Interface IExtensionRegistry


  • public interface IExtensionRegistry
    The extension registry holds the master list of all discovered namespaces, extension points and extensions.

    The extension registry can be queried, by name, for extension points and extensions.

    The various objects that describe the contents of the extension registry (IExtensionPoint, IExtension, and IConfigurationElement) 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 on these object except isValid() will throw InvalidRegistryObjectException. 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 if it accesses extension registry objects, because it's at risk if plug-in are removed. Similarly, tools that analyze or display the extension registry are vulnerable. Client code can pre-test for invalid objects by calling isValid(), which never throws this exception. However, pre-tests are usually not sufficient because of the possibility of the extension registry 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.

    Extensions and extension points are declared by generic entities called namespaces. The only fact known about namespaces is that they have unique string-based identifiers. One example of a namespace is a plug-in, for which the namespace id is the plug-in id.

    This interface can be used without OSGi running.

    This interface is not intended to be implemented by clients.

    Since:
    3.0
    Restriction:
    This interface is not intended to be implemented by clients.
    • Method Detail

      • addRegistryChangeListener

        void addRegistryChangeListener​(IRegistryChangeListener listener,
                                       String namespace)
        Note: for new implementations consider using addListener(IRegistryEventListener, String).

        Adds the given listener for registry change events related to extension points in the given namespace. Has no effect if an identical listener is already registered. After completion of this method, the given listener will be registered for events related to extension points in the specified namespace. If no namespace is specified, the listener will receive notifications for changes to extension points in any namespace.

        Once registered, a listener starts receiving notification of changes to the registry. Registry change notifications are sent asynchronously. The listener continues to receive notifications until it is removed.

        Parameters:
        listener - the listener
        namespace - the namespace in which to listen for changes
        See Also:
        IRegistryChangeListener, IRegistryChangeEvent, removeRegistryChangeListener(IRegistryChangeListener)
      • getConfigurationElementsFor

        IConfigurationElement[] getConfigurationElementsFor​(String extensionPointId)
        Returns all configuration elements from all extensions configured into the identified extension point. Returns an empty array if the extension point does not exist, has no extensions configured, or none of the extensions contain configuration elements.
        Parameters:
        extensionPointId - the unique identifier of the extension point (e.g. "org.eclipse.core.resources.builders")
        Returns:
        the configuration elements
      • getConfigurationElementsFor

        IConfigurationElement[] getConfigurationElementsFor​(String namespace,
                                                            String extensionPointName)
        Returns all configuration elements from all extensions configured into the identified extension point. Returns an empty array if the extension point does not exist, has no extensions configured, or none of the extensions contain configuration elements.
        Parameters:
        namespace - the namespace for the extension point (e.g. "org.eclipse.core.resources")
        extensionPointName - the simple identifier of the extension point (e.g. "builders")
        Returns:
        the configuration elements
      • getConfigurationElementsFor

        IConfigurationElement[] getConfigurationElementsFor​(String namespace,
                                                            String extensionPointName,
                                                            String extensionId)
        Returns all configuration elements from the identified extension. Returns an empty array if the extension does not exist or contains no configuration elements.
        Parameters:
        namespace - the namespace for the extension point (e.g. "org.eclipse.core.resources")
        extensionPointName - the simple identifier of the extension point (e.g. "builders")
        extensionId - the unique identifier of the extension (e.g. "com.example.acme.coolbuilder")
        Returns:
        the configuration elements
      • getExtension

        IExtension getExtension​(String extensionId)
        Returns the specified extension in this extension registry, or null if there is no such extension.
        Parameters:
        extensionId - the unique identifier of the extension (e.g. "com.example.acme.coolbuilder")
        Returns:
        the extension, or null
      • getExtension

        IExtension getExtension​(String extensionPointId,
                                String extensionId)
        Returns the specified extension in this extension registry, or null if there is no such extension. The first parameter identifies the extension point, and the second parameter identifies an extension plugged in to that extension point.
        Parameters:
        extensionPointId - the unique identifier of the extension point (e.g. "org.eclipse.core.resources.builders")
        extensionId - the unique identifier of the extension (e.g. "com.example.acme.coolbuilder")
        Returns:
        the extension, or null
      • getExtension

        IExtension getExtension​(String namespace,
                                String extensionPointName,
                                String extensionId)
        Returns the specified extension in this extension registry, or null if there is no such extension. The first two parameters identify the extension point, and the third parameter identifies an extension plugged in to that extension point.
        Parameters:
        namespace - the namespace for the extension point (e.g. "org.eclipse.core.resources")
        extensionPointName - the simple identifier of the extension point (e.g. "builders")
        extensionId - the unique identifier of the extension (e.g. "com.example.acme.coolbuilder")
        Returns:
        the extension, or null
      • getExtensionPoint

        IExtensionPoint getExtensionPoint​(String extensionPointId)
        Returns the extension point with the given extension point identifier in this extension registry, or null if there is no such extension point.
        Parameters:
        extensionPointId - the unique identifier of the extension point (e.g., "org.eclipse.core.resources.builders")
        Returns:
        the extension point, or null
      • getExtensionPoint

        IExtensionPoint getExtensionPoint​(String namespace,
                                          String extensionPointName)
        Returns the extension point in this extension registry with the given namespace and extension point simple identifier, or null if there is no such extension point.
        Parameters:
        namespace - the namespace for the given extension point (e.g. "org.eclipse.core.resources")
        extensionPointName - the simple identifier of the extension point (e.g. "builders")
        Returns:
        the extension point, or null
      • getExtensionPoints

        IExtensionPoint[] getExtensionPoints()
        Returns all extension points known to this extension registry. Returns an empty array if there are no extension points.
        Returns:
        the extension points known to this extension registry
      • getExtensionPoints

        IExtensionPoint[] getExtensionPoints​(String namespace)
        Returns all extension points declared in the given namespace. Returns an empty array if there are no extension points declared in the namespace.
        Parameters:
        namespace - the namespace for the extension points (e.g. "org.eclipse.core.resources")
        Returns:
        the extension points in this registry declared in the given namespace
      • getExtensionPoints

        IExtensionPoint[] getExtensionPoints​(IContributor contributor)
        Returns all extension points supplied by the contributor, or null if there are no such extension points.
        Parameters:
        contributor - the contributor for the extensions (for OSGi registry, bundles and fragments are different contributors)
        Returns:
        the extension points, or null
        Since:
        3.4
      • getExtensions

        IExtension[] getExtensions​(String namespace)
        Returns all extensions declared in the given namespace. Returns an empty array if no extensions are declared in the namespace.
        Parameters:
        namespace - the namespace for the extensions (e.g. "org.eclipse.core.resources")
        Returns:
        the extensions in this registry declared in the given namespace
      • getExtensions

        IExtension[] getExtensions​(IContributor contributor)
        Returns all extensions supplied by the contributor, or null if there are no such extensions.
        Parameters:
        contributor - the contributor for the extensions (for OSGi registry, bundles and fragments are different contributors)
        Returns:
        the extensions, or null
        Since:
        3.4
      • getNamespaces

        String[] getNamespaces()
        Returns all namespaces currently used by extensions and extension points in this registry. Returns an empty array if there are no known extensions/extension points in this registry.

        The fully-qualified name of an extension point or an extension consist of a namespace and a simple name (much like a qualified Java class name consist of a package name and a class name). The simple names are presumed to be unique in the namespace.

        Returns:
        all namespaces known to this registry
      • addContribution

        boolean addContribution​(InputStream is,
                                IContributor contributor,
                                boolean persist,
                                String name,
                                ResourceBundle translationBundle,
                                Object token)
                         throws IllegalArgumentException
        Adds to this extension registry an extension point(s), extension(s), or a combination of those described by the XML file. The information in the XML file should be supplied in the same format as the plugin.xml; in fact, Plug-in Manifest editor can be used to prepare the XML file. The top token of the contribution (normally, "plugin" or "fragment" in the Plug-in Manifest editor) is ignored by this method.

        This method is an access controlled method. Proper token (master token or user token) should be passed as an argument. Two registry keys are set in the registry constructor RegistryFactory.createRegistry(org.eclipse.core.runtime.spi.RegistryStrategy, Object, Object): master token and a user token. Master token allows all operations; user token allows non-persisted registry elements to be modified.

        Parameters:
        is - stream open on the XML file. The XML file can contain an extension point(s) or/and extension(s) described in the format similar to plugin.xml. The method closes the stream before returning
        contributor - the contributor making this contribution.
        persist - indicates if the contribution(s) should be stored in the registry cache. If false, contribution is not persisted in the registry cache and is lost on Eclipse restart
        name - optional name of the contribution. Used for error reporting; might be null
        translationBundle - optional resource bundle used for translations; might be null
        token - the key used to check permissions
        Returns:
        true if the contribution was successfully processed and false otherwise
        Throws:
        IllegalArgumentException - if an incorrect token is passed
        Since:
        org.eclipse.equinox.registry 3.2
        See Also:
        IContributor
      • removeExtension

        boolean removeExtension​(IExtension extension,
                                Object token)
                         throws IllegalArgumentException
        Removes the given extension from this registry.

        This method is an access controlled method. Proper token (master token or user token) should be passed as an argument. Two registry keys are set in the registry constructor RegistryFactory.createRegistry(org.eclipse.core.runtime.spi.RegistryStrategy, Object, Object): master token and a user token. Master token allows all operations; user token only allows non-persisted registry elements to be modified.

        Parameters:
        extension - extension to be removed
        token - the key used to check permissions
        Returns:
        true if the extension was successfully removed, and false otherwise
        Throws:
        IllegalArgumentException - if an incorrect token is passed
        Since:
        org.eclipse.equinox.registry 3.2
      • removeExtensionPoint

        boolean removeExtensionPoint​(IExtensionPoint extensionPoint,
                                     Object token)
                              throws IllegalArgumentException
        Removes the specified extension point from this registry.

        This method is an access controlled method. Proper token (master token or user token) should be passed as an argument. Two registry keys are set in the registry constructor RegistryFactory.createRegistry(org.eclipse.core.runtime.spi.RegistryStrategy, Object, Object): master token and a user token. Master token allows all operations; user token only allows non-persisted registry elements to be modified.

        Parameters:
        extensionPoint - extension point to be removed
        token - the key used to check permissions
        Returns:
        true if the extension point was successfully removed, and false otherwise
        Throws:
        IllegalArgumentException - if incorrect token is passed
        Since:
        org.eclipse.equinox.registry 3.2
      • addListener

        void addListener​(IRegistryEventListener listener)
        Adds the given listener for registry change events. Listener will be notified on changes to all extension points and underlying extensions.

        Depending on activity, listeners of this type might receive a large number of modifications and negatively impact overall system performance. Whenever possible, consider registering listener specific to an extension point rather than a "global" listener.

        Once registered, a listener starts receiving notification of changes to the registry. Registry change notifications are sent asynchronously. The listener continues to receive notifications until it is removed.

        This method has no effect if the listener is already registered.

        Parameters:
        listener - the listener
        Since:
        org.eclipse.equinox.registry 3.4
      • addListener

        void addListener​(IRegistryEventListener listener,
                         String extensionPointId)
        Adds the given listener for registry change events related to specified extension point.

        Once registered, a listener starts receiving notification of changes to the registry. Registry change notifications are sent asynchronously. The listener continues to receive notifications until it is removed.

        This method has no effect if the listener is already registered.

        Parameters:
        listener - the listener
        extensionPointId - the unique identifier of extension point
        Since:
        org.eclipse.equinox.registry 3.4
        See Also:
        IExtensionPoint.getUniqueIdentifier()
      • isMultiLanguage

        boolean isMultiLanguage()
        Call this method to determine if this extension registry supports multiple languages.

        See the runtime option "-registryMultiLanguage" for enabling multi-language support.

        Returns:
        true if multiple languages are supported by this instance of the extension registry; false otherwise.
        Since:
        org.eclipse.equinox.registry 3.5