10 Client Object Model SharePoint 2013 Interview Questions and Answers

Client Object Model (CSOM) in SharePoint 2013 is a powerful framework that allows developers to interact with SharePoint data from client-side applications. It provides a way to perform operations such as CRUD (Create, Read, Update, Delete) on SharePoint objects without needing to be on the server, making it highly versatile for various development scenarios. CSOM is particularly useful for remote operations and is supported in multiple programming environments, including .NET, JavaScript, and REST.

This article offers a curated selection of interview questions designed to test your understanding and proficiency with the Client Object Model in SharePoint 2013. By reviewing these questions and their detailed answers, you will be better prepared to demonstrate your technical expertise and problem-solving abilities in your upcoming interviews.

Client Object Model SharePoint 2013 Interview Questions and Answers

1. Explain the differences between CSOM and REST API in SharePoint 2013.

CSOM (Client-Side Object Model) and REST API are two approaches to interact with SharePoint 2013.

CSOM is a set of libraries for client-side applications, providing a rich set of classes and methods similar to the server-side object model. It is typically used in .NET applications, Silverlight, and JavaScript, and is suited for complex operations with strong typing and IntelliSense support.

REST API, on the other hand, is a web service that allows interaction with SharePoint data using standard HTTP requests. It is language-agnostic and can be used from any platform that supports HTTP requests, making it ideal for CRUD operations with a lightweight, stateless communication protocol.

Key differences:

• Language Support: CSOM is primarily for .NET languages, while REST API can be used with any language supporting HTTP requests.
• Complexity: CSOM offers a comprehensive object model, whereas REST API provides a simpler approach.
• Performance: CSOM can be more efficient for batch operations, while REST API may require multiple HTTP requests.
• Ease of Use: CSOM offers strong typing and IntelliSense, making it easier in environments like Visual Studio. REST API requires manual handling of HTTP requests and responses.
• Flexibility: REST API is more flexible and suitable for cross-platform applications.

2. What are the different ways to handle authentication in CSOM?

In SharePoint 2013, CSOM provides several authentication methods:

• Network Credentials: Uses Windows credentials, common in environments where client and server are within the same domain.
• Forms-Based Authentication (FBA): Used when SharePoint is configured for forms-based authentication, involving sending credentials to the server and receiving an authentication cookie.
• OAuth: Suitable for app authentication, allowing apps to access SharePoint resources on behalf of a user by obtaining an access token.
• Client Certificate Authentication: Uses a client certificate, often in high-security environments.

3. How do you handle exceptions in CSOM?

In CSOM for SharePoint 2013, exceptions can be handled using try-catch blocks, similar to other .NET applications. Catch specific exceptions relevant to SharePoint operations, such as ClientRequestException and ServerException.

Example:

using Microsoft.SharePoint.Client;

ClientContext context = new ClientContext("http://yoursharepointsite");
try
{
    Web web = context.Web;
    context.Load(web);
    context.ExecuteQuery();
    Console.WriteLine(web.Title);
}
catch (ClientRequestException cre)
{
    Console.WriteLine("Client Request Exception: " + cre.Message);
}
catch (ServerException se)
{
    Console.WriteLine("Server Exception: " + se.Message);
}
catch (Exception ex)
{
    Console.WriteLine("General Exception: " + ex.Message);
}

4. Explain how to work with large lists efficiently using CSOM.

Working with large lists in SharePoint 2013 can be challenging due to performance issues and throttling limits. CSOM provides a way to interact with SharePoint data from client-side code, allowing for more efficient handling of large lists.

To work with large lists efficiently using CSOM, use techniques such as pagination, filtering, and batching requests. Pagination helps in retrieving data in smaller chunks, reducing the load on the server. Filtering allows you to retrieve only the necessary data, and batching requests can minimize the number of server round-trips.

Example:

using (ClientContext context = new ClientContext("http://yoursharepointsite"))
{
    List list = context.Web.Lists.GetByTitle("LargeList");
    CamlQuery query = new CamlQuery();
    query.ViewXml = "<View><RowLimit>100</RowLimit></View>";

    ListItemCollection items;
    do
    {
        items = list.GetItems(query);
        context.Load(items);
        context.ExecuteQuery();

        foreach (ListItem item in items)
        {
            Console.WriteLine(item["Title"]);
        }

        query.ListItemCollectionPosition = items.ListItemCollectionPosition;
    }
    while (query.ListItemCollectionPosition != null);
}

In this example, the code retrieves items from a large list in chunks of 100 items at a time using CAML query pagination. The ListItemCollectionPosition property is used to keep track of the position in the list and continue retrieving items until all items are processed.

5. How can you query list items using CAML queries in CSOM?

CAML (Collaborative Application Markup Language) is an XML-based language used to query and manipulate data in SharePoint. When working with CSOM in SharePoint 2013, CAML queries can be used to retrieve specific list items based on certain criteria.

Here is an example of how to use CAML queries in CSOM to query list items:

using System;
using Microsoft.SharePoint.Client;

class Program
{
    static void Main()
    {
        string siteUrl = "https://yoursharepointsite";
        ClientContext clientContext = new ClientContext(siteUrl);
        Web web = clientContext.Web;
        List list = web.Lists.GetByTitle("YourListName");

        CamlQuery query = new CamlQuery();
        query.ViewXml = "<View><Query><Where><Eq><FieldRef Name='Title'/><Value Type='Text'>YourValue</Value></Eq></Where></Query></View>";

        ListItemCollection items = list.GetItems(query);
        clientContext.Load(items);
        clientContext.ExecuteQuery();

        foreach (ListItem listItem in items)
        {
            Console.WriteLine("ID: {0} Title: {1}", listItem.Id, listItem["Title"]);
        }
    }
}

In this example, a CAML query is used to retrieve items from a SharePoint list where the Title field matches a specific value. The CamlQuery object is created and its ViewXml property is set to the CAML query string. The query is then executed using the GetItems method of the List object, and the results are loaded and iterated through.

6. Describe how to manage permissions on a list or item using CSOM.

In SharePoint 2013, managing permissions on a list or item using CSOM involves breaking the role inheritance and then assigning specific permissions to users or groups. This allows for fine-grained control over who can access or modify specific lists or items.

Example:

using Microsoft.SharePoint.Client;

// ClientContext object to connect to SharePoint site
ClientContext context = new ClientContext("https://yoursharepointsite");

// Get the list
List list = context.Web.Lists.GetByTitle("Your List Title");

// Get the item
ListItem item = list.GetItemById(1);

// Break role inheritance
item.BreakRoleInheritance(true, false);

// Create a role definition binding collection
RoleDefinitionBindingCollection roleDefBindings = new RoleDefinitionBindingCollection(context);

// Add the role definition (e.g., Contribute)
roleDefBindings.Add(context.Web.RoleDefinitions.GetByType(RoleType.Contributor));

// Get the user
User user = context.Web.EnsureUser("domain\\username");

// Assign the role to the user
item.RoleAssignments.Add(user, roleDefBindings);

// Execute the query
context.ExecuteQuery();

7. Explain how to create a subsite using CSOM.

To create a subsite using CSOM, connect to the SharePoint site, define the properties of the new subsite, and execute the creation operation.

Example:

using Microsoft.SharePoint.Client;

public void CreateSubsite(string siteUrl, string subsiteTitle, string subsiteUrl)
{
    ClientContext context = new ClientContext(siteUrl);
    Web web = context.Web;

    WebCreationInformation creationInfo = new WebCreationInformation
    {
        Title = subsiteTitle,
        Url = subsiteUrl,
        WebTemplate = "STS#0", // Team Site template
        UseSamePermissionsAsParentSite = true
    };

    Web newWeb = web.Webs.Add(creationInfo);
    context.ExecuteQuery();
}

8. How can you execute batch operations in CSOM?

Batch operations in CSOM for SharePoint 2013 allow you to execute multiple requests to the server in a single round trip, improving performance by reducing server calls.

In CSOM, you can batch operations by queuing them up and then executing them all at once using the ExecuteQuery method. This is particularly useful when you need to perform multiple actions, such as creating, updating, or deleting items, and want to minimize server interactions.

Example:

using (ClientContext context = new ClientContext("http://yoursharepointsite"))
{
    // Load the web
    Web web = context.Web;
    context.Load(web);

    // Create a new list
    ListCreationInformation creationInfo = new ListCreationInformation();
    creationInfo.Title = "New List";
    creationInfo.TemplateType = (int)ListTemplateType.GenericList;
    List newList = web.Lists.Add(creationInfo);

    // Add an item to the list
    ListItemCreationInformation itemCreateInfo = new ListItemCreationInformation();
    ListItem newItem = newList.AddItem(itemCreateInfo);
    newItem["Title"] = "New Item";
    newItem.Update();

    // Execute all operations in a single batch
    context.ExecuteQuery();
}

In this example, we load the web, create a new list, and add an item to the list. All these operations are batched together and executed in a single call to the server using context.ExecuteQuery().

9. How do you handle throttling in CSOM?

Throttling in SharePoint 2013 controls the number of API requests to maintain server performance. When the server is under heavy load, it may throttle requests, causing them to fail with a 429 (Too Many Requests) or 503 (Service Unavailable) status code. Handling throttling in CSOM involves implementing retry logic with exponential backoff.

Exponential backoff is a strategy where the wait time between retries increases exponentially. This approach helps to reduce the load on the server and increases the chances of the request succeeding on subsequent attempts.

Example:

public void ExecuteWithRetry(Action action)
{
    int retryCount = 0;
    int maxRetries = 5;
    int delay = 1000; // Initial delay in milliseconds

    while (retryCount < maxRetries)
    {
        try
        {
            action();
            return; // Exit if the action succeeds
        }
        catch (ServerException ex) when (ex.StatusCode == 429 || ex.StatusCode == 503)
        {
            retryCount++;
            System.Threading.Thread.Sleep(delay);
            delay *= 2; // Exponential backoff
        }
    }

    throw new Exception("Maximum retry attempts exceeded.");
}

In this example, the ExecuteWithRetry method takes an Action delegate as a parameter and attempts to execute it. If a ServerException with a status code of 429 or 503 is caught, the method waits for an exponentially increasing delay before retrying. If the maximum number of retries is exceeded, an exception is thrown.

10. How do you manage versioning in SharePoint lists and libraries using CSOM?

In SharePoint 2013, versioning allows you to track changes to items and documents in lists and libraries. Using CSOM, you can programmatically manage versioning settings and retrieve version history.

To enable versioning in a SharePoint list or library using CSOM, set the EnableVersioning property to true. Additionally, specify the number of major and minor versions to retain. Retrieving version history involves accessing the Versions property of a list item or document.

Example:

using (ClientContext context = new ClientContext("https://yoursharepointsite"))
{
    Web web = context.Web;
    List list = web.Lists.GetByTitle("Documents");

    // Enable versioning
    list.EnableVersioning = true;
    list.Update();
    context.ExecuteQuery();

    // Retrieve version history
    ListItem item = list.GetItemById(1);
    context.Load(item, i => i.Versions);
    context.ExecuteQuery();

    foreach (ListItemVersion version in item.Versions)
    {
        Console.WriteLine("Version: " + version.VersionLabel);
    }
}