nocodb/packages/nc-gui/helpers/fileReader.js

// Ref : https://stackoverflow.com/a/12002275

// Tested in Mozilla Firefox browser, Chrome
function ReadFileAllBrowsers(FileElement, CallBackFunction) {
  try {
    if (!FileElement.files || !FileElement.files.length) { return CallBackFunction() }

    const file = FileElement.files[0]

    if (file) {
      const reader = new FileReader()
      reader.readAsText(file, 'UTF-8')
      reader.onload = function(evt) {
        CallBackFunction(evt.target.result)
      }
      reader.onerror = function(evt) {
        CallBackFunction()
      }
    }
  } catch (Exception) {
    const fallBack = ieReadFile(FileElement.value)
    // eslint-disable-next-line eqeqeq
    if (fallBack != false) {
      CallBackFunction(fallBack)
    }
  }
}

/// Reading files with Internet Explorer
function ieReadFile(filename) {
  try {
    // eslint-disable-next-line no-undef
    const fso = new ActiveXObject('Scripting.FileSystemObject')
    const fh = fso.OpenTextFile(filename, 1)
    const contents = fh.ReadAll()
    fh.Close()
    return contents
  } catch (Exception) {
    return false
  }
}

export default ReadFileAllBrowsers