I'm fetching WordPress posts asynchronously via getStaticProps()
...
export async function getStaticProps({ params, preview = false, previewData }) {
const data = await getPostsByCategory(params.slug, preview, previewData)
return {
props: {
preview,
posts: data?.posts
},
}
}
... and passing them to useState
:
const [filteredArticles, setFilteredArticles] = useState(posts?.edges)
Then, I pass the state to a component:
router.isFallback ? (
// If we're still fetching data...
<div>Loading…</div>
) : (
<ArticleGrid myArticles={filteredArticles} />
This is necessary because another component will setFilteredArticles
with a filter function.
But when we are passing the state to ArticlesGrid
, the data is not ready when the component loads. This is confusing to me since we passing the state within a router.isFallback
condition.
Even if we set state within useEffect
...
const [filteredArticles, setFilteredArticles] = useState()
useEffect(() => {
setFilteredArticles(posts)
}, [posts?.edges])
... the data arrives too late for the component.
I'm new to Next.js. I can probably hack my way through this, but I assume there's an elegant solution.
Let's look at some useEffect
examples:
useEffect(() => {
console.log("Hello there");
});
This useEffect
is executed after the first render and on each subsequent rerender.
useEffect(() => {
console.log("Hello there once");
}, []);
This useEffect
is executed only once, after the first render .
Some possible solutions to your problem:
No articles case
You probably want to treat this case in your ArticleGrid component anyway, in order to prevent any potential errors.
In ArticleGrid.js:
const {myArticles} = props;
if(!myArticles) {
return (<div>Your custom no data component... </div>);
}
// normal logic
return ...
Alternatively, you could also treat this case in the parent component:
{
router.isFallback ? (
// If we're still fetching data...
<div>Loading…</div>
) : (
<>
{
filteredArticles
? <ArticleGrid myArticles={filteredArticles} />
: <div>Your custom no data component... </div>
}
</>
)
}
Use initial props
Send the initial props in case the filteres haven't been set:
const myArticles = filteredArticles || posts?.edges;
and then:
<ArticleGrid myArticles={myArticles} />
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