@cmk/fe_utils/src/utils/file.ts

frontend utility library

export function createAndDownloadFileWithText(filename: string, text: string) {
  const element = document.createElement('a')
  element.setAttribute(
    'href',
    'data:text/plain;charset=utf-8,' + encodeURIComponent(text)
  )
  element.setAttribute('download', filename)
  element.style.display = 'none'
  document.body.appendChild(element)
  element.click()
  document.body.removeChild(element)
}

export const toBase64 = (file: File) =>
  new Promise((resolve, reject) => {
    const reader = new FileReader()
    reader.readAsDataURL(file)
    reader.onload = () => resolve(reader.result)
    reader.onerror = reject
  })

export const labeledBase64PdfToPureBase64File = (
  labeledBase64: string
): string => labeledBase64.replace(/data:image\/.*;base64,/, '')

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