U2U Blog Center

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U2U has built up the last 10 years a huge amount of expertise in the Microsoft .NET Framework. Expertise they have always shared in the community. Below you can find a list of the blogs maintained by U2U trainers.

Watch out with calculated DateTime fields in CSOM

var localDateOnlyValue = ctx.Web.RegionalSettings.TimeZone.UTCToLocalTime((DateTime)item.FieldValues["DateOnly"]); ctx.ExecuteQuery(); I recently came across a baffling issue when using CSOM to connect to a SharePoint Online list to retrieve values from a Date and Time field and another field calculated based on the first one.To illustrate the issue, I created a dummy list with 2 colums: DateOnly: Date and Time (show Date Only) CalculatedDateOnly: Calculated with formula [DateOnly] + 1 (Also showing as Date Only)   When creating new items in this list, all looks well. The Date Only and calculations are done correctly. The story in CSOM Now, up to CSOM, when accessing this list with the following code: var list = ctx.Web.Lists.GetByTitle("TestDateTime"); var item = list.GetItemById(1); ctx.Load(item); ctx.ExecuteQuery(); var dateOnlyValue = item.FieldValues["DateOnly"]; var calculatedDataOnlyValue = item.FieldValues["CalculatedDateOnly"];   The values in the dateOnlyValue and calculatedDataOnlyValue are not what you might expect: Observe that the DateOnlyValue is –2 hours from what was originally selected. Now this is perfectly explainable. SharePoint stores the DateTime values in UTC, and when using the web interface, SharePoint takes into account the regional settings of your site to convert between local and UTC. If you use CSOM however, you get the value in UTC, no problem here. However, my calculated field, that just did a +1 (add a day) is not returned in UTC, which is confusing, because i just said that CSOM would return datetime in UTC. Assuming that the dateOnlyValue is UTC, you can convert this to local time as follows (the inverse also exists): var localDateOnlyValue = ctx.Web.RegionalSettings.TimeZone.UTCToLocalTime((DateTime)item.FieldValues["DateOnly"]); ctx.ExecuteQuery(); Now, imagine you need to use these field values to forward to the user or some business process, then you might need logic to convert UTC values to local (for the dateOnlyValue) and other logic that does nothing for the calculated field (calculatedDateOnly). So basicaly, you have to assume that DateTime fields will be UTC and calculated ones will not be UTC. Let’s make that assumption … The story in REST Remember the assumption from CSOM: DateTime fields will be UTC and calculated ones will not be UTC. Let’s see if this assumption stays valid when making REST calls. The following REST call was used to retrieve the values: /_api/lists/getbytitle('TestDateTime')/Items(1)?$select=DateOnly,CalculatedDateOnly and the result shows the following (baffling result) <content type="application/xml"> <m:properties> <d:DateOnly m:type="Edm.DateTime">2017-04-24T22:00:00Z</d:DateOnly> <d:CalculatedDateOnly>2017-04-25T22:00:00Z</d:CalculatedDateOnly> </m:properties> </content> Now both are in UTC!!!!! So I will have to change my assumption to: DateTime fields will be UTC, but in CSOM calculated DateTime fields are local. Solution Now what about a solution that works in CSOM? If your goal is to use the values from SharePoint as they are “shown” to the users. Then you’re better off using the property FieldValuesAsText on a listitem. var list = ctx.Web.Lists.GetByTitle("TestDateTime"); var item = list.GetItemById(1); ctx.Load(item, it => it.FieldValuesAsText); ctx.ExecuteQuery(); var dateOnlyValue = item.FieldValuesAsText["DateOnly"]; var calculatedDataOnlyValue = item.FieldValuesAsText["CalculatedDateOnly"];   Then both variables will contain the date values as shown in the web interface:

What’s new in SharePoint 2016 CSOM (DocumentSets)

With SharePoint 2016 RC available, it’s interesting to see what new additions we have in CSOM and/or REST APIs. Doing some research in the differences between the SharePoint 2013 RTM CSOM and SharePoint 2016 RC CSOM, I noticed several differences. This post will describe the differences related to DocumentSets. In SharePoint 2013, the only thing you could do with document sets from within CSOM was to create one, given a parent folder, name and the contenttype id of the document set. You weren’t able to do anything else. So what’s new? You’re now also able to do the following things: Create/alter the contenttype definition of a documentset contenttype. Get a document set based on a listitem/folder. Export a document set to a zip file (I mean OpenXML file). Import a document set from a zip file (again … OpenXML file). DocumentSetTemplate There is a new class available that allows you to change the definition of a documentset contenttype. It gives you access to the SharedFields, Templates, AllowedContentTypes, …You can use it as follows: var documentSetTemplate = DocumentSetTemplate.GetDocumentSetTemplate(ctx, ct); documentSetTemplate.AllowedContentTypes.Add(ct_document.Id); documentSetTemplate.DefaultDocuments.Add("template.odt", ct_document.Id, bytes); documentSetTemplate.SharedFields.Add(field_customer); documentSetTemplate.WelcomePageFields.Add(field_customer); documentSetTemplate.Update(true); ctx.ExecuteQuery(); Where ct and ct_document are respectively a documentset contenttype and a document contenttype. Unfortunately, you’re still not able to directly set the default document set view, nor alter the url of the docsethomepage.aspx. Export Document Set You can now export a documentset to an OpenXML (zip) file as follows: ListItem item = GetDocumentSet(...); // DocumentSet item ctx.Load(item, it => it.Folder); ctx.ExecuteQuery(); var documentSet = DocumentSet.GetDocumentSet(ctx, item.Folder); ctx.Load(documentSet); ctx.ExecuteQuery(); var stream = documentSet.ExportDocumentSet(); ctx.ExecuteQuery(); using(FileStream fs = new FileStream("docset.zip", FileMode.Create, FileAccess.Write, FileShare.None)) { stream.Value.CopyTo(fs); } Result: Import Document Set You can now import an exported document set as follows: using(FileStream fs = new FileStream("docset.zip", FileMode.Open, FileAccess.Read, FileShare.None)) { DocumentSet docSet = DocumentSet.ImportDocumentSet(ctx, fs, "Imported", list.RootFolder, ct.Id); ctx.ExecuteQuery(); } Result: