org.apache.commons.digester

Class Substitutor

Known Direct Subclasses:
VariableSubstitutor

public abstract class Substitutor
extends java.lang.Object

(Logical) Interface for substitution strategies. (It happens to be implemented as a Java abstract class to allow future additions to be made without breaking backwards compatibility.)

Usage: When Digester.setSubstitutor(Substitutor) is set, Digester calls the methods in this interface to create substitute values which will be passed into the Rule implementations. Of course, it is perfectly acceptable for implementations not to make substitutions and simply return the inputs.

Different strategies are supported for attributes and body text.

Since:
1.6

Method Summary

abstract Attributes
substitute(Attributes attributes)
Substitutes the attributes (before they are passed to the Rule implementations's).
abstract String
substitute(String bodyText)
Substitutes for the body text.

Method Details

substitute

public abstract Attributes substitute(Attributes attributes)
Substitutes the attributes (before they are passed to the Rule implementations's).

Digester will only call this method a second time once the original Attributes instance can be safely reused. The implementation is therefore free to reuse the same Attributes instance for all calls.

Parameters:
attributes - the Attributes passed into Digester by the SAX parser, not null (but may be empty)
Returns:
Attributes to be passed to the Rule implementations. This method may pass back the Attributes passed in. Not null but possibly empty.

substitute

public abstract String substitute(String bodyText)
Substitutes for the body text. This method may substitute values into the body text of the elements that Digester parses.
Parameters:
bodyText - the body text (as passed to Digester)
Returns:
the body text to be passed to the Rule implementations

Copyright 2001-2005 The Apache Software Foundation.