从OfficeJS加载项进行EWS REST API调用会随机失败

Question

我们最近切换到在Outlook加载项中使用REST API执行loadAsyncProperties [1]和saveAsync [2]操作，并且遇到了以下行为：

1. 第一次打开邮件（随机发生）时，restUrl为空

2. EWS REST端点偶尔返回以下错误：

{
    "error": {
        "code": "ErrorAccessDenied",
        "message": "The api you are trying to access does not support item scoped OAuth."
    }
}

{
    "error": {
        "code": "ErrorAccessDenied",
        "message": "Access is denied. Check credentials and try again."
    }
}

{
    "error": {
        "code": "ErrorItemNotFound",
        "message": "The specified object was not found in the store., The process failed to get the correct properties."
    }
}

再次执行相同的操作时，将返回预期的响应。

1. getCallbackTokenAsync将随机返回null

为什么这会偶尔发生？

复制步骤

1. 通过调用restUrl属性获取REST URL
2. 通过调用getCallbackTokenAsync获取REST令牌
3. 使用以下请求检索自定义属性

GET https://outlook.office365.com/api/v2.0/me/messages('<message>')?$expand=SingleValueExtendedProperties($filter=PropertyId eq 'String {00020329-0000-0000-C000-000000000046} Name <>')

上下文

我们无法检索自定义属性。

环境

• 平台[PC台式机，Mac，iOS，Office Online]：Windows，Mac
• 主机[Excel，Word，PowerPoint等]：Outlook
• Office版本号：2016
• 操作系统：Windows 10，Mac

参考

[1] https://docs.microsoft.com/en-us/office/dev/add-ins/reference/objectmodel/requirement-set-1.5/office.context.mailbox.item?view=office-js#loadcustompropertiesasynccallback-usercontext

[2] https://docs.microsoft.com/en-us/office/dev/add-ins/reference/objectmodel/requirement-set-1.5/office.context.mailbox.item?view=office-js#saveasyncoptions-callback

[3] https://docs.microsoft.com/en-us/office/dev/add-ins/reference/objectmodel/requirement-set-1.5/office.context.mailbox?view=office-js#resturl-string