Next.js Image component props onLoadingComplete not working?

Question

I'm trying to get the naturalWidth and naturalHeight from onLoadingComplete props: https://nextjs.org/docs/api-reference/next/image#onloadingcomplete but its not working? Perhaps I'm doing it wrong?

I have this function:

const handleImageLoad = (e) => {
  console.log("load", e);
};

then I have this component from next.js

<Image
  onLoadingComplete={(e) => handleImageLoad(e)}
  className=""
  src={image["data_url"]}
  alt=""
  layout="fill"
  objectFit="contain"
/>

When the image is loaded, it doesn't do anything, if I try to console log, it works, but I don't know why its not working when I'm passing the handleImageLoad

onLoadingComplete={() => handleImageLoad()}

Answer 1

Edit: Fixed in v11.1.3-canary.33

---

It appears that the next/image component is not invoking onLoadingComplete handler in case provided src is a data URI. (And I can see you've opened an issue here for the same.)

For now a workaround can be to use Object URLs. If you wish, you can implement this quite directly. Refer this thread or the linked questions.

If you want to keep using react-images-uploading, you can use the methods mentioned in this thread and others, to convert the provided data URI to Object URL then pass it as src to next/image. Obviously, this will be more performance heavy operation that handling the uploaded file yourself.

Here is a working example: https://codesandbox.io/s/jolly-ellis-4htdl?file=/pages/index.js

Just adding an alternative for the sake of completeness:

import { useState } from "react";
import Image from "next/image";

const IndexPage = () => {
  const [src, setSrc] = useState("");

  const handleChange = (e) => {
    setSrc(URL.createObjectURL(e.target.files[0]));
    return true;
  };

  const handleImageLoad = (e) => {
    console.log("load", e);
  };

  return (
    <>
      <input
        type="file"
        id="foo"
        name="foo"
        accept="image/png, image/jpeg"
        onChange={handleChange}
      />
      <div
        style={{
          marginTop: "1rem",
          width: 600,
          height: 600,
          backgroundColor: "blue",
          position: "relative"
        }}
      >
        {src?.length > 0 && (
          <Image
            onLoadingComplete={(e) => {
              handleImageLoad(e);
            }}
            src={src}
            alt=""
            layout="fill"
            objectFit="contain"
          />
        )}
      </div>
    </>
  );
};

export default IndexPage;