Package org.eclipse.core.expressions

Class ExpressionConverter

java.lang.Object

org.eclipse.core.expressions.ExpressionConverter

public final class ExpressionConverter
extends Object

An expression converter converts an XML expression represented by an IConfigurationElement or Element (DOM) subtree into a corresponding expression tree.

An expression converter manages a list of ElementHandlers. Element handlers are responsible to do the actual conversion. The element handlers build a chain of responsibility.

Since:

3.0

Constructor Summary

Constructors

Constructor	Description
ExpressionConverter(ElementHandler[] handlers)	Creates a new expression converter with the given list of element handlers.

Method Summary

Modifier and Type	Method	Description
static ExpressionConverter	getDefault()	Returns the default expression converter.
Expression	perform(IConfigurationElement root)	Converts the tree of configuration elements represented by the given root element and returns a corresponding expression tree.
Expression	perform(Element root)	Converts the tree of DOM elements represented by the given root element and returns a corresponding expression tree.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExpressionConverter

public ExpressionConverter(ElementHandler[] handlers)

Creates a new expression converter with the given list of element handlers. The element handlers build a chain of responsibility meaning that the first handler in the list is first used to convert the configuration element. If this handler isn't able to convert the configuration element the next handler in the array is used.

Parameters:

handlers - the array of element handlers

Method Detail

getDefault

public static ExpressionConverter getDefault()

Returns the default expression converter. The default expression converter can cope with all expression elements defined by the common expression language.

Returns:

the default expression converter

perform

public Expression perform(IConfigurationElement root)
                   throws CoreException

Converts the tree of configuration elements represented by the given root element and returns a corresponding expression tree.

Parameters:

root - the configuration element to be converted

Returns:

the corresponding expression tree or null if the configuration element cannot be converted

Throws:

CoreException - if the configuration element can't be converted. Reasons include: (a) no handler is available to cope with a certain configuration element or (b) the XML expression tree is malformed.

perform

public Expression perform(Element root)
                   throws CoreException

Converts the tree of DOM elements represented by the given root element and returns a corresponding expression tree.

Parameters:

root - the element to be converted

Returns:

the corresponding expression tree or null if the element cannot be converted

Throws:

CoreException - if the element can't be converted. Reasons include: (a) no handler is available to cope with a certain element or (b) the XML expression tree is malformed.

Since:

3.3