// Copyright (C) 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.caja.parser.js;
import com.google.caja.lexer.FilePosition;
import com.google.caja.lexer.TokenConsumer;
import com.google.caja.lexer.escaping.Escaping;
import com.google.caja.parser.AbstractParseTreeNode;
import com.google.caja.render.Concatenator;
import com.google.caja.render.JsPrettyPrinter;
import com.google.caja.reporting.RenderContext;
import com.google.caja.util.Callback;
import java.io.IOException;
import java.util.List;
/**
* An element of a {@code DirectivePrologue}.
*
* @author mikesamuel@gmail.com
* @see DirectivePrologue
*/
public final class Directive extends AbstractParseTreeNode {
private static final long serialVersionUID = 946831596035589021L;
/**
* The directive strings recognized by Caja.
*/
public enum RecognizedValue {
/**
* Directive invoking ES5 "strict" mode.
*/
USE_STRICT("use strict");
private final String directiveString;
RecognizedValue(String directiveString) {
this.directiveString = directiveString;
}
/**
* @return the representation of this directive in source code.
*/
public String getDirectiveString() { return directiveString; }
public static boolean isDirectiveStringRecognized(String directiveString) {
for (RecognizedValue v : values()) {
if (v.directiveString.equals(directiveString)) { return true; }
}
return false;
}
}
private final String directiveString;
/** @param children unused. This ctor is provided for reflection. */
@ReflectiveCtor
public Directive(
FilePosition pos, String directiveString, List<NoChildren> children) {
this(pos, directiveString);
}
public Directive(FilePosition pos, String directiveString) {
super(pos);
if (directiveString == null) { throw new NullPointerException(); }
this.directiveString = directiveString;
}
@Override
protected void childrenChanged() {
super.childrenChanged();
if (!children().isEmpty()) { throw new IndexOutOfBoundsException(); }
}
@Override
public String getValue() { return directiveString; }
public String getDirectiveString() { return directiveString; }
public void render(RenderContext rc) {
StringBuilder escaped = new StringBuilder();
escaped.append('\''); // Not allowed in JSON so always use single quotes.
Escaping.escapeJsString(getValue(), true, true, escaped);
escaped.append('\'');
String escapedString = escaped.toString();
if (!escapedString.contains(directiveString)) {
// Escaping has modified the directive. Render nothing.
// See http://code.google.com/p/google-caja/issues/detail?id=1111
return;
}
rc.getOut().consume(escapedString);
rc.getOut().consume(";");
}
public final TokenConsumer makeRenderer(
Appendable out, Callback<IOException> exHandler) {
return new JsPrettyPrinter(new Concatenator(out, exHandler));
}
}