Iterating with v-for on dynamic item - vue.js

Question

I'm trying to iterate through a db object I fetch during created(), I get the values in a console.log but the v-for template part remains empty. My sub-question is : is this good practice ? I'm quite new to Vue and my searches on this issue make me think it's a lifecycle issue.
Thanks for the help.
TEMPLATE PART :
.content(v-for="(content, key, index) in contents")
h3 {{key}}
.line
| {{getValue(content)}} // this is blank
METHODS PART:
getValue(value) {
PagesService.fetchDataWrap({
id: value
}).then((response) => {
const test = response.data.values[0].value
console.log(test) //this is working and gives the right value
return test
})
},
getPage() {
PagesService.fetchPage({
id: this.$route.params.page
}).then((response) => {
this.name = response.data.result.name
this.langs = response.data.result.langs
this.project = response.data.result.parent
this.contents = response.data.result.values
})
this.getProject()
}
console.log(this.contents) result :
{__ob__: Observer}
footer: "5a29943b719236225dce6191"
header: "5a29a9f080568b2484b31ee1"
which is the values I want to send when v-for iterates on contents so the getValue can process it to fetch corresponding values

Answer 1

I wouldn't recommend attempting to output the value of an asynchronous method. It's highly unlikely that it will work correctly.
Instead, populate your contents array / object fully during the created hook. For example, this can replace the contents hash value with whatever comes back from fetchDataWrap...
getPage () {
PagesService.fetchPage({
id: this.$route.params.page
}).then(response => {
this.name = response.data.result.name
this.langs = response.data.result.langs
this.project = response.data.result.parent
let contents = response.data.result.values
Promise.all(Object.keys(contents).map(key => {
// map each key to a "fetchDataWrap" promise
return PageService.fetchDataWrap({
id: contents[key]
}).then(res => {
// replace the hash with the resolved value
contents[key] = res.data.values[0].value
})
}).then(() => {
// all done, assign the data property
this.contents = contents
})
})
}
Then you can trust that the content has been loaded for rendering
.content(v-for="(content, key, index) in contents")
h3 {{key}}
.line
| {{content}}