org.apache.wicket.markup

Class MarkupFactory

java.lang.Object

org.apache.wicket.markup.MarkupFactory

public class MarkupFactory
extends Object

Factory to load markup either from cache or from a resource.

This class is the main entry point to load markup. Nothing else should be required by Components. It manages caching markup as well as loading and merging (inheritance) of markup.

The markup returned is immutable as it gets re-used across multiple Component instances.

Author:

Juergen Donnerstag

Constructor Summary

Constructors

Constructor and Description
MarkupFactory() Construct.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkMarkupType(MarkupContainer container) Without a markup type we can not search for a file and we can not construct the cacheKey.
static MarkupFactory	get()
Class<?>	getContainerClass(MarkupContainer container, Class<?> clazz) Gets and checks the container class
Markup	getMarkup(MarkupContainer container, boolean enforceReload) Get the markup associated with the container.
Markup	getMarkup(MarkupContainer container, Class<?> clazz, boolean enforceReload) Get the markup associated with the container.
IMarkupCache	getMarkupCache() Get the markup cache which is registered with the factory.
IMarkupLoader	getMarkupLoader() MarkupLoaders are responsible to find and load the markup for a component.
MarkupResourceStream	getMarkupResourceStream(MarkupContainer container, Class<?> clazz) Create a new markup resource stream for the container and optionally the Class.
protected IMarkupResourceStreamProvider	getMarkupResourceStreamProvider(MarkupContainer container) Get the markup resource stream provider registered with the factory.
boolean	hasMarkupCache()
Markup	loadMarkup(MarkupContainer container, MarkupResourceStream markupResourceStream, boolean enforceReload) Loads markup from a resource stream.
MarkupParser	newMarkupParser(MarkupResourceStream resource) Create a new markup parser.
protected IXmlPullParser	newXmlPullParser() Subclasses can override this to use custom parsers.
protected IMarkupFilter	onAppendMarkupFilter(IMarkupFilter filter) A callback method that is invoked prior to any IMarkupFilter being registered with MarkupParser.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MarkupFactory

public MarkupFactory()

Construct.

Method Detail

get

public static MarkupFactory get()

Returns:

Gets the markup factory registered with the Wicket application

getMarkupLoader

public IMarkupLoader getMarkupLoader()

MarkupLoaders are responsible to find and load the markup for a component. That may be a single file, but e.g. like in markup inheritance it could also be that the markup from different sources must be merged.

Returns:

By default an instance of DefaultMarkupLoader will be returned. Via subclassing you may return your own markup loader (chain).

newMarkupParser

public MarkupParser newMarkupParser(MarkupResourceStream resource)

Create a new markup parser. Markup parsers read the markup and dissect it in Wicket relevant pieces MarkupElement's (kind of Wicket's DOM).

MarkupParser's can be extended by means of IMarkupFilter. You can add your own filter as follows:

    public MyMarkupFactory {
      ...
      public MarkupParser newMarkupParser(final MarkupResourceStream resource) {
         MarkupParser parser = super.newMarkupParser(resource);
         parser.add(new MyFilter());
         return parser;
      }
    }
 

Parameters:

resource - The resource containing the markup

Returns:

A fresh instance of MarkupParser

See Also:

onAppendMarkupFilter(IMarkupFilter)

newXmlPullParser

protected IXmlPullParser newXmlPullParser()

Subclasses can override this to use custom parsers.

Returns:

parser instance used by MarkupParser to parse markup.

onAppendMarkupFilter

protected IMarkupFilter onAppendMarkupFilter(IMarkupFilter filter)

A callback method that is invoked prior to any IMarkupFilter being registered with MarkupParser. Hence it allows to:

• tweak the default configuration of a filter
• replace a filter with another one
• avoid filters being used by returning null

Note that a new MarkupParser instance is created for each markup resources being loaded.

Parameters:

filter - The filter to be registered with the MarkupParser

Returns:

The filter to be added. Null to ignore.

getMarkupCache

public IMarkupCache getMarkupCache()

Get the markup cache which is registered with the factory. Since the factory is registered with the application, only one cache per application exists.

Please note that markup cache is a pull through cache. It'll invoke a factory method getMarkupResourceStream(MarkupContainer, Class) to load the markup if not yet available in the cache.

Returns:

Null, to disable caching.

hasMarkupCache

public boolean hasMarkupCache()

Returns:

true if markup cache is available. Make sure you called getMarkupCache() at least once before to initialize the cache.

getMarkup

public final Markup getMarkup(MarkupContainer container,
                              boolean enforceReload)

Get the markup associated with the container.

Parameters:

container - The container to find the markup for

enforceReload - If true, the cache will be ignored and all, including inherited markup files, will be reloaded. Whatever is in the cache, it will be ignored

Returns:

The markup associated with the container. Null, if the markup was not found or could not yet be loaded (e.g. getMarkupType() == null). Wicket Exception in case of errors.

getMarkup

public final Markup getMarkup(MarkupContainer container,
                              Class<?> clazz,
                              boolean enforceReload)

Get the markup associated with the container. Check the cache first. If not found, than load the markup and update the cache.

The clazz parameter usually can be null, except for base (inherited) markup.

There are several means to disable markup caching. Caching can be disabled alltogether - getMarkupCache() return null -, or individually (cacheKey == null).

Parameters:

container - The container to find the markup for

clazz - Must be the container class or any of its super classes. May be null.

enforceReload - The cache will be ignored and all, including inherited markup files, will be reloaded. Whatever is in the cache, it will be ignored

Returns:

The markup associated with the container. Null, if the markup was not found or could not yet be loaded (e.g. getMarkupType() == null). Wicket Exception in case of errors.

checkMarkupType

protected final boolean checkMarkupType(MarkupContainer container)

Without a markup type we can not search for a file and we can not construct the cacheKey. We can not even load associated markup as required for Panels. Though every MarkupContainer can provide it's own type, by default they refer to the Page. Hence, no markup type is an indicator, that the component or any of its parents, has not yet been added.

Parameters:

container - The MarkupContainer which markup type has to checked

Returns:

true, if container.getMarkupType() != null

getMarkupResourceStreamProvider

protected final IMarkupResourceStreamProvider getMarkupResourceStreamProvider(MarkupContainer container)

Get the markup resource stream provider registered with the factory.

If the 'container' implements IMarkupResourceStreamProvider, the container itself will be asked to provide the resource stream. Else Wicket's default implementation will be used.

Parameters:

container - The MarkupContainer requesting the markup resource stream

Returns:

IMarkupResourceStreamProvider

getMarkupResourceStream

public final MarkupResourceStream getMarkupResourceStream(MarkupContainer container,
                                                          Class<?> clazz)

Create a new markup resource stream for the container and optionally the Class. The Class must be provided in case of base (inherited) markup. Else it might be null (standard use case).

Parameters:

container - The MarkupContainer which requests to load the Markup resource stream

clazz - Either the container class or any super class. Might be null.

Returns:

A IResourceStream if the resource was found

getContainerClass

public final Class<?> getContainerClass(MarkupContainer container,
                                        Class<?> clazz)

Gets and checks the container class

Parameters:

container - The MarkupContainer which requests to load the Markup resource stream

clazz - Either null, or a super class of container

Returns:

The container class to be used

loadMarkup

public final Markup loadMarkup(MarkupContainer container,
                               MarkupResourceStream markupResourceStream,
                               boolean enforceReload)

Loads markup from a resource stream. It'll call the registered markup loader to load the markup.

Though the 'enforceReload' attribute seem to imply that the cache is consulted to retrieve the markup, the cache in fact is only checked for retrieving the base (inherited) markup. Please see getMarkup(MarkupContainer, boolean) as well.

Parameters:

container - The original requesting markup container

markupResourceStream - The markup resource stream to load, if already known.

enforceReload - The cache will be ignored and all, including inherited markup files, will be reloaded. Whatever is in the cache, it will be ignored

Returns:

The markup. Null, if the markup was not found. Wicket Exception in case of errors.