ValueTransformer (Apache Commons Configuration 2.15.1 API)
Description: declaration: package: org.apache.commons.configuration2.convert, interface: ValueTransformer

Package org.apache.commons.configuration2.convert

# Interface ValueTransformer

public interface ValueTransformer

Definition of an interface used by `ListDelimiterHandler` to perform additional transformations on behalf of a configuration when a property value is escaped.

Some `Configuration` implementations require a special encoding of their property values before they get written on disk. In some constellations, for example when a property with multiple values is to be forced on a single line, this encoding has to be done together with the escaping of list delimiter characters - which is in the responsibility of `ListDelimiterHandler`.

In order to allow a proper collaboration between the parties involved, this interface was introduced. A configuration object provides an implementation of `ValueTransformer` and passes it to the `ListDelimiterHandler` when escaping of properties is needed. The delimiter handler can then call back to perform the additional encoding as its pleasure.

Since:
  2.0

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Object`
  `transformValue(Object value)`
  Performs an arbitrary encoding of the passed in value object.

- ## Method Details

  - ### transformValue

    Object transformValue(Object value)
    Performs an arbitrary encoding of the passed in value object. This method is called by a `ListDelimiterHandler` implementation before or after list delimiters have been escaped.
    Parameters:
      `value` - the property value to be transformed
    Returns:
      the transformed property value