10 Web Parts Interview Questions and Answers

Web Parts are essential components in modern web development, enabling modular and customizable web pages. They allow developers to create reusable, interactive elements that can be easily integrated and managed within a web application. This modular approach not only enhances the user experience but also streamlines the development process, making it more efficient and scalable.

This article offers a curated selection of interview questions focused on Web Parts, designed to help you demonstrate your expertise and problem-solving abilities. By familiarizing yourself with these questions and their answers, you will be better prepared to showcase your knowledge and skills in any technical interview setting.

Web Parts Interview Questions and Answers

1. Describe the architecture of a Web Part in SharePoint.

A Web Part in SharePoint is a modular unit of information that forms the building blocks of a SharePoint page. The architecture consists of several key components:

• Web Part Class: The core class that defines the Web Part, inheriting from the base WebPart class.
• Properties: Configurable settings for customization of behavior and appearance.
• Render Method: Generates the HTML output for display, typically by overriding the RenderContents method.
• Events: Handles various lifecycle events like initialization and unloading.
• Configuration Interface: The user interface for configuring properties, often using custom editor parts or property panes.

2. How do you create a custom property for a Web Part?

Creating a custom property involves defining it in the Web Part class and using attributes to make it configurable through the property pane. This allows users to modify property values directly from the interface.

Example in C#:

using System.Web.UI.WebControls.WebParts;

public class CustomWebPart : WebPart
{
    private string _customProperty;

    [WebBrowsable(true),
     WebDisplayName("Custom Property"),
     WebDescription("This is a custom property."),
     Personalizable(PersonalizationScope.Shared),
     Category("Custom Settings")]
    public string CustomProperty
    {
        get { return _customProperty; }
        set { _customProperty = value; }
    }

    protected override void RenderContents(HtmlTextWriter writer)
    {
        writer.Write("Custom Property Value: " + CustomProperty);
    }
}

Attributes like WebBrowsable, WebDisplayName, and Personalizable make the property visible and configurable.

3. How can you implement caching in a Web Part?

Caching in a Web Part enhances performance by storing frequently accessed data in memory, reducing server fetches. In ASP.NET, use the HttpRuntime.Cache object for caching.

Example:

public class MyWebPart : WebPart
{
    protected override void RenderContents(HtmlTextWriter writer)
    {
        string cacheKey = "MyWebPartData";
        string data = HttpRuntime.Cache[cacheKey] as string;

        if (data == null)
        {
            data = GetDataFromDataSource();
            HttpRuntime.Cache.Insert(cacheKey, data, null, DateTime.Now.AddMinutes(10), Cache.NoSlidingExpiration);
        }

        writer.Write(data);
    }

    private string GetDataFromDataSource()
    {
        return "Hello, world!";
    }
}

The RenderContents method checks for cached data, fetching and caching it if absent.

4. What are the differences between classic Web Parts and modern Web Parts in SharePoint?

Classic and modern Web Parts in SharePoint differ in user experience, customization, and compatibility.

Classic Web Parts:

• Part of the traditional SharePoint experience, often more complex to configure.
• Rely on server-side rendering, leading to slower performance.
• Customization requires older technologies like SharePoint Designer.
• Compatible with older SharePoint versions, used in legacy systems.

Modern Web Parts:

• Part of the new SharePoint experience, designed to be user-friendly and responsive.
• Use client-side rendering for improved performance.
• Customization is straightforward with modern web technologies.
• Mobile-friendly and compatible with the latest SharePoint versions.

5. Explain how to integrate third-party APIs within a Web Part.

Integrating third-party APIs within a Web Part involves making an HTTP request to the API endpoint, handling the response, parsing the data, and updating the UI.

Example using the Fetch API:

class MyWebPart {
    constructor() {
        this.apiUrl = 'https://api.example.com/data';
    }

    fetchData() {
        fetch(this.apiUrl)
            .then(response => response.json())
            .then(data => this.updateUI(data))
            .catch(error => console.error('Error fetching data:', error));
    }

    updateUI(data) {
        console.log('Data received:', data);
    }
}

const webPart = new MyWebPart();
webPart.fetchData();

The fetchData method makes an HTTP GET request, parses the response as JSON, and updates the UI.

6. What are some performance optimization techniques for Web Parts?

Performance optimization for Web Parts involves techniques like:

• Caching: Store frequently accessed data to reduce server fetches.
• Minimize Resource Usage: Optimize scripts and stylesheets, and use lazy loading.
• Efficient Data Retrieval: Use pagination and filtering to limit data processing.
• Asynchronous Loading: Load Web Parts asynchronously to maintain page responsiveness.
• Optimize Queries: Ensure database queries are efficient.
• Compression: Use Gzip to reduce data transfer size.
• Content Delivery Network (CDN): Serve static resources via CDNs.

7. How do you deploy a Web Part to a SharePoint site?

Deploying a Web Part to a SharePoint site involves:

1. Develop the Web Part: Create it using a development environment like Visual Studio.
2. Package the Web Part: Package it into a SharePoint solution file (.wsp).
3. Upload the Solution Package: Upload the .wsp file to the SharePoint site.
4. Deploy the Solution: Deploy the solution to make the Web Part available.
5. Add the Web Part to a Page: Add the Web Part to a SharePoint page through the interface.

8. How do you connect two Web Parts using provider and consumer interfaces?

Provider and consumer interfaces enable communication between two Web Parts. The provider supplies data, while the consumer uses it.

Example:

// Define the provider interface
public interface IProvider
{
    string GetData();
}

// Define the consumer interface
public interface IConsumer
{
    void SetData(string data);
}

// Provider Web Part
public class ProviderWebPart : WebPart, IProvider
{
    public string GetData()
    {
        return "Hello from Provider";
    }
}

// Consumer Web Part
public class ConsumerWebPart : WebPart, IConsumer
{
    private string _data;

    public void SetData(string data)
    {
        _data = data;
    }

    protected override void RenderContents(HtmlTextWriter writer)
    {
        writer.Write(_data);
    }
}

The framework manages the connection, ensuring data transfer from provider to consumer.

9. What are the best practices for testing Web Parts?

Testing Web Parts involves:

• Unit Testing: Test individual components in isolation using frameworks like Jest.
• Integration Testing: Ensure components work together using tools like Selenium.
• User Acceptance Testing (UAT): Final testing phase with actual users.
• Performance Testing: Measure performance metrics with tools like JMeter.
• Security Testing: Verify security using tools like OWASP ZAP.
• Accessibility Testing: Ensure accessibility with tools like Axe.

10. How do you integrate Web Parts with the SharePoint Framework (SPFx)?

Integrating Web Parts with the SharePoint Framework (SPFx) involves:

• Set up your development environment: Install Node.js, Yeoman, and Gulp.
• Create a new SPFx project: Use the Yeoman SharePoint generator.
• Add a Web Part: Specify its name and configurations during setup.
• Develop the Web Part: Implement logic using TypeScript and React.
• Test the Web Part: Use the local or SharePoint Online workbench.
• Deploy the Web Part: Package and deploy to SharePoint Online.

Example:

# Install the Yeoman generator for SharePoint
npm install -g @microsoft/generator-sharepoint

# Create a new SPFx project
yo @microsoft/sharepoint

In the project, implement your Web Part logic in the generated file.

import * as React from 'react';
import { IMyWebPartProps } from './IMyWebPartProps';

const MyWebPart: React.FC<IMyWebPartProps> = (props) => {
  return (
    <div>
      <h1>Hello, SharePoint!</h1>
      <p>This is a custom Web Part built with SPFx.</p>
    </div>
  );
};

export default MyWebPart;