Upload file with XHR

gistfile1.coffee

xhr = new XMLHttpRequest()

# 进度
xhr.upload.addEventListener "progress", uploadProgress, false

# 完成
xhr.addEventListener "load", uploadComplete, false

xhr.addEventListener "error", console.log, false
xhr.addEventListener "abort", console.log, false

fd = new FormData()

fd.append "file", file

uploadPoint = "/file_upload"

xhr.open "POST", uploadPoint, true

xhr.send fd

uploadProgress = (evt) ->
  return progress = Math.round(evt.loaded * 100 / evt.total) if evt.lengthComputable?
  progress = "无法计算进度..."

# 上传完毕
uploadComplete = (evt) ->  
  # do wtf you want.
  console.log evt