org.eclipse.core.runtime.IExtension Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 2009 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.core.runtime;
/**
* An extension declared in a plug-in.
* All information is obtained from the declaring plug-in's
* manifest (plugin.xml) file.
*
* These registry objects are intended for relatively short-term use. Clients that
* deal with these objects must be aware that they may become invalid if the
* declaring plug-in is updated or uninstalled. If this happens, all methods except
* {@link #isValid()} will throw {@link InvalidRegistryObjectException}.
* For extension objects, the most common case is code in a plug-in dealing
* with extensions contributed to one of the extension points it declares.
* Code in a plug-in that has declared that it is not dynamic aware (or not
* declared anything) can safely ignore this issue, since the registry
* would not be modified while it is active. However, code in a plug-in that
* declares that it is dynamic aware must be careful when accessing the extension
* objects because they become invalid if the contributing plug-in is removed.
* Similarly, tools that analyze or display the extension registry are vulnerable.
* Client code can pre-test for invalid objects by calling {@link #isValid()},
* which never throws this exception. However, pre-tests are usually not sufficient
* because of the possibility of the extension object becoming invalid as a
* result of a concurrent activity. At-risk clients must treat
* InvalidRegistryObjectException as if it were a checked exception.
* Also, such clients should probably register a listener with the extension registry
* so that they receive notification of any changes to the registry.
*
* This interface can be used without OSGi running.
*
* This interface is not intended to be implemented by clients.
*
* @noimplement This interface is not intended to be implemented by clients.
*/
public interface IExtension {
/**
* Returns all configuration elements declared by this extension.
* These elements are a direct reflection of the configuration
* markup supplied in the manifest (plugin.xml)
* file for the plug-in that declares this extension.
* Returns an empty array if this extension does not declare any
* configuration elements.
*
* @return the configuration elements declared by this extension
* @throws InvalidRegistryObjectException if this extension is no longer valid
*/
public IConfigurationElement[] getConfigurationElements() throws InvalidRegistryObjectException;
/**
* Returns the namespace for this extension. This value can be used
* in various global facilities to discover this extension's provider.
*
* @return the namespace for this extension
* @throws InvalidRegistryObjectException if this extension is no longer valid
* @see IExtensionRegistry
* @since 3.0
* @deprecated As namespace is no longer restricted to the contributor name,
* use {@link #getNamespaceIdentifier()} to obtain namespace name or {@link #getContributor()}
* to get the name of the contributor of this registry element.
*
* In the past namespace was dictated by the name of the bundle. If bundle org.abc
* contributed registry element with Id of MyId, the namespace of
* the element was always set to org.abc, producing the qualified name of
* org.abc.MyId.
*
* The namespace used to be the same as the bundle name. As a result, the {@link #getNamespace()}
* method was used both to obtain the name of the bundle and to obtain the namespace of a registry
* element.
*
* Since 3.2, the extension registry allows elements to specify qualified name. The extension point
* of the plug-in org.abc could specify org.zzz.MyExtPoint as
* an Id. In this case, namespace name is org.zzz, but the contributor
* name is org.abc.
*
* (The use of a simple Id is still a preferred way. Whenever possible, specify only the simple
* Id and let runtime take care of the rest.)
*
* If your code used the {@link #getNamespace()} to obtain the name of the contributing bundle,
* use {@link #getContributor()}. The typical usage pattern here is to find a bundle name to obtain
* some information from the corresponding OSGi bundle. For example, deducing the file location
* specified as a relative path to the bundle install location would fall into this group.
*
* If your code used the {@link #getNamespace()} to obtain the namespace of the registry element,
* use {@link #getNamespaceIdentifier()}. Typically, this is the case when code is trying to process
* registry elements belonging to some logical group. For example, processing notifications for all
* elements belonging to the org.abc namespace would fall into this category.
*
*/
public String getNamespace() throws InvalidRegistryObjectException;
/**
* Returns the namespace name for this extension.
*
* @return the namespace name for this extension
* @throws InvalidRegistryObjectException if this extension is no longer valid
* @since org.eclipse.equinox.registry 3.2
*/
public String getNamespaceIdentifier() throws InvalidRegistryObjectException;
/**
* Returns the contributor of this extension.
*
* @return the contributor for this extension
* @throws InvalidRegistryObjectException if this extension is no longer valid
* @since org.eclipse.equinox.registry 3.2
*/
public IContributor getContributor() throws InvalidRegistryObjectException;
/**
* Returns the unique identifier of the extension point
* to which this extension should be contributed.
*
* @return the unique identifier of the relevant extension point
* @throws InvalidRegistryObjectException if this extension is no longer valid
*/
public String getExtensionPointUniqueIdentifier() throws InvalidRegistryObjectException;
/**
* Returns a displayable label for this extension.
* Returns the empty string if no label for this extension
* is specified in the plug-in manifest file.
* Note that any translation specified in the plug-in manifest
* file is automatically applied.
*
*
* @return a displayable string label for this extension,
* possibly the empty string
* @throws InvalidRegistryObjectException if this extension is no longer valid
*/
public String getLabel() throws InvalidRegistryObjectException;
/**
* When multi-language support is enabled, this method returns a displayable label for this
* extension in the specified locale. Returns the empty string if no label for this extension
* is specified in the plug-in manifest file.
*
* The locale matching tries to find the best match between available translations and
* the requested locale, falling back to a more generic locale ("en") when the specific
* locale ("en_US") is not available.
*
* If multi-language support is not enabled, this method is equivalent to the method
* {@link #getLabel()}.
*
* @param locale the requested locale
* @return a displayable string label for this extension,
* possibly the empty string
* @throws InvalidRegistryObjectException if this extension is no longer valid
* @see IExtensionRegistry#isMultiLanguage()
* @since 3.5
*/
public String getLabel(String locale) throws InvalidRegistryObjectException;
/**
* Returns the simple identifier of this extension, or null
* if this extension does not have an identifier.
* This identifier is specified in the plug-in manifest (plugin.xml)
* file as a non-empty string containing no period characters
* ('.') and must be unique within the namespace.
*
* @return the simple identifier of the extension (e.g. "main")
* or null
* @throws InvalidRegistryObjectException if this extension is no longer valid
*/
public String getSimpleIdentifier() throws InvalidRegistryObjectException;
/**
* Returns the unique identifier of this extension, or null
* if this extension does not have an identifier.
* If available, this identifier is unique within the plug-in registry, and
* is composed of the namespace where this extension
* was declared and this extension's simple identifier.
*
* @return the unique identifier of the extension
* (e.g. "com.example.acme.main"), or null
* @throws InvalidRegistryObjectException if this extension is no longer valid
*/
public String getUniqueIdentifier() throws InvalidRegistryObjectException;
/* (non-javadoc)
* @see Object#equals(java.lang.Object)
*/
public boolean equals(Object o);
/**
* Returns whether this extension object is valid.
*
* @return true if the object is valid, and false
* if it is no longer valid
* @since 3.1
*/
public boolean isValid();
}