)
left.value = answer.response //{leftA:'A', leftB:'B'...}
// Set the loaded flag as true here. Also make sure its set as false inside the setup()
})
Option-3
{{left.leftA}} // here show me 8
<CustomCard
:left="sendVal"
In computed....
computed: {
sendVal() {
if(left && left.left1) return left.left1;
return '';
}
}