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Web Development with Blazor

You're reading from   Web Development with Blazor A practical guide to start building interactive UIs with C# 11 and .NET 7

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Product type Paperback
Published in Mar 2023
Publisher Packt
ISBN-13 9781803241494
Length 360 pages
Edition 2nd Edition
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Author (1):
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Jimmy Engström Jimmy Engström
Author Profile Icon Jimmy Engström
Jimmy Engström
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Table of Contents (22) Chapters Close

Preface 1. Hello Blazor 2. Creating Your First Blazor App FREE CHAPTER 3. Managing State – Part 1 4. Understanding Basic Blazor Components 5. Creating Advanced Blazor Components 6. Building Forms with Validation 7. Creating an API 8. Authentication and Authorization 9. Sharing Code and Resources 10. JavaScript Interop 11. Managing State – Part 2 12. Debugging the Code 13. Testing 14. Deploy to Production 15. Moving from, or Combining, an Existing Site 16. Going Deeper into WebAssembly 17. Examining Source Generators 18. Visiting .NET MAUI 19. Where to Go from Here 20. Other Books You May Enjoy
21. Index

Adding validation

We have already touched on the subject of validation; there are some built-in functionalities in the input components as well as EditForm to handle validation.

One way to add validation to our form is to use DataAnnotations. By using data annotations, we don't have to write any custom logic to make sure the data in the form is correct; we can instead add attributes to the data model and let DataAnnotationsValidator take care of the rest.

There are a bunch of DataAnnotations instances in .NET already that we can use; we can also build our own annotations.

Some of the built-in data annotations are as follows:

  • Required: Makes the field required
  • Email: Will check that the entered value is an email address
  • MinLength: Will check that the number of characters is not fewer than the value specified
  • MaxLength: Will check that the number of characters is not exceeded
  • Range: Will check that the value is within a certain range

There are many more annotations that can help...

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