How to convert image source into a JavaScript File object

Question

I have an image URL "https://cdn.shopify.com/s/files/1/0234/8017/2591/products/young-man-in-bright-fashion_925x_f7029e2b-80f0-4a40-a87b-834b9a283c39.jpg", and want to convert it into javaScript File Type object.

: File
   lastModified: 1591250106736
   lastModifiedDate: Thu Jun 04 2020 11:25:06 GMT+0530 (India Standard 
   Time) {}
   name: "7.jpeg"
   size: 369742
   type: "image/jpeg"
   webkitRelativePath: ""

Answer 1

Convert your image src https://cdn.shopify.com/s/files/1/0234/8017/2591/products/young-man-in-bright-fashion_925x_f7029e2b-80f0-4a40-a87b-834b9a283c39.jpg into Base64 ULR format and than convert Base64 URL into javaScript File Object.

***Here is the code for converting "image source" (url) to "Base64".***

let url = 'https://cdn.shopify.com/s/files/1/0234/8017/2591/products/young-man-in-bright-fashion_925x_f7029e2b-80f0-4a40-a87b-834b9a283c39.jpg'
const toDataURL = url => fetch(url)
      .then(response => response.blob())
      .then(blob => new Promise((resolve, reject) => {
      const reader = new FileReader()
      reader.onloadend = () => resolve(reader.result)
      reader.onerror = reject
      reader.readAsDataURL(blob)
     }))


***Here is code for converting "Base64" to javascript "File Object".***

  function dataURLtoFile(dataurl, filename) {
     var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
     bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
     while(n--){
     u8arr[n] = bstr.charCodeAt(n);
     }
   return new File([u8arr], filename, {type:mime});
  }


*** Calling both function ***

  toDataURL(url)
  .then(dataUrl => {
     console.log('Here is Base64 Url', dataUrl)
     var fileData = dataURLtoFile(dataUrl, "imageName.jpg");
     console.log("Here is JavaScript File Object",fileData)
     fileArr.push(fileData)
   })

Answer 2

I'm assuming you want to run this in a browser environment. You can use the native fetch() method, read the response as Blob and convert it to a File object.

contentType should be based on the type of the actual image downloaded.

You can read more about several approaches and browser support to convert a Blob to File here:

Convert blob to file

How to convert Blob to File in JavaScript

const url = 'https://cdn.shopify.com/s/files/1/0234/8017/2591/products/young-man-in-bright-fashion_925x_f7029e2b-80f0-4a40-a87b-834b9a283c39.jpg?v=1572867553'
const fileName = 'myFile.jpg'

fetch(url)
  .then(async response => {
    const contentType = response.headers.get('content-type')
    const blob = await response.blob()
    const file = new File([blob], fileName, { contentType })
    // access file here
  })

Answer 3

For more elegant solution use this

const getUrlExtension = (url) => {
    return url
      .split(/[#?]/)[0]
      .split(".")
      .pop()
      .trim();
  }

const onImageEdit = async (imgUrl) => {
    var imgExt = getUrlExtension(imgUrl);

    const response = await fetch(imgUrl);
    const blob = await response.blob();
    const file = new File([blob], "profileImage." + imgExt, {
      type: blob.type,
    });
}