Building Web APIs with ASP.NET Core

6 Data validation and error handling

This chapter covers

• Overview of model binding and data validation
• Built-in and custom validation attributes
• ModelState validation approaches
• Error and exception handling techniques

For simplicity, up to this point we’ve assumed that the data coming from clients is always correct and adequate for our web API’s endpoints. Unfortunately, this is not always the case: whether we like it or not, we often have to deal with erroneous HTTP requests, which can be caused by several factors (including malicious attacks) but always occur because our application is facing unexpected or unhandled behavior.

In this chapter, we’ll discuss a series of techniques for handling unexpected scenarios during the client-server interaction. ...