/*
* This file is part of the Wayback archival access software
* (http://archive-access.sourceforge.net/projects/wayback/).
*
* Licensed to the Internet Archive (IA) by one or more individual
* contributors.
*
* The IA licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.archive.wayback.replay.html.rules;
import java.io.IOException;
import javax.servlet.ServletException;
import org.archive.wayback.replay.html.ReplayParseEventDelegator;
import org.archive.wayback.replay.html.ReplayParseEventDelegatorVisitor;
import org.archive.wayback.replay.html.ReplayParseContext;
import org.archive.wayback.util.htmllex.ParseContext;
import org.archive.wayback.util.htmllex.handlers.OpenTagHandler;
import org.htmlparser.Node;
import org.htmlparser.nodes.TagNode;
/**
* This Rule fires just after the BODY start tag, emitting the result of the
* replay .jsp into the resulting page at that point.
*
* Sounds simple, BUT, it's possible there is no BODY start tag...
*
* In case this happens, we watch *ALL* tags go by, before they've been output,
* and if we see any start tags not of the following types:
*
* html,head,base,link,meta,title,style,script
*
* we emit our content then and there.
*
* We also ensure we don't emit twice by storing a flag in the ParseContext once
* we do emit.
*
* Lastly, if we see a "FRAMESET" tag in the page, we hold off on inserting
* our content.
*
* @author brad
*
*/
public class AfterBodyStartTagJSPExecRule extends JSPExecRule
implements ReplayParseEventDelegatorVisitor, OpenTagHandler {
private final String[] okHeadTags = {
"![CDATA[*", "!DOCTYPE","HTML","HEAD","BASE","LINK","META","TITLE",
"STYLE","SCRIPT"
};
private final static String FRAMESET_TAG = "FRAMESET";
private final static String FERRET_DONE_KEY =
AfterBodyStartTagJSPExecRule.class.toString();
public void visit(ReplayParseEventDelegator rules) {
rules.getPostModifyDelegator().addOpenTagHandler(this,"BODY");
rules.getPreModifyDelegator().addOpenTagHandler(this);
}
public void emit(ReplayParseContext context, Node node) throws IOException {
String found = context.getData(FERRET_DONE_KEY);
if(found == null) {
context.putData(FERRET_DONE_KEY,"1");
try {
super.emit(context, node);
} catch (ServletException e) {
e.printStackTrace();
throw new IOException(e.getMessage());
}
}
}
private boolean isNotTagAppearingInHead(TagNode node) {
String thisTag = node.getTagName();
if(thisTag.startsWith("!")) return false;
for(String tag : okHeadTags) {
if(thisTag.equals(tag)) {
return false;
}
}
return true;
}
public void handleOpenTagNode(ParseContext pContext, TagNode node)
throws IOException {
ReplayParseContext context = (ReplayParseContext) pContext;
if(context.getData(FERRET_DONE_KEY) == null) {
// we haven't emitted yet:
// are we running in post-emit?
if(context.getPhase() == ReplayParseEventDelegator.PHASE_POST_OUTPUT) {
// emit if it is a body tag:
if(node.getTagName().equals("BODY")) {
emit((ReplayParseContext) context,node);
}
} else {
// must be PHASE_PRE_MODIFY: if it's a body tag, emit now:
if(isNotTagAppearingInHead(node)) {
if(node.getTagName().equals(FRAMESET_TAG)) {
// don't put content in pages with a FRAMESET:
context.putData(FERRET_DONE_KEY,"1");
} else {
// and this is a tag that shouldn't be in the HEAD. Emit:
emit((ReplayParseContext) context,node);
}
}
}
}
}
}