# Package org.apache.tapestry5

Root package for Tapestry, containing common interfaces and data types used throughout the framework.

- Interface Summary
  Interface | Description
  --- | ---
  Asset | An Asset is any kind of resource that can be exposed to the client web browser.
  Binding | A binding is a connection between a component and its container (another component), that allows the embedded component to gain access to resources defined by the container.
  Binding2 | Extension to `Binding` that adds a method to access the generic property type.
  Block | A block is a collection of static text and elements, and components, derived from a component template.
  BooleanHook | Encapsulates a bit of information that can be represented as a boolean.
  ClientBodyElement | Extends `ClientElement` with the concept of a body, a Block that can be rendered to provide the content within.
  ClientElement | Interface for any kind of object (typically, a component) that can provide a client-side id, typically used in the generation of client-side (JavaScript) logic.
  ComponentAction<T> | An action that is associated with a component.
  ComponentEventCallback<T> | Callback interface for a render phase event or `ComponentEvent`, notified when a non-null value is returned from some event handler method.
  ComponentResources | Provides a component instance with the resources provided by the framework.
  ComponentResourcesCommon | Operations shared by the public `ComponentResources` interface and `ComponentPageElement` interface (on the internal side).
  ContextAwareException | An interface implemented by exceptions that get special handling in the default `RequestExceptionHandler` service.
  EventContext | A collection of parameters that may eventually be passed to an event handler method.
  ExceptionHandlerAssistant | A contribution to the default `RequestExceptionHandler` service, this is mapped to an exception class, allowing class specific (based on an inheritance search) handling of an exception.
  Field | Defines a field within a form.
  FieldTranslator<T> | A wrapper around `Translator` that combines the translator for a specific `Field` and (sometimes) an override of the default validation message (used when an input value can't be parsed).
  FieldValidationSupport | Services to help with field validation and translation.
  FieldValidator<T> | Responsible for validation of a single field.
  FormValidationControl | Allows control over the validation concerns of a Form component.
  MarkupWriter | An interface used by objects, such as Tapestry components, that need to render themselves as some form of XML markup.
  MarkupWriterListener | An interface that allows objects to be alerted after an element is started, and after an element is ended.
  NullFieldStrategy | Defines a strategy, used by `Field` components such as `TextField`, to handle the case where either the server-side value to be sent (as a string) to the client, or the client-side string passed back up to the server, is null or blank.
  OptionGroupModel | Defines a group of related options.
  OptionModel | A single option within a `OptionGroupModel`.
  PropertyOverrides | Provides access to blocks and messages used when overriding property labels, and property display or edit blocks.
  RadioContainer | A container of `Radio` components, used to identify the element name used when rendering the individual radio buttons.
  Renderable | Base interface for objects that can render markup output using a `MarkupWriter`.
  SelectModel | Defines the possible options and option groups for a <select> [X]HTML element.
  SelectModelVisitor | Callback interface that allows for visiting the option groups and option models of a select model in correct order order.
  StreamResponse | An alternate response from a component event handler method used to directly provide a stream of data to be sent to the client, rather than indicating what page to send a render redirect request to.
  TrackableComponentEventCallback<T> | Extends `ComponentEventCallback` with a way to determine if the underlying event has been aborted due to a some event returning an acceptable, non-null value.
  Translator<T> | Translates between client-side and server-side values.
  ValidationDecorator | Deprecated. Deprecated in 5.4 with no replacement.
  ValidationTracker | Tracks information related to user input validations.
  Validator<C,​T> | Used by a `Field` to enforce a constraint related to a form submission.
  ValueEncoder<V> | A ValueEncoder is used to convert server side objects to unique client-side strings (typically IDs) and back.

- Class Summary
  Class | Description
  --- | ---
  AbstractOptionModel | Base class for implementing `OptionModel`.
  BaseOptimizedSessionPersistedObject | Base implementation of `OptimizedSessionPersistedObject`.
  BaseValidationDecorator | Base implementation of `ValidationDecorator` that does nothing.
  BindingConstants | Constants for the built-in binding prefixes.
  ComponentParameterConstants | Constants for core component parameters defined by `Symbol`
  CookieBuilder | A fluent API to create and write cookies.
  CSSClassConstants | Deprecated. Deprecated in 5.4 with no replacement.
  EventConstants | Constant values for common event names fired by Tapestry components.
  MarkupConstants | Constants used when rendering page markup.
  MarkupUtils | Utility methods related to generating markup.
  MarkupWriterAdapter | Default, empty implementation of `MarkupWriterListener`.
  MetaDataConstants | Meta-data keys that are applied to components and pages.
  PageCallback | A way of capturing the name of a page and the page activation context so that, at a future date, the page can be invoked with that data.
  PersistenceConstants | Constants for persistent field strategies.
  QueryParameterConstants | Defines constants for common query parameters passed in requests from the client.
  SymbolConstants | Defines the names of symbols used to configure Tapestry.
  TapestryConstants | Constants needed by end-user classes.
  TapestryFilter | The TapestryFilter is responsible for intercepting all requests into the web application.
  TapestryMarkers | A set of markers used internally by Tapestry when logging in code related to paqes and components.
  ValidationTrackerImpl | Standard implementation of `ValidationTracker`.
  ValidationTrackerWrapper | Wrapper around a `ValidationTracker` that delegates all methods to the wrapped instance.
  VersionUtils | Utility methods related to managing framework version numbers.

- Enum Summary
  Enum | Description
  --- | ---
  FieldFocusPriority | Used to determine which field on a page should receive focus, based on its status.

- Exception Summary
  Exception | Description
  --- | ---
  BlockNotFoundException | Exception thrown when a `Block` is requested but not found.
  ValidationException | An exception associated with parsing client input, or validating the input against a constraint.