Package org.eclipse.core.runtime

Interface IConfigurationElement

public interface IConfigurationElement

A configuration element, with its attributes and children, directly reflects the content and structure of the extension section within the declaring plug-in's manifest (plugin.xml) file.

This interface also provides a way to create executable extension objects.

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 isValid() will throw InvalidRegistryObjectException. For configuration element 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 and configuration element 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 isValid(), which never throws this exception. However, pre-tests are usually not sufficient because of the possibility of the extension or configuration element 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.

Restriction:

This interface is not intended to be implemented by clients.

Method Summary

Modifier and Type	Method	Description
Object	createExecutableExtension(String propertyName)	Creates and returns a new instance of the executable extension identified by the named attribute of this configuration element.
boolean	equals(Object o)
String	getAttribute(String name)	Returns the named attribute of this configuration element, or null if none.
String	getAttribute(String attrName, String locale)	When multi-language support is enabled, this method returns the named attribute of this configuration element in the specified locale, or null if none.
String	getAttributeAsIs(String name)	Deprecated. The method is equivalent to the getAttribute(String).
String[]	getAttributeNames()	Returns the names of the attributes of this configuration element.
IConfigurationElement[]	getChildren()	Returns all configuration elements that are children of this configuration element.
IConfigurationElement[]	getChildren(String name)	Returns all child configuration elements with the given name.
IContributor	getContributor()	Returns the contributor of this configuration element.
IExtension	getDeclaringExtension()	Returns the extension that declares this configuration element.
int	getHandleId()	Returns unique identifier of the registry object from which this element was created.
String	getName()	Returns the name of this configuration element.
String	getNamespace()	Deprecated. As namespace is no longer restricted to the contributor name, use getNamespaceIdentifier() to obtain namespace name or getContributor() to get the name of the contributor of this registry element.
String	getNamespaceIdentifier()	Returns the namespace name for this configuration element.
Object	getParent()	Returns the element which contains this element.
String	getValue()	Returns the text value of this configuration element.
String	getValue(String locale)	When multi-language support is enabled, this method returns the text value of this configuration element in the specified locale, or null if none.
String	getValueAsIs()	Deprecated. The method is equivalent to the getValue().
boolean	isValid()	Returns whether this configuration element object is valid.

Method Detail

createExecutableExtension

Object createExecutableExtension(String propertyName)
                          throws CoreException

Creates and returns a new instance of the executable extension identified by the named attribute of this configuration element. The named attribute value must contain a fully qualified name of a Java class. The class can either refer to a class implementing the executable extension or to a factory capable of returning the executable extension.

The specified class is instantiated using its 0-argument public constructor.

Then the following checks are done:
If the specified class implements the IExecutableExtension interface, the method IExecutableExtension.setInitializationData(IConfigurationElement, String, Object) is called, passing to the object the configuration information that was used to create it.

If the specified class implements IExecutableExtensionFactory interface, the method IExecutableExtensionFactory.create() is invoked.

Unlike other methods on this object, invoking this method may activate the plug-in.

Parameters:

propertyName - the name of the property

Returns:

the executable instance

Throws:

CoreException - if an instance of the executable extension could not be created for any reason

InvalidRegistryObjectException - if this configuration element is no longer valid

See Also:

IExecutableExtension.setInitializationData(IConfigurationElement, String, Object), IExecutableExtensionFactory

getAttribute

String getAttribute(String name)
             throws InvalidRegistryObjectException

Returns the named attribute of this configuration element, or null if none.

The names of configuration element attributes are the same as the attribute names of the corresponding XML element. For example, the configuration markup

 <bg pattern="stripes"/>
 

corresponds to a configuration element named "bg" with an attribute named "pattern" with attribute value "stripes".

Note that any translation specified in the plug-in manifest file is automatically applied.

Parameters:

name - the name of the attribute

Returns:

attribute value, or null if none

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

getAttribute

String getAttribute(String attrName,
                    String locale)
             throws InvalidRegistryObjectException

When multi-language support is enabled, this method returns the named attribute of this configuration element in the specified locale, or null if none.

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 getAttribute(String).

Parameters:

attrName - the name of the attribute

locale - the requested locale

Returns:

attribute value, or null if none

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

Since:

org.eclipse.equinox.registry 3.5

See Also:

getAttribute(String), IExtensionRegistry.isMultiLanguage()

getAttributeAsIs

@Deprecated
String getAttributeAsIs(String name)
                 throws InvalidRegistryObjectException

Deprecated.

The method is equivalent to the getAttribute(String). Contrary to its description, this method returns a translated value. Use the getAttribute(String) method instead.

Returns the named attribute of this configuration element, or null if none.

The names of configuration element attributes are the same as the attribute names of the corresponding XML element. For example, the configuration markup

 <bg pattern="stripes"/>
 

corresponds to a configuration element named "bg" with an attribute named "pattern" with attribute value "stripes".

Note that any translation specified in the plug-in manifest file for this attribute is not automatically applied.

Parameters:

name - the name of the attribute

Returns:

attribute value, or null if none

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

getAttributeNames

String[] getAttributeNames()
                    throws InvalidRegistryObjectException

Returns the names of the attributes of this configuration element. Returns an empty array if this configuration element has no attributes.

The names of configuration element attributes are the same as the attribute names of the corresponding XML element. For example, the configuration markup

 <bg color="blue" pattern="stripes"/>
 

corresponds to a configuration element named "bg" with attributes named "color" and "pattern".

Returns:

the names of the attributes

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

getChildren

IConfigurationElement[] getChildren()
                             throws InvalidRegistryObjectException

Returns all configuration elements that are children of this configuration element. Returns an empty array if this configuration element has no children.

Each child corresponds to a nested XML element in the configuration markup. For example, the configuration markup

 <view>
        <verticalHint>top</verticalHint>
        <horizontalHint>left</horizontalHint>
 </view>
 

corresponds to a configuration element, named "view", with two children.

Returns:

the child configuration elements

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

See Also:

getChildren(String)

getChildren

IConfigurationElement[] getChildren(String name)
                             throws InvalidRegistryObjectException

Returns all child configuration elements with the given name. Returns an empty array if this configuration element has no children with the given name.

Parameters:

name - the name of the child configuration element

Returns:

the child configuration elements with that name

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

See Also:

getChildren()

getDeclaringExtension

IExtension getDeclaringExtension()
                          throws InvalidRegistryObjectException

Returns the extension that declares this configuration element.

Returns:

the extension

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

getName

String getName()
        throws InvalidRegistryObjectException

Returns the name of this configuration element. The name of a configuration element is the same as the XML tag of the corresponding XML element. For example, the configuration markup

 <wizard name="Create Project"/>
 

corresponds to a configuration element named "wizard".

Returns:

the name of this configuration element

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

getParent

Object getParent()
          throws InvalidRegistryObjectException

Returns the element which contains this element. If this element is an immediate child of an extension, the returned value can be downcast to IExtension. Otherwise the returned value can be downcast to IConfigurationElement.

Returns:

the parent of this configuration element or null

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

Since:

3.0

getValue

String getValue()
         throws InvalidRegistryObjectException

Returns the text value of this configuration element. For example, the configuration markup

 <script lang="javascript">.\scripts\cp.js</script>
 

corresponds to a configuration element "script" with value ".\scripts\cp.js".

Values may span multiple lines (i.e., contain carriage returns and/or line feeds).

Note that any translation specified in the plug-in manifest file is automatically applied.

Returns:

the text value of this configuration element or null

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

getValue

String getValue(String locale)
         throws InvalidRegistryObjectException

When multi-language support is enabled, this method returns the text value of this configuration element in the specified locale, or null if none.

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 getValue().

Parameters:

locale - the requested locale

Returns:

the text value of this configuration element in the specified locale, or null

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

Since:

org.eclipse.equinox.registry 3.5

See Also:

getValue(String), IExtensionRegistry.isMultiLanguage()

getValueAsIs

@Deprecated
String getValueAsIs()
             throws InvalidRegistryObjectException

Deprecated.

The method is equivalent to the getValue(). Contrary to its description, this method returns a translated value. Use the getValue() method instead.

Returns the untranslated text value of this configuration element. For example, the configuration markup

 <script lang="javascript">.\scripts\cp.js</script>
 

corresponds to a configuration element "script" with value ".\scripts\cp.js".

Values may span multiple lines (i.e., contain carriage returns and/or line feeds).

Note that translation specified in the plug-in manifest file is not automatically applied. For example, the configuration markup

 <tooltip>#hattip</tooltip>
 

corresponds to a configuration element, named "tooltip", with value "#hattip".

Returns:

the untranslated text value of this configuration element or null

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

getNamespace

@Deprecated
String getNamespace()
             throws InvalidRegistryObjectException

Deprecated.

As namespace is no longer restricted to the contributor name, use getNamespaceIdentifier() to obtain namespace name or 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 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 getNamespace() to obtain the name of the contributing bundle, use 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 getNamespace() to obtain the namespace of the registry element, use 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.

Returns the namespace for this configuration element. This value can be used in various global facilities to discover this configuration element's contributor.

Returns:

the namespace for this configuration element

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

Since:

3.1

See Also:

IExtensionRegistry

getNamespaceIdentifier

String getNamespaceIdentifier()
                       throws InvalidRegistryObjectException

Returns the namespace name for this configuration element.

Returns:

the namespace name for this configuration element

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

Since:

org.eclipse.equinox.registry 3.2

getContributor

IContributor getContributor()
                     throws InvalidRegistryObjectException

Returns the contributor of this configuration element.

Returns:

the contributor for this configuration element

Throws:

InvalidRegistryObjectException - if this configuration element is no longer valid

Since:

org.eclipse.equinox.registry 3.2

equals

boolean equals(Object o)

Overrides:

equals in class Object

Returns:

true if the given element has same handle id

See Also:

getHandleId()

isValid

boolean isValid()

Returns whether this configuration element object is valid.

Returns:

true if the object is valid, and false if it is no longer valid

Since:

3.1

getHandleId

int getHandleId()

Returns unique identifier of the registry object from which this element was created. Two configuration element instances are considered to be equal if their handle id's are same.

Returns:

The handle id of the registry object from which this configuration element was created.

Since:

3.8

See Also:

equals(Object)