Package com.vaadin.flow.data.binder

Interface Binder.BindingBuilder<BEAN,TARGET>

Type Parameters:
BEAN - the bean type
TARGET - the target data type of the binding, matches the field type until a converter has been set
All Superinterfaces:
Serializable
All Known Implementing Classes:
Binder.BindingBuilderImpl
Enclosing class:
Binder<BEAN>
public static interface Binder.BindingBuilder<BEAN,TARGET> extends Serializable
Creates a binding between a field and a data property.
See Also:

  • Method Details

    • getField

      com.vaadin.flow.component.HasValue<?,?> getField()
      Gets the field the binding is being built for.
      Returns:
      the field this binding is being built for

    • bind

      Binder.Binding<BEAN,TARGET> bind(com.vaadin.flow.function.ValueProvider<BEAN,TARGET> getter, Setter<BEAN,TARGET> setter)
      Completes this binding using the given getter and setter functions representing a backing bean property. The functions are used to update the field value from the property and to store the field value to the property, respectively.

      When a bean is bound with Binder.setBean(Object), the field value is set to the return value of the given getter. The property value is then updated via the given setter whenever the field value changes. The setter may be null; in that case the property value is never updated and the binding is said to be read-only.

      If the Binder is already bound to some bean, the newly bound field is associated with the corresponding bean property as described above.

      If the bound field implements HasValidator, then the binding instance returned by this method will subscribe for field's ValidationStatusChangeEvents and will validate itself upon receiving them.

      The getter and setter can be arbitrary functions, for instance implementing user-defined conversion or validation. However, in the most basic use case you can simply pass a pair of method references to this method as follows: 

       class Person {
     public String getName() { ... }
     public void setName(String name) { ... }
 }

 TextField nameField = new TextField();
 binder.forField(nameField).bind(Person::getName, Person::setName);

      Note: when a null setter is given the field will be marked as readonly by invoking HasValue.setReadOnly(boolean).

      Parameters:
      getter - the function to get the value of the property to the field, not null
      setter - the function to write the field value to the property or null if read-only
      Returns:
      the newly created binding
      Throws:
      IllegalStateException - if bind has already been called on this binding

    • bindReadOnly

      Binder.Binding<BEAN,TARGET> bindReadOnly(com.vaadin.flow.function.ValueProvider<BEAN,TARGET> getter)
      Completes this binding using the given getter function representing a backing bean property. The function is used to update the field value from the property. The field value is not written back to the bean so the binding is read-only.

      When a bean is bound with Binder.setBean(Object), the field value is set to the return value of the given getter.

      If the Binder is already bound to some bean, the newly bound field is associated with the corresponding bean property as described above.

      The getter can be arbitrary functions, for instance implementing user-defined conversion or validation. However, in the most basic use case you can simply a method references to this method as follows: 

       class Person {
     public String getName() { ... }
 }

 TextField nameField = new TextField();
 binder.forField(nameField).bindReadOnly(Person::getName);
      Note: the field will be marked as readonly by invoking HasValue.setReadOnly(boolean).

      This is a shorthand for bind(ValueProvider, Setter) method called with null setter.

      Parameters:
      getter - the function to get the value of the property to the field, not null
      Returns:
      the newly created binding
      Throws:
      IllegalStateException - if bind has already been called on this binding
      See Also:

    • bind

      Binder.Binding<BEAN,TARGET> bind(String propertyName)
      Completes this binding by connecting the field to the property with the given name. The getter and setter of the property are looked up using a PropertySet.

      For a Binder created using the Binder(Class) constructor, introspection will be used to find a Java Bean property. If a JSR-303 bean validation implementation is present on the classpath, a BeanValidator is also added to the binding.

      The property must have an accessible getter method. It need not have an accessible setter; in that case the property value is never updated and the binding is said to be read-only. Nested property, when supported, can be referenced using the bean path, starting from the root class, for example 'address.streetName'. All intermediate getters must exist (e.g. getAddress()), and should never return null, otherwise binding will fail.

      Note: when the binding is read-only the field will be marked as readonly by invoking HasValue.setReadOnly(boolean).

      Parameters:
      propertyName - the name of the property to bind, not null
      Returns:
      the newly created binding
      Throws:
      IllegalArgumentException - if the property name is invalid
      IllegalArgumentException - if the property has no accessible getter
      IllegalStateException - if the binder is not configured with an appropriate PropertySet
      See Also:

    • bindReadOnly

      Binder.Binding<BEAN,TARGET> bindReadOnly(String propertyName)
      Completes this binding by connecting the field to the property with the given name. The getter of the property is looked up using a PropertySet. The field value is not written back to the bean so the binding is read-only.

      For a Binder created using the Binder(Class) constructor, introspection will be used to find a Java Bean property. If a JSR-303 bean validation implementation is present on the classpath, a BeanValidator is also added to the binding.

      The property must have an accessible getter method. Nested property, when supported, can be referenced using the bean path, starting from the root class, for example 'address.streetName'. All intermediate getters must exist (e.g. getAddress()), and should never return null, otherwise binding will fail.

      Note: the field will be marked as readonly by invoking HasValue.setReadOnly(boolean).

      Parameters:
      propertyName - the name of the property to bind, not null
      Returns:
      the newly created binding
      Throws:
      IllegalArgumentException - if the property name is invalid
      IllegalArgumentException - if the property has no accessible getter
      IllegalStateException - if the binder is not configured with an appropriate PropertySet
      See Also:

    • withValidator

      Binder.BindingBuilder<BEAN,TARGET> withValidator(Validator<? super TARGET> validator)
      Adds a validator to this binding. Validators are applied, in registration order, when the field value is written to the backing property. If any validator returns a failure, the property value is not updated.
      Parameters:
      validator - the validator to add, not null
      Returns:
      this binding, for chaining
      Throws:
      IllegalStateException - if bind has already been called
      See Also:

    • withValidator

      default Binder.BindingBuilder<BEAN,TARGET> withValidator(com.vaadin.flow.function.SerializablePredicate<? super TARGET> predicate, String message)
      A convenience method to add a validator to this binding using the Validator.from(SerializablePredicate, String) factory method.

      Validators are applied, in registration order, when the field value is written to the backing property. If any validator returns a failure, the property value is not updated.

      Parameters:
      predicate - the predicate performing validation, not null
      message - the error message to report in case validation failure
      Returns:
      this binding, for chaining
      Throws:
      IllegalStateException - if bind has already been called
      See Also:

    • withValidator

      default Binder.BindingBuilder<BEAN,TARGET> withValidator(com.vaadin.flow.function.SerializablePredicate<? super TARGET> predicate, String message, ErrorLevel errorLevel)
      A convenience method to add a validator to this binding using the Validator.from(SerializablePredicate, String, ErrorLevel) factory method.

      Validators are applied, in registration order, when the field value is written to the backing property. If any validator returns a failure, the property value is not updated.

      Parameters:
      predicate - the predicate performing validation, not null
      message - the error message to report in case validation failure
      errorLevel - the error level for failures from this validator, not null
      Returns:
      this binding, for chaining
      Throws:
      IllegalStateException - if bind has already been called
      See Also:

    • withValidator

      default Binder.BindingBuilder<BEAN,TARGET> withValidator(com.vaadin.flow.function.SerializablePredicate<? super TARGET> predicate, ErrorMessageProvider errorMessageProvider)
      A convenience method to add a validator to this binding using the Validator.from(SerializablePredicate, ErrorMessageProvider) factory method.

      Validators are applied, in registration order, when the field value is written to the backing property. If any validator returns a failure, the property value is not updated.

      Parameters:
      predicate - the predicate performing validation, not null
      errorMessageProvider - the provider to generate error messages, not null
      Returns:
      this binding, for chaining
      Throws:
      IllegalStateException - if bind has already been called
      See Also:

    • withValidator

      default Binder.BindingBuilder<BEAN,TARGET> withValidator(com.vaadin.flow.function.SerializablePredicate<? super TARGET> predicate, ErrorMessageProvider errorMessageProvider, ErrorLevel errorLevel)
      A convenience method to add a validator to this binding using the Validator.from(SerializablePredicate, ErrorMessageProvider, ErrorLevel) factory method.

      Validators are applied, in registration order, when the field value is written to the backing property. If any validator returns a failure, the property value is not updated.

      Parameters:
      predicate - the predicate performing validation, not null
      errorMessageProvider - the provider to generate error messages, not null
      errorLevel - the error level for failures from this validator, not null
      Returns:
      this binding, for chaining
      Throws:
      IllegalStateException - if bind has already been called
      See Also:

    • withConverter

      <NEWTARGET> Binder.BindingBuilder<BEAN,NEWTARGET> withConverter(Converter<TARGET,NEWTARGET> converter)
      Maps the binding to another data type using the given Converter.

      A converter is capable of converting between a presentation type, which must match the current target data type of the binding, and a model type, which can be any data type and becomes the new target type of the binding. When invoking bind(ValueProvider, Setter), the target type of the binding must match the getter/setter types.

      For instance, a TextField can be bound to an integer-typed property using an appropriate converter such as a StringToIntegerConverter.

      The converted value is applied back to the field by default, this can be controlled with the method Binder.Binding.setConvertBackToPresentation(boolean).

      Type Parameters:
      NEWTARGET - the type to convert to
      Parameters:
      converter - the converter to use, not null
      Returns:
      this BindingBuilder configured with the specified converter
      Throws:
      IllegalStateException - if bind has already been called
      See Also:

    • withConverter

      default <NEWTARGET> Binder.BindingBuilder<BEAN,NEWTARGET> withConverter(com.vaadin.flow.function.SerializableFunction<TARGET,NEWTARGET> toModel, com.vaadin.flow.function.SerializableFunction<NEWTARGET,TARGET> toPresentation)
      Maps the binding to another data type using the mapping functions and a possible exception as the error message.

      The mapping functions are used to convert between a presentation type, which must match the current target data type of the binding, and a model type, which can be any data type and becomes the new target type of the binding. When invoking bind(ValueProvider, Setter), the target type of the binding must match the getter/setter types.

      For instance, a TextField can be bound to an integer-typed property using appropriate functions such as: withConverter(Integer::valueOf, String::valueOf);

      The converted value is applied back to the field by default, this can be controlled with the method Binder.Binding.setConvertBackToPresentation(boolean).

      Type Parameters:
      NEWTARGET - the type to convert to
      Parameters:
      toModel - the function which can convert from the old target type to the new target type
      toPresentation - the function which can convert from the new target type to the old target type
      Returns:
      this BindingBuilder configured with a new converter that maps between TARGET and NEWTARGET
      Throws:
      IllegalStateException - if bind has already been called
      See Also:

    • withConverter

      default <NEWTARGET> Binder.BindingBuilder<BEAN,NEWTARGET> withConverter(com.vaadin.flow.function.SerializableFunction<TARGET,NEWTARGET> toModel, com.vaadin.flow.function.SerializableFunction<NEWTARGET,TARGET> toPresentation, String errorMessage)
      Maps the binding to another data type using the mapping functions and the given error error message if a value cannot be converted to the new target type.

      The mapping functions are used to convert between a presentation type, which must match the current target data type of the binding, and a model type, which can be any data type and becomes the new target type of the binding. When invoking bind(ValueProvider, Setter), the target type of the binding must match the getter/setter types.

      For instance, a TextField can be bound to an integer-typed property using appropriate functions such as: withConverter(Integer::valueOf, String::valueOf);

      The converted value is applied back to the field by default, this can be controlled with the method Binder.Binding.setConvertBackToPresentation(boolean).

      Type Parameters:
      NEWTARGET - the type to convert to
      Parameters:
      toModel - the function which can convert from the old target type to the new target type
      toPresentation - the function which can convert from the new target type to the old target type
      errorMessage - the error message to use if conversion using toModel fails
      Returns:
      this BindingBuilder configured with the appropriate type
      Throws:
      IllegalStateException - if bind has already been called
      See Also:

    • withNullRepresentation

      default Binder.BindingBuilder<BEAN,TARGET> withNullRepresentation(TARGET nullRepresentation)
      Maps binding value null to given null representation and back to null when converting back to model value.
      Parameters:
      nullRepresentation - the value to use instead of null
      Returns:
      this BindingBuilder with null representation handling.

    • withStatusLabel

      default Binder.BindingBuilder<BEAN,TARGET> withStatusLabel(com.vaadin.flow.component.HasText label)
      Sets the given label to show an error message if validation fails.

      The validation state of each field is updated whenever the user modifies the value of that field. With this method, possible validation error message will be shown in the label provided. Additionally, the field's invalid state will be updated to provide visual feedback (e.g., red background) for fields implementing HasValidation.

      This is just a shorthand for withValidationStatusHandler(BindingValidationStatusHandler) method where the handler instance hides the label if there is no error and shows it with validation error message if validation fails. It means that it cannot be called after withValidationStatusHandler(BindingValidationStatusHandler) method call or withValidationStatusHandler(BindingValidationStatusHandler) after this method call.

      Parameters:
      label - label to show validation status for the field
      Returns:
      this binding, for chaining
      See Also:

    • withValidationStatusHandler

      Binder.BindingBuilder<BEAN,TARGET> withValidationStatusHandler(BindingValidationStatusHandler handler)
      Sets a BindingValidationStatusHandler to track validation status changes.

      The validation state of each field is updated whenever the user modifies the value of that field.

      This method allows to customize the way a binder displays error messages.

      The method may be called only once. It means there is no chain unlike withValidator(Validator) or withConverter(Converter). Also it means that the shorthand method withStatusLabel(HasText) also may not be called after this method.

      Parameters:
      handler - status change handler
      Returns:
      this binding, for chaining
      See Also:

    • withDefaultValidator

      Binder.BindingBuilder<BEAN,TARGET> withDefaultValidator(boolean defaultValidatorEnabled)
      Sets up this binding to either enable or disable the default field validator (e.g. min/max validators in DatePicker). This binding-level setting will override the Binder-level setting for this property. By default, all bindings will use the Binder-level setting if no value is set for them.
      Parameters:
      defaultValidatorEnabled - true to enable default validator for this binding, false to disable it
      Returns:
      this binding, for chaining
      See Also:

    • asRequired

      default Binder.BindingBuilder<BEAN,TARGET> asRequired(String errorMessage)
      Sets the field to be required. This means two things:
      1. the required indicator is visible
      2. the field value is validated for not being empty*
      For localizing the error message, use asRequired(ErrorMessageProvider).

      *Value not being the equal to what HasValue.getEmptyValue() returns.

      Parameters:
      errorMessage - the error message to show for the invalid value
      Returns:
      this binding, for chaining
      See Also:

    • asRequired

      default Binder.BindingBuilder<BEAN,TARGET> asRequired()
      Sets the field to be required. This means two things:
      1. the required indicator will be displayed for this field
      2. the field value is validated for not being empty, i.e. that the field's value is not equal to what HasValue.getEmptyValue() returns

      For setting an error message, use asRequired(String).

      For localizing the error message, use asRequired(ErrorMessageProvider).

      Returns:
      this binding, for chaining
      See Also:

    • asRequired

      Binder.BindingBuilder<BEAN,TARGET> asRequired(ErrorMessageProvider errorMessageProvider)
      Sets the field to be required. This means two things:
      1. the required indicator is visible
      2. the field value is validated for not being empty*
      *Value not being the equal to what HasValue.getEmptyValue() returns.
      Parameters:
      errorMessageProvider - the provider for localized validation error message
      Returns:
      this binding, for chaining
      See Also:
      • HasValue.setRequiredIndicatorVisible(boolean)
      • HasValue.isEmpty()

    • asRequired

      Binder.BindingBuilder<BEAN,TARGET> asRequired(Validator<TARGET> customRequiredValidator)
      Sets the field to be required and delegates the required check to a custom validator. This means two things:
      1. the required indicator will be displayed for this field
      2. the field value is validated by customRequiredValidator
      Parameters:
      customRequiredValidator - validator responsible for the required check
      Returns:
      this binding, for chaining
      See Also:
      • HasValue.setRequiredIndicatorVisible(boolean)

    • withEqualityPredicate

      default Binder.BindingBuilder<BEAN,TARGET> withEqualityPredicate(com.vaadin.flow.function.SerializableBiPredicate<TARGET,TARGET> equalityPredicate)
      Sets the equalityPredicate used to compare the current value of a field with its initial value.

      By default it is null, meaning the initial value comparison is not active. Once it is set, the value of the field will be compared with its initial value. If the value of the field is set back to its initial value, it will not be considered as having uncommitted changes.

      Parameters:
      equalityPredicate - the predicate to use for equality comparison
      Returns:
      this BindingBuilder, for method chaining