Can you give me a short fetch example with promises and async so that I can understand it again in vanilla javascript, I forgot how it works....
#explain promises and async for me
hard chasm
buoyant ridgeBOT
Hi @hard chasm. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave:
Sure, I can provide you with an example using the fetch API with async/await in JavaScript. This example is based on the information provided in the extracts from the Next.js documentation and blogs.
Here's a simple example of how you can use fetch with async/await:
async function getData() {
const res = await fetch('<https://api.example.com/...'>);
// The return value is *not* serialized
// You can return Date, Map, Set, etc.
return res.json();
}
async function showData() {
const data = await getData();
console.log(data);
}
showData();
In this example, getData is an asynchronous function that fetches data from a URL. The await keyword is used to pause the execution of the function until the promise returned by fetch is resolved. Once the promise is resolved, the function continues execution and returns the result of res.json(), which is another promise. This promise resolves with the result of parsing the body text as JSON.
The showData function then calls getData, again using await to pause execution until the promise returned by getData is resolved. Once the promise is resolved, the function logs the data to the console.
This is a basic example and doesn't include error handling. In a real-world application, you'd want to use a try/catch block to handle any errors that might occur during the fetch operation.
For more detailed information, you can refer to the Next.js documentation on Data Fetching (https://nextjs.org/docs/app/building-your-application/data-fetching/fetching-caching-and-revalidating) and the Next.js blog (https://nextjs.org/blog/next-13).
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
hard chasm
@buoyant ridge give the context I want to save the data content into a variable and I have to make multiple requests and want the all in one variable how would i do that?
buoyant ridgeBOT
Let me check the knowledge base for you. One moment! :books:
If you need to make multiple requests and want to save all the data into one variable, you can use Promise.all(). This function returns a single Promise that resolves when all of the promises passed as an iterable have resolved, or rejects with the reason of the first promise that rejects.
Here's an example based on the information provided in the extracts:
async function getArtist(username) {
const res = await fetch(`<https://api.example.com/artist/${username}`>);
return res.json();
}
async function getArtistAlbums(username) {
const res = await fetch(`<https://api.example.com/artist/${username}/albums`>);
return res.json();
}
async function getAllData(username) {
// Initiate both requests in parallel
const artistData = getArtist(username);
const albumsData = getArtistAlbums(username);
// Wait for the promises to resolve
const [artist, albums] = await Promise.all([artistData, albumsData]);
return { artist, albums };
}
async function showData() {
const username = 'example';
const data = await getAllData(username);
console.log(data);
}
showData();
In this example, getAllData is an asynchronous function that initiates two fetch requests in parallel, then waits for both promises to resolve using Promise.all(). The results are then returned as an object.
The showData function then calls getAllData, again using await to pause execution until the promise returned by getAllData is resolved. Once the promise is resolved, the function logs the data to the console.