google-glass - 视频附件缺少 contentUrl

Question

我尝试将视频分享到我的应用程序。它收到了通知，但没有 contentUrl 来加载视频。以下是通知中的附件字段:

attachments: [{contentType: 'video/mp4', 'id': 'ps:5870152408634447570'}]

isProcessingContent 字段也不存在。它尝试等待一段时间(也许视频正在处理中)，但这没有什么区别。

https://developers.google.com/glass/v1/reference/timeline/attachments

有办法访问视频文件吗？

Answer 1

TimelineItem元数据中未提供附件的contentUrl，您需要向mirror.timeline.attachments.get发送授权请求用于检索有关附件的更多信息的端点:

from apiclient import errors
# ...

def print_attachment_metadata(service, item_id, attachment_id):
  """Print an attachment's metadata

  Args:
    service: Authorized Mirror service.
    item_id: ID of the timeline item the attachment belongs to.
    attachment_id: ID of the attachment to print metadata for.
  """
  try:
    attachment = service.timeline().attachments().get(
        itemId=item_id, attachmentId=attachment_id).execute()
    print 'Attachment content type: %s' % attachment['contentType']
    print 'Attachment content URL: %s' % attachment['contentUrl']
  except errors.HttpError, error:
    print 'An error occurred: %s' % error

获取附件的元数据后，检查 isProcessingContent 属性:需要将其设置为 False 才能检索 contentUrl 。不幸的是，当属性更改值时没有推送通知，并且您的服务必须使用指数退避进行轮询以节省配额和资源。

当 contentUrl 可用时，您可以从附件的元数据中检索附件的内容，如下所示:

def download_attachment(service, attachment):
  """Download an attachment's content

  Args:
    service: Authorized Mirror service.
    attachment: Attachment's metadata.
  Returns:
    Attachment's content if successful, None otherwise.
  """
  resp, content = service._http.request(attachment['contentUrl'])
  if resp.status == 200:
    return content
  else:
    print 'An error occurred: %s' % resp
    return None