How To Selenium: Page Objects – Partial Classes Fluent API

This is the latest post as part of the Huddle Selenium series.

Each month on the first Tuesday of the month, we will post a new blog post to take you through a step-by-step guide on how to address a particular aspect of using Selenium as part of our How To series.

This is the fourth article from the WebDriver Page Objects Series. It is dedicated to page objects using partial classes and the so-called fluent API.

In the previous articles from the series, I showed you how to create more maintainable page objects through separating the code of the pages in three different files. Moreover, you are no more obligated to use the Selenium.Support NuGet package. Here we will create a different way for accessing the methods of the page in a single uninterrupted chain.

If you are using Selenium WebDriver often, you may find useful my Most Complete Selenium WebDriver C# Cheat Sheet. All you need to know- the most basic operations to the most advanced configurations.


In software engineering, a fluent interface is a method for constructing object-oriented APIs, where the readability of the source code is close to that of ordinary written prose. A fluent interface is usually implemented by using method cascading to relay the instruction context of a subsequent call.

Test Case

We will once again automate the main Bing page. However, this time we will write logic for using the advanced images’ filtering options.


Bing Partial Classes

Page Objects using Fluent API Code

For each filter option, we have a dedicated enum- Colors, Dates, Layouts, Licenses, People, Sizes and Types.

We will use these enums in the primary class of our page. The code of the rest of the enums is identical.



Most of the differences compared to the other implementations of the pattern are located in this file.

Everything stays the same with the difference that each service method now returns the instance of the page itself. This way the fluent syntax is supported.



The map does not contain any differences compared to the other versions. Here, the file contains the various elements present in the advanced filtering menu.


To support the fluent API, the assert method returns the instance of the page.

As you can observe in the code above, we do not call the methods in separate calls. Instead, we create a single chain of methods to create the test case. Some people believe that this way the writing process is simplified and the code more readable. I am a little bit sceptic, but you can try it.


Download Source Code

In future articles, I will share with you other modifications of the design pattern that can make your tests even more maintainable. You can find even more articles dedicated to the design patterns in automated testing on my site.

Read the previous article in the series here.

See more articles in the How To Selenium Series


About The Author:

anton aangelov-august-2017-version2I am Anton Angelov, a Quality Assurance Architect at Innovative Labs. I am passionate about automation testing and designing test harness and tools, having the best industry development practices in mind. Furthermore, I am the owner and Chief Editor of Automate The Planet. I am ardent about technologies such as C#, .NET Framework, T4, WPF, SQL Server, Selenium WebDriver, Jenkins. I won MVP status at Code Project (2016, 2017) and MVB (Most Valuable Blogger) at DZone. You can find even more information on my site.

About the Author

Ronan Healy

Hi everyone. I'm part of the EuroSTAR team. I'm here to help you engage with the EuroSTAR Huddle Community and get the best out of your membership. Together with software testing experts, we have a range of webinars and eBooks for you to enjoy and we have lots of opportunities for you to come together online. If you have any thoughts about the community, please get in contact with me.
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