Flutter: Input Validation with RegExp
Today I’m launching a new video about Input Validation and RegExp.
As part of this, I’ll give you an overview of regular expressions (regex) and how they works by using a live web regex validator.
Then we will see how to implement a Regex validator in Dart and integrate it with Flutter’s TextField widget, so that we can validate user input.
I will use a demo app to illustrate two sample use cases:
- Make a payment (numeric validator with 2 decimal digits, 4 non-decimal digits)
- Forgot password (email input validation)
Highlights
- What is Regex and how to use it.
- Implementing a Regex validator in Dart.
- How to configure TextField to validate text input and provide hints for the user.
- Email and number input validation via Regex.
- Putting it together: building a configurable input validation page.
Relevant classes: RegExp, TextField, TextInputFormatter, InputDecoration, FocusNode.
Full source code is available here:
My previous articles about BottomAppBar navigation with FAB:
Happy coding!
UPDATE: My Flutter & Firebase Udemy course is now available for Early Access. Use this link to enroll (discount code included):
For more articles and video tutorials, check out Code With Andrea.
I’m @biz84 on Twitter. You can also see my GitHub page. Did you like this article? Then smash that clap 👏 button! It makes me feel awesome so I can write more about Flutter. 😎
