index.js

/*global FormData, XMLHttpRequest, FileList*/
function parseResponse (xhr) {
  if (xhr.response) {
    try {
      return JSON.parse(xhr.response)
    } catch (e) {}
  }
  return null
}

var uploadController = function (files, options) {
  if (!options.url) {
    console.warn('upload-controller: options must contain url')
    return
  }

  if (files && files instanceof FileList) {
    var formData = new FormData()
    formData.append('file', files[0])
    if (options.query && Array.isArray(options.query)) {
      options.query.forEach(function (param) {
        if (param.key && param.value) {
          formData.append(param.key, param.value)
        }
      })
    }
    var xhr = new XMLHttpRequest()

    xhr.onreadystatechange = function () {
      if (xhr.readyState === 4 && xhr.status === 200) {
        if (options.onEnd) {
          options.onEnd(parseResponse(xhr))
        }
      }
      if (xhr.status >= 400) {
        if (options.onError) {
          options.onError(parseResponse(xhr))
        }
      }
    }

    xhr.open('POST', options.url, true)

    if (options.headers && Array.isArray(options.headers)) {
      options.headers.forEach(function (header) {
        if (header.key && header.value) {
          xhr.setRequestHeader(header.key, header.value)
        }
      })
    }

    xhr.upload.onprogress = function (e) {
      if (options.onProgress) {
        var percentComplete = (e.loaded / e.total) * 100
        options.onProgress({percentComplete: percentComplete.toFixed(0)})
      }
    }

    xhr.send(formData)
  }
}

module.exports = uploadController