我最终想通了。
我最初感到困惑的原因是因为实际上有两种情况：
- 当用户来自登录时，基本上管道得到执行时。
- 刷新令牌时调用用户社交身份验证方法
refresh_token
解决第一种情况
我为管道创建了一个新函数：
def set_last_update(details, *args, **kwargs): # pylint: disable=unused-argument
"""
Pipeline function to add extra information about when the social auth
profile has been updated.
Args:
details (dict): dictionary of informations about the user
Returns:
dict: updated details dictionary
"""
details['updated_at'] = datetime.utcnow().timestamp()
return details
在设置中，我在load_extra_data之前的管道中添加了它
SOCIAL_AUTH_PIPELINE = (
'social.pipeline.social_auth.social_details',
'social.pipeline.social_auth.social_uid',
'social.pipeline.social_auth.auth_allowed',
'social.pipeline.social_auth.social_user',
'social.pipeline.user.get_username',
'social.pipeline.user.create_user',
'social.pipeline.social_auth.associate_user',
# the following custom pipeline func goes before load_extra_data
'backends.pipeline_api.set_last_update',
'social.pipeline.social_auth.load_extra_data',
'social.pipeline.user.user_details',
'backends.pipeline_api.update_profile_from_edx',
'backends.pipeline_api.update_from_linkedin',
)
而且，我仍然在设置中的额外数据中添加了新字段。
SOCIAL_AUTH_EDXORG_EXTRA_DATA = ['updated_at']
对于第二种情况：
我重写了后端的refresh_token 方法以添加额外的字段。
def refresh_token(self, token, *args, **kwargs):
"""
Overridden method to add extra info during refresh token.
Args:
token (str): valid refresh token
Returns:
dict of information about the user
"""
response = super(EdxOrgOAuth2, self).refresh_token(token, *args, **kwargs)
response['updated_at'] = datetime.utcnow().timestamp()
return response
仍然在后端类中，我添加了一个额外的字段来提取来自服务器的expires_in 字段。
EXTRA_DATA = [
('refresh_token', 'refresh_token', True),
('expires_in', 'expires_in'),
('token_type', 'token_type', True),
('scope', 'scope'),
]
此时我有创建访问令牌时的时间戳 (updated_at) 以及它将有效的秒数 (expires_in)。
注意：updated_at 是一个近似值，因为它是在客户端而不是提供者服务器上创建的。
现在唯一缺少的是一个检查是否该刷新访问令牌的函数。
def _send_refresh_request(user_social):
"""
Private function that refresh an user access token
"""
strategy = load_strategy()
try:
user_social.refresh_token(strategy)
except HTTPError as exc:
if exc.response.status_code in (400, 401,):
raise InvalidCredentialStored(
message='Received a {} status code from the OAUTH server'.format(
exc.response.status_code),
http_status_code=exc.response.status_code
)
raise
def refresh_user_token(user_social):
"""
Utility function to refresh the access token if is (almost) expired
Args:
user_social (UserSocialAuth): a user social auth instance
"""
try:
last_update = datetime.fromtimestamp(user_social.extra_data.get('updated_at'))
expires_in = timedelta(seconds=user_social.extra_data.get('expires_in'))
except TypeError:
_send_refresh_request(user_social)
return
# small error margin of 5 minutes to be safe
error_margin = timedelta(minutes=5)
if datetime.utcnow() - last_update >= expires_in - error_margin:
_send_refresh_request(user_social)
我希望这对其他人有帮助。