Package org.codehaus.plexus.interpolation

Class PrefixedValueSourceWrapper

java.lang.Object

org.codehaus.plexus.interpolation.PrefixedValueSourceWrapper

All Implemented Interfaces:

FeedbackEnabledValueSource, QueryEnabledValueSource, ValueSource

public class PrefixedValueSourceWrapper
extends java.lang.Object
implements FeedbackEnabledValueSource, QueryEnabledValueSource

ValueSource implementation which simply wraps another value source, and trims any of a set of possible expression prefixes before delegating the modified expression to be resolved by the real value source.

Version:

$Id$

Author:

jdcasey

Constructor Summary

Constructors

Constructor	Description
PrefixedValueSourceWrapper(ValueSource valueSource, java.lang.String prefix)	Wrap the given value source, but first trim the given prefix from any expressions before they are passed along for resolution.
PrefixedValueSourceWrapper(ValueSource valueSource, java.lang.String prefix, boolean allowUnprefixedExpressions)	Wrap the given value source, but first trim the given prefix from any expressions before they are passed along for resolution.
PrefixedValueSourceWrapper(ValueSource valueSource, java.util.List<java.lang.String> possiblePrefixes)	Wrap the given value source, but first trim one of the given prefixes from any expressions before they are passed along for resolution.
PrefixedValueSourceWrapper(ValueSource valueSource, java.util.List<java.lang.String> possiblePrefixes, boolean allowUnprefixedExpressions)	Wrap the given value source, but first trim one of the given prefixes from any expressions before they are passed along for resolution.

Method Summary

Modifier and Type	Method	Description
void	clearFeedback()	If the nested ValueSource implements FeedbackEnabledValueSource, then clear that source's feedback list.
java.util.List	getFeedback()	If the nested ValueSource implements FeedbackEnabledValueSource, then return that source's feedback list.
java.lang.String	getLastExpression()	If the nested ValueSource implements QueryEnabledValueSource, then return that source's last expression.
java.lang.Object	getValue(java.lang.String expression)	Uses ValueSourceUtils.trimPrefix(String, java.util.Collection, boolean) to get the trimmed expression.

Methods inherited from class java.lang.Object

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

Constructor Detail

PrefixedValueSourceWrapper

public PrefixedValueSourceWrapper(ValueSource valueSource,
                                  java.lang.String prefix)

Wrap the given value source, but first trim the given prefix from any expressions before they are passed along for resolution. If an expression doesn't start with the given prefix, do not resolve it.

Parameters:

valueSource - The ValueSource to wrap.

prefix - The expression prefix to trim.

PrefixedValueSourceWrapper

public PrefixedValueSourceWrapper(ValueSource valueSource,
                                  java.lang.String prefix,
                                  boolean allowUnprefixedExpressions)

Wrap the given value source, but first trim the given prefix from any expressions before they are passed along for resolution. If an expression doesn't start with the given prefix and the allowUnprefixedExpressions flag is set to true, simply pass the expression through to the nested value source unchanged. If this flag is false, only allow resolution of those expressions that start with the specified prefix.

Parameters:

valueSource - The ValueSource to wrap.

prefix - The expression prefix to trim.

allowUnprefixedExpressions - Flag telling the wrapper whether to continue resolving expressions that don't start with the prefix it tracks.

PrefixedValueSourceWrapper

public PrefixedValueSourceWrapper(ValueSource valueSource,
                                  java.util.List<java.lang.String> possiblePrefixes)

Wrap the given value source, but first trim one of the given prefixes from any expressions before they are passed along for resolution. If an expression doesn't start with one of the given prefixes, do not resolve it.

Parameters:

valueSource - The ValueSource to wrap.

possiblePrefixes - The List of expression prefixes to trim.

PrefixedValueSourceWrapper

public PrefixedValueSourceWrapper(ValueSource valueSource,
                                  java.util.List<java.lang.String> possiblePrefixes,
                                  boolean allowUnprefixedExpressions)

Wrap the given value source, but first trim one of the given prefixes from any expressions before they are passed along for resolution. If an expression doesn't start with the given prefix and the allowUnprefixedExpressions flag is set to true, simply pass the expression through to the nested value source unchanged. If this flag is false, only allow resolution of those expressions that start with the specified prefix.

Parameters:

valueSource - The ValueSource to wrap.

possiblePrefixes - The List of expression prefixes to trim.

allowUnprefixedExpressions - Flag telling the wrapper whether to continue resolving expressions that don't start with one of the prefixes it tracks.

Method Detail

getValue

public java.lang.Object getValue(java.lang.String expression)

Uses ValueSourceUtils.trimPrefix(String, java.util.Collection, boolean) to get the trimmed expression. If this expression is null (because the original expression was null, or because the expression is unprefixed and unprefixed expressions are not allowed here), then return null; otherwise, return the nested ValueSource.getValue(String) result.

Specified by:

getValue in interface ValueSource

Returns:

the value related to the expression, or null if not found.

getFeedback

public java.util.List getFeedback()

If the nested ValueSource implements FeedbackEnabledValueSource, then return that source's feedback list. Otherwise, return Collections.EMPTY_LIST.

Specified by:

getFeedback in interface ValueSource

Returns:

a combination of String and Throwable instances, where strings related to throwables are listed first.

getLastExpression

public java.lang.String getLastExpression()

If the nested ValueSource implements QueryEnabledValueSource, then return that source's last expression. Otherwise, return the last expression that was processed by the wrapper itself.

Specified by:

getLastExpression in interface QueryEnabledValueSource

Returns:

the most recent expression processed by this value source, or null.

clearFeedback

public void clearFeedback()

If the nested ValueSource implements FeedbackEnabledValueSource, then clear that source's feedback list.

Specified by:

clearFeedback in interface ValueSource