sunlabs.brazil.filter
Class HighlightFilter

java.lang.Object
  sunlabs.brazil.filter.HighlightFilter (view source)

All Implemented Interfaces:

Filter, Handler

public class HighlightFilter
extends Object
implements Filter

Rewrite text between markup (and not in links) based on re sub's.

sub

The substitution pattern

noCase

true for case insensitive matches.

trailer

Markup to add at end of document (before </body>)

The values for "re", "sub", and "trailer" are recomputed at each request, and ${...} substitutions are evaluated.

Sample usage:

 re=test 
 sub=&
 

will cause every occurance of the word "test" in the html content to be colored red.

Constructor Summary

HighlightFilter()

Method Summary

byte[]	filter(Request request, MimeHeaders headers, byte[] content) Filters the content generated by the wrapped Handler.
boolean	init(Server server, String prefix) Initializes the handler.
boolean	respond(Request request) Responds to an HTTP request.
boolean	shouldFilter(Request request, MimeHeaders headers) Gives this Filter the chance to examine the HTTP response headers from the wrapped Handler, before the content has been retrieved.

Methods inherited from class java.lang.Object

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

Constructor Detail

HighlightFilter

public HighlightFilter()

Method Detail

init

public boolean init(Server server,
                    String prefix)

Description copied from interface: Handler

Initializes the handler.

Specified by:

init in interface Handler

Parameters:

server - The HTTP server that created this Handler. Typical Handlers will use Server.props to obtain run-time configuration information.

prefix - The handlers name. The string this Handler may prepend to all of the keys that it uses to extract configuration information from Server.props. This is set (by the Server and ChainHandler) to help avoid configuration parameter namespace collisions.

Returns:

true if this Handler initialized successfully, false otherwise. If false is returned, this Handler should not be used.

respond

public boolean respond(Request request)

Description copied from interface: Handler

Responds to an HTTP request.

Specified by:

respond in interface Handler

Parameters:

request - The Request object that represents the HTTP request.

Returns:

true if the request was handled. A request was handled if a response was supplied to the client, typically by calling Request.sendResponse() or Request.sendError.

shouldFilter

public boolean shouldFilter(Request request,
                            MimeHeaders headers)

Description copied from interface: Filter

Gives this Filter the chance to examine the HTTP response headers from the wrapped Handler, before the content has been retrieved.

If this Filter does want to examine and possibly rewrite the content, it should return true; once the content is available, the filter method will be invoked. For instance, if this Filter is only interested in rewriting "text/html" pages, it should return false if the "Content-Type" is "image/jpeg". If all filters return false for the shouldFilter method, the FilterHandler can switch to a more effient mechanism of delivering content to the client.

The MIME headers may also be modified by this Filter, for instance, to change the "Content-Type" of a web page. The "Content-Length" will automatically be computed.

Specified by:

shouldFilter in interface Filter

Parameters:

request - The in-progress HTTP request.

headers - The MIME headers generated by the wrapped Handler.

Returns:

true if this filter would like to examine and possibly rewrite the content, false otherwise.

filter

public byte[] filter(Request request,
                     MimeHeaders headers,
                     byte[] content)

Description copied from interface: Filter

Filters the content generated by the wrapped Handler. The content may be arbitrarily rewritten by this method.

The MIME headers may also be modified by this Filter, for instance, to change the "Content-Type" of a web page. The "Content-Length" will automatically be computed by the FilterHandler.

Specified by:

filter in interface Filter

Parameters:

request - The finished HTTP request.

headers - The MIME headers generated by the Handler.

content - The output from the Handler that this Filter may rewrite.

Returns:

The rewritten content. The Filter may return the original content unchanged. The Filter may return null to indicate that the FilterHandler should stop processing the request and should not return any content to the client.