Package com.vaadin.flow.component.textfield

Class TextArea

java.lang.Object
com.vaadin.flow.component.Component
com.vaadin.flow.component.AbstractField<C,T>
com.vaadin.flow.component.AbstractSinglePropertyField<TComponent,TValue>
com.vaadin.flow.component.textfield.TextFieldBase<TextArea,String>
com.vaadin.flow.component.textfield.TextArea
All Implemented Interfaces:
AttachNotifier, BlurNotifier<TextArea>, CompositionNotifier, DetachNotifier, Focusable<TextArea>, FocusNotifier<TextArea>, HasAriaLabel, HasElement, HasEnabled, HasHelper, HasLabel, HasSize, HasStyle, HasTheme, HasValidation, HasValue<AbstractField.ComponentValueChangeEvent<TextArea,String>,String>, HasValueAndElement<AbstractField.ComponentValueChangeEvent<TextArea,String>,String>, InputNotifier, KeyNotifier, HasAllowedCharPattern, HasClearButton, HasClientValidation, HasPrefix, HasSuffix, HasThemeVariant<TextAreaVariant>, HasTooltip, HasValidationProperties, HasAutocapitalize, HasAutocomplete, HasAutocorrect, HasPrefixAndSuffix, HasValidator<String>, HasValueChangeMode, Serializable
@Tag("vaadin-text-area") @NpmPackage(value="@vaadin/polymer-legacy-adapter",version="24.1.4") @NpmPackage(value="@vaadin/text-area",version="24.1.4") @JsModule("@vaadin/polymer-legacy-adapter/style-modules.js") @JsModule("@vaadin/text-area/src/vaadin-text-area.js") public class TextArea extends TextFieldBase<TextArea,String> implements HasAllowedCharPattern, HasThemeVariant<TextAreaVariant>
Text Area is an input field component for multi-line text input. Text Area is typically used for descriptions, comments, and other longer free-form content.
Author:
Vaadin Ltd.
See Also:

  • Constructor Details

  • Method Details

    • setMaxLength

      public void setMaxLength(int maxLength)
      Maximum number of characters (in Unicode code points) that the user can enter.
      Parameters:
      maxLength - the maximum length

    • getMaxLength

      public int getMaxLength()
      Maximum number of characters (in Unicode code points) that the user can enter.
      Returns:
      the maxlength property from the webcomponent

    • setMinLength

      public void setMinLength(int minLength)
      Minimum number of characters (in Unicode code points) that the user can enter.
      Parameters:
      minLength - the minimum length

    • getMinLength

      public int getMinLength()
      Minimum number of characters (in Unicode code points) that the user can enter.
      Returns:
      the minlength property from the webcomponent

    • setRequired

      public void setRequired(boolean required)

      Specifies that the user must fill in a value.

      NOTE: The required indicator will not be visible, if there is no label property set for the textfield.
      Overrides:
      setRequired in class TextFieldBase<TextArea,String>
      Parameters:
      required - the boolean value to set

    • setPattern

      public void setPattern(String pattern)
      Sets a regular expression for the value to pass on the client-side. The pattern must be a valid JavaScript Regular Expression that matches the entire value, not just some subset.
      Parameters:
      pattern - the new String pattern
      See Also:

    • getPattern

      public String getPattern()
      A regular expression that the value is checked against. The pattern must match the entire value, not just some subset.
      Returns:
      the pattern property

    • getEmptyValue

      public String getEmptyValue()
      Description copied from interface: HasValue
      Returns the value that represents an empty value.

      By default HasValue is expected to support null as empty values. Specific implementations might not support this.

      Specified by:
      getEmptyValue in interface HasValue<AbstractField.ComponentValueChangeEvent<TextArea,String>,String>
      Overrides:
      getEmptyValue in class AbstractField<TextArea,String>
      Returns:
      empty value

    • setValue

      public void setValue(String value)
      Sets the value of this text area. If the new value is not equal to getValue(), fires a value change event. Throws NullPointerException, if the value is null.

      Note: Binder will take care of the null conversion when integrates with text area, as long as no new converter is defined.

      Specified by:
      setValue in interface HasValue<AbstractField.ComponentValueChangeEvent<TextArea,String>,String>
      Overrides:
      setValue in class AbstractField<TextArea,String>
      Parameters:
      value - the new value, not null

    • getValue

      public String getValue()
      Returns the current value of the text area. By default, the empty text area will return an empty string.
      Specified by:
      getValue in interface HasValue<AbstractField.ComponentValueChangeEvent<TextArea,String>,String>
      Overrides:
      getValue in class AbstractField<TextArea,String>
      Returns:
      the current value.

    • setRequiredIndicatorVisible

      public void setRequiredIndicatorVisible(boolean requiredIndicatorVisible)
      Description copied from interface: HasValue
      Sets the required indicator visible or not.

      If set visible, it is visually indicated in the user interface.

      The method is intended to be used with Binder which does server-side validation. In case HTML element has its own (client-side) validation it should be disabled when setRequiredIndicatorVisible(true) is called and re-enabled back on setRequiredIndicatorVisible(false). It's responsibility of each component implementation to follow the contract so that the method call doesn't do anything else than show/hide the "required" indication. Usually components provide their own setRequired method which should be called in case the client-side validation is required.

      Specified by:
      setRequiredIndicatorVisible in interface HasValue<AbstractField.ComponentValueChangeEvent<TextArea,String>,String>
      Specified by:
      setRequiredIndicatorVisible in interface HasValueAndElement<AbstractField.ComponentValueChangeEvent<TextArea,String>,String>
      Parameters:
      requiredIndicatorVisible - true to make the required indicator visible, false if not

    • getDefaultValidator

      public Validator<String> getDefaultValidator()
      Description copied from interface: HasValidator
      Returns a validator that checks the state of the Value. This should be overridden for components with internal value conversion or validation, e.g. when the user is providing a string that has to be parsed into a date. An invalid input from user will be exposed to a Binder and can be seen as a validation failure.
      Specified by:
      getDefaultValidator in interface HasValidator<String>
      Returns:
      state validator

    • addValidationStatusChangeListener

      public Registration addValidationStatusChangeListener(ValidationStatusChangeListener<String> listener)
      Description copied from interface: HasValidator
      Enables the implementing components to notify changes in their validation status to the observers.

      Note: This method can be overridden by the implementing classes e.g. components, to enable the associated Binder.Binding instance subscribing for their validation change events and revalidate itself.

      This method primarily designed for notifying the Binding about the validation status changes of a bound component at the client-side. WebComponents such as <vaadin-date-picker> or any other component that accept a formatted text as input should be able to communicate their invalid status to their server-side instance, and a bound server-side component instance must notify its binding about this validation status change as well. When the binding instance revalidates, a chain of validators and convertors get executed one of which is the default validator provided by HasValidator.getDefaultValidator(). Thus, In order for the binding to be able to show/clear errors for its associated bound field, it is important that implementing components take that validation status into account while implementing any validator and converter including HasValidator.getDefaultValidator(). Here is an example: 

       @Tag("date-picker-demo")
 public class DatePickerDemo implements HasValidator<LocalDate> {

     // Each web component has a way to communicate its validation status
     // to its server-side component instance. The following clientSideValid
     // state is introduced here just for the sake of simplicity of this code
     // snippet:
     boolean clientSideValid = true;

     /**
      * Note how clientSideValid engaged in the definition
      * of this method. It is important to reflect this status either
      * in the returning validation result of this method or any other
      * validation that is associated with this component.
      */
     @Override
     public Validator getDefaultValidator() {
          return (value, valueContext) -> clientSideValid ? ValidationResult.ok()
                 : ValidationResult.error("Invalid date format");
     }

     private final Collection<ValidationStatusChangeListener<LocalDate>>
         validationStatusListeners = new ArrayList<>();

     /**
      * This enables the binding to subscribe for the validation status
      * change events that are fired by this component and revalidate
      * itself respectively.
      */
     @Override
     public Registration addValidationStatusChangeListener(
             ValidationStatusChangeListener<LocalDate> listener) {
         validationStatusListeners.add(listener);
         return () -> validationStatusListeners.remove(listener);
     }

     private void fireValidationStatusChangeEvent(
             boolean newValidationStatus) {
         if (this.clientSideValid != newValidationStatus) {
             this.clientSideValid = newValidationStatus;
             var event = new ValidationStatusChangeEvent<>(this,
                     newValidationStatus);
             validationStatusListeners.forEach(
                     listener -> listener.validationStatusChanged(event));
         }
     }
 }
      Specified by:
      addValidationStatusChangeListener in interface HasValidator<String>
      Returns:
      Registration of the added listener.
      See Also:

    • validate

      protected void validate()
      Performs server-side validation of the current value. This is needed because it is possible to circumvent the client-side validation constraints using browser development tools.

    • onAttach

      protected void onAttach(AttachEvent attachEvent)
      Description copied from class: Component
      Called when the component is attached to a UI.

      The default implementation does nothing.

      This method is invoked before the AttachEvent is fired for the component.

      Overrides:
      onAttach in class Component
      Parameters:
      attachEvent - the attach event