Introduction
When designing APIs, it's essential to handle errors gracefully and provide meaningful feedback to consumers. In .NET applications, there are generally two approaches to structure API responses for error handling: enhancing an existing response class or creating a separate, dedicated server response class. This post explores both methods with practical examples to help you decide which fits best with your application's architecture.
API Error Handling Approaches in .NET – 2 Approaches:
There are two approaches to handle error for API Schema. First approach is to add variable in the existing class and second approach is to make new separate server response class.
1. Using First Approach - adding variable in the existing class:
a. Add Message property inside the ResTransaction class.
- Firstly, create a new empty string “message” variable and assign the values to this variable according to your code structure using the concatenation. Here, first we have appended the string “Going to process the transaction”. Once, the transaction has been processed successfully we have appended the string “The transaction has been processed and successful”.
- By default, if no value is assigned to a Message property, it will have a null value. The “restransaction” is an instance of the class “ResTransaction” that contains the “Message” property, assign the message variable to this Message property of ResTransaction class.
- You will get the below response:
- Using Second Approach - making new separate server response class.
- Creating new separate server response class with constants and properties.
- Now, creating a new instance of the “ServerResponse” class using the default constructor and assigns it to the “response” variable.
Then, sets the “ResponseCode” property of the “response” object to the “SUCCESS” constant of the “ServerResponse” class using the dot notation.
- Using try-catch you can display your own messages. In try block set a Result and Message properties to the response object of “ServerResponse” class as a Transaction successful and similarly set a Result, ResponseCode and Message property to the response object of “ServerResponse” class as a Transaction failure.
- You will get the below response:
Conclusion
Choosing between extending an existing response class and creating a dedicated server response structure depends on the complexity and consistency you require in your API responses. While modifying an existing class is quicker and simpler, a separate response class offers greater control, flexibility, and cleaner separation of concerns—especially in larger projects.