Azure Function 和 SharePoint webhook：未从 Z97F02F6993B93736DFEZ0D 列表中获取更改

Question

I'm using a couple of Azure Functions with SharePoint webhook.

The first function is the one used to save messages from SharePoint webhook to a queue (Azure storage queue). This is the function content:

    [FunctionName("QueueFunction")]
    public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = null)]HttpRequestMessage req, TraceWriter log)
    {
         log.Info($"Webhook was triggered!");

        // Grab the validationToken URL parameter
        string validationToken = req.GetQueryNameValuePairs()
            .FirstOrDefault(q => string.Compare(q.Key, "validationtoken", true) == 0)
            .Value;

        // If a validation token is present, we need to respond within 5 seconds by  
        // returning the given validation token. This only happens when a new 
        // web hook is being added
        if (validationToken != null)
        {
            log.Info($"Validation token {validationToken} received");
            var response = req.CreateResponse(HttpStatusCode.OK);
            response.Content = new StringContent(validationToken);
            return response;
        }

        log.Info($"SharePoint triggered our webhook...great :-)");
        var content = await req.Content.ReadAsStringAsync();
        log.Info($"Received following payload: {content}");

        var notifications = JsonConvert.DeserializeObject<ResponseModel<NotificationModel>>(content).Value;
        log.Info($"Found {notifications.Count} notifications");

        if (notifications.Count > 0)
        {
            // get the cloud storage account
            string queueName = "MYQUEUE";
            CloudStorageAccount storageAccount = CloudStorageAccount.Parse(Environment.GetEnvironmentVariable("AzureWebJobsStorage"));
            CloudQueueClient queueClient = storageAccount.CreateCloudQueueClient();
            CloudQueue queue = queueClient.GetQueueReference(queueName);
            await queue.CreateIfNotExistsAsync();

            // store each notification as a queue item
            foreach (var notification in notifications)
            {
                string message = JsonConvert.SerializeObject(notification);
                log.Info($"Adding to {queueName}: {message}");
                await queue.AddMessageAsync(new CloudQueueMessage(message));
                log.Info($"added.");
            }

        // if we get here we assume the request was well received
        return new HttpResponseMessage(HttpStatusCode.OK);
    }

The message in queue is correctly added.

Then I've another function triggered by queue. This is the code of the function:

[FunctionName("OCRFunction")]
    public static void Run([QueueTrigger("MYQUEUE", Connection = "QueueConn")]string myQueueItem, TraceWriter log)
    {
        log.Info($"C# Queue trigger function processed: {myQueueItem}");
        string siteUrl = "https://MYSHAREPOINT.sharepoint.com/sites/MYSITE";
        log.Info($"Processing notifications...");
        string json = myQueueItem;
        var data = (JObject)JsonConvert.DeserializeObject(json);
        string notificationResource = data["resource"].Value<string>();
        
        ClientContext SPClientContext = LoginSharePoint(siteUrl);
        log.Info($"Logged in SharePoint");
        GetChanges(SPClientContext, notificationResource, log);
       
    }

    public static ClientContext LoginSharePoint(string BaseUrl)
    {
        // Login using UserOnly Credentials (User Name and User PW)
        ClientContext cntReturn;

        string myUserName = config["spUN"];
        string myPassword = config["spPWD"];

        SecureString securePassword = new SecureString();
        foreach (char oneChar in myPassword) securePassword.AppendChar(oneChar);
        SharePointOnlineCredentials myCredentials = new SharePointOnlineCredentials(myUserName, securePassword);

        cntReturn = new ClientContext(BaseUrl);
        cntReturn.Credentials = myCredentials;

        return cntReturn;
    }

    static void GetChanges(ClientContext SPClientContext, string ListId, TraceWriter log)
    {
        Web spWeb = SPClientContext.Web;
        List myList = spWeb.Lists.GetByTitle("MY LIST");
        SPClientContext.Load(myList);
        SPClientContext.ExecuteQuery();

        ChangeQuery myChangeQuery = GetChangeQueryNew(ListId);

        var allChanges = myList.GetChanges(myChangeQuery);
        SPClientContext.Load(allChanges);
        SPClientContext.ExecuteQuery();

        log.Info($"---- Changes found : " + allChanges.Count());
        foreach (Change oneChange in allChanges)
        {
            if (oneChange is ChangeItem)
            {
                int myItemId = (oneChange as ChangeItem).ItemId;

                log.Info($"---- Changed ItemId : " + myItemId);
                ListItem myItem = myList.GetItemById(myItemId);
                Microsoft.SharePoint.Client.File myFile = myItem.File;
                ClientResult<System.IO.Stream> myFileStream = myFile.OpenBinaryStream();
                SPClientContext.Load(myFile);
                SPClientContext.ExecuteQuery();

                byte[] myFileBytes = ConvertStreamToByteArray(myFileStream);
                [...] SOME CODE HERE [...]
                myItem["OCRText"] = myText;
                myItem.Update();
                SPClientContext.ExecuteQuery();
                log.Info($"---- Text Analyze OCR added to SharePoint Item");
            }
        }
    }

    public static ChangeQuery GetChangeQueryNew(string ListId)
    {
        ChangeToken lastChangeToken = new ChangeToken();
        lastChangeToken.StringValue = string.Format("1;3;{0};{1};-1", ListId, DateTime.Now.AddMinutes(-1).ToUniversalTime().Ticks.ToString());
        ChangeToken newChangeToken = new ChangeToken();
        newChangeToken.StringValue = string.Format("1;3;{0};{1};-1", ListId, DateTime.Now.ToUniversalTime().Ticks.ToString());
        ChangeQuery myChangeQuery = new ChangeQuery(false, false);
        myChangeQuery.Item = true;  // Get only Item changes
        myChangeQuery.Add = true;   // Get only the new Items
        myChangeQuery.ChangeTokenStart = lastChangeToken;
        myChangeQuery.ChangeTokenEnd = newChangeToken;

        return myChangeQuery;
    }

    public static Byte[] ConvertStreamToByteArray(ClientResult<System.IO.Stream> myFileStream)
    {
        Byte[] bytReturn = null;

        using (System.IO.MemoryStream myFileMemoryStream = new System.IO.MemoryStream())
        {
            if (myFileStream != null)
            {
                myFileStream.Value.CopyTo(myFileMemoryStream);
                bytReturn = myFileMemoryStream.ToArray();
            }
        }

        return bytReturn;
    }

    public static async Task<TextAnalyzeOCRResult> GetAzureTextAnalyzeOCR(byte[] myFileBytes)
    {
        TextAnalyzeOCRResult resultReturn = new TextAnalyzeOCRResult();

        HttpClient client = new HttpClient();

        client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", "XXXXXXXXXXXXXXXXXXXX");
        string requestParameters = "language=unk&detectOrientation=true";

        /* OCR API */
        string uri = "https://MYOCRSERVICE.cognitiveservices.azure.com/vision/v3.0/ocr" + "?" + requestParameters;

        string contentString = string.Empty;

        HttpResponseMessage response;

        using (ByteArrayContent content = new ByteArrayContent(myFileBytes))
        {
            content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");

            response = await client.PostAsync(uri, content);

            contentString = await response.Content.ReadAsStringAsync();

            resultReturn = JsonConvert.DeserializeObject<TextAnalyzeOCRResult>(contentString);
            return resultReturn;
        }
    }

Before current approach with two functions, I was using a single function where I managed the notifications and I executed some code to update a field in my SharePoint list. This method was having some problem when I was receiving many notifications from SharePoint so I decided to use queue as suggested in Microsoft documentation. This solution was working fine with a single notification received and my SharePoint list item were updated without problem.

To avoid problems with multiple notification, I decided to split functions, one registering notifications in a queue and the other executing some operations and updating a SharePoint field. The first one function QueueFunction is working fine, the second one is triggering correctly but it is not getting changes from SharePoint list even if I just add one item. I've tried to check GetChanges code to find why it is always returning no changes, but the code is the same of the one I used when I had only one function, so I can't understand why the behaviour is changed.

What's wrong with my approach? Is there something I could do to correct the second function?

Answer 1

According to the comments, just summarize the solution as below for other communities reference:

Use a function to save the message in a queue and then call an azure web job, the problem was caused by the the running time of the function may exceed 5 minutes.

By the way, the default timeout of azure function(with consumption plan) is 5 minutes, we can see all of the default timeout for different plan on this page (also shown as below screenshot).

If we want longer timeout, we can set the functionTimeout property in host.json of the function(but can not exceed the Maximum timeout). Or we can also use higher plan for the function app, such as Premium plan and App Service plan.