org.apache.tapestry
Interface ValueEncoder<V>

All Known Implementing Classes:

EnumValueEncoder, HibernateEntityValueEncoder, StringValueEncoder

public interface ValueEncoder<V>

Used to convert server side values to client-side strings. This is used when generating a EventContext as part of a URL, or when components (such as Select) generated other client-side strings.

Often a custom implementation is needed for entity type objects, where the toClient(Object) method extracts a primary key, and the toValue(String) re-acquires the corresponding entity object.

See Also:

SelectModel, ValueEncoderSource, PrimaryKeyEncoder

Method Summary

String	toClient(V value) Converts a value into a client-side representation.
V	toValue(String clientValue) Converts a client-side representation, provided by toClient(Object), back into a server-side value.

Method Detail

toClient

String toClient(V value)

Converts a value into a client-side representation. The value should be parseable by toValue(String). In some cases, what is returned is an identifier used to locate the true object, rather than a string representation of the value itself.

Parameters:

value - to be encoded

Returns:

a string representation of the value, or the value's identity

toValue

V toValue(String clientValue)

Converts a client-side representation, provided by toClient(Object), back into a server-side value.

Parameters:

clientValue - string representation of the value's identity

Returns:

the corresponding entity, or null if not found