Component (Wicket Core 7.3.0 API)

java.lang.Object
- org.apache.wicket.Component

All Implemented Interfaces:

Serializable, IEventSink, IEventSource, IConverterLocator, IHeaderContributor, IRequestableComponent, IHierarchical<Component>, IClusterable

Direct Known Subclasses:

MarkupContainer, WebComponent
```
public abstract class Component
extends Object
implements IClusterable, IConverterLocator, IRequestableComponent, IHeaderContributor, IHierarchical<Component>, IEventSink, IEventSource
```
Component serves as the highest level abstract base class for all components.
- Identity - All Components must have a non-null id which is retrieved by calling getId(). The id must be unique within the MarkupContainer that holds the Component, but does not have to be globally unique or unique within a Page's component hierarchy.
- Hierarchy - A component has a parent which can be retrieved with getParent(). If a component is an instance of MarkupContainer, it may have children. In this way it has a place in the hierarchy of components contained on a given page.
  The path from the Page at the root of the component hierarchy to a given Component is simply the concatenation with colon separators of each id along the way. For example, the path "a:b:c" would refer to the component named "c" inside the MarkupContainer named "b" inside the container named "a". The path to a component can be retrieved by calling getPath(). To get a Component path relative to the page that contains it, you can call getPageRelativePath().
- LifeCycle - Components participate in the following lifecycle phases:
  - Construction - A Component is constructed with the Java language new operator. Children may be added during construction if the Component is a MarkupContainer. IComponentInstantiationListeners are notified of component instantiation.
    onInitialize() is called on the component as soon as the component is part of a page's component tree. At this state the component is able to access its markup.
  - Request Handling - An incoming request is processed by a protocol request handler such as WicketFilter. An associated Application object creates Session, Request and Response objects for use by a given Component in updating its model and rendering a response. These objects are stored inside a container called RequestCycle which is accessible via getRequestCycle(). The convenience methods getRequest(), getResponse() and getSession() provide easy access to the contents of this container.
  - Listener Invocation - If the request references an IRequestListener on an existing Component (or one of its Behaviors, see below), that listener is notified, allowing arbitrary user code to handle events such as link clicks or form submits. Although arbitrary listeners are supported in Wicket, the need to implement a new class of listener is unlikely for a web application and even the need to implement a listener interface directly is highly discouraged. Instead, calls to listeners are routed through logic specific to the event, resulting in calls to user code through other overridable methods. See Form for an example of a component which listens for events via IFormSubmitListener.
  - Rendering - Before a page or part of a page (in case of Ajax updates) is rendered, all containing components are able to prepare for rendering via two hook methods: onConfigure() (regardless whether they are visible or not) and onBeforeRender() (if visible only) .
    A markup response is generated by the Component via render(), which calls subclass implementation code contained in onRender(). Once this phase begins, a Component becomes immutable. Attempts to alter the Component will result in a WicketRuntimeException.
  - Detachment - Each request cycle finishes by detaching all touched components. Subclasses should clean up their state by overriding onDetach() or more specifically detachModels() if they keep references to models beside the default model.
- Visibility - If a component is not visible (see setVisible(boolean)) it will not render a response (nor will their children).
- Enabling - Component subclasses take into account their enabled state (see setEnabled(boolean) when rendering, and in case of a FormComponent will not not update its model while the request is handled.
- Models - The primary responsibility of a component is to use its model (an object that implements IModel) to render a response in an appropriate markup language, such as HTML. In addition, FormComponents know how to update their models based on request information, see FormComponent.updateModel(). Since the IModel interface is a wrapper around another object, a convenience method getDefaultModelObject() is provided to retrieve the object from its IModel wrapper. A further convenience method, getDefaultModelObjectAsString(), is provided for the very common operation of converting the wrapped object to a String.
  The component's model can be passed in the constructor or set via setDefaultModel(IModel). In neither case a model can be created on demand with initModel().
  Note that a component can have more models besides its default model.
- Behaviors - You can add multiple Behaviors to any component if you need to dynamically alter the behavior of components, e.g. manipulate attributes of the markup tag to which a Component is attached. Behaviors take part in the component's lifecycle through various callback methods.
- Locale - The Locale for a Component is available through getLocale(), which delegates to its parent's locale, finally consulting the Session's locale.
- Style - The Session's style ("skin") is available through getStyle(). Styles are intended to give a particular look to all components or resources in a session that is independent of its Locale. For example, a style might be a set of resources, including images and markup files, which gives the design look of "ocean" to the user. If the Session's style is set to "ocean" and these resources are given names suffixed with "_ocean", Wicket's resource management logic will prefer these resources to other resources, such as default resources, which are not as good of a match.
- Variation - Whereas styles are Session (user) specific, variations are component specific. E.g. if the Style is "ocean" and getVariation() returnss "NorthSea", than the resources are given the names suffixed with "_ocean_NorthSea".
- String Resources - Components can have associated String resources via the Application's Localizer, which is available through the method getLocalizer(). The convenience methods getString(String key) and getString(String key, IModel model) wrap the identical methods on the Application Localizer for easy access in Components.
- Feedback Messages - The debug(Serializable), info(Serializable), warn(Serializable), error(java.io.Serializable) and fatal(Serializable) methods associate feedback messages with a Component. It is generally not necessary to use these methods directly since Wicket validators automatically register feedback messages on Components. Feedback message for a given Component can be retrieved with getFeedbackMessages().
- Versioning - Pages are the unit of versioning in Wicket, but fine-grained control of which Components should participate in versioning is possible via the setVersioned(boolean) method. The versioning participation of a given Component can be retrieved with isVersioned().
- Page - The Page containing any given Component can be retrieved by calling getPage(). If the Component is not attached to a Page, an IllegalStateException will be thrown. An equivalent method, findPage() is available for special circumstances where it might be desirable to get a null reference back instead.
- Application - The getApplication() method provides convenient access to the Application for a Component.
- AJAX support- Components can be re-rendered after the whole Page has been rendered at least once by calling doRender().
- Security - All components are subject to an IAuthorizationStrategy which controls instantiation, visibility and enabling. See SimplePageAuthorizationStrategy for a simple implementation.
Author:

Jonathan Locke, Chris Turner, Eelco Hillenius, Johan Compagner, Juergen Donnerstag, Igor Vaynberg (ivaynberg)

See Also:
Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static Action`	`ENABLE` Action used with IAuthorizationStrategy to determine whether a component is allowed to be enabled.
`protected static int`	`FLAG_AFTER_RENDERING`
`protected static int`	`FLAG_INITIALIZED` onInitialize called
`protected static int`	`FLAG_PREPARED_FOR_RENDER`
`protected static int`	`FLAG_REMOVING_FROM_HIERARCHY` True when a component is being removed from the hierarchy
`protected static int`	`FLAG_RENDERING` Flag that makes we are in before-render callback phase Set after component.onBeforeRender is invoked (right before invoking beforeRender on children)
`protected static int`	`FLAG_RESERVED1` Reserved subclass-definable flag bit
`protected static int`	`FLAG_RESERVED2` Reserved subclass-definable flag bit
`protected static int`	`FLAG_RESERVED3` Reserved subclass-definable flag bit
`protected static int`	`FLAG_RESERVED4` Reserved subclass-definable flag bit
`protected static int`	`FLAG_RESERVED5` Reserved subclass-definable flag bit
`protected static int`	`FLAG_RESERVED8` Reserved subclass-definable flag bit
`static String`	`PARENT_PATH` Path segment that represents this component's parent
`static char`	`PATH_SEPARATOR` Separator for component paths
`static Action`	`RENDER` Action used with IAuthorizationStrategy to determine whether a component and its children are allowed to be rendered.
`protected static short`	`RFLAG_CONTAINER_DEQUEING`

Constructor Summary

Constructors
Constructor and Description

Component(String id)
Constructor.

Component(String id, IModel<?> model)
Constructor.

Constructors
Constructor and Description
`Component(String id)` Constructor.
`Component(String id, IModel<?> model)` Constructor.

Method Summary

Methods
Modifier and Type	Method and Description
`Component`	`add(Behavior... behaviors)` Adds a behavior modifier to the component.
`protected void`	`addStateChange()` TODO WICKET-NG rename to something more useful - like componentChanged(), this method used to be called with a Change object Adds state change to page.
`void`	`afterRender()` Called on every component after the page is rendered.
`void`	`beforeRender()` Called for every component when the page is getting to be rendered.
`boolean`	`canCallListenerInterface(Method method)` Checks whether or not a listener method can be invoked on this component.
`boolean`	`canCallListenerInterfaceAfterExpiry()`
`protected void`	`checkComponentTag(ComponentTag tag, String name)` Checks whether the given type has the expected name.
`protected void`	`checkComponentTagAttribute(ComponentTag tag, String key, String... values)` Checks that a given tag has a required attribute value.
`protected void`	`checkHierarchyChange(Component component)` Checks whether the hierarchy may be changed at all, and throws an exception if this is not the case.
`void`	`clearOriginalDestination()` Clears any data about previously intercepted page.
`void`	`configure()` Triggers `onConfigure()` to be invoked on this component if it has not already during this request.
`void`	`continueToOriginalDestination()` Redirects to any intercept page previously specified by a call to redirectToInterceptPage.
`void`	`debug(Serializable message)` Registers a debug feedback message for this component
`void`	`detach()` Detaches the component.
`protected void`	`detachModel()` Detaches the model for this component if it is detachable.
`void`	`detachModels()` Detaches all models
`boolean`	`determineVisibility()` Determines whether or not a component should be visible, taking into account all the factors: `isVisible()`, `isVisibilityAllowed()`, `isRenderAllowed()`
`void`	`error(Serializable message)` Registers an error feedback message for this component
`protected String`	`exceptionMessage(String message)` Suffixes an exception message with useful information about this.
`void`	`fatal(Serializable message)` Registers a fatal feedback message for this component
`protected MarkupStream`	`findMarkupStream()` Finds the markup stream for this component.
`protected Page`	`findPage()` If this Component is a Page, returns self.
`<Z> Z`	`findParent(Class<Z> c)` Finds the first container parent of this component of the given class.
`MarkupContainer`	`findParentWithAssociatedMarkup()`
`Component`	`get(String path)` Gets the component at the given path.
`String`	`getAjaxRegionMarkupId()` Returns the id of the markup region that will be updated via ajax.
`Application`	`getApplication()` Gets interface to application that this component is a part of.
`Behavior`	`getBehaviorById(int id)` Gets the behavior for the specified id
`int`	`getBehaviorId(Behavior behavior)` Gets a stable id for the specified behavior.
`List<? extends Behavior>`	`getBehaviors()` Gets the currently coupled `Behavior`s as a unmodifiable list.
`<M extends Behavior> List<M>`	`getBehaviors(Class<M> type)` Gets the subset of the currently coupled `Behavior`s that are of the provided type as an unmodifiable list.
`String`	`getClassRelativePath()`
`<C> IConverter<C>`	`getConverter(Class<C> type)` Gets the converter that should be used by this component.
`IModel<?>`	`getDefaultModel()` Gets the model.
`Object`	`getDefaultModelObject()` Gets the backing model object.
`String`	`getDefaultModelObjectAsString()` Gets a model object as a string.
`String`	`getDefaultModelObjectAsString(Object modelObject)` Gets a model object as a string.
`boolean`	`getEscapeModelStrings()` Gets whether model strings should be escaped.
`FeedbackMessages`	`getFeedbackMessages()` Gets feedback messages for this component.
`protected boolean`	`getFlag(int flag)` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`String`	`getId()` Gets the id of this component.
`IModel<?>`	`getInnermostModel()`
`protected IModel<?>`	`getInnermostModel(IModel<?> model)` Finds the innermost IModel object for an IModel that might contain nested IModel(s).
`Locale`	`getLocale()` Gets the locale for this component.
`Localizer`	`getLocalizer()` Convenience method to provide easy access to the localizer object within any component.
`IMarkupFragment`	`getMarkup()` Get the Markup associated with the Component.
`ValueMap`	`getMarkupAttributes()` THIS IS WICKET INTERNAL ONLY.
`String`	`getMarkupId()` Retrieves id by which this component is represented within the markup.
`String`	`getMarkupId(boolean createIfDoesNotExist)` Retrieves id by which this component is represented within the markup.
`String`	`getMarkupIdFromMarkup()`
`Object`	`getMarkupIdImpl()` Get the markupId
`protected IMarkupSourcingStrategy`	`getMarkupSourcingStrategy()` Get the markup sourcing strategy for the component.
`<M extends Serializable> M`	`getMetaData(MetaDataKey<M> key)` Gets metadata for this component using the given key.
`IModelComparator`	`getModelComparator()` Gets the component's current model comparator.
`boolean`	`getOutputMarkupId()` Gets whether or not component will output id attribute into the markup.
`boolean`	`getOutputMarkupPlaceholderTag()` Gets whether or not an invisible component will render a placeholder tag.
`Page`	`getPage()` Gets the page holding this component.
`String`	`getPageRelativePath()` Gets the path to this component relative to its containing page, i.e.
`MarkupContainer`	`getParent()` Gets any parent container, or null if there is none.
`String`	`getPath()` Gets this component's path.
`boolean`	`getRenderBodyOnly()` If false the component's tag will be printed as well as its body (which is default).
`Request`	`getRequest()`
`RequestCycle`	`getRequestCycle()` Gets the active request cycle for this component
`protected boolean`	`getRequestFlag(short flag)` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`Response`	`getResponse()`
`Session`	`getSession()` Gets the current Session object.
`long`	`getSizeInBytes()`
`protected boolean`	`getStatelessHint()` Returns whether the component can be stateless.
`String`	`getString(String key)`
`String`	`getString(String key, IModel<?> model)`
`String`	`getString(String key, IModel<?> model, String defaultValue)`
`String`	`getStyle()` A convenience method to access the Sessions's style.
`String`	`getVariation()` Gets the variation string of this component that will be used to look up markup for this component.
`boolean`	`hasBeenRendered()` Gets whether this component was rendered at least once.
`boolean`	`hasErrorMessage()`
`boolean`	`hasFeedbackMessage()`
`void`	`info(Serializable message)` Registers an informational feedback message for this component
`protected IModel<?>`	`initModel()` Called when a null model is about to be retrieved in order to allow a subclass to provide an initial model.
`void`	`internalInitialize()` THIS METHOD IS NOT PART OF THE PUBLIC API, DO NOT CALL IT Used to call `onInitialize()`
`protected void`	`internalOnModelChanged()` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`void`	`internalPrepareForRender(boolean setRenderingFlag)` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`void`	`internalRenderComponent()` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`void`	`internalRenderHead(HtmlHeaderContainer container)` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`boolean`	`isActionAuthorized(Action action)` Authorizes an action for a component.
`boolean`	`isAuto()`
`protected boolean`	`isBehaviorAccepted(Behavior behavior)` Components are allowed to reject behavior modifiers.
`boolean`	`isEnableAllowed()`
`boolean`	`isEnabled()` Gets whether this component is enabled.
`boolean`	`isEnabledInHierarchy()` Calculates enabled state of the component taking its hierarchy into account.
`protected boolean`	`isIgnoreAttributeModifier()` If true, all attribute modifiers will be ignored
`boolean`	`isRenderAllowed()` Checks the security strategy if the `RENDER` action is allowed on this component
`boolean`	`isRendering()` Says if the component is rendering or not checking the corresponding flag.
`boolean`	`isStateless()` Returns if the component is stateless or not.
`boolean`	`isVersioned()`
`boolean`	`isVisibilityAllowed()` Gets whether or not visibility is allowed on this component.
`boolean`	`isVisible()` Gets whether this component and any children are visible.
`boolean`	`isVisibleInHierarchy()` Checks if the component itself and all its parents are visible.
`void`	`markRendering(boolean setRenderingFlag)` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`void`	`modelChanged()` Called to indicate that the model content for this component has been changed
`void`	`modelChanging()` Called to indicate that the model content for this component is about to change
`protected IMarkupSourcingStrategy`	`newMarkupSourcingStrategy()` If `getMarkupSourcingStrategy()` returns null, this method will be called.
`protected void`	`onAfterRender()` Called just after a component is rendered.
`protected void`	`onAfterRenderChildren()`
`protected void`	`onBeforeRender()` Called just before a component is rendered only if the component is visible.
`protected void`	`onComponentTag(ComponentTag tag)` Processes the component tag.
`void`	`onComponentTagBody(MarkupStream markupStream, ComponentTag openTag)` Processes the body.
`protected void`	`onConfigure()` Called once per request on components before they are about to be rendered.
`protected void`	`onDetach()` Called to allow a component to detach resources after use.
`void`	`onEvent(IEvent<?> event)` Called when an event is sent to this sink
`protected void`	`onInitialize()` This method is meant to be used as an alternative to initialize components.
`protected void`	`onModelChanged()` Called anytime a model is changed after the change has occurred
`protected void`	`onModelChanging()` Called anytime a model is changed, but before the change actually occurs
`protected void`	`onReAdd()` This method is called whenever a component is re-added to the page's component tree, if it had been removed at some earlier time, i.e., if it is already initialized (see `isInitialized()`).
`protected void`	`onRemove()` Called to notify the component it is being removed from the component hierarchy Overrides of this method MUST call the super implementation, the most logical place to do this is the last line of the override method.
`protected abstract void`	`onRender()` Implementation that renders this component.
`void`	`prepareForRender()` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`void`	`redirectToInterceptPage(Page page)` Redirects browser to an intermediate page such as a sign-in page.
`void`	`remove()` Removes this component from its parent.
`Component`	`remove(Behavior... behaviors)` Removes behavior from component
`void`	`render()` Render the Component.
`protected void`	`renderComponentTag(ComponentTag tag)` Writes a simple tag out to the response stream.
`void`	`rendered()` Called to indicate that a component has been rendered.
`void`	`renderHead(Component component, IHeaderResponse response)` CAUTION: this method is not meant to be overridden like it was in wicket 1.4 when implementing `IHeaderContributor`.
`void`	`renderHead(IHeaderResponse response)` Render to the web response whatever the component wants to contribute to the head section.
`protected void`	`renderPlaceholderTag(ComponentTag tag, Response response)` Renders a placeholder tag for the component when it is invisible and `setOutputMarkupPlaceholderTag(boolean)` has been called with `true`.
`protected void`	`replaceComponentTagBody(MarkupStream markupStream, ComponentTag tag, CharSequence body)` Replaces the body with the given one.
`Component`	`replaceWith(Component replacement)` Replaces this component with another.
`boolean`	`sameInnermostModel(Component component)`
`boolean`	`sameInnermostModel(IModel<?> model)`
`<T> void`	`send(IEventSink sink, Broadcast type, T payload)` Sends an event
`protected Component`	`setAuto(boolean auto)`
`Component`	`setDefaultModel(IModel<?> model)` Sets the given model.
`Component`	`setDefaultModelObject(Object object)` Sets the backing model object.
`Component`	`setEnabled(boolean enabled)` Sets whether this component is enabled.
`Component`	`setEscapeModelStrings(boolean escapeMarkup)` Sets whether model strings should be escaped.
`protected Component`	`setFlag(int flag, boolean set)` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`protected Component`	`setIgnoreAttributeModifier(boolean ignore)` If true, all attribute modifiers will be ignored
`Component`	`setMarkup(IMarkupFragment markup)` Set the markup for the component.
`Component`	`setMarkupId(String markupId)` Sets this component's markup id to a user defined value.
`void`	`setMarkupIdImpl(Object markupId)` Set markup ID, which must be String or Integer
`<M extends Serializable> Component`	`setMetaData(MetaDataKey<M> key, M object)` Sets the metadata for this component using the given key.
`Component`	`setOutputMarkupId(boolean output)` Sets whether or not component will output id attribute into the markup.
`Component`	`setOutputMarkupPlaceholderTag(boolean outputTag)` Render a placeholder tag when the component is not visible.
`void`	`setParent(MarkupContainer parent)` THIS IS A WICKET INTERNAL API.
`Component`	`setRenderBodyOnly(boolean renderTag)` If false the component's tag will be printed as well as its body (which is default).
`protected Component`	`setRequestFlag(short flag, boolean set)` THIS METHOD IS NOT PART OF THE WICKET PUBLIC API.
`<C extends IRequestablePage> void`	`setResponsePage(Class<C> cls)` Sets the page that will respond to this request
`<C extends IRequestablePage> void`	`setResponsePage(Class<C> cls, PageParameters parameters)` Sets the page class and its parameters that will respond to this request
`void`	`setResponsePage(IRequestablePage page)` Sets the page that will respond to this request
`Component`	`setVersioned(boolean versioned)`
`Component`	`setVisibilityAllowed(boolean allowed)` Sets whether or not this component is allowed to be visible.
`Component`	`setVisible(boolean visible)` Sets whether this component and any children are visible.
`void`	`success(Serializable message)` Registers an success feedback message for this component
`String`	`toString()` Gets the string representation of this component.
`String`	`toString(boolean detailed)`
`CharSequence`	`urlFor(Behavior behaviour, RequestListenerInterface listener, PageParameters parameters)` Gets a URL for the listener interface on a behavior (e.g.
`<C extends Page> CharSequence`	`urlFor(Class<C> pageClass, PageParameters parameters)` Returns a bookmarkable URL that references a given page class using a given set of page parameters.
`CharSequence`	`urlFor(IRequestHandler requestHandler)` Returns a URL that references the given request target.
`CharSequence`	`urlFor(RequestListenerInterface listener, PageParameters parameters)` Gets a URL for the listener interface (e.g.
`CharSequence`	`urlFor(ResourceReference resourceReference, PageParameters parameters)` Returns a URL that references a shared resource through the provided resource reference.
`<R,C extends MarkupContainer> R`	`visitParents(Class<C> parentClass, IVisitor<C,R> visitor)` Traverses all parent components of the given class in this parentClass, calling the visitor's visit method at each one.
`<R,C extends MarkupContainer> R`	`visitParents(Class<C> parentClass, IVisitor<C,R> visitor, IVisitFilter filter)` Traverses all parent components of the given class in this parentClass, calling the visitor's visit method at each one.
`void`	`warn(Serializable message)` Registers a warning feedback message for this component.
`protected <V> IModel<V>`	`wrap(IModel<V> model)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - ENABLE
```
public static final Action ENABLE
```
    Action used with IAuthorizationStrategy to determine whether a component is allowed to be enabled.
    If enabling is authorized, a component may decide by itself (typically using it's enabled property) whether it is enabled or not. If enabling is not authorized, the given component is marked disabled, regardless its enabled property.
    When a component is not allowed to be enabled (in effect disabled through the implementation of this interface), Wicket will try to prevent model updates too. This is not completely fail safe, as constructs like:
```
 
 User u = (User)getModelObject();
 u.setName("got you there!");
 
 
```
    can't be prevented. Indeed it can be argued that any model protection is best dealt with in your model objects to be completely secured. Wicket will catch all normal framework-directed use though.
  - PATH_SEPARATOR
```
public static final char PATH_SEPARATOR
```
    Separator for component paths
    
    See Also:
    Constant Field Values
  - PARENT_PATH
```
public static final String PARENT_PATH
```
    Path segment that represents this component's parent
    
    See Also:
    Constant Field Values
  - RENDER
```
public static final Action RENDER
```
    Action used with IAuthorizationStrategy to determine whether a component and its children are allowed to be rendered.
    There are two uses for this method:
    - The 'normal' use is for controlling whether a component is rendered without having any effect on the rest of the processing. If a strategy lets this method return 'false', then the target component and its children will not be rendered, in the same fashion as if that component had visibility property 'false'.
    - The other use is when a component should block the rendering of the whole page. So instead of 'hiding' a component, what we generally want to achieve here is that we force the user to logon/give-credentials for a higher level of authorization. For this functionality, the strategy implementation should throw a AuthorizationException, which will then be handled further by the framework.
  - FLAG_RESERVED1
```
protected static final int FLAG_RESERVED1
```
    Reserved subclass-definable flag bit
    
    See Also:
    Constant Field Values
  - FLAG_RESERVED2
```
protected static final int FLAG_RESERVED2
```
    Reserved subclass-definable flag bit
    
    See Also:
    Constant Field Values
  - FLAG_RESERVED3
```
protected static final int FLAG_RESERVED3
```
    Reserved subclass-definable flag bit
    
    See Also:
    Constant Field Values
  - FLAG_RESERVED4
```
protected static final int FLAG_RESERVED4
```
    Reserved subclass-definable flag bit
    
    See Also:
    Constant Field Values
  - FLAG_RESERVED5
```
protected static final int FLAG_RESERVED5
```
    Reserved subclass-definable flag bit
    
    See Also:
    Constant Field Values
  - FLAG_INITIALIZED
```
protected static final int FLAG_INITIALIZED
```
    onInitialize called
    
    See Also:
    Constant Field Values
  - FLAG_RESERVED8
```
protected static final int FLAG_RESERVED8
```
    Reserved subclass-definable flag bit
    
    See Also:
    Constant Field Values
  - FLAG_REMOVING_FROM_HIERARCHY
```
protected static final int FLAG_REMOVING_FROM_HIERARCHY
```
    True when a component is being removed from the hierarchy
    
    See Also:
    Constant Field Values
  - FLAG_RENDERING
```
protected static final int FLAG_RENDERING
```
    Flag that makes we are in before-render callback phase Set after component.onBeforeRender is invoked (right before invoking beforeRender on children)
    
    See Also:
    Constant Field Values
  - FLAG_PREPARED_FOR_RENDER
```
protected static final int FLAG_PREPARED_FOR_RENDER
```
    See Also:
    Constant Field Values
  - FLAG_AFTER_RENDERING
```
protected static final int FLAG_AFTER_RENDERING
```
    See Also:
    Constant Field Values
  - RFLAG_CONTAINER_DEQUEING
```
protected static final short RFLAG_CONTAINER_DEQUEING
```
    See Also:
    Constant Field Values
- Constructor Detail
  - Component
```
public Component(String id)
```
    Constructor. All components have names. A component's id cannot be null. This is the minimal constructor of component. It does not register a model.
    
    Parameters:
    id - The non-null id of this component
    
    Throws:
    
    WicketRuntimeException - Thrown if the component has been given a null id.
  - Component
```
public Component(String id,
         IModel<?> model)
```
    Constructor. All components have names. A component's id cannot be null. This constructor includes a model.
    
    Parameters:
    id - The non-null id of this component
    model - The component's model
    
    Throws:
    
    WicketRuntimeException - Thrown if the component has been given a null id.
- Method Detail
  - getMarkup
```
public IMarkupFragment getMarkup()
```
    Get the Markup associated with the Component. If not subclassed, the parent container is asked to return the markup of this child component.
    Components like Panel and Border should return the "calling" markup fragment, e.g. <span wicket:id="myPanel">body</span>. You may use Panel/Border/Enclosure.getMarkup(null) to return the associated markup file. And Panel/Border/Enclosure.getMarkup(child) will search the child in the appropriate markup fragment.
    
    Returns:
    The markup fragment
    See Also:
    MarkupContainer.getMarkup(Component)
  - getMarkupIdFromMarkup
```
public final String getMarkupIdFromMarkup()
```
    Returns:
    The 'id' attribute from the associated markup tag
  - setMarkup
```
public final Component setMarkup(IMarkupFragment markup)
```
    Set the markup for the component. Note that the component's markup variable is transient and thus must only be used for one render cycle. E.g. auto-component are using it. You may also it if you subclassed getMarkup().
    
    Parameters:
    markup -
  - onConfigure
```
protected void onConfigure()
```
    Called once per request on components before they are about to be rendered. This method should be used to configure such things as visibility and enabled flags.
    Overrides must call super.onConfigure(), usually before any other code
    NOTE: Component hierarchy should not be modified inside this method, instead it should be done in onBeforeRender()
    NOTE: Why this method is preferrable to directly overriding isVisible() and isEnabled()? Because those methods are called multiple times even for processing of a single request. If they contain expensive logic they can slow down the response time of the entire page. Further, overriding those methods directly on form components may lead to inconsistent or unexpected state depending on when those methods are called in the form processing workflow. It is a better practice to push changes to state rather than pull.
    NOTE: If component's visibility or another property depends on another component you may call other.configure() followed by other.isVisible() as mentioned in configure() javadoc.
    NOTE: Why should onBeforeRender() not be used for this? Because if a component's visibility is controlled inside onBeforeRender(), once invisible the component will never become visible again.
  - onInitialize
```
protected void onInitialize()
```
    This method is meant to be used as an alternative to initialize components. Usually the component's constructor is used for this task, but sometimes a component cannot be initialized in isolation, it may need to access its parent component or its markup in order to fully initialize. This method is invoked once per component's lifecycle when a path exists from this component to the Page thus providing the component with an atomic callback when the component's environment is built out.
    Overrides must call super#onInitialize(). Usually this should be the first thing an override does, much like a constructor.
    
    Parent containers are guaranteed to be initialized before their children
    
    It is safe to use getPage() in this method
    
    NOTE:The timing of this call is not precise, the contract is that it is called sometime before onBeforeRender().
  - internalInitialize
```
public void internalInitialize()
```
    THIS METHOD IS NOT PART OF THE PUBLIC API, DO NOT CALL IT Used to call onInitialize()
  - afterRender
```
public final void afterRender()
```
    Called on every component after the page is rendered. It will call onAfterRender for it self and its children.
  - beforeRender
```
public final void beforeRender()
```
    Called for every component when the page is getting to be rendered. it will call configure() and onBeforeRender() for this component and all the child components
  - configure
```
public final void configure()
```
    Triggers onConfigure() to be invoked on this component if it has not already during this request.
    This method should be invoked before any calls to isVisible() or isEnabled(). Usually this method will be called by the framework before the component is rendered and so users should not need to call it; however, in cases where visibility or enabled or other state of one component depends on the state of another this method should be manually invoked on the other component by the user. EG to link visiliby of two markup containers the following should be done:
```
 final WebMarkupContainer source=new WebMarkupContainer("a") {
        protected void onConfigure() {
    setVisible(Math.rand()>0.5f);
  }
 };
 
 WebMarkupContainer linked=new WebMarkupContainer("b") {
        protected void onConfigure() {
                source.configure(); // make sure source is configured
                setVisible(source.isVisible());
  }
 }
 
```
  - continueToOriginalDestination
```
public final void continueToOriginalDestination()
```
    Redirects to any intercept page previously specified by a call to redirectToInterceptPage. The redirect is done by throwing an exception. If there is no intercept page no exception will be thrown and the program flow will continue uninterrupted. Example:
```
 add(new Link("login")
 {
        protected void onClick()
        {
                if (authenticate())
                {
                        continueToOriginalDestination();
                        // if we reach this line there was no intercept page, so go to home page
                        setResponsePage(WelcomePage.class);
                }
        }
 });
```
    See Also:
    redirectToInterceptPage(Page)
  - clearOriginalDestination
```
public final void clearOriginalDestination()
```
    Clears any data about previously intercepted page.
  - debug
```
public final void debug(Serializable message)
```
    Registers a debug feedback message for this component
    
    Parameters:
    message - The feedback message
  - detach
```
public final void detach()
```
    Detaches the component. This is called at the end of the request for all the pages that are touched in that request.
    
    Specified by:
    
    detach in interface IRequestableComponent
  - detachModels
```
public void detachModels()
```
    Detaches all models
  - error
```
public final void error(Serializable message)
```
    Registers an error feedback message for this component
    
    Parameters:
    message - The feedback message
  - fatal
```
public final void fatal(Serializable message)
```
    Registers a fatal feedback message for this component
    
    Parameters:
    message - The feedback message
  - findParent
```
public final <Z> Z findParent(Class<Z> c)
```
    Finds the first container parent of this component of the given class.
    
    Type Parameters:
    Z - type of parent
    Parameters:
    c - MarkupContainer class to search for
    
    Returns:
    First container parent that is an instance of the given class, or null if none can be found
  - findParentWithAssociatedMarkup
```
public final MarkupContainer findParentWithAssociatedMarkup()
```
    Returns:
    The nearest markup container with associated markup
  - getApplication
```
public final Application getApplication()
```
    Gets interface to application that this component is a part of.
    
    Returns:
    The application associated with the session that this component is in.
    See Also:
    Application
  - getClassRelativePath
```
public final String getClassRelativePath()
```
    Returns:
    A path of the form [page-class-name]:[page-relative-path]
    See Also:
    getPageRelativePath()
  - getConverter
```
public <C> IConverter<C> getConverter(Class<C> type)
```
    Gets the converter that should be used by this component.
    
    Specified by:
    
    getConverter in interface IConverterLocator
    
    Type Parameters:
    C - The object to convert from and to String
    Parameters:
    type - The type to convert to
    
    Returns:
    The converter that should be used by this component
  - getEscapeModelStrings
```
public final boolean getEscapeModelStrings()
```
    Gets whether model strings should be escaped.
    
    Returns:
    Returns whether model strings should be escaped
  - getId
```
public String getId()
```
    Gets the id of this component.
    
    Specified by:
    
    getId in interface IRequestableComponent
    
    Returns:
    The id of this component
  - getInnermostModel
```
public final IModel<?> getInnermostModel()
```
    Returns:
    Innermost model for this component
  - getLocale
```
public Locale getLocale()
```
    Gets the locale for this component. By default, it searches its parents for a locale. If no parents (it's a recursive search) returns a locale, it gets one from the session.
    
    Returns:
    The locale to be used for this component
    See Also:
    Session.getLocale()
  - getLocalizer
```
public final Localizer getLocalizer()
```
    Convenience method to provide easy access to the localizer object within any component.
    
    Returns:
    The localizer object
  - getMarkupAttributes
```
public final ValueMap getMarkupAttributes()
```
    THIS IS WICKET INTERNAL ONLY. DO NOT USE IT. Get a copy of the markup's attributes which are associated with the component.
    Modifications to the map returned don't change the tags attributes. It is just a copy.
    Note: The component must have been added (directly or indirectly) to a container with an associated markup file (Page, Panel or Border).
    
    Returns:
    markup attributes
  - getMarkupIdImpl
```
public final Object getMarkupIdImpl()
```
    Get the markupId
    
    Returns:
    MarkupId
  - getMarkupId
```
public String getMarkupId(boolean createIfDoesNotExist)
```
    Retrieves id by which this component is represented within the markup. This is either the id attribute set explicitly via a call to setMarkupId(String), id attribute defined in the markup, or an automatically generated id - in that order.
    If no id is set and createIfDoesNotExist is false, this method will return null. Otherwise it will generate an id value which by default will be unique in the page. This is the preferred way as there is no chance of id collision. This will also enable setOutputMarkupId(boolean).
    
    Note: This method should only be called after the component or its parent have been added to the page.
    
    Parameters:
    createIfDoesNotExist - When there is no existing markup id, determines whether it should be generated or whether null should be returned.
    
    Returns:
    markup id of the component
  - getMarkupId
```
public String getMarkupId()
```
    Retrieves id by which this component is represented within the markup. This is either the id attribute set explicitly via a call to setMarkupId(String), id attribute defined in the markup, or an automatically generated id - in that order.
    If no explicit id is set this function will generate an id value that will be unique in the page. This is the preferred way as there is no chance of id collision. This will also enable setOutputMarkupId(boolean).
    Note: This method should only be called after the component or its parent have been added to the page.
    
    Returns:
    markup id of the component
  - getMetaData
```
public final <M extends Serializable> M getMetaData(MetaDataKey<M> key)
```
    Gets metadata for this component using the given key.
    
    Type Parameters:
    M - The type of the metadata.
    Parameters:
    key - The key for the data
    
    Returns:
    The metadata or null of no metadata was found for the given key
    See Also:
    MetaDataKey
  - getDefaultModel
```
public final IModel<?> getDefaultModel()
```
    Gets the model. It returns the object that wraps the backing model.
    
    Returns:
    The model
  - getDefaultModelObject
```
public final Object getDefaultModelObject()
```
    Gets the backing model object. Unlike getDefaultModel().getObject(), this method returns null for a null model.
    
    Returns:
    The backing model object
  - getDefaultModelObjectAsString
```
public final String getDefaultModelObjectAsString()
```
    Gets a model object as a string. Depending on the "escape model strings" flag of the component, the string is either HTML escaped or not. "HTML escaped" meaning that only HTML sensitive chars are escaped but not all none-ascii chars. Proper HTML encoding should be used instead. In case you really need a fully escaped model string you may call Strings.escapeMarkup(CharSequence, boolean, boolean) on the model string returned.
    
    Returns:
    Model object for this component as a string
    See Also:
    Strings.escapeMarkup(CharSequence, boolean, boolean), getEscapeModelStrings()
  - getDefaultModelObjectAsString
```
public final String getDefaultModelObjectAsString(Object modelObject)
```
    Gets a model object as a string. Depending on the "escape model strings" flag of the component, the string is either HTML escaped or not. "HTML escaped" meaning that only HTML sensitive chars are escaped but not all none-ascii chars. Proper HTML encoding should be used instead. In case you really need a fully escaped model string you may call Strings.escapeMarkup(CharSequence, boolean, boolean) on the model string returned.
    
    Parameters:
    modelObject - Model object to convert to string
    
    Returns:
    The string
    See Also:
    Strings.escapeMarkup(CharSequence, boolean, boolean), getEscapeModelStrings()
  - getOutputMarkupId
```
public final boolean getOutputMarkupId()
```
    Gets whether or not component will output id attribute into the markup. id attribute will be set to the value returned from getMarkupId().
    
    Returns:
    whether or not component will output id attribute into the markup
  - getOutputMarkupPlaceholderTag
```
public final boolean getOutputMarkupPlaceholderTag()
```
    Gets whether or not an invisible component will render a placeholder tag.
    
    Returns:
    true if a placeholder tag should be rendered
  - getPage
```
public final Page getPage()
```
    Gets the page holding this component.
    
    Specified by:
    
    getPage in interface IRequestableComponent
    
    Returns:
    The page holding this component
    
    Throws:
    
    IllegalStateException - Thrown if component is not yet attached to a Page.
  - getPageRelativePath
```
public final String getPageRelativePath()
```
    Gets the path to this component relative to its containing page, i.e. without leading page id.
    
    Specified by:
    
    getPageRelativePath in interface IRequestableComponent
    
    Returns:
    The path to this component relative to the page it is in
  - getParent
```
public final MarkupContainer getParent()
```
    Gets any parent container, or null if there is none.
    
    Specified by:
    
    getParent in interface IHierarchical<Component>
    
    Returns:
    Any parent container, or null if there is none
  - getPath
```
public final String getPath()
```
    Gets this component's path.
    
    Returns:
    Colon separated path to this component in the component hierarchy
  - getRenderBodyOnly
```
public final boolean getRenderBodyOnly()
```
    If false the component's tag will be printed as well as its body (which is default). If true only the body will be printed, but not the component's tag.
    
    Returns:
    If true, the component tag will not be printed
  - getRequest
```
public final Request getRequest()
```
    Returns:
    The request for this component's active request cycle
  - getRequestCycle
```
public final RequestCycle getRequestCycle()
```
    Gets the active request cycle for this component
    
    Returns:
    The request cycle
  - getResponse
```
public final Response getResponse()
```
    Returns:
    The response for this component's active request cycle
  - getSession
```
public Session getSession()
```
    Gets the current Session object.
    
    Returns:
    The Session that this component is in
  - getSizeInBytes
```
public long getSizeInBytes()
```
    Returns:
    Size of this Component in bytes. Returns 0 - if the size cannot be calculated for some reason
  - getString
```
public final String getString(String key)
```
    Parameters:
    key - Key of string resource in property file
    
    Returns:
    The String
    See Also:
    Localizer
  - getString
```
public final String getString(String key,
               IModel<?> model)
```
    Parameters:
    key - The resource key
    model - The model
    
    Returns:
    The formatted string
    See Also:
    Localizer
  - getString
```
public final String getString(String key,
               IModel<?> model,
               String defaultValue)
```
    Parameters:
    key - The resource key
    model - The model
    defaultValue - A default value if the string cannot be found
    
    Returns:
    The formatted string
    See Also:
    Localizer
  - getStyle
```
public final String getStyle()
```
    A convenience method to access the Sessions's style.
    
    Returns:
    The style of this component respectively the style of the Session.
    See Also:
    Session.getStyle()
  - getVariation
```
public String getVariation()
```
    Gets the variation string of this component that will be used to look up markup for this component. Subclasses can override this method to define by an instance what markup variation should be picked up. By default it will return null or the value of a parent.
    
    Returns:
    The variation of this component.
  - hasBeenRendered
```
public final boolean hasBeenRendered()
```
    Gets whether this component was rendered at least once.
    
    Returns:
    true if the component has been rendered before, false if it is merely constructed
  - getFeedbackMessages
```
public FeedbackMessages getFeedbackMessages()
```
    Gets feedback messages for this component. This method will instantiate a FeedbackMessages instance and add it to the component metadata, even when called on a component that has no feedback messages, to avoid the overhead use hasFeedbackMessage()
    
    Returns:
    feedback messages instance
  - hasErrorMessage
```
public final boolean hasErrorMessage()
```
    Returns:
    True if this component has an error message
  - hasFeedbackMessage
```
public final boolean hasFeedbackMessage()
```
    Returns:
    True if this component has some kind of feedback message
  - info
```
public final void info(Serializable message)
```
    Registers an informational feedback message for this component
    
    Parameters:
    message - The feedback message
  - success
```
public final void success(Serializable message)
```
    Registers an success feedback message for this component
    
    Parameters:
    message - The feedback message
  - isActionAuthorized
```
public final boolean isActionAuthorized(Action action)
```
    Authorizes an action for a component.
    
    Parameters:
    action - The action to authorize
    
    Returns:
    True if the action is allowed
    
    Throws:
    
    AuthorizationException - Can be thrown by implementation if action is unauthorized
  - isEnableAllowed
```
public final boolean isEnableAllowed()
```
    Returns:
    true if this component is authorized to be enabled, false otherwise
  - isEnabled
```
public boolean isEnabled()
```
    Gets whether this component is enabled. Specific components may decide to implement special behavior that uses this property, like web form components that add a disabled='disabled' attribute when enabled is false.
    
    Returns:
    Whether this component is enabled.
  - isRenderAllowed
```
public final boolean isRenderAllowed()
```
    Checks the security strategy if the RENDER action is allowed on this component
    
    Returns:
    ture if RENDER action is allowed, false otherwise
  - isStateless
```
public final boolean isStateless()
```
    Returns if the component is stateless or not. It checks the stateless hint if that is false it returns directly false. If that is still true it checks all its behaviors if they can be stateless.
    
    Returns:
    whether the component is stateless.
  - isVersioned
```
public boolean isVersioned()
```
    Returns:
    true if this component should notify its holding page about changes in its state. If a Page is not versioned then it wont track changes in its components and will use the same Page.getPageId() during its lifetime
  - isVisible
```
public boolean isVisible()
```
    Gets whether this component and any children are visible.
    WARNING: this method can be called multiple times during a request. If you override this method, it is a good idea to keep it cheap in terms of processing. Alternatively, you can call setVisible(boolean).
    
    Returns:
    True if component and any children are visible
  - isVisibleInHierarchy
```
public final boolean isVisibleInHierarchy()
```
    Checks if the component itself and all its parents are visible.
    
    Returns:
    true if the component and all its parents are visible.
  - markRendering
```
public final void markRendering(boolean setRenderingFlag)
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT! Sets the RENDERING flag and removes the PREPARED_FOR_RENDER flag on component and it's children.
    
    Parameters:
    setRenderingFlag - if this is false only the PREPARED_FOR_RENDER flag is removed from component, the RENDERING flag is not set.
    See Also:
    internalPrepareForRender(boolean)
  - modelChanged
```
public final void modelChanged()
```
    Called to indicate that the model content for this component has been changed
  - modelChanging
```
public final void modelChanging()
```
    Called to indicate that the model content for this component is about to change
  - internalPrepareForRender
```
public void internalPrepareForRender(boolean setRenderingFlag)
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT!
    Prepares the component and it's children for rendering. On whole page render this method must be called on the page. On AJAX request, this method must be called on the updated component.
    
    Parameters:
    setRenderingFlag - Whether to set the rendering flag. This must be true if the page is about to be rendered. However, there are usecases to call this method without an immediate render (e.g. on stateless listener request target to build the component hierarchy), in that case setRenderingFlag should be false.
  - prepareForRender
```
public final void prepareForRender()
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT! Prepares the component and it's children for rendering. On whole page render this method must be called on the page. On AJAX request, this method must be called on updated component.
  - redirectToInterceptPage
```
public final void redirectToInterceptPage(Page page)
```
    Redirects browser to an intermediate page such as a sign-in page. The current request's url is saved for future use by method continueToOriginalDestination(); Only use this method when you plan to continue to the current url at some later time; otherwise just use setResponsePage or - when you are in a constructor or checkAccessMethod, call redirectTo.
    
    Parameters:
    page - The sign in page
    See Also:
    continueToOriginalDestination()
  - remove
```
public final void remove()
```
    Removes this component from its parent. It's important to remember that a component that is removed cannot be referenced from the markup still.
    You must not use this method in your callback to any of the MarkupContainer.visitChildren(IVisitor) methods. See WICKET-3329.
  - render
```
public final void render()
```
    Render the Component.
  - renderPlaceholderTag
```
protected void renderPlaceholderTag(ComponentTag tag,
                        Response response)
```
    Renders a placeholder tag for the component when it is invisible and setOutputMarkupPlaceholderTag(boolean) has been called with true.
    
    Parameters:
    tag - component tag
    response - response
  - getAjaxRegionMarkupId
```
public final String getAjaxRegionMarkupId()
```
    Returns the id of the markup region that will be updated via ajax. This can be different to the markup id of the component if a IAjaxRegionMarkupIdProvider behavior has been added.
    
    Returns:
    the markup id of the region to be updated via ajax.
  - internalRenderComponent
```
public final void internalRenderComponent()
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT.
    Renders the component at the current position in the given markup stream. The method onComponentTag() is called to allow the component to mutate the start tag. The method onComponentTagBody() is then called to permit the component to render its body.
  - rendered
```
public final void rendered()
```
    Called to indicate that a component has been rendered. This method should only very rarely be called at all. Some components may render its children without calling render() on them. These components need to call rendered() to indicate that its child components were actually rendered, the framework would think they had never been rendered, and in development mode this would result in a runtime exception.
  - getMarkupSourcingStrategy
```
protected final IMarkupSourcingStrategy getMarkupSourcingStrategy()
```
    Get the markup sourcing strategy for the component. If null, newMarkupSourcingStrategy() will be called.
    
    Returns:
    Markup sourcing strategy
  - newMarkupSourcingStrategy
```
protected IMarkupSourcingStrategy newMarkupSourcingStrategy()
```
    If getMarkupSourcingStrategy() returns null, this method will be called. By default it returns null, which means that a default markup strategy will be attached to the component.
    Please note that markup source strategies are not persisted. Instead they get re-created by calling this method again. That's ok since markup sourcing strategies usually do not maintain a state.
    
    Returns:
    Markup sourcing strategy
  - internalRenderHead
```
public void internalRenderHead(HtmlHeaderContainer container)
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT. Print to the web response what ever the component wants to contribute to the head section. Make sure that all attached behaviors are asked as well.
    NOT intended for overriding by framework clients. Rather, use renderHead(org.apache.wicket.markup.head.IHeaderResponse)
    
    Parameters:
    container - The HtmlHeaderContainer
  - replaceWith
```
public Component replaceWith(Component replacement)
```
    Replaces this component with another. The replacing component must have the same component id as this component. This method serves as a shortcut to this.getParent().replace(replacement) and provides a better context for errors.
    Usage: component = component.replaceWith(replacement);
    
    Parameters:
    replacement - component to replace this one
    
    Returns:
    the component which replaced this one
    Since:
    
    1.2.1
  - sameInnermostModel
```
public final boolean sameInnermostModel(Component component)
```
    Parameters:
    component - The component to compare with
    
    Returns:
    True if the given component's model is the same as this component's model.
  - sameInnermostModel
```
public final boolean sameInnermostModel(IModel<?> model)
```
    Parameters:
    model - The model to compare with
    
    Returns:
    True if the given component's model is the same as this component's model.
  - setEnabled
```
public final Component setEnabled(boolean enabled)
```
    Sets whether this component is enabled. Specific components may decide to implement special behavior that uses this property, like web form components that add a disabled='disabled' attribute when enabled is false. If it is not enabled, it will not be allowed to call any listener method on it (e.g. Link.onClick) and the model object will be protected (for the common use cases, not for programmer's misuse)
    
    Parameters:
    enabled - whether this component is enabled
    
    Returns:
    This
  - setEscapeModelStrings
```
public final Component setEscapeModelStrings(boolean escapeMarkup)
```
    Sets whether model strings should be escaped.
    
    Parameters:
    escapeMarkup - True is model strings should be escaped
    
    Returns:
    This
  - setMarkupIdImpl
```
public final void setMarkupIdImpl(Object markupId)
```
    Set markup ID, which must be String or Integer
    
    Parameters:
    markupId -
  - setMarkupId
```
public Component setMarkupId(String markupId)
```
    Sets this component's markup id to a user defined value. It is up to the user to ensure this value is unique.
    The recommended way is to let wicket generate the value automatically, this method is here to serve as an override for that value in cases where a specific id must be used.
    If null is passed in the user defined value is cleared and markup id value will fall back on automatically generated value
    
    Parameters:
    markupId - markup id value or null to clear any previous user defined value
    
    Returns:
    this for chaining
    See Also:
    getMarkupId()
  - setMetaData
```
public final <M extends Serializable> Component setMetaData(MetaDataKey<M> key,
                                             M object)
```
    Sets the metadata for this component using the given key. If the metadata object is not of the correct type for the metadata key, an IllegalArgumentException will be thrown. For information on creating MetaDataKeys, see MetaDataKey.
    
    Type Parameters:
    M - The type of the metadata
    Parameters:
    key - The singleton key for the metadata
    object - The metadata object
    
    Throws:
    
    IllegalArgumentException
    See Also:
    MetaDataKey
  - setDefaultModel
```
public Component setDefaultModel(IModel<?> model)
```
    Sets the given model.
    WARNING: DO NOT OVERRIDE THIS METHOD UNLESS YOU HAVE A VERY GOOD REASON FOR IT. OVERRIDING THIS MIGHT OPEN UP SECURITY LEAKS AND BREAK BACK-BUTTON SUPPORT.
    
    Parameters:
    model - The model
    
    Returns:
    This
  - setDefaultModelObject
```
public final Component setDefaultModelObject(Object object)
```
    Sets the backing model object. Unlike getDefaultModel().setObject(object), this method checks authorisation and model comparator, and invokes modelChanging and modelChanged if the value really changes.
    
    Parameters:
    object - The object to set
    
    Returns:
    This
  - setOutputMarkupId
```
public final Component setOutputMarkupId(boolean output)
```
    Sets whether or not component will output id attribute into the markup. id attribute will be set to the value returned from getMarkupId().
    
    Parameters:
    output - True if the component will output the id attribute into markup. Please note that the default behavior is to use the same id as the component. This means that your component must begin with [a-zA-Z] in order to generate a valid markup id according to: http://www.w3.org/TR/html401/types.html#type-name
    
    Returns:
    this for chaining
  - setOutputMarkupPlaceholderTag
```
public final Component setOutputMarkupPlaceholderTag(boolean outputTag)
```
    Render a placeholder tag when the component is not visible. The tag is of form: <componenttag style="display:none;" id="markupid"/>. This method will also call setOutputMarkupId(true). This is useful, for example, in ajax situations where the component starts out invisible and then becomes visible through an ajax update. With a placeholder tag already in the markup you do not need to repaint this component's parent, instead you can repaint the component directly. When this method is called with parameter false the outputmarkupid flag is not reverted to false.
    
    Parameters:
    outputTag -
    
    Returns:
    this for chaining
  - setRenderBodyOnly
```
public final Component setRenderBodyOnly(boolean renderTag)
```
    If false the component's tag will be printed as well as its body (which is default). If true only the body will be printed, but not the component's tag.
    
    Parameters:
    renderTag - If true, the component tag will not be printed
    
    Returns:
    This
  - setResponsePage
```
public final <C extends IRequestablePage> void setResponsePage(Class<C> cls)
```
    Sets the page that will respond to this request
    
    Type Parameters:
    C -
    Parameters:
    cls - The response page class
    See Also:
    RequestCycle.setResponsePage(Class)
  - setResponsePage
```
public final <C extends IRequestablePage> void setResponsePage(Class<C> cls,
                                                PageParameters parameters)
```
    Sets the page class and its parameters that will respond to this request
    
    Type Parameters:
    C -
    Parameters:
    cls - The response page class
    parameters - The parameters for this bookmarkable page.
    See Also:
    RequestCycle.setResponsePage(Class, PageParameters)
  - setResponsePage
```
public final void setResponsePage(IRequestablePage page)
```
    Sets the page that will respond to this request
    
    Parameters:
    page - The response page
    See Also:
    RequestCycle.setResponsePage(org.apache.wicket.request.component.IRequestablePage)
  - setVersioned
```
public Component setVersioned(boolean versioned)
```
    Parameters:
    versioned - True to turn on versioning for this component, false to turn it off for this component and any children.
    
    Returns:
    This
  - setVisible
```
public final Component setVisible(boolean visible)
```
    Sets whether this component and any children are visible.
    
    Parameters:
    visible - True if this component and any children should be visible
    
    Returns:
    This
  - toString
```
public String toString()
```
    Gets the string representation of this component.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    The path to this component
  - toString
```
public String toString(boolean detailed)
```
    Parameters:
    detailed - True if a detailed string is desired
    
    Returns:
    The string
  - urlFor
```
public final <C extends Page> CharSequence urlFor(Class<C> pageClass,
                                   PageParameters parameters)
```
    Returns a bookmarkable URL that references a given page class using a given set of page parameters. Since the URL which is returned contains all information necessary to instantiate and render the page, it can be stored in a user's browser as a stable bookmark.
    
    Type Parameters:
    C -
    Parameters:
    pageClass - Class of page
    parameters - Parameters to page
    
    Returns:
    Bookmarkable URL to page
    See Also:
    RequestCycle.urlFor(Class, org.apache.wicket.request.mapper.parameter.PageParameters)
  - urlFor
```
public final CharSequence urlFor(Behavior behaviour,
                  RequestListenerInterface listener,
                  PageParameters parameters)
```
    Gets a URL for the listener interface on a behavior (e.g. IBehaviorListener on AjaxPagingNavigationBehavior).
    
    Parameters:
    behaviour - The behavior that the URL should point to
    listener - The listener interface that the URL should call
    parameters - The parameters that should be rendered into the urls
    
    Returns:
    The URL
  - urlFor
```
public final CharSequence urlFor(IRequestHandler requestHandler)
```
    Returns a URL that references the given request target.
    
    Parameters:
    requestHandler - the request target to reference
    
    Returns:
    a URL that references the given request target
    See Also:
    RequestCycle.urlFor(IRequestHandler)
  - urlFor
```
public final CharSequence urlFor(RequestListenerInterface listener,
                  PageParameters parameters)
```
    Gets a URL for the listener interface (e.g. ILinkListener).
    
    Parameters:
    listener - The listener interface that the URL should call
    parameters - The parameters that should be rendered into the urls
    
    Returns:
    The URL
    See Also:
    RequestCycle.urlFor(IRequestHandler)
  - urlFor
```
public final CharSequence urlFor(ResourceReference resourceReference,
                  PageParameters parameters)
```
    Returns a URL that references a shared resource through the provided resource reference.
    
    Parameters:
    resourceReference - The resource reference
    parameters - parameters or null if none
    
    Returns:
    The url for the shared resource
    See Also:
    RequestCycle.urlFor(IRequestHandler)
  - visitParents
```
public final <R,C extends MarkupContainer> R visitParents(Class<C> parentClass,
                                           IVisitor<C,R> visitor)
```
    Traverses all parent components of the given class in this parentClass, calling the visitor's visit method at each one.
    
    Type Parameters:
    R - the type of the result object
    Parameters:
    parentClass - Class
    visitor - The visitor to call at each parent of the given type
    
    Returns:
    First non-null value returned by visitor callback
  - visitParents
```
public final <R,C extends MarkupContainer> R visitParents(Class<C> parentClass,
                                           IVisitor<C,R> visitor,
                                           IVisitFilter filter)
```
    Traverses all parent components of the given class in this parentClass, calling the visitor's visit method at each one.
    
    Type Parameters:
    R - the type of the result object
    Parameters:
    parentClass - the class of the parent component
    visitor - The visitor to call at each parent of the given type
    filter - a filter that adds an additional logic to the condition whether a parent container matches
    
    Returns:
    First non-null value returned by visitor callback
  - warn
```
public final void warn(Serializable message)
```
    Registers a warning feedback message for this component.
    
    Parameters:
    message - The feedback message
  - addStateChange
```
protected final void addStateChange()
```
    TODO WICKET-NG rename to something more useful - like componentChanged(), this method used to be called with a Change object Adds state change to page.
  - checkComponentTag
```
protected final void checkComponentTag(ComponentTag tag,
                     String name)
```
    Checks whether the given type has the expected name.
    
    Parameters:
    tag - The tag to check
    name - The expected tag name
    
    Throws:
    
    MarkupException - Thrown if the tag is not of the right name
  - checkComponentTagAttribute
```
protected final void checkComponentTagAttribute(ComponentTag tag,
                              String key,
                              String... values)
```
    Checks that a given tag has a required attribute value.
    
    Parameters:
    tag - The tag
    key - The attribute key
    values - The required value for the attribute key
    
    Throws:
    
    MarkupException - Thrown if the tag does not have the required attribute value
  - checkHierarchyChange
```
protected void checkHierarchyChange(Component component)
```
    Checks whether the hierarchy may be changed at all, and throws an exception if this is not the case.
    
    Parameters:
    component - the component which is about to be added or removed
  - detachModel
```
protected void detachModel()
```
    Detaches the model for this component if it is detachable.
  - exceptionMessage
```
protected final String exceptionMessage(String message)
```
    Suffixes an exception message with useful information about this. component.
    
    Parameters:
    message - The message
    
    Returns:
    The modified message
  - findMarkupStream
```
protected final MarkupStream findMarkupStream()
```
    Finds the markup stream for this component.
    
    Returns:
    The markup stream for this component. Since a Component cannot have a markup stream, we ask this component's parent to search for it.
  - findPage
```
protected final Page findPage()
```
    If this Component is a Page, returns self. Otherwise, searches for the nearest Page parent in the component hierarchy. If no Page parent can be found, null is returned.
    
    Returns:
    The Page or null if none can be found
  - getBehaviors
```
public <M extends Behavior> List<M> getBehaviors(Class<M> type)
```
    Gets the subset of the currently coupled Behaviors that are of the provided type as an unmodifiable list. Returns an empty list if there are no behaviors coupled to this component.
    
    Type Parameters:
    M - A class derived from Behavior
    Parameters:
    type - The type or null for all
    
    Returns:
    The subset of the currently coupled behaviors that are of the provided type as an unmodifiable list
  - getFlag
```
protected final boolean getFlag(int flag)
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT!
    
    Parameters:
    flag - The flag to test
    
    Returns:
    True if the flag is set
  - getRequestFlag
```
protected final boolean getRequestFlag(short flag)
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT!
    
    Parameters:
    flag - The flag to test
    
    Returns:
    True if the flag is set
  - getInnermostModel
```
protected final IModel<?> getInnermostModel(IModel<?> model)
```
    Finds the innermost IModel object for an IModel that might contain nested IModel(s).
    
    Parameters:
    model - The model
    
    Returns:
    The innermost (most nested) model
  - getModelComparator
```
public IModelComparator getModelComparator()
```
    Gets the component's current model comparator. Implementations can be used for testing the current value of the components model data with the new value that is given.
    
    Returns:
    the value defaultModelComparator
  - getStatelessHint
```
protected boolean getStatelessHint()
```
    Returns whether the component can be stateless. Also the component behaviors must be stateless, otherwise the component will be treat as stateful. In order for page to be stateless (and not to be stored in session), all components (and component behaviors) must be stateless.
    
    Returns:
    whether the component can be stateless
  - initModel
```
protected IModel<?> initModel()
```
    Called when a null model is about to be retrieved in order to allow a subclass to provide an initial model.
    By default this implementation looks components in the parent chain owning a IComponentInheritedModel to provide a model for this component via IComponentInheritedModel.wrapOnInheritance(Component).
    For example a FormComponent has the opportunity to instantiate a model on the fly using its id and the containing Form's model, if the form holds a CompoundPropertyModel.
    
    Returns:
    The model
  - internalOnModelChanged
```
protected void internalOnModelChanged()
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT CALL OR OVERRIDE.
    Called anytime a model is changed via setModel or setModelObject.
  - isBehaviorAccepted
```
protected boolean isBehaviorAccepted(Behavior behavior)
```
    Components are allowed to reject behavior modifiers.
    
    Parameters:
    behavior -
    
    Returns:
    False, if the component should not apply this behavior
  - isIgnoreAttributeModifier
```
protected final boolean isIgnoreAttributeModifier()
```
    If true, all attribute modifiers will be ignored
    
    Returns:
    True, if attribute modifiers are to be ignored
  - onAfterRender
```
protected void onAfterRender()
```
    Called just after a component is rendered.
  - onBeforeRender
```
protected void onBeforeRender()
```
    Called just before a component is rendered only if the component is visible.
    NOTE: If you override this, you *must* call super.onBeforeRender() within your implementation. Because this method is responsible for cascading onBeforeRender() call to its children it is strongly recommended that super call is made at the end of the override.
    Changes to the component tree can be made only before calling super.onBeforeRender().
    
    See Also:
    MarkupContainer.addOrReplace(Component...)
  - onComponentTag
```
protected void onComponentTag(ComponentTag tag)
```
    Processes the component tag. Overrides of this method most likely should call the super implementation.
    
    Parameters:
    tag - Tag to modify
  - onComponentTagBody
```
public void onComponentTagBody(MarkupStream markupStream,
                      ComponentTag openTag)
```
    Processes the body.
    
    Parameters:
    markupStream - The markup stream
    openTag - The open tag for the body
  - onDetach
```
protected void onDetach()
```
    Called to allow a component to detach resources after use. Overrides of this method MUST call the super implementation, the most logical place to do this is the last line of the override method.
  - onRemove
```
protected void onRemove()
```
    Called to notify the component it is being removed from the component hierarchy Overrides of this method MUST call the super implementation, the most logical place to do this is the last line of the override method.
  - onModelChanged
```
protected void onModelChanged()
```
    Called anytime a model is changed after the change has occurred
  - onModelChanging
```
protected void onModelChanging()
```
    Called anytime a model is changed, but before the change actually occurs
  - onRender
```
protected abstract void onRender()
```
    Implementation that renders this component.
  - renderComponentTag
```
protected final void renderComponentTag(ComponentTag tag)
```
    Writes a simple tag out to the response stream. Any components that might be referenced by the tag are ignored. Also undertakes any tag attribute modifications if they have been added to the component.
    
    Parameters:
    tag - The tag to write
  - replaceComponentTagBody
```
protected final void replaceComponentTagBody(MarkupStream markupStream,
                           ComponentTag tag,
                           CharSequence body)
```
    Replaces the body with the given one.
    
    Parameters:
    markupStream - The markup stream to replace the tag body in
    tag - The tag
    body - The new markup
  - setAuto
```
protected final Component setAuto(boolean auto)
```
    Parameters:
    auto - True to put component into auto-add mode
  - setFlag
```
protected final Component setFlag(int flag,
                boolean set)
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT!
    
    Parameters:
    flag - The flag to set
    set - True to turn the flag on, false to turn it off
  - setRequestFlag
```
protected final Component setRequestFlag(short flag,
                       boolean set)
```
    THIS METHOD IS NOT PART OF THE WICKET PUBLIC API. DO NOT USE IT!
    
    Parameters:
    flag - The flag to set
    set - True to turn the flag on, false to turn it off
  - setIgnoreAttributeModifier
```
protected final Component setIgnoreAttributeModifier(boolean ignore)
```
    If true, all attribute modifiers will be ignored
    
    Parameters:
    ignore - If true, all attribute modifiers will be ignored
    
    Returns:
    This
  - wrap
```
protected final <V> IModel<V> wrap(IModel<V> model)
```
    Type Parameters:
    V - The model type
    Parameters:
    model - The model to wrap if need be
    
    Returns:
    The wrapped model
  - get
```
public Component get(String path)
```
    Gets the component at the given path.
    
    Specified by:
    
    get in interface IRequestableComponent
    
    Parameters:
    path - Path to component
    
    Returns:
    The component at the path
  - isAuto
```
public final boolean isAuto()
```
    Returns:
    True if this component or any of its parents is in auto-add mode
  - onAfterRenderChildren
```
protected void onAfterRenderChildren()
```
  - setParent
```
public final void setParent(MarkupContainer parent)
```
    THIS IS A WICKET INTERNAL API. DO NOT USE IT. Sets the parent of a component. Typically what you really want is parent.add(child).
    Note that calling setParent() and not parent.add() will connect the child to the parent, but the parent will not know the child. This might not be a problem in some cases, but e.g. child.onDetach() will not be invoked (since the parent doesn't know it is his child).
    
    Parameters:
    parent - The parent container
  - setVisibilityAllowed
```
public final Component setVisibilityAllowed(boolean allowed)
```
    Sets whether or not this component is allowed to be visible. This method is meant to be used by components to control visibility of other components. A call to setVisible(boolean) will not always have a desired effect because that component may have isVisible() overridden. Both setVisibilityAllowed(boolean) and isVisibilityAllowed() are final so their contract is enforced always.
    
    Parameters:
    allowed -
    
    Returns:
    this for chaining
  - isVisibilityAllowed
```
public final boolean isVisibilityAllowed()
```
    Gets whether or not visibility is allowed on this component. See setVisibilityAllowed(boolean) for details.
    
    Returns:
    true if this component is allowed to be visible, false otherwise.
  - determineVisibility
```
public final boolean determineVisibility()
```
    Determines whether or not a component should be visible, taking into account all the factors: isVisible(), isVisibilityAllowed(), isRenderAllowed()
    
    Returns:
    true if the component should be visible, false otherwise
  - isEnabledInHierarchy
```
public boolean isEnabledInHierarchy()
```
    Calculates enabled state of the component taking its hierarchy into account. A component is enabled iff it is itself enabled (isEnabled() and isEnableAllowed() both return true), and all of its parents are enabled.
    
    Returns:
    true if this component is enabled
  - isRendering
```
public final boolean isRendering()
```
    Says if the component is rendering or not checking the corresponding flag.
    
    Returns:
    true if this component is rendering, false otherwise.
  - canCallListenerInterface
```
public boolean canCallListenerInterface(Method method)
```
    Checks whether or not a listener method can be invoked on this component. Usually components deny these invocations if they are either invisible or disabled in hierarchy. Components can examine which listener interface is being invoked by examining the declaring class of the passed in method parameter.
    WARNING: be careful when overriding this method because it may open security holes - such as allowing a user to click on a link that should be disabled.
    
    Example usecase for overriding: Suppose you are building an component that displays images. The component generates a callback to itself using IRequestListener interface and uses this callback to stream image data. If such a component is placed inside a disabled webmarkupcontainer we still want to allow the invocation of the request listener callback method so that image data can be streamed. Such a component would override this method and return true if the listener method belongs to IRequestListener.
    
    Parameters:
    method - listener method about to be invoked on this component. Could be null - in this case it means any method.
    
    Returns:
    true iff the listener method can be invoked on this component
  - renderHead
```
public final void renderHead(Component component,
              IHeaderResponse response)
```
    CAUTION: this method is not meant to be overridden like it was in wicket 1.4 when implementing IHeaderContributor. overload renderHead(org.apache.wicket.markup.head.IHeaderResponse) instead to contribute to the response header.
    
    Parameters:
    component -
    response -
  - renderHead
```
public void renderHead(IHeaderResponse response)
```
    Render to the web response whatever the component wants to contribute to the head section.
    
    Specified by:
    
    renderHead in interface IHeaderContributor
    
    Parameters:
    response - Response object
  - onEvent
```
public void onEvent(IEvent<?> event)
```
    Called when an event is sent to this sink
    
    Specified by:
    
    onEvent in interface IEventSink
  - send
```
public final <T> void send(IEventSink sink,
            Broadcast type,
            T payload)
```
    Sends an event
    
    Specified by:
    
    send in interface IEventSource
    
    Type Parameters:
    T - type of payload
    Parameters:
    sink - object that will receive the event
    type - if the object that receives the event needs to broadcast it to others, this is the type of broadcast that should be used
    payload - event payload
  - remove
```
public Component remove(Behavior... behaviors)
```
    Removes behavior from component
    
    Parameters:
    behaviors - behaviors to remove
    
    Returns:
    this (to allow method call chaining)
  - getBehaviorById
```
public final Behavior getBehaviorById(int id)
```
    Gets the behavior for the specified id
    
    Specified by:
    
    getBehaviorById in interface IRequestableComponent
    
    Returns:
    behavior or null if none
  - getBehaviorId
```
public final int getBehaviorId(Behavior behavior)
```
    Gets a stable id for the specified behavior. The id remains stable from the point this method is first called for the behavior until the behavior has been removed from the component
    
    Specified by:
    
    getBehaviorId in interface IRequestableComponent
    
    Returns:
    a stable id for the specified behavior
  - add
```
public Component add(Behavior... behaviors)
```
    Adds a behavior modifier to the component.
    
    Parameters:
    behaviors - The behavior modifier(s) to be added
    
    Returns:
    this (to allow method call chaining)
  - getBehaviors
```
public final List<? extends Behavior> getBehaviors()
```
    Gets the currently coupled Behaviors as a unmodifiable list. Returns an empty list rather than null if there are no behaviors coupled to this component.
    
    Returns:
    The currently coupled behaviors as a unmodifiable list
  - canCallListenerInterfaceAfterExpiry
```
public boolean canCallListenerInterfaceAfterExpiry()
```
    Specified by:
    
    canCallListenerInterfaceAfterExpiry in interface IRequestableComponent
    
    Returns:
    true if it is save to call the listener interface on this component when the owner page is freshly created after expiration
  - onReAdd
```
protected void onReAdd()
```
    This method is called whenever a component is re-added to the page's component tree, if it had been removed at some earlier time, i.e., if it is already initialized (see isInitialized()). This is similar to onInitialize, but only comes after the component has been removed and then added again:
    - onInitialize is only called the very first time a component is added
    - onReAdd is not called the first time, but every time it is re-added after having been removed
    You can think of it as the opposite of onRemove. A component that was once removed will not be re-initialized but only re-added. Subclasses that override this must call super.onReAdd().

Class Component

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ENABLE

PATH_SEPARATOR

PARENT_PATH

RENDER

FLAG_RESERVED1

FLAG_RESERVED2

FLAG_RESERVED3

FLAG_RESERVED4

FLAG_RESERVED5

FLAG_INITIALIZED

FLAG_RESERVED8

FLAG_REMOVING_FROM_HIERARCHY

FLAG_RENDERING

FLAG_PREPARED_FOR_RENDER

FLAG_AFTER_RENDERING

RFLAG_CONTAINER_DEQUEING

Constructor Detail

Component

Component

Method Detail

getMarkup

getMarkupIdFromMarkup

setMarkup

onConfigure

onInitialize

internalInitialize

afterRender

beforeRender

configure

continueToOriginalDestination

clearOriginalDestination

debug

detach

detachModels

error

fatal

findParent

findParentWithAssociatedMarkup

getApplication

getClassRelativePath

getConverter

getEscapeModelStrings

getId

getInnermostModel

getLocale

getLocalizer

getMarkupAttributes

getMarkupIdImpl

getMarkupId

getMarkupId

getMetaData

getDefaultModel

getDefaultModelObject

getDefaultModelObjectAsString

getDefaultModelObjectAsString

getOutputMarkupId

getOutputMarkupPlaceholderTag

getPage

getPageRelativePath

getParent

getPath

getRenderBodyOnly

getRequest

getRequestCycle

getResponse

getSession

getSizeInBytes

getString

getString

getString

getStyle

getVariation

hasBeenRendered

getFeedbackMessages