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ValidationKomensky for Android

A simple library for validating user input in forms using annotations.

alt text


  • Validate all views at once and show feedback to user. With one line of code.
  • Live validation - check user input as he moves between views with immediate feedback.
  • Extensible library - you can add your own validations or adapters for custom views.

How to include it in your project:

With Gradle:

compile ''


  • clone the project
  • add it as library project in your IDE

How to validate

First, annotate your views like this:

@NotEmpty(messageId = R.string.validation_name)
@MinLength(value = 3, messageId = R.string.validation_name_length, order = 2)
private EditText mNameEditText;

Now you are ready to:

FormValidator.validate(this, new SimpleErrorPopupCallback(this));

You will receive collection of all failed validations in a callback and you can present them to the user as you want. Or simply use prepared callbacks (like SimpleErrorPopupCallback).

Live validation

To start and stop live validation, simply call:

FormValidator.startLiveValidation(this, new SimpleErrorPopupCallback(this));

List of all supported validation annotations

Validations supported out of the box:

@NotEmpty(messageId = R.string.validation_name, order = 1)
private EditText mNameEditText;
@MinLength(value = 1, messageId = R.string.validation_participants, order = 2)
private EditText mNameEditText;
@MinValue(value = 2L, messageId = R.string.validation_name_length)
private EditText mEditNumberOfParticipants;
@MinNumberValue(value = "5.5", messageId = R.string.validation_name_length)
private EditText mEditPotentialOfHydrogen;
@RegExp(value = EMAIL, messageId = R.string.validation_valid_email)
private EditText mEditEmail;
@RegExp(value = "^[0-9]+$", messageId = R.string.validation_valid_count)
private EditText mEditCount;
@DateInFuture(messageId = R.string.validation_date)
private TextView mTxtDate;
@DateNoWeekend(messageId = R.string.validation_date_weekend)
private TextView mTxtDate;
@Custom(value = MyVeryOwnValidator.class, messageId = R.string.validation_custom)
private EditText mNameEditText;


Should you need to use the proguard, copy these rules:

-keepattributes *Annotation*
-keep class** { *; }
-keep class * implements
-keep class * implements
-keep class * implements
-keepclassmembers class ** {** *;

Why 'Komensky'?

Jan Ámos Komenský was a famous Czech educator, father of modern education methods.  Teachers tend to correct you, just like this library. You won't miss any errors in the user input.

See our other Czech personalities who help with #AndroidDev.

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