How to Update an Object with Non-NULL Properties in C# ?

Discover a more efficient way to update object properties in C# WebAPI without using cumbersome if statements. Learn how to streamline your code using AutoMapper for non-NULL properties.
---
This video is based on the question https://stackoverflow.com/q/66115463/ asked by the user 'Roman Suska' ( https://stackoverflow.com/u/3872681/ ) and on the answer https://stackoverflow.com/a/66116511/ provided by the user 'Jonas Høgh' ( https://stackoverflow.com/u/85215/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to update an object with non-NULL properties?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/licensing
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Update an Object with Non-NULL Properties in C# ?

When developing a WebAPI, one common challenge developers face is updating object properties while avoiding the cumbersome task of handling NULL values. In many cases, you need to update an object in the database with only specific fields, leaving out those that aren't provided. In this post, we’ll explore a clean and efficient way to handle this using C# .

The Challenge

You might have encountered a scenario where you are required to update some properties of a database object based on a client request. Ideally, you’d want to send an object to your API endpoint that contains only those properties that should be updated. However, checking if each property is NULL before deciding to update it can lead to messy and hard-to-maintain code.

For instance, using multiple if statements to check each property like this:

[[See Video to Reveal this Text or Code Snippet]]

While functional, this approach can quickly become unmanageable as the number of properties grows.

A Cleaner Solution: Using AutoMapper

To overcome this limitation, you can utilize AutoMapper, a powerful library in C# that helps in mapping properties of different objects conveniently. AutoMapper allows you to set up conditional mappings for your object properties, thereby omitting any that are NULL in an elegant manner.

Step-by-step Implementation

Install AutoMapper:
First, make sure you have AutoMapper installed in your project. You can do this via NuGet Package Manager by running the following command:

[[See Video to Reveal this Text or Code Snippet]]

Create Your Classes:
Define the source and destination classes that represent your object properties.

[[See Video to Reveal this Text or Code Snippet]]

Configure AutoMapper:
In your main program or in a configuration class, set up the mapping configuration. Use the ForAllMembers method to apply a condition that checks if properties are non-NULL.

[[See Video to Reveal this Text or Code Snippet]]

Perform the Mapping:
Create instances of your source and destination objects, and map them using AutoMapper.

[[See Video to Reveal this Text or Code Snippet]]

Result:
After running the mapping, your destination object (dest) will retain its original values for any NULL properties in source. For instance:

dest.Prop1 will still be "p3"

dest.Prop2 will now be "p2"

Conclusion

By leveraging AutoMapper for conditional mapping, you simplify your code and avoid repetitive null checks, making your logic more maintainable and cleaner. This approach not only enhances productivity but also ensures that your updates occur only when valid data is provided.

If you are looking for a more effective way to handle property updates in your WebAPI, consider using AutoMapper. It's a powerful tool that reduces boilerplate code and streamlines your development process.

Happy coding!

Видео How to Update an Object with Non-NULL Properties in C# ? канала vlogize