Q1) In my reactjs application, I am trying to fetch an API from my backend Nodejs server. The API responds with an image file on request.
I can access and see image file on http://192.168.22.124:3000/source/592018124023PM-pexels-photo.jpg
But in my reactjs client side I get this error on console log.
Uncaught (in promise) SyntaxError: Unexpected token � in JSON at position 0
Reactjs:
let fetchURL = 'http://192.168.22.124:3000/source/';
let image = name.map((picName) => {
return picName
})
fetch(fetchURL + image)
.then(response => response.json())
.then(images => console.log(fetchURL + images));
Nodejs:
app.get('/source/:fileid', (req, res) => {
const { fileid } = req.params;
res.sendFile(__dirname + /data/ + fileid);
});
Is there any better way to do than what I am doing above?
Q2) Also, how can I assign a value to an empty variable (which lives outside the fetch function)
jpg = fetchURL + images; So I can access it somewhere.
The response from the server is a binary file, not JSON formatted text. You need to read the response stream as a Blob.
const imageUrl = "https://.../image.jpg";
fetch(imageUrl)
// vvvv
.then(response => response.blob())
.then(imageBlob => {
// Then create a local URL for that image and print it
const imageObjectURL = URL.createObjectURL(imageBlob);
console.log(imageObjectURL);
});
Equivalent to solution by @maxpaj, but using async and await.
async function load_pic() {
const url = '<REPLACE-WITH-URL>'
const options = {
method: "GET"
}
let response = await fetch(url, options)
if (response.status === 200) {
const imageBlob = await response.blob()
const imageObjectURL = URL.createObjectURL(imageBlob);
const image = document.createElement('img')
image.src = imageObjectURL
const container = document.getElementById("your-container")
container.append(image)
}
else {
console.log("HTTP-Error: " + response.status)
}
}
This question is 4 years old and I think in 2022 there are many ways to solve this. This is ES6 version using async calls.
First, I don't know if you are trying to download the image or insert the image into a img
tag. So I will assume we want to download the image.
The process is simple: a) fetch the image as a blob
; b) convert blob to Base64
using URL.createObjectURL(blob)
; and c) trigger the download using a ghost a
tag.
const $btn = document.getElementById('downloadImage') const url = 'https://s3-ap-southeast-1.amazonaws.com/tksproduction/bmtimages/pY3BnhPQYpTxasKfx.jpeg' const fetchImage = async url => { const response = await fetch(url) const blob = await response.blob() return blob } const downloadImage = async url => { const imageBlob = await fetchImage(url) const imageBase64 = URL.createObjectURL(imageBlob) console.log({imageBase64}) const a = document.createElement('a') a.style.setProperty('display', 'none') document.body.appendChild(a) a.download = url.replace(/^.*[\\\/]/, '') a.href = imageBase64 a.click() a.remove() } $btn.onclick = event => downloadImage(url)
<button id="downloadImage">Download Image</button>
StackOverflow uses a sandboxed iframe
's so we can test the download but you can use my codepen
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