Package com.vaadin.flow.data.binder

Class Binder<BEAN>

java.lang.Object
com.vaadin.flow.data.binder.Binder<BEAN>
Type Parameters:
BEAN - the bean type
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
BeanValidationBinder, CollaborationBinder
public class Binder<BEAN> extends Object implements Serializable
Connects one or more Field components to properties of a backing data type such as a bean type. With a binder, input components can be grouped together into forms to easily create and update business objects with little explicit logic needed to move data between the UI and the data layers of the application.

A binder is a collection of bindings, each representing the mapping of a single field, through converters and validators, to a backing property.

A binder instance can be bound to a single bean instance at a time, but can be rebound as needed. This allows usage patterns like a master-details view, where a select component is used to pick the bean to edit.

Bean level validators can be added using the withValidator(Validator) method and will be run on the bound bean once it has been updated from the values of the bound fields. Bean level validators are also run as part of writeBean(Object) and writeBeanIfValid(Object) if all field level validators pass.

Note: For bean level validators, the bean must be updated before the validators are run. If a bean level validator fails in writeBean(Object) or writeBeanIfValid(Object), the bean will be reverted to the previous state before returning from the method. You should ensure that the getters/setters in the bean do not have side effects.

Unless otherwise specified, Binder method arguments cannot be null.

Since:
1.0.
Author:
Vaadin Ltd
See Also:

  • Constructor Details

    • Binder

      protected Binder(PropertySet<BEAN> propertySet)
      Creates a binder using a custom PropertySet implementation for finding and resolving property names for bindInstanceFields(Object), bind(HasValue, String) and Binder.BindingBuilder.bind(String).
      Parameters:
      propertySet - the property set implementation to use, not null.

    • Binder

      public Binder(Class<BEAN> beanType)
      Creates a new binder that uses reflection based on the provided bean or record type to resolve its properties. Nested properties are resolved lazily, when bound to a field.
      Parameters:
      beanType - the bean type to use, not null

    • Binder

      public Binder()
      Creates a new binder without support for creating bindings based on property names. Use an alternative constructor, such as Binder(Class), to create a binder that support creating bindings based on instance fields through bindInstanceFields(Object), or based on a property name through bind(HasValue, String) or Binder.BindingBuilder.bind(String).

    • Binder

      public Binder(Class<BEAN> beanType, boolean scanNestedDefinitions)
      Creates a new binder that uses reflection based on the provided bean or record type to resolve its properties. If scanNestedDefinitions is true, nested properties are detected eagerly. Otherwise, they will be discovered lazily when the property is bound to a field.
      Parameters:
      beanType - the bean type to use, not null
      scanNestedDefinitions - if true, scan for nested property definitions as well

  • Method Details

    • withPropertySet

      public static <BEAN> Binder<BEAN> withPropertySet(PropertySet<BEAN> propertySet)
      Creates a binder using a custom PropertySet implementation for finding and resolving property names for bindInstanceFields(Object), bind(HasValue, String) and Binder.BindingBuilder.bind(String).

      This functionality is provided as static method instead of as a public constructor in order to make it possible to use a custom property set without creating a subclass while still leaving the public constructors focused on the common use cases.

      Type Parameters:
      BEAN - the bean type
      Parameters:
      propertySet - the property set implementation to use, not null.
      Returns:
      a new binder using the provided property set, not null
      See Also:

    • handleFieldValueChange

      protected void handleFieldValueChange(Binder.Binding<BEAN,?> binding)
      Informs the Binder that a value in Binding was changed. If readBean(Object) was used, this method will only validate the changed binding and ignore state of other bindings. If setBean(Object) was used, all pending changed bindings will be validated and non-changed ones will be ignored. The changed value will be written to the bean immediately, assuming that Binder-level validators also pass.
      Parameters:
      binding - the binding whose value has been changed

    • getBean

      public BEAN getBean()
      Returns the bean that has been bound with bind(com.vaadin.flow.component.HasValue<?, FIELDVALUE>, com.vaadin.flow.function.ValueProvider<BEAN, FIELDVALUE>, com.vaadin.flow.data.binder.Setter<BEAN, FIELDVALUE>), or null if a bean is not currently bound.
      Returns:
      the currently bound bean if any

    • forField

      public <FIELDVALUE> Binder.BindingBuilder<BEAN,FIELDVALUE> forField(HasValue<?,FIELDVALUE> field)
      Creates a new binding for the given field. The returned builder may be further configured before invoking Binder.BindingBuilder.bind(ValueProvider, Setter) which completes the binding. Until Binding.bind is called, the binding has no effect.

      Note: Not all HasValue implementations support passing null as the value. For these the Binder will automatically change null to a null representation provided by HasValue.getEmptyValue(). This conversion is one-way only, if you want to have a two-way mapping back to null, use Binder.BindingBuilder.withNullRepresentation(Object).

      Type Parameters:
      FIELDVALUE - the value type of the field
      Parameters:
      field - the field to be bound, not null
      Returns:
      the new binding
      See Also:

    • forMemberField

      public <FIELDVALUE> Binder.BindingBuilder<BEAN,FIELDVALUE> forMemberField(HasValue<?,FIELDVALUE> field)
      Creates a new binding for the given field. The returned builder may be further configured before invoking bindInstanceFields(Object). Unlike with the forField(HasValue) method, no explicit call to Binder.BindingBuilder.bind(String) is needed to complete this binding in the case that the name of the field matches a field name found in the bean.
      Type Parameters:
      FIELDVALUE - the value type of the field
      Parameters:
      field - the field to be bound, not null
      Returns:
      the new binding builder
      See Also:

    • bind

      public <FIELDVALUE> Binder.Binding<BEAN,FIELDVALUE> bind(HasValue<?,FIELDVALUE> field, ValueProvider<BEAN,FIELDVALUE> getter, Setter<BEAN,FIELDVALUE> setter)
      Binds a field to a bean property represented by the given getter and setter pair. The functions are used to update the field value from the property and to store the field value to the property, respectively.

      Use the forField(HasValue) overload instead if you want to further configure the new binding.

      Note: Not all HasValue implementations support passing null as the value. For these the Binder will automatically change null to a null representation provided by HasValue.getEmptyValue(). This conversion is one-way only, if you want to have a two-way mapping back to null, use forField(HasValue) and Binder.BindingBuilder.withNullRepresentation(Object).

      When a bean is bound with 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.

      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.bind(nameField, Person::getName, Person::setName);

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

      Type Parameters:
      FIELDVALUE - the value type of the field
      Parameters:
      field - the field to bind, not null
      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

    • bindReadOnly

      public <FIELDVALUE> Binder.Binding<BEAN,FIELDVALUE> bindReadOnly(HasValue<?,FIELDVALUE> field, ValueProvider<BEAN,FIELDVALUE> getter)
      Binds a field to a bean property represented by the given getter. 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.

      Use the forField(HasValue) overload instead if you want to further configure the new binding.

      Note: Not all HasValue implementations support passing null as the value. For these the Binder will automatically change null to a null representation provided by HasValue.getEmptyValue(). This conversion is one-way only, if you want to have a two-way mapping back to null, use forField(HasValue) and Binder.BindingBuilder.withNullRepresentation(Object).

      When a bean is bound with 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 function, 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() { ... }
 }

 TextField nameField = new TextField();
 binder.bindReadOnly(nameField, Person::getName);

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

      Type Parameters:
      FIELDVALUE - the value type of the field
      Parameters:
      field - the field to bind, not null
      getter - the function to get the value of the property to the field, not null
      Returns:
      the newly created binding

    • bind

      public <FIELDVALUE> Binder.Binding<BEAN,FIELDVALUE> bind(HasValue<?,FIELDVALUE> field, String propertyName)
      Binds the given 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 properties support depends on the PropertySet type used to build the Binder. If support is available, for example using the default BeanPropertySet, nested property are supported and 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.

      Type Parameters:
      FIELDVALUE - the value type of the field to bind
      Parameters:
      field - the field to bind, not null
      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

      public <FIELDVALUE> Binder.Binding<BEAN,FIELDVALUE> bindReadOnly(HasValue<?,FIELDVALUE> field, String propertyName)
      Binds the given 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 properties support depends on the PropertySet type used to build the Binder. If support is available, for example using the default BeanPropertySet, nested property are supported and 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.

      Type Parameters:
      FIELDVALUE - the value type of the field to bind
      Parameters:
      field - the field to bind, not null
      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:

    • setBean

      public void setBean(BEAN bean)
      Binds the given bean to all the fields added to this Binder. A null value removes a currently bound bean.

      When a bean is bound, the field values are updated by invoking their corresponding getter functions. Any changes to field values are reflected back to their corresponding property values of the bean as long as the bean is bound.

      Note: Any change made in one of the bound fields runs validation for only the changed Binder.Binding, and additionally any bean level validation for this binder (bean level validators are added using withValidator(Validator). As a result, the bean set via this method is not guaranteed to always be in a valid state. This means also that possible StatusChangeListener and BinderValidationStatusHandler are called indicating a successful validation, even though some bindings can be in a state that would not pass validation. If bean validity is required at all times, readBean(Object) and writeBean(Object) should be used instead.

      After updating each field, the value is read back from the field and the bean's property value is updated if it has been changed from the original value by the field or a converter.

      Parameters:
      bean - the bean to edit, or null to remove a currently bound bean and clear bound fields
      Throws:
      IllegalStateException - if the Binder's model type is record
      See Also:

    • removeBean

      public void removeBean()
      Removes the currently set bean and clears bound fields. If there is no bound bean, does nothing.

      This is a shorthand for setBean(Object) with null bean.

    • readBean

      public void readBean(BEAN bean)
      Reads the bound property values from the given bean or record to the corresponding fields.

      The bean or record is not otherwise associated with this binder; in particular its property values are not bound to the field value changes. To achieve that, use setBean(Object).

      Parameters:
      bean - the bean or record whose property values to read or null to clear bound fields
      See Also:

    • readRecord

      public void readRecord(BEAN record)
      Reads the bound property values from the given record to the corresponding fields.

      The record is not otherwise associated with this binder; in particular its property values are not bound to the field value changes.

      Parameters:
      record - the record whose property values to read or null to clear bound fields
      Throws:
      IllegalArgumentException - if the given object's type is not a record
      See Also:

    • refreshFields

      public void refreshFields()
      Refreshes the fields values by reading them again from the currently associated bean via invoking their corresponding value provider methods.

      If no bean is currently associated with this binder (setBean(Object) has not been called before invoking this method), the bound fields will be cleared.

      See Also:

    • writeBean

      public void writeBean(BEAN bean) throws ValidationException
      Writes changes from the bound fields to the given bean if all validators (binding and bean level) pass.

      If any field binding validator fails, no values are written and a ValidationException is thrown.

      If all field level validators pass, the given bean is updated and bean level validators are run on the updated bean. If any bean level validator fails, the bean updates are reverted and a ValidationException is thrown.

      Parameters:
      bean - the object to which to write the field values, not null
      Throws:
      ValidationException - if some of the bound field values fail to validate
      See Also:

    • writeBean

      public void writeBean(BEAN bean, Collection<Binder.Binding<BEAN,?>> bindingsToWrite) throws ValidationException
      Writes changes from the given bindings to the given bean if all validators (binding and bean level) pass.

      If any field binding validator fails, no values are written and a ValidationException is thrown.

      If all field level validators pass, the given bean is updated and bean level validators are run on the updated bean. If any bean level validator fails, the bean updates are reverted and a ValidationException is thrown.

      Parameters:
      bean - the object to which to write the field values, not null
      bindingsToWrite - Collection of bindings to use in writing the bean
      Throws:
      ValidationException - if some of the bound field values fail to validate
      IllegalArgumentException - if bindingsToWrite contains bindings not belonging to this Binder
      See Also:

    • writeChangedBindingsToBean

      public void writeChangedBindingsToBean(BEAN bean) throws ValidationException
      Writes changes from the changed bindings to the given bean if all validators (binding and bean level) pass. If the bean is the same instance where Binder read the bean, this method updates the bean with the changes.

      If any field binding validator fails, no values are written and a ValidationException is thrown.

      If all field level validators pass, the given bean is updated and bean level validators are run on the updated bean. If any bean level validator fails, the bean updates are reverted and a ValidationException is thrown.

      Parameters:
      bean - the object to which to write the field values, not null
      Throws:
      ValidationException - if some of the bound field values fail to validate
      See Also:

    • getChangedBindings

      public Set<Binder.Binding<BEAN,?>> getChangedBindings()
      Get the immutable Set of changed bindings.
      Returns:
      Immutable set of bindings.
      See Also:

    • writeBeanAsDraft

      public void writeBeanAsDraft(BEAN bean)
      Writes successfully converted and validated changes from the bound fields to the bean even if there are other fields with non-validated changes.
      Parameters:
      bean - the object to which to write the field values, not null
      See Also:

    • writeBeanAsDraft

      public void writeBeanAsDraft(BEAN bean, boolean forced)
      Writes successfully converted changes from the bound fields bypassing all the Validation or all fields passing conversion if forced = true. If the conversion fails, the value written to the bean will be null.
      Parameters:
      bean - the object to which to write the field values, not null
      forced - disable all Validators during write
      See Also:

    • writeBeanIfValid

      public boolean writeBeanIfValid(BEAN bean)
      Writes changes from the bound fields to the given bean if all validators (binding and bean level) pass.

      If any field binding validator fails, no values are written and false is returned.

      If all field level validators pass, the given bean is updated and bean level validators are run on the updated bean. If any bean level validator fails, the bean updates are reverted and false is returned.

      Parameters:
      bean - the object to which to write the field values, not null
      Returns:
      true if there was no validation errors and the bean was updated, false otherwise
      See Also:

    • writeRecord

      public BEAN writeRecord() throws ValidationException
      Writes values from the bound fields to a new record instance if all validators (binding and bean level) pass. This method can only be used if Binder was originally configured to use a record type.

      If any field binding validator fails, no values are written and a ValidationException is thrown.

      If all field level validators pass, a record is intanciated and bean level validators are run on the new record. If any bean level validator fails a ValidationException is thrown.

      Returns:
      a record instance with current values
      Throws:
      ValidationException - if some of the bound field values fail to validate
      IllegalStateException - if a record component does not have a binding, or if the Binder's model type is bean
      IllegalArgumentException - if record instantiation fails for any reason
      See Also:

    • restoreBeanState

      protected void restoreBeanState(BEAN bean, Map<Binder.Binding<BEAN,?>,Object> oldValues)
      Restores the state of the bean from the given values.
      Parameters:
      bean - the bean
      oldValues - the old values

    • getBeanState

      protected Map<Binder.Binding<BEAN,?>,Object> getBeanState(BEAN bean, Collection<Binder.Binding<BEAN,?>> bindings)
      Stores the state of the given bean.
      Parameters:
      bean - the bean to store the state of
      bindings - the bindings to store
      Returns:
      map from binding to value

    • withValidator

      public Binder<BEAN> withValidator(Validator<? super BEAN> validator)
      Adds an bean level validator.

      Bean level validators are applied on the bean instance after the bean is updated. If the validators fail, the bean instance is reverted to its previous state.

      Parameters:
      validator - the validator to add, not null
      Returns:
      this binder, for chaining
      See Also:

    • withValidator

      public Binder<BEAN> withValidator(SerializablePredicate<BEAN> predicate, String message)
      A convenience method to add a validator to this binder using the Validator.from(SerializablePredicate, String) factory method.

      Bean level validators are applied on the bean instance after the bean is updated. If the validators fail, the bean instance is reverted to its previous state.

      Parameters:
      predicate - the predicate performing validation, not null
      message - the error message to report in case validation failure
      Returns:
      this binder, for chaining
      See Also:

    • withValidator

      public Binder<BEAN> withValidator(SerializablePredicate<BEAN> predicate, ErrorMessageProvider errorMessageProvider)
      A convenience method to add a validator to this binder using the Validator.from(SerializablePredicate, ErrorMessageProvider) factory method.

      Bean level validators are applied on the bean instance after the bean is updated. If the validators fail, the bean instance is reverted to its previous state.

      Parameters:
      predicate - the predicate performing validation, not null
      errorMessageProvider - the provider to generate error messages, not null
      Returns:
      this binder, for chaining
      See Also:

    • validate

      public BinderValidationStatus<BEAN> validate()
      Validates the values of all bound fields and returns the validation status.

      If all field level validators pass, and setBean(Object) has been used to bind to a bean, bean level validators are run for that bean.

      Note:Bean level validators are ignored if there is no bound bean or if any field level validator fails.

      Note: This method will attempt to temporarily apply all current changes to the set bean and run full bean validation for it. The changes are reverted after bean validation is run.

      Returns:
      validation status for the binder

    • validate

      protected BinderValidationStatus<BEAN> validate(boolean fireEvent)
      Validates the values of all bound fields and returns the validation status. This method can skip firing the event, based on the given boolean.
      Parameters:
      fireEvent - true to fire validation status events; false to not
      Returns:
      validation status for the binder

    • isValid

      public boolean isValid()
      Runs all currently configured field level validators, as well as all bean level validators if a bean is currently set with setBean(Object), and returns whether any of the validators failed.

      Note: Calling this method will not trigger status change events, unlike validate() and will not modify the UI. To also update error indicators on fields, use validate().isOk().

      Note:Bean level validators are ignored if there is no bound bean or if any field level validator fails.

      Note: This method will attempt to temporarily apply all current changes to the set bean and run full bean validation for it. The changes are reverted after bean validation is run.

      Returns:
      whether this binder is in a valid state
      Throws:
      IllegalStateException - if bean level validators have been configured and no bean is currently set
      See Also:

    • setDefaultValidatorsEnabled

      public void setDefaultValidatorsEnabled(boolean defaultValidatorsEnabled)
      Sets up the Binder to either enable or disable the default field validators (e.g. min/max validators in DatePicker) of all bound fields. This Binder-level setting can be overridden for each binding via either the binding object itself, or the binding builder.

      Defaults to true.

      Parameters:
      defaultValidatorsEnabled - true to enable default validators of bound fields, false to disable them

    • isDefaultValidatorsEnabled

      public boolean isDefaultValidatorsEnabled()
      Returns the Binder-level setting for enabling default validators of bound fields.
      Returns:
      true if default validators of bound fields are enabled, false if they are disabled

    • setStatusLabel

      public void setStatusLabel(HasText statusLabel)
      Sets the label to show the binder level validation errors not related to any specific field.

      Only the one validation error message is shown in this label at a time.

      This is a convenience method for setValidationStatusHandler(BinderValidationStatusHandler), which means that this method cannot be used after the handler has been set. Also the handler cannot be set after this label has been set.

      Parameters:
      statusLabel - the status label to set
      See Also:

    • getStatusLabel

      public Optional<HasText> getStatusLabel()
      Gets the status label or an empty optional if none has been set.
      Returns:
      the optional status label
      See Also:

    • setValidationStatusHandler

      public void setValidationStatusHandler(BinderValidationStatusHandler<BEAN> statusHandler)
      Sets the status handler to track form status changes.

      Setting this handler will override the default behavior, which is to let fields show their validation status messages and show binder level validation errors or OK status in the label set with setStatusLabel(HasText).

      This handler cannot be set after the status label has been set with setStatusLabel(HasText), or setStatusLabel(HasText) cannot be used after this handler has been set.

      Parameters:
      statusHandler - the status handler to set, not null
      Throws:
      NullPointerException - for null status handler
      See Also:

    • getValidationStatusHandler

      public BinderValidationStatusHandler<BEAN> getValidationStatusHandler()
      Gets the status handler of this form.

      If none has been set with setValidationStatusHandler(BinderValidationStatusHandler), the default implementation is returned.

      Returns:
      the status handler used, never null
      See Also:

    • getValidationErrorHandler

      public BinderValidationErrorHandler getValidationErrorHandler()
      Gets the validation error of this form.

      If none has been set with setValidationErrorHandler(BinderValidationErrorHandler), the default implementation is returned.

      Returns:
      the error handler used, never null
      See Also:

    • setValidationErrorHandler

      public void setValidationErrorHandler(BinderValidationErrorHandler handler)
      Sets the validation error handler to update error status for fields when the user input is validated.

      The error handler is invoked by methods handleError(HasValue, ValidationResult) and clearError(HasValue).

      DefaultBinderValidationErrorHandler instance is used if the handler is not explicitly set.

      Parameters:
      handler - the status handler to set, not null
      Throws:
      NullPointerException - for null status handler
      See Also:

    • addStatusChangeListener

      public Registration addStatusChangeListener(StatusChangeListener listener)
      Adds status change listener to the binder.

      The Binder status is changed whenever any of the following happens:

      Parameters:
      listener - status change listener to add, not null
      Returns:
      a registration for the listener
      See Also:

    • addListener

      protected <T> Registration addListener(Class<T> eventType, SerializableConsumer<T> method)
      Adds a listener to the binder.
      Type Parameters:
      T - the event type
      Parameters:
      eventType - the type of the event
      method - the consumer method of the listener
      Returns:
      a registration for the listener

    • addValueChangeListener

      public Registration addValueChangeListener(HasValue.ValueChangeListener<? super HasValue.ValueChangeEvent<?>> listener)
      Adds field value change listener to all the fields in the binder.

      Added listener is notified every time after any bound field value is changed, i.e. the UI component value was changed and passed or failed any conversions and validations. If conversions and validations passed, the value in the bean will be updated before the listener is executed. The same functionality can be achieved by adding a HasValue.ValueChangeListener to all fields in the Binder.

      The listener is added to all fields regardless of whether the method is invoked before or after field is bound.

      Parameters:
      listener - a field value change listener
      Returns:
      a registration for the listener
      See Also:

    • createBinding

      protected <FIELDVALUE, TARGET> Binder.BindingBuilder<BEAN,TARGET> createBinding(HasValue<?,FIELDVALUE> field, Converter<FIELDVALUE,TARGET> converter, BindingValidationStatusHandler handler)
      Creates a new binding with the given field.
      Type Parameters:
      FIELDVALUE - the value type of the field
      TARGET - the target data type
      Parameters:
      field - the field to bind, not null
      converter - the converter for converting between FIELDVALUE and TARGET types, not null
      handler - the handler to notify of status changes, not null
      Returns:
      the new incomplete binding

    • doCreateBinding

      protected <FIELDVALUE, TARGET> Binder.BindingBuilder<BEAN,TARGET> doCreateBinding(HasValue<?,FIELDVALUE> field, Converter<FIELDVALUE,TARGET> converter, BindingValidationStatusHandler handler)

    • handleError

      protected void handleError(HasValue<?,?> field, ValidationResult result)
      Handles a validation error emitted when trying to write the value of the given field.

      TODO:

      Parameters:
      field - the field with the invalid value
      result - the validation error result

    • clearError

      protected void clearError(HasValue<?,?> field)
      Clears the error condition of the given field, if any.

      TODO

      Parameters:
      field - the field with an invalid value

    • handleValidationStatus

      protected void handleValidationStatus(BindingValidationStatus<?> status)
      Default BindingValidationStatusHandler functional method implementation.
      Parameters:
      status - the validation status

    • getBindings

      protected Collection<Binder.BindingImpl<BEAN,?,?>> getBindings()
      Returns the bindings for this binder.
      Returns:
      a list of the bindings

    • handleBinderValidationStatus

      protected void handleBinderValidationStatus(BinderValidationStatus<BEAN> binderStatus)
      The default binder level status handler.

      Passes all field related results to the Binding status handlers. All other status changes are displayed in the status label, if one has been set with setStatusLabel(HasText).

      Parameters:
      binderStatus - status of validation results from binding and/or bean level validators

    • hasChanges

      public boolean hasChanges()
      Check whether any of the bound fields' have uncommitted changes since last explicit call to readBean(Object), removeBean(), writeBean(Object) or writeBeanIfValid(Object). Unsuccessful write operations will not affect this value.

      Note that if you use setBean(Object) method, Binder tries to commit changes as soon as all validators have passed. Thus, when using this method with it seldom makes sense and almost always returns false. Return values for each case are compiled into the following table:

      Return values
      After readBean, setBean or removeBean After valid user changes After invalid user changes After successful writeBean or writeBeanIfValid After unsuccessful writeBean or writeBeanIfValid
      A bean is currently bound false false true false no change
      No bean is currently bound false true true false no change
      Returns:
      whether any bound field's value has changed since last call to setBean, readBean, writeBean or writeBeanIfValid

    • hasChanges

      public boolean hasChanges(Binder.Binding<BEAN,?> binding)
      Checks whether a bound field has uncomitted changes.
      Parameters:
      binding - Binding to be checked
      Returns:
      true if field has been changed.

    • setReadOnly

      public void setReadOnly(boolean readOnly)
      Sets the read only state to the given value for all currently bound fields.

      This is just a shorthand for calling Binder.Binding.setReadOnly(boolean) for all current bindings. It means that bindings added after this method call won't be set read-only.

      Parameters:
      readOnly - true to set the bindings to read-only, false to set them to read-write

    • configureBinding

      protected Binder.BindingBuilder<BEAN,?> configureBinding(Binder.BindingBuilder<BEAN,?> binding, PropertyDefinition<BEAN,?> definition)
      Configures the binding with the property definition definition before it's being bound.
      Parameters:
      binding - a binding to configure
      definition - a property definition information
      Returns:
      the new configured binding

    • bindInstanceFields

      public void bindInstanceFields(Object objectWithMemberFields)
      Binds member fields found in the given object.

      This method processes all (Java) member fields whose type extends HasValue and that can be mapped to a property id. Property name mapping is done based on the field name or on a @PropertyId annotation on the field. All non-null unbound fields for which a property name can be determined are bound to the property name using Binder.BindingBuilder.bind(String).

      For example: 

       public class MyForm extends VerticalLayout {
 private TextField firstName = new TextField("First name");
 @PropertyId("last")
 private TextField lastName = new TextField("Last name");

 MyForm myForm = new MyForm();
 ...
 binder.bindInstanceFields(myForm);
      This binds the firstName TextField to a "firstName" property in the item, lastName TextField to a "last" property.

      It's not always possible to bind a field to a property because their types are incompatible. E.g. custom converter is required to bind HasValue<String> and Integer property (that would be a case of "age" property). In such case, an attempt is made to get a suitable converter from a ConverterFactory but, if there is no match, an IllegalStateException will be thrown, unless the field has been configured manually before calling the bindInstanceFields(Object) method.

      It's always possible to do custom binding for any field: the bindInstanceFields(Object) method doesn't override existing bindings.

      Parameters:
      objectWithMemberFields - The object that contains (Java) member fields to bind
      Throws:
      IllegalStateException - if there are incompatible HasValue<T> and property types
      See Also:

    • getConverterFactory

      protected ConverterFactory getConverterFactory()
      Gets an instance of ConverterFactory that can be used to detect a suitable converter for bindings when presentation and model types are not compatible and a converter has not been explicitly configured. By default, returns a factory capable of handling standard converters. Subclasses can override this method to provide additional or customized conversion rules by creating a completely new factory implementation or composing with the default one.
      Returns:
      an instance of ConverterFactory, never null.

    • getBinding

      public Optional<Binder.Binding<BEAN,?>> getBinding(String propertyName)
      Gets the binding for a property name. Bindings are available by property name if bound using bind(HasValue, String), Binder.BindingBuilder.bind(String) or indirectly using bindInstanceFields(Object).
      Parameters:
      propertyName - the property name of the binding to get
      Returns:
      the binding corresponding to the property name, or an empty optional if there is no binding with that property name

    • getFields

      public Stream<HasValue<?,?>> getFields()
      Returns the fields this binder has been bound to.
      Returns:
      the fields with bindings

    • removeBinding

      public void removeBinding(HasValue<?,?> field)
      Finds and removes all Bindings for the given field.
      Parameters:
      field - the field to remove from bindings

    • removeBinding

      public void removeBinding(Binder.Binding<BEAN,?> binding)
      Removes the given Binding from this Binder.
      Parameters:
      binding - the binding to remove

    • removeBindingInternal

      protected void removeBindingInternal(Binder.Binding<BEAN,?> binding)
      Removes (internally) the Binding from the bound properties map (if present) and from the list of Bindings. Note that this DOES NOT remove the ValueChangeListener that the Binding might have registered with any HasValues or decouple the Binder from within the Binding. To do that, use Binder.Binding.unbind() This method should just be used for internal cleanup.
      Parameters:
      binding - The Binding to remove from the binding map

    • removeBinding

      public void removeBinding(String propertyName)
      Finds and removes the Binding for the given property name.
      Parameters:
      propertyName - the propertyName to remove from bindings

    • setValidatorsDisabled

      public void setValidatorsDisabled(boolean validatorsDisabled)
      Control whether validators including bean level validators are disabled or enabled globally for this Binder.
      Parameters:
      validatorsDisabled - Boolean value.

    • isValidatorsDisabled

      public boolean isValidatorsDisabled()
      Returns if the validators including bean level validators are disabled or enabled for this Binder.
      Returns:
      Boolean value

    • setFieldsValidationStatusChangeListenerEnabled

      public void setFieldsValidationStatusChangeListenerEnabled(boolean fieldsValidationStatusChangeListenerEnabled)
      Control whether bound fields implementing HasValidator subscribe for field's ValidationStatusChangeEvents and will validate upon receiving them.
      Parameters:
      fieldsValidationStatusChangeListenerEnabled - Boolean value.

    • isFieldsValidationStatusChangeListenerEnabled

      public boolean isFieldsValidationStatusChangeListenerEnabled()
      Returns if the bound fields implementing HasValidator subscribe for field's ValidationStatusChangeEvents and will validate upon receiving them.
      Returns:
      Boolean value

    • setChangeDetectionEnabled

      public void setChangeDetectionEnabled(boolean changeDetectionEnabled)
      Sets change/revert detection enabled or disabled. When set to true, any binding that is first changed and then reverted to its original value will be removed from the list of changed bindings. By default, Objects.equals(Object, Object) is used for value comparison, but it can be overridden on binding level using Binder.BindingBuilder.withEqualityPredicate(SerializableBiPredicate).
      Parameters:
      changeDetectionEnabled - Boolean value

    • isChangeDetectionEnabled

      public boolean isChangeDetectionEnabled()
      Returns if change/revert detection is enabled. When set to true, any binding that is first changed and then reverted to its original value will be removed from the list of changed bindings. By default, Objects.equals(Object, Object) is used for value comparison, but it can be overridden on binding level using Binder.BindingBuilder.withEqualityPredicate(SerializableBiPredicate).
      Returns:
      Boolean value

    • setBindingExceptionHandler

      public void setBindingExceptionHandler(BindingExceptionHandler handler)
      Sets a handler to customize the RuntimeException thrown by delegates (like Setter, ValueProvider, HasValue) used inside Binder to be able to identify the bound field.

      It allows to set a custom binding exception handler in case of exception details provided be the default handler are not enough, or, in other way around, it should be reduced.

      DefaultBindingExceptionHandler instance is used if the handler is not explicitly set.

      Parameters:
      handler - the exception handler, not null
      See Also:

    • getBindingExceptionHandler

      public BindingExceptionHandler getBindingExceptionHandler()
      Gets the current exception handler.

      If none has been set with setBindingExceptionHandler(BindingExceptionHandler), the default implementation is returned.

      Returns:
      the exception handler, not null