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com.vaadin.flow.data.binder.
Interface Validator<T>
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Type Parameters:
T- the type of the value to validateAll Superinterfaces:
All Known Implementing Classes:
AbstractValidator, BeanValidator, BigDecimalRangeValidator, BigIntegerRangeValidator, ByteRangeValidator, DateRangeValidator, DateTimeRangeValidator, DoubleRangeValidator, EmailValidator, FloatRangeValidator, IntegerRangeValidator, LongRangeValidator, RangeValidator, RegexpValidator, ShortRangeValidator, StringLengthValidator
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public interface Validator<T> extends BiFunction<T,ValueContext,ValidationResult>, SerializableA functional interface for validating user input or other potentially invalid data. When a validator instance is applied to a value of the corresponding type, it returns a result signifying that the value either passed or failed the validation.
For instance, the following validator checks if a number is positive:
Validator<Integer> v = num -> { if (num >= 0) return ValidationResult.ok(); else return ValidationResult.error("number must be positive"); };Since:
1.0.
Author:
Vaadin Ltd
See Also:
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Method Summary
All Methods Modifier and Type Method and Description static <T> Validator<T>alwaysPass()Returns a validator that passes any value.
ValidationResultapply(T value, ValueContext context)Validates the given value.
static <T> Validator<T>from(SerializablePredicate<T> guard, ErrorMessageProvider errorMessageProvider)Builds a validator out of a conditional function and an error message provider.
static <T> Validator<T>from(SerializablePredicate<T> guard, ErrorMessageProvider errorMessageProvider, ErrorLevel errorLevel)Builds a validator out of a conditional function and an error message provider.
static <T> Validator<T>from(SerializablePredicate<T> guard, String errorMessage)Builds a validator out of a conditional function and an error message.
static <T> Validator<T>from(SerializablePredicate<T> guard, String errorMessage, ErrorLevel errorLevel)Builds a validator out of a conditional function and an error message.
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Methods inherited from interface java.util.function.BiFunction
andThen
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Method Detail
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apply
ValidationResult apply(T value, ValueContext context)Validates the given value. Returns a
ValidationResultinstance representing the outcome of the validation.Specified by:
applyin interfaceBiFunction<T,ValueContext,ValidationResult>Parameters:
value- the input value to validatecontext- the value context for validationReturns:
the validation result
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alwaysPass
static <T> Validator<T> alwaysPass()Returns a validator that passes any value.
Type Parameters:
T- the value typeReturns:
an always-passing validator
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from
static <T> Validator<T> from(SerializablePredicate<T> guard, String errorMessage)Builds a validator out of a conditional function and an error message. If the function returns true, the validator returns
Result.ok(); if it returns false or throws an exception,ValidationResult.error(String)is returned with the given message and error levelErrorLevel.ERROR.For instance, the following validator checks if a number is between 0 and 10, inclusive:
Validator<Integer> v = Validator.from(num -> num >= 0 && num <= 10, "number must be between 0 and 10");Type Parameters:
T- the value typeParameters:
guard- the function used to validate, not nullerrorMessage- the message returned if validation fails, not nullReturns:
the new validator using the function
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from
static <T> Validator<T> from(SerializablePredicate<T> guard, String errorMessage, ErrorLevel errorLevel)Builds a validator out of a conditional function and an error message. If the function returns true, the validator returns
Result.ok(); if it returns false or throws an exception,ValidationResult.error(String)is returned with the given message and error level.For instance, the following validator checks if a number is between 0 and 10, inclusive:
Validator<Integer> v = Validator.from(num -> num >= 0 && num <= 10, "number must be between 0 and 10", ErrorLevel.ERROR);Type Parameters:
T- the value typeParameters:
guard- the function used to validate, not nullerrorMessage- the message returned if validation fails, not nullerrorLevel- the error level for failures from this validator, not nullReturns:
the new validator using the function
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from
static <T> Validator<T> from(SerializablePredicate<T> guard, ErrorMessageProvider errorMessageProvider)Builds a validator out of a conditional function and an error message provider. If the function returns true, the validator returns
Result.ok(); if it returns false or throws an exception,Result.error()is returned with the message from the provider.Type Parameters:
T- the value typeParameters:
guard- the function used to validate, not nullerrorMessageProvider- the provider to generate error messages, not nullReturns:
the new validator using the function
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from
static <T> Validator<T> from(SerializablePredicate<T> guard, ErrorMessageProvider errorMessageProvider, ErrorLevel errorLevel)Builds a validator out of a conditional function and an error message provider. If the function returns true, the validator returns
Result.ok(); if it returns false or throws an exception,Result.error()is returned with the message from the provider.Type Parameters:
T- the value typeParameters:
guard- the function used to validate, not nullerrorMessageProvider- the provider to generate error messages, not nullerrorLevel- the error level for failures from this validator, not nullReturns:
the new validator using the function
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