🔥 Validate your user inputs like never before with highly intuitive constraints pipeline.

✨ Easy to use pre-defined constraints covering most of your everyday validation needs.

🖍 Better still, you can create your own constraints on the go.

🏎 Set your own order in which constraints are evaluated.

🚜 Receive a list of constraints that got violated or receive the first one that was violated in the pipeline.


valify works in an extremely simple manner.

Valify Pipeline

  • You have a list of constraints as part of your validation/constraints pipeline.
  • The way you list defines the order in which those constraints are evaluated.
  • Once you give it a run, at the end your pipeline you receive a list of constraints that were violated by your input.
  • If no constraints were violated, you receive an empty list.
  • Optionally, you can get access to only the first violation or you can simply check if any violation did occur at all.


To use valify, you'd have to add the following dependency under your pubspec.yaml/depencencies section.

# pubspec.yaml
  valify: ^0.0.5

Let's get started.

Creating a valifying pipeline

import 'package:valify/valifier.dart';

final valifier = Valifier(
    constraints: [
            maxLength: 64,
            minLength: 8,
            specialCharacters: ['@', '$', '-', '%'],

After having created the above valifer object, it's very simple to validate any strings thereafter.

Validating userInput using valifying pipeline

// Let's assume user has entered something that is captured in the variable [userInput]
final violatedConstraints = valifier.allConstraintsViolatedOn(userInput);

if (violatedConstraints.isEmpty) {
    // User didn't violate any constraints.
    print('Awesome user. You did\'t violate any constraints.');
} else {
    // Some constraints were violated.
    print('Uh oh! Some constraints were violated.');
        (violatedConstraint) => print(violatedConstraint.violationMessage),
  • You may also just fetch the first violation that occurred on the given input by using firstConstraintViolatedOn() method of the Valifier.
  • Or you may not even go that far as you can easily get to know if any constraints were violated at all by using areAllConstraintsSatisfiedOn() method of the Valifier.

___ NOTE ___

You can optionally pass-in a violationMessage parameter to any of your constraints. This violationMessage can be useful later on as shown above `print(violatedConstraint.violationMessage)`.

For more details, you may look at example file of this package.

Want to contribute?

I'll be more than happy to receive your PR at

Where do we need the most contribution?

  • Write unit tests. I need help in increasing the code coverage of test cases. The more, the better. For contributing on test cases front, you may follow this article on unit testing dart code.

  • Improve documentation.

  • Create more constraint classes or write generic pipelines such as those for passwords, emails, etc.

  • You can just leave a like at this repo. 👍