net.enilink.commons.util.extensions

Class RegistryReader

java.lang.Object

net.enilink.commons.util.extensions.RegistryReader

All Implemented Interfaces:

EventListener, org.eclipse.core.runtime.IRegistryChangeListener

public abstract class RegistryReader
extends Object
implements org.eclipse.core.runtime.IRegistryChangeListener

Template implementation of a registry reader that creates objects representing registry contents. Typically, an extension contains one element, but this reader handles multiple elements per extension. To start reading the extensions from the registry for an extension point, call the method readRegistry. To read children of an IConfigurationElement, call the method readElementChildren from your implementation of the method readElement, as it will not be done by default.

Field Summary

Fields

Modifier and Type	Field and Description
protected static String	TAG_DESCRIPTION

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RegistryReader(org.eclipse.core.runtime.IExtensionRegistry registry, String pluginId, String extensionPoint) The constructor.
protected	RegistryReader(String pluginId, String extensionPoint) The constructor.

Method Summary

Modifier and Type	Method and Description
protected String	getDescription(org.eclipse.core.runtime.IConfigurationElement config) This method extracts description as a subelement of the given element.
protected static void	logError(org.eclipse.core.runtime.IConfigurationElement element, String text) Logs the error in the workbench log using the provided text and the information in the configuration element.
protected static void	logMissingAttribute(org.eclipse.core.runtime.IConfigurationElement element, String attributeName) Logs a very common registry error when a required attribute is missing.
protected static void	logMissingElement(org.eclipse.core.runtime.IConfigurationElement element, String elementName) Logs a very common registry error when a required child is missing.
protected static void	logUnknownElement(org.eclipse.core.runtime.IConfigurationElement element) Logs a registry error when the configuration element is unknown.
protected org.eclipse.core.runtime.IExtension[]	orderExtensions(org.eclipse.core.runtime.IExtension[] extensions) Apply a reproducable order to the list of extensions provided, such that the order will not change as extensions are added or removed.
protected boolean	readElement(org.eclipse.core.runtime.IConfigurationElement element) Implement this method to read element's attributes.
protected boolean	readElement(org.eclipse.core.runtime.IConfigurationElement element, boolean add) Implement this method to read element attributes for the purpose of adding or removing their registrations.
protected void	readElementChildren(org.eclipse.core.runtime.IConfigurationElement element, boolean add) Read the element's children.
protected void	readElements(org.eclipse.core.runtime.IConfigurationElement[] elements, boolean add) Read each element one at a time by calling the subclass implementation of readElement.
protected void	readExtension(org.eclipse.core.runtime.IExtension extension, boolean add) Read one extension by looping through its configuration elements.
void	readRegistry() Start the registry reading process using the supplied plugin ID and extension point.
void	registerListener() Registers change listener to extension registry
void	registryChanged(org.eclipse.core.runtime.IRegistryChangeEvent event)
void	unregisterListener() Unregisters change listener from extension registry

Methods inherited from class java.lang.Object

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

Field Detail

TAG_DESCRIPTION

protected static final String TAG_DESCRIPTION

See Also:

Constant Field Values

Constructor Detail

RegistryReader

protected RegistryReader(org.eclipse.core.runtime.IExtensionRegistry registry,
                         String pluginId,
                         String extensionPoint)

The constructor.

RegistryReader

protected RegistryReader(String pluginId,
                         String extensionPoint)

The constructor.

Method Detail

getDescription

protected String getDescription(org.eclipse.core.runtime.IConfigurationElement config)

This method extracts description as a subelement of the given element.

Returns:

description string if defined, or empty string if not.

logError

protected static void logError(org.eclipse.core.runtime.IConfigurationElement element,
                               String text)

Logs the error in the workbench log using the provided text and the information in the configuration element.

logMissingAttribute

protected static void logMissingAttribute(org.eclipse.core.runtime.IConfigurationElement element,
                                          String attributeName)

Logs a very common registry error when a required attribute is missing.

logMissingElement

protected static void logMissingElement(org.eclipse.core.runtime.IConfigurationElement element,
                                        String elementName)

Logs a very common registry error when a required child is missing.

logUnknownElement

protected static void logUnknownElement(org.eclipse.core.runtime.IConfigurationElement element)

Logs a registry error when the configuration element is unknown.

orderExtensions

protected org.eclipse.core.runtime.IExtension[] orderExtensions(org.eclipse.core.runtime.IExtension[] extensions)

Apply a reproducable order to the list of extensions provided, such that the order will not change as extensions are added or removed.

readElement

protected boolean readElement(org.eclipse.core.runtime.IConfigurationElement element)

Implement this method to read element's attributes. If children should also be read, then implementor is responsible for calling readElementChildren. Implementor is also responsible for logging missing attributes.

Returns:

true if element was recognized, false if not.

readElement

protected boolean readElement(org.eclipse.core.runtime.IConfigurationElement element,
                              boolean add)

Implement this method to read element attributes for the purpose of adding or removing their registrations. If this element has child elements, the reader will recursively cycle through them and will call this method, so don't do it here.

readElementChildren

protected void readElementChildren(org.eclipse.core.runtime.IConfigurationElement element,
                                   boolean add)

Read the element's children. This is called by the subclass' readElement method when it wants to read the children of the element.

readElements

protected void readElements(org.eclipse.core.runtime.IConfigurationElement[] elements,
                            boolean add)

Read each element one at a time by calling the subclass implementation of readElement. Logs an error if the element was not recognized.

readExtension

protected void readExtension(org.eclipse.core.runtime.IExtension extension,
                             boolean add)

Read one extension by looping through its configuration elements.

readRegistry

public void readRegistry()

Start the registry reading process using the supplied plugin ID and extension point.

registerListener

public void registerListener()

Registers change listener to extension registry

unregisterListener

public void unregisterListener()

Unregisters change listener from extension registry

registryChanged

public void registryChanged(org.eclipse.core.runtime.IRegistryChangeEvent event)

Specified by:

registryChanged in interface org.eclipse.core.runtime.IRegistryChangeListener