com.epimorphics.lda.shortnames

Class Transcoding

java.lang.Object

com.epimorphics.lda.shortnames.Transcoding

public class Transcoding
extends Object

Transcoding deals with the encoding of arbitrary URIs within the syntax of short names. This is necessary when rendering arbitrary predicates into XML, since legal NCNames need not be legal shortnames, and there may be no prefix available for the namespace. (Allocating and remembering prefixes would be stateful and would mean that the set of legal shortnames would depend on what renderings had been done since the last server restart.)

What we do is to define the /light encoding/ as: leave the lower-case letters alone and prefix any upper-case letter or "_" with "_". The well-known special characters (:/.-?&#) are translated to a mnemonic upper-case letter, and the other special characters are translated to _HH where the HH are (lower-case) hex digits. Additionally, a leading :// is converted to X (because CSS looks wrong) and a Z is inserted before the first character of the encoded local name. This encoding is reversible.

For a URI N:L where N is the namespace and L is the local name, N has prefix P, and L is a legal shortname, we encode as P_L.

If L isn't a legal shortname, we encode as pre_P_L', where L' is the light encoding of L.

In the remaining case, where there's no prefix for N, we give up and generate unknown_N'L'.

This requisitions the two pseudo-prefix names 'pre' and 'unknown', but we'll have to live with that.

Constructor Summary

Constructors

Constructor and Description
Transcoding()

Method Summary

Methods

Modifier and Type	Method and Description
static String	decode(com.hp.hpl.jena.shared.PrefixMapping pm, String shortName) Answer the decoding (expansion) of the given shortname if it is in transcoded form "unknown_ENCODED" or "pre_APREFIX_ENCODED", or if it is of the form prefixName_localName, or null if it is not.
static String	decodeLightly(String encoded)
static String	decodeMaybePrefixed(com.hp.hpl.jena.shared.PrefixMapping pm, String shortName)
static String	encode(com.hp.hpl.jena.shared.PrefixMapping pm, String any) Encode the URI string any into a "short"name.

Methods inherited from class java.lang.Object

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

Constructor Detail

Transcoding

public Transcoding()

Method Detail

decode

public static String decode(com.hp.hpl.jena.shared.PrefixMapping pm,
            String shortName)

Answer the decoding (expansion) of the given shortname if it is in transcoded form "unknown_ENCODED" or "pre_APREFIX_ENCODED", or if it is of the form prefixName_localName, or null if it is not.

decodeMaybePrefixed

public static String decodeMaybePrefixed(com.hp.hpl.jena.shared.PrefixMapping pm,
                         String shortName)

encode

public static String encode(com.hp.hpl.jena.shared.PrefixMapping pm,
            String any)

Encode the URI string any into a "short"name. If any can be expressed as a legal shortname pre_local where pre is the prefix for any's namespace and local is the local name of any, return that. Otherwise, if the local name isn't a legal shortname but a prefix exists, return pre_thatPrefix_localnameEncoded. Otherwise, return uri_theEntireURIencoded.

decodeLightly

public static String decodeLightly(String encoded)