org.apache.jasper.compiler.TextOptimizer Maven / Gradle / Ivy
/*
* Copyright 1999,2004 The Apache Software Foundation.
*
* 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 org.apache.jasper.compiler;
import org.apache.jasper.JasperException;
import org.apache.jasper.Options;
/**
*/
public class TextOptimizer {
/**
* A visitor to concatenate contiguous template texts.
*/
static class TextCatVisitor extends Node.Visitor {
private Options options;
private int textNodeCount = 0;
private Node.TemplateText firstTextNode = null;
private StringBuffer textBuffer;
private final String emptyText = new String("");
public TextCatVisitor(Compiler compiler) {
options = compiler.getCompilationContext().getOptions();
}
public void doVisit(Node n) throws JasperException {
collectText();
}
/*
* The following directis are ignored in text concatenation
*/
public void visit(Node.PageDirective n) throws JasperException {
}
public void visit(Node.TagDirective n) throws JasperException {
}
public void visit(Node.TaglibDirective n) throws JasperException {
}
public void visit(Node.AttributeDirective n) throws JasperException {
}
public void visit(Node.VariableDirective n) throws JasperException {
}
/*
* Don't concatenate text across body boundaries
*/
public void visitBody(Node n) throws JasperException {
super.visitBody(n);
collectText();
}
public void visit(Node.TemplateText n) throws JasperException {
if (options.getTrimSpaces() && n.isAllSpace()) {
n.setText(emptyText);
return;
}
if (textNodeCount++ == 0) {
firstTextNode = n;
textBuffer = new StringBuffer(n.getText());
} else {
// Append text to text buffer
textBuffer.append(n.getText());
n.setText(emptyText);
}
}
/**
* This method breaks concatenation mode. As a side effect it copies
* the concatenated string to the first text node
*/
private void collectText() {
if (textNodeCount > 1) {
// Copy the text in buffer into the first template text node.
firstTextNode.setText(textBuffer.toString());
}
textNodeCount = 0;
}
}
public static void concatenate(Compiler compiler, Node.Nodes page)
throws JasperException {
TextCatVisitor v = new TextCatVisitor(compiler);
page.visit(v);
// Cleanup, in case the page ends with a template text
v.collectText();
}
}