In SingleBlogPost.jsx i have:
export async function getStaticPaths() {
const res = await fetch("http://localhost:1337/api/posts");
let { data } = await res.json();
const paths = data.map((data) => ({
params: { slug: data.attributes.slug },
}));
return {
paths,
fallback: "blocking",
};
}
where I generate blog pages by their slug. But then in getStaticProps I need to fetch single post by slug but I want to do it by id.
export async function getStaticProps(context) {
console.log("context", context);
const { slug } = context.params;
console.log("slug is:", slug);
const res = await fetch("http://localhost:1337/api/posts");
const { data } = await res.json();
return {
props: {
data,
},
revalidate: 10, // In seconds
};
}
And I want to keep url like /blog/:slug , I dont want to include id. in url .When I already fetch all posts in getStaticPaths how I can access post id in getStaticProps to avoid fetching by slug?
I found a concise work around that uses the object-hash package. I basically create a hash of the params object and use that to create the tmp filename both on set and get. The tmp file contains a json with the data I want to pass between the two infamous static callbacks.
The gist of it:
function setParamsData({params, data}) {
const hash = objectHash(params)
const tmpFile = `/tmp/${hash}.json`
fs.writeFileSync(tmpFile, JSON.stringify(data))
}
function getParamsData (context) {
const hash = objectHash(context.params)
const tmpFile = `/tmp/${hash}.json`
context.data = JSON.parse(fs.readFileSync(tmpFile))
return context
}
We can then use these helpers in the getStaticPaths and getStaticProps callbacks to pass data between them.
export function getStaticPaths(context) {
setParamsData({...context, data: {some: 'extra data'})
return {
paths: [],
fallback: false,
}
}
export function getStaticProps(context) {
context = getParamsData(context)
context.data // => {some: 'extra data'}
}
I'm sure someone can think of a nicer API then re-assigning a argument variable.
The tmp file creation is likely not OS independent enough and could use some improvement.
It looks like recently released a workaround using a file system cache.
The crux of the solution is that they save the body object in memory, using something like this:
this.cache = Object.create(null)
and creating methods to update and fetch data from the cache.
Discussion here: https://github.com/vercel/next.js/discussions/11272#discussioncomment-2257876