/*
* Copyright 2008 Google Inc.
*
* Licensed 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 com.google.template.soy.sharedpasses;
import com.google.template.soy.base.IdGenerator;
import com.google.template.soy.soytree.AbstractSoyNodeVisitor;
import com.google.template.soy.soytree.RawTextNode;
import com.google.template.soy.soytree.SoyFileSetNode;
import com.google.template.soy.soytree.SoyNode;
import com.google.template.soy.soytree.SoyNode.ParentSoyNode;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Visitor for removing HTML comments from raw text. Note that this is a best-effort process.
* Currently, we only remove HTML comments that are completely contained within a single
* RawTextNode.
*
* @author Kai Huang
*/
public class RemoveHtmlCommentsVisitor extends AbstractSoyNodeVisitor<Void> {
// TODO: Make sure this doesn't remove escaping text spans in CSS or JavaScript.
// E.g. <style><!-- ... --></style>
// <script>while (i<!--x) { ... } while (j-->0) { ... }</script>
/** Regex pattern for an HTML comment. */
private static final Pattern HTML_COMMENT = Pattern.compile("<!--.*?-->");
/** The node id generator for the parse tree. Retrieved from the root SoyFileSetNode. */
private IdGenerator nodeIdGen;
@Override public Void exec(SoyNode node) {
nodeIdGen = null;
visit(node);
return null;
}
// -----------------------------------------------------------------------------------------------
// Implementations for specific nodes.
@Override protected void visitRawTextNode(RawTextNode node) {
Matcher matcher = HTML_COMMENT.matcher(node.getRawText());
if (!matcher.find()) {
return;
}
// Build the new raw text string.
matcher.reset();
StringBuffer newRawText = new StringBuffer();
while (matcher.find()) {
matcher.appendReplacement(newRawText, "");
}
matcher.appendTail(newRawText);
// If the new raw text string is nonempty, then create a new RawTextNode to replace this node,
// else simply remove this node.
if (newRawText.length() > 0) {
if (nodeIdGen == null) {
// Retrieve the node id generator from the root of the parse tree.
nodeIdGen = node.getNearestAncestor(SoyFileSetNode.class).getNodeIdGenerator();
}
RawTextNode newRawTextNode = new RawTextNode(nodeIdGen.genId(), newRawText.toString());
node.getParent().replaceChild(node, newRawTextNode);
} else {
node.getParent().removeChild(node);
}
}
// -----------------------------------------------------------------------------------------------
// Fallback implementation.
@Override protected void visitSoyNode(SoyNode node) {
if (node instanceof ParentSoyNode<?>) {
visitChildrenAllowingConcurrentModification((ParentSoyNode<?>) node);
}
}
}