Sending excel file generated using EPPlus as a response in Web API

I created a web service using ASP.NET Web API to allow users to export data from a SharePoint list into an excel. I chose EPPlus .NET library to generate the excel file as it is one of the most comprehensive libraries out there in reading/writing excel files.

I initially created and tested my code in a console application by saving the excel in the file system. The excel opened fine with all the data. I ported the same code to a web API service and returned the file as HttpResponseMessage as shown below –

string contentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
using (MemoryStream excelStream = export.ExportViewAsExcel(siteUrl, listName))
{
	//set stream position to zero
	excelStream.Position = 0;

	// processing the stream.
	var result = new HttpResponseMessage(HttpStatusCode.OK)
	{
		Content = new ByteArrayContent(excelStream.GetBuffer())
	};
	result.Content.Headers.ContentDisposition =
		new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment")
		{
			FileName = "export.xlsx";
		};
	result.Content.Headers.ContentType =
		new MediaTypeHeaderValue(contentType);

	return result;
}

Once I opened the downloaded excel I got the below warning –

We found a problem with some content in ‘export.xlsx’. Do you want us to try to recover as much as we can? If you trust the source of this workbook, click Yes.

After spending ridiculously large amount of time in figuring this out I finally found that I just had to set the “content-length” header to avoid the warning as below –

result.Content.Headers.Add("content-length", excelStream.Length.ToString());

Hope this saves someone’s time!

Approve workflow tasks using REST API in SharePoint 2013

Recently I had a requirement to approve a workflow task programmatically. I found some useful posts here and here but they were related to SharePoint 2010 and the code did not work with SharePoint 2013 as it is.

After doing some modifications the below code worked fine and the workflow moved ahead after the task was approved.

//Some times outcome field's internal name could be different
//Go to list settings of your Workflow Tasks to verify the internal names of all the fields below
var item = {
	"__metadata": { "type": "SP.Data.Workflow_x0020_TasksListItem" },
	"WorkflowOutcome" : "Approved",
	"Status" : "Approved",
	"PercentComplete" : 1,
	"Checkmark" : "Yes"
};

//URL here is the direct uri to the item which can be obtained by doing a GET request for the item and reading data.__metadata.uri from the response
$.ajax({
	url: "http://yoursite/PG/_api/Web/Lists(guid'3c871781-7c22-4bd2-8b2c-310babe69ccd')/Items(3)",
	type: "POST",
	contentType: "application/json;odata=verbose",
	data: JSON.stringify(item),
	headers: {
		"Accept": "application/json;odata=verbose",
		"X-RequestDigest": $("#__REQUESTDIGEST").val(),
		"X-HTTP-Method": "MERGE",
		"If-Match": "*"
	},
	success: function (data) {
		debugger;
	},
	error: function (data) {
		debugger;
	}
});

SharePoint 2010 – Check if user in a specific group using Client Object Model

This post is just a modification of the solution provided by Vadim Gremyachev for SharePoint 2013 here. I’ve modified the code to work with SharePoint 2010 (since getByName() is not available in SP 2010)

function IsCurrentUserMemberOfGroup(groupName, OnComplete) {
 try{
    var context = new SP.ClientContext.get_current();
    var currentWeb = context.get_web();
 
    var currentUser = context.get_web().get_currentUser();
    context.load(currentUser);
 
    var allGroups = currentWeb.get_siteGroups();
    context.load(allGroups);
 
    context.executeQueryAsync(
       function(sender, args){
          var count = allGroups.get_count();
          for(i = 0; i < count; i++){
             var grp = allGroups.getItemAtIndex(i);
             //provide your group name
             if(grp.get_loginName() == groupName){
                var groupUsers = grp.get_users();
                //load users of the group
                context.load(groupUsers);
                context.executeQueryAsync(
                   function(sender2, args2){
                      var userInGroup = false;
                      var groupUserEnumerator = groupUsers.getEnumerator();
                      while (groupUserEnumerator.moveNext()) {
                         var groupUser = groupUserEnumerator.get_current();
                         //check if current user is in the group members
                         if (groupUser.get_id() == currentUser.get_id()) {
                            userInGroup = true;
                            break;
                         }
                      }
                      OnComplete(userInGroup);
                   },
                   function onFailureGrp(sender2, args2){
                      OnComplete(false);
                   }
               );
            }
         }
       },
       function onFailure(sender, args){
          OnComplete(false);
       }
    );
 }
 catch(e){
    OnComplete(false);
 }
}

And this is how you the function should be invoked –

function IsCurrentUserAManager() 
{
		try{
			IsCurrentUserMemberOfGroup("Managers", function (isCurrentUserInGroup) {
				if(!isCurrentUserInGroup)
				{
				    //user in group		    
				}
			});
		}
		catch(e){			
		}		
}

People picker not resolving entities in SharePoint 2010

In one of the applications I was working lately, one usual day I was informed that the people picker suddenly stopped working across the site. It sounded very weird at first. After reviewing all the changes that were done recently in the site I found that the custom master page the application was using was updated to support IE9 compatibility which was breaking all the people picker controls in all the pages. So changing back it to IE8 fixed the issue.

Not compatible –

<meta http-equiv=”X-UA-Compatible” content=”IE=9″/>

Change it to –

<meta http-equiv=”X-UA-Compatible” content=”IE=8″/>

“The Subscription Settings service and corresponding application and proxy needs to be running in order to make changes to these settings” – even after configuring subscription Settings Service

I completed configuring my SharePoint 2013 box yesterday and with at most curiosity of creating my first app I opened Visual Studio 2012 and create a SharePoint hosted app. And I was greeted with my first error message on SharePoint 2013.

‘Apps are disabled on the site‘.

I then learnt that the ‘App Management Service’ and the ‘Microsoft SharePoint Foundation Subscription Settings Service’ should be up and running before I can configure the App URLs in Central Administration and deploying apps.

(Note: You must create a separate app domain for deploying your apps before all these which I have done already following this article)

The former is created automatically while installing SP 2013 but to get the later running we have to do it manually by creating a service application. This can be done through the powershell –

add-pssnapin </code><code>"Microsoft.Sharepoint.Powershell"
$manaccount = Get-SPManagedAccount nlv\Administrator
Remove-SPServiceApplicationPool -Identity SettingsServiceAppPool
$appPoolService = New-SPServiceApplicationPool -Name SettingsServiceAppPool -Account $manaccount
$appService = New-SPSubscriptionSettingsServiceApplication -ApplicationPool $appPoolService -Name SettingsServiceApp -DatabaseName SettingsServiceDB
$proxyService = New-SPSubscriptionSettingsServiceApplicationProxy -ServiceApplication $appService

So now I see that both the services are up and running.

So again I navigated to Apps -> Configure Apps URLs in CA and again daang! Same message –

‘The Subscription Settings service and corresponding application and proxy needs to be running in order to make changes to these settings’

I was googling for an hour and found everywhere that only these two service applications have to be started to configure app URLs. And finally I found the silly step which has to be done after creating subscription settings service application given by chaks here.

You have to do an IISRESET and bingo! Now you will able to configure App URLs in CA.