com.communote.server.web.commons.resource.impl

Class PropertyResourceManager

java.lang.Object

com.communote.server.web.commons.resource.impl.PropertyResourceManager

public class PropertyResourceManager
extends Object

Component that manages property resources for resource categories. A property resource is a resource (e.g. set of CSS rules) that can be updated at runtime and is stored as an application property. A property can also have a fallback file that is provided by the plugin that defines the property resource. The fallback will be used when the application property has no value. When several plugins provide a property resource for the same category the property belonging to the plugin that added the property resource as the last will overlay the others. The manager caches the resources as files on disk to avoid database access.

Author:

Communote GmbH - http://www.communote.com/

Constructor Summary

Constructors

Constructor and Description
PropertyResourceManager(String keyPrefix, String minimizedSuffix) Create a new manager

Method Summary

Modifier and Type	Method and Description
boolean	addPropertyResource(String identifier, String categoryName, String propertyResourceFallback) Add a property resource for the given category and plugin.
CachedFileDescriptor	getPropertyResource(String categoryName) Get the current property resource for the given category name
PropertyResourceContent	getPropertyResourceContent(String identifier, String categoryName) The content of the property resource.
void	init(File cacheDir) Init the manager
boolean	removePropertyResource(String identifier, String categoryName) Remove a property resource added by plugin for the given category.
boolean	updatePropertyResource(String identifier, String categoryName, String propertyValue) Update the property resource for the given category and plugin.

Methods inherited from class java.lang.Object

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

Constructor Detail

PropertyResourceManager

public PropertyResourceManager(String keyPrefix,
                               String minimizedSuffix)

Create a new manager

Parameters:

keyPrefix - the prefix to use when creating the application property key. The category name will be appended to that prefix.

minimizedSuffix - the filename suffix that marks a resource as the minimized version

Method Detail

addPropertyResource

public boolean addPropertyResource(String identifier,
                                   String categoryName,
                                   String propertyResourceFallback)
                            throws PropertyResourceManagerException

Add a property resource for the given category and plugin. If another plugin has already added a property resource for this category the new one will overlay it. This means that a request for the property resource for the category only the application property and fallback of this plugin will be considered until this property resource is removed again (via removePropertyResource(String, String)).

Parameters:

identifier - the identifier of the plugin

categoryName - the name of the category

propertyResourceFallback - absolute path to the location of the fallback resource file that should be rendered when the property is not set. If null there will be no fallback.

Returns:

true if the current property resource for that category changed and the concatenated file needs to be re-created

Throws:

PropertyResourceManagerException - in case the property resource could not be added

getPropertyResource

public CachedFileDescriptor getPropertyResource(String categoryName)

Get the current property resource for the given category name

Parameters:

categoryName - the name of the category

Returns:

the cached property resource or null if there is none for the given category

getPropertyResourceContent

public PropertyResourceContent getPropertyResourceContent(String identifier,
                                                          String categoryName)
                                                   throws PropertyResourceManagerException

The content of the property resource. Note: when needing the current property resource getPropertyResource(String) should be used

Parameters:

identifier - the plugin bundle name

categoryName - name of the category whose resource content should be updated. The category name is used for the property key

Returns:

the content or null if the plugin did not define a property resource for the category. The value of the content might be null.

Throws:

PropertyResourceManagerException - in case reading the content failed

init

public void init(File cacheDir)

Init the manager

Parameters:

cacheDir - the directory where the property resource will be cached

removePropertyResource

public boolean removePropertyResource(String identifier,
                                      String categoryName)

Remove a property resource added by plugin for the given category. This method should be called if the plugin is removed. If the property resource is the current property resource for that category the current property resource is updated by the property resource of the plugin that added the resource before this plugin. If there is no such resource the property resource is removed. The stored application property is not removed.

Parameters:

identifier - the identifier of the plugin

categoryName - the name of the category

Returns:

if the current property resource changed and thus the concatenated file needs to re-built

updatePropertyResource

public boolean updatePropertyResource(String identifier,
                                      String categoryName,
                                      String propertyValue)
                               throws PropertyResourceManagerException

Update the property resource for the given category and plugin. The application property of the plugin is updated or removed and if the property resource is the current one, it will be updated.

Parameters:

identifier - the identifier of the plugin

categoryName - the name of the category

propertyValue - the new value. Can be null to clear the application property and use the fallback of the plugin.

Returns:

whether the current property resource changed and thus the concatenated file for the category needs to be re-created

Throws:

PropertyResourceManagerException - in case the category or plugin is not known or the update failed