Tuesday, June 25, 2019

How to get localized field titles via CSOM in Sharepoint

Some time ago I wrote article which shows how to localize web part titles via CSOM. If you are not familiar with it I recommend to read it before continue as it has useful information about Sharepoint MUI feature in general: Localize web part titles via client object model in Sharepoint. In current post I will show how to get localized field titles via CSOM in Sharepoint. This technique can be used both in on-prem and online versions.

Currently CSOM has Field.TitleResource property and it looks suitable when you want to get localized title of some field. However this is not the case. In order to get localized fields’ titles you still have to use Field.Title property but with little tuning of ClientContext – similar to those which is mentioned in the article above. More specifically you need to specify target language via “Accept-Language” HTTP header associated with ClientContext and then request field titles (of course assuming that fields have these localized titles provisioned. See e.g. Provision multilingual sites with PnP templates to see how to provision multilingual fields’ titles using PnP templates). Here is the code which shows this concept:

string siteUrl = "...";
string clientId = "...";
string clientSecret = "...";
int lcid = ...;
using (var ctx = new OfficeDevPnP.Core.AuthenticationManager().GetAppOnlyAuthenticatedContext(siteUrl, clientId, clientSecret))
 ctx.PendingRequest.RequestExecutor.WebRequest.Headers["Accept-Language"] = new CultureInfo(lcid).Name;
 ctx.Load(ctx.Web.Fields, f => f.Include(c => c.Id, c => c.Title));

As result when you will iterate through site columns retrieved this way they will contain titles localized for language specified with lcid parameter.

Thursday, June 13, 2019

Use pagination with Sharepoint search API

Often search request return a lot of data. It may be insufficient to show all this data at once on the page – performance may suffer, page may be overloaded with data, etc. In order to address these issues we may use pagination i.e. get data by chunks. But how it often happens with Sharepoint there are own considerations related with pagination in search API.

If we will check documentation of SharePoint Search REST API we will find several properties which affect pagination logic:

  • StartRow: The first row that is included in the search results that are returned. You use this parameter when you want to implement paging for search results.
  • RowLimit: The maximum number of rows overall that are returned in the search results. Compared to RowsPerPage, RowLimit is the maximum number of rows returned overall.
  • RowsPerPage: The maximum number of rows to return per page. Compared to RowLimit, RowsPerPage refers to the maximum number of rows to return per page, and is used primarily when you want to implement paging for search results.

So based on this description we may assume that most obvious way to get paginated data is to use StartRow and RowsPerPage:

var searchUrl = "http://{tenant}.sharepoint.com/_api/search/query?querytext='" + query + "'&selectproperties='Title'&startRow=" + startRow + "&rowsPerPage=" + pageSize;

It will work but with one condition: if page size is less than default page size which is 10 items per page. If page size is greater than default page size it won’t work: in this case you have to use RowLimit which will work as page size even though documentation says different:

var searchUrl = "http://{tenant}.sharepoint.com/_api/search/query?querytext='" + query + "'&selectproperties='Title'&startRow=" + startRow + "&rowLimit=" + pageSize;

This approach will allow to implement pagination with page size bigger than default search page size (10 items per page).

Thursday, June 6, 2019

Grant permissions and trust SharePoint app automatically via PowerShell

In Sharepoint app model we may need to grant permissions to Sharepoint app on AppInv.aspx page by providing appropriate permissions request xml. If permissions are granted on Tenant level you need to open AppInv.aspx in context of Central admin i.e. https://{tenant}-admin.sharepoint.com:

It was historically quite painful to automate this process as automatic permissions grant is not currently possible. There were attempts to automate O365 login and automate trust process using COM automation in PowerShell (using New-Object -com internetexplorer.application): https://github.com/wulfland/ScriptRepository/blob/master/Apps/Apps/Deploy-SPApp.ps1. With this approach script opens AppInv.aspx page and simulates user’s input.

However O365 login experience was changed since this script was implemented and there is no guarantee that it won’t be changed further. Also there may be several login scenarios:

  • user may be already logged in if chose Remember credentials during previous login
  • user may use MFA with SMS, authenticator app or something else which will make login automation even more complicated

Keeping that in mind I implemented the following semi-automatic way of granting app permissions and trust the app:

1. app is registered in Azure AD via PowerShell (in Sharepoint Online it is not necessary to register app which will be used for communicating with Sharepoint via AppRegNew.aspx. You may also register it in Azure Portal > App Registrations). See e.g. Create an Azure Active Directory Application and Key using PowerShell for example

2. Then script opens AppInv.aspx page in IE (using Start-Process cmdlet) and asks user to authenticate him/herself manually. After that user returns to the script and clicks Enter – all other steps (grant permissions and trust the app) are performed by the following PowerShell script:

function Trust-SPAddIn {
        [Parameter(Mandatory=$true, Position=0)]

        [Parameter(Mandatory=$true, Position=1)]

        [parameter(Mandatory=$true, Position=2)] 

        [parameter(Mandatory=$true, Position=3)] 

    $ie = New-Object -com internetexplorer.application
    try {
  Log-Warn ("Script will now open $WebUrl. Please authenticate yourself and wait until Admin Center home page will be loaded.")
  Log-Warn ("After that leave Admin Center window opened (don't close it), return to the script and follow provided instructions.")
  Log-Warn ("In case you are already signed in Admin Center window will be opened without asking to login. In this case wait until Admin Center window will be loaded, leave it opened and return to the script.")
  if (-not $silently) {
   Log-Warn ("Press Enter to open $WebUrl...")
        $ie.Visible = $true
  if (-not $silently) {
   Log-Warn ("Wait until Admin Center window will be fully loaded and press Enter to continue installation")
   Log-Warn ("Don't close Admin Center window - script will close it automatically")
  $authorizeURL = "$($WebUrl.TrimEnd('/'))/_layouts/15/appinv.aspx"
  Log-Info ("Open $authorizeURL...")
  $ie.Visible = $false
  WaitFor-IEReady $ie -initialWaitInSeconds 3

  Log-Info ("Grant permissions to the app...")
  $appIdInput = $ie.Document.getElementById("ctl00_ctl00_PlaceHolderContentArea_PlaceHolderMain_IdTitleEditableInputFormSection_ctl01_TxtAppId")
  $appIdInput.value = $AppInstanceId
  $lookupBtn = $ie.Document.getElementById("ctl00_ctl00_PlaceHolderContentArea_PlaceHolderMain_IdTitleEditableInputFormSection_ctl01_BtnLookup")
  WaitFor-IEReady $ie -initialWaitInSeconds 3
  Log-Info ("Step 1 of 2 done")
  $appIdInput = $ie.Document.getElementById("ctl00_ctl00_PlaceHolderContentArea_PlaceHolderMain_TitleDescSection_ctl01_TxtPerm")
  $appIdInput.value = '<AppPermissionRequests AllowAppOnlyPolicy="true"><AppPermissionRequest Scope="http://sharepoint/content/tenant" Right="FullControl" /></AppPermissionRequests>'
  $createBtn = $ie.Document.getElementById("ctl00_ctl00_PlaceHolderContentArea_PlaceHolderMain_ctl01_RptControls_BtnCreate")
  WaitFor-IEReady $ie -initialWaitInSeconds 3
  Log-Info ("Step 2 of 2 done")

  Log-Info ("Trust the app...")
  $trustBtn = $ie.Document.getElementById("ctl00_ctl00_PlaceHolderContentArea_PlaceHolderMain_BtnAllow")
  WaitFor-IEReady $ie -initialWaitInSeconds 3

  Log-Info ("All steps are done")
    finally {

WaitFor-IEReady helper method is given from original script mentioned above so credits go to it’s author:

function WaitFor-IEReady {
        [Parameter(Mandatory=$true, ValueFromPipelineByPropertyName=$true, Position=0)]

        [Parameter(Mandatory=$false, Position=1)]
        $initialWaitInSeconds = 1

    sleep -Seconds $initialWaitInSeconds

    while ($ie.Busy) {

        sleep -milliseconds 50

Log-Info and Log-Warn are basic logger methods and you may implement them as needed for your scenario. Since we delegated login to the end user we don’t need to handle different O365 login scenarios and script is greatly simplified, e.g. there is no need to perform javascript activities which work not very stable via COM automation.