Question

我正在将BreezeJS与SharePoint适配器一起使用，并在客户端的第二个和后续POST请求中获得一致的无效etag错误。奇怪的是，这不会发生在IE11或最新的谷歌Chrome浏览器中。

以下是有关正在发生的事情的一些细节：

议程项目（ID 3）从服务器中提取并具有etag值W /＆＃34; 4＆＃34;
议程项目的更新以etag值W /＆＃34; 4＆＃34;
同一项目的另一次更新以etag值W /＆＃34; 4＆＃34;
我收到错误消息：etag值＆＃39; 4＆＃39;在其中一个请求标头中指定的无效。请确保只指定了一个etag值且有效

错误消息非常有意义，因为我们不能在两个不同的请求中使用相同的ETAG值。使用谷歌浏览器，第二个（和后续的）POST请求具有正确递增的etag值。所以在这种情况下它会发送W /＆＃34; 5＆＃34;一切都会好的。

我注意到第一个POST请求返回新的ETAG（W /＆＃34; 5＆＃34;）但它没有应用于第二个POST请求。我使用以下版本：

BreezeJS：1.4.13
休息适配器：0.2.3
SharePoint适配器：0.2.3

作为参考，我已经包含了来自Fiddler的三个操作的请求和响应。

获取议程项目

GET http://intranet/test/_vti_bin/listdata.svc/Agenda?$filter=Id%20eq%203 HTTP/1.1
DataServiceVersion: 2.0
Accept: application/json;odata=verbose
X-Requested-With: XMLHttpRequest
Referer: http://intranet/test/SitePages/test.aspx#inmeeting/2
Accept-Language: da
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; InfoPath.3)
Host: intranet
Connection: Keep-Alive


HTTP/1.1 200 OK
Cache-Control: no-cache
Content-Type: application/json;charset=utf-8
Vary: Accept-Encoding
Server: Microsoft-IIS/7.5
SPRequestGuid: e4a8e96a-d476-41e8-8445-ecd50fe8f78e
X-SharePointHealthScore: 0
DataServiceVersion: 2.0;
X-AspNet-Version: 2.0.50727
X-Powered-By: ASP.NET
MicrosoftSharePointTeamServices: 14.0.0.7015
X-MS-InvokeApp: 1; RequireReadOnly
Date: Fri, 15 Aug 2014 10:28:59 GMT
Content-Length: 1491

{
"d" : {
"results": [
{
"__metadata": {
"uri": "http://intranet/test/_vti_bin/listdata.svc/Agenda(3)", "etag": "W/\"4\"", "type": "Microsoft.SharePoint.DataService.AgendaItem"
}, "ContentTypeID": "0x0100EF440AFE5EDF49AD87D3B9A9484C2C0300ACA340FAC0DE1D49B8514C10085EC342", "Title": "Welcome", "Meeting": {
"__deferred": {
"uri": "http://intranet/test/_vti_bin/listdata.svc/Agenda(3)/Meeting"
}
}, "MeetingId": 2, "Documents": {
"__deferred": {
"uri": "http://intranet/test/_vti_bin/listdata.svc/Agenda(3)/Documents"
}
}, "Links": {
"__deferred": {
"uri": "http://intranet/test/_vti_bin/listdata.svc/Agenda(3)/Links"
}
}, "Responsible": {
"__deferred": {
"uri": "http://intranet/test/_vti_bin/listdata.svc/Agenda(3)/Responsible"
}
}, "ResponsibleId": 1, "StartTime": "\/Date(1408622400000)\/", "EndTime": "\/Date(1408623120000)\/", "DurationInMinutes": 12, "Done": true, "Comments": null, "Sort": 0, "Id": 3, "ContentType": "Meeting Agenda", "Modified": "\/Date(1408105622000)\/", "Created": "\/Date(1408010077000)\/", "CreatedBy": {
"__deferred": {
"uri": "http://intranet/test/_vti_bin/listdata.svc/Agenda(3)/CreatedBy"
}
}, "CreatedById": 1, "ModifiedBy": {
"__deferred": {
"uri": "http://intranet/test/_vti_bin/listdata.svc/Agenda(3)/ModifiedBy"
}
}, "ModifiedById": 1, "Owshiddenversion": 4, "Version": "4.0", "Attachments": {
"__deferred": {
"uri": "http://intranet/test/_vti_bin/listdata.svc/Agenda(3)/Attachments"
}
}, "Path": "/test/Lists/Agenda"
}
]
}
}

议程项目的第一次更新

POST http://intranet/test/_vti_bin/listdata.svc/Agenda(3) HTTP/1.1
Accept: application/json;odata=verbose
Content-Type: application/json;odata=verbose
DataServiceVersion: 2.0
X-RequestDigest: 0x5B15EE86ACA321A71DA9A2939E8FE1E2A29D3F6A60A6424C4F497DFFCD4D509836B6FB85A127CBBC947547D8AB7AE0E91CE6C72E7C359D6CF83351C024858D84,15 Aug 2014 10:26:46 -0000
X-HTTP-Method: MERGE
If-Match: W/"4"
X-Requested-With: XMLHttpRequest
Referer: http://intranet/test/SitePages/test.aspx#inmeeting/2
Accept-Language: da
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; InfoPath.3)
Host: intranet
Content-Length: 82
Connection: Keep-Alive
Pragma: no-cache

{"Done":false,"__metadata":{"type":"Microsoft.SharePoint.DataService.AgendaItem"}}

HTTP/1.1 204 No Content
Cache-Control: no-cache
ETag: W/"5"
Server: Microsoft-IIS/7.5
SPRequestGuid: dc4896d6-91b9-4894-a169-c70889ad0747
X-SharePointHealthScore: 0
DataServiceVersion: 1.0;
X-AspNet-Version: 2.0.50727
X-Powered-By: ASP.NET
MicrosoftSharePointTeamServices: 14.0.0.7015
X-MS-InvokeApp: 1; RequireReadOnly
Date: Fri, 15 Aug 2014 10:29:02 GMT

议程项目的第二次更新

POST http://intranet/test/_vti_bin/listdata.svc/Agenda(3) HTTP/1.1
Accept: application/json;odata=verbose
Content-Type: application/json;odata=verbose
DataServiceVersion: 2.0
X-RequestDigest: 0x5B15EE86ACA321A71DA9A2939E8FE1E2A29D3F6A60A6424C4F497DFFCD4D509836B6FB85A127CBBC947547D8AB7AE0E91CE6C72E7C359D6CF83351C024858D84,15 Aug 2014 10:26:46 -0000
X-HTTP-Method: MERGE
If-Match: W/"4"
X-Requested-With: XMLHttpRequest
Referer: http://intranet/test/SitePages/test.aspx#inmeeting/2
Accept-Language: da
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; InfoPath.3)
Host: intranet
Content-Length: 81
Connection: Keep-Alive
Pragma: no-cache

{"Done":true,"__metadata":{"type":"Microsoft.SharePoint.DataService.AgendaItem"}}
HTTP/1.1 412 Precondition Failed
Cache-Control: private
Content-Type: application/json
Server: Microsoft-IIS/7.5
SPRequestGuid: 965fbf16-8911-426b-9a90-8b21b4a78008
X-SharePointHealthScore: 0
DataServiceVersion: 1.0;
X-AspNet-Version: 2.0.50727
X-Powered-By: ASP.NET
MicrosoftSharePointTeamServices: 14.0.0.7015
X-MS-InvokeApp: 1; RequireReadOnly
Date: Fri, 15 Aug 2014 10:29:02 GMT
Content-Length: 214

{
"error": {
"code": "", "message": {
"lang": "en-US", "value": "The etag value '4' specified in one of the request headers is not valid. Please make sure only one etag value is specified and is valid."
}
}
}

更新1

我已完成一些调试，并从SPAdapter的_processSavedEntity方法开始。在Chrome中，它从响应中接收新的ETAG值，在IE9中它变为null。追溯到此后，我在第15156行的breeze.debug.js（1.4.13）中结束了响应进入系统。在jqXHR上调用getAllResponseHeaders（）方法会在IE9中返回一个空字符串，而Fiddler会显示存在的标题（与上面相同）。所以，这有点神秘。 BTW。我使用的是jQuery 1.9.1。

Answer 1

问题是IE9和之前的，当收到响应代码204 No Content时，抛弃所有响应头。这里讨论jQuery.ajax with POST or PUT has no response headers for IE8 and IE9

如果没有并发问题，驱动程序可以嗅探IE9和之前的版本并发出HEAD（我不知道SharePoint是否支持它）或同一实体的GET。但两种黑客都会产生并发问题。哪一个更糟糕取决于上下文。在任何情况下，使用ETag进行乐观并发的整个目的都被打败了。我担心在IE9和之前的版本中，没有办法完全支持OData的乐观并发。

BreezeJS和IE9的ETAG错误无效

1 个答案: