// Copyright (C) 2010 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.plugin.stages;
import com.google.caja.lang.css.CssSchema;
import com.google.caja.lang.html.HtmlSchema;
import com.google.caja.lexer.FilePosition;
import com.google.caja.lexer.TokenConsumer;
import com.google.caja.parser.html.Nodes;
import com.google.caja.parser.js.Block;
import com.google.caja.parser.js.Expression;
import com.google.caja.parser.js.ExpressionStmt;
import com.google.caja.parser.js.Statement;
import com.google.caja.parser.js.StringLiteral;
import com.google.caja.parser.js.TranslatedCode;
import com.google.caja.parser.quasiliteral.QuasiBuilder;
import com.google.caja.plugin.Job;
import com.google.caja.render.Concatenator;
import com.google.caja.reporting.RenderContext;
import java.net.URI;
import org.w3c.dom.Node;
import java.util.Collections;
/**
* Converts HTML to a block of JavaScript.
*
* @author mikesamuel@gmail.com
*/
public final class HtmlToJsStage extends CompileHtmlStage {
public HtmlToJsStage(CssSchema cssSchema, HtmlSchema htmlSchema) {
super(cssSchema, htmlSchema);
}
@Override
Job makeJobFromHtml(Node html, URI baseUri) {
return hasContent(html)
? Job.jsJob(makeEmitStaticStmt(html), baseUri) : null;
}
private static Statement makeEmitStaticStmt(Node node) {
return (Statement) QuasiBuilder.substV(
"'use strict'; @stmt;",
"stmt", new TranslatedCode(new Block(
FilePosition.UNKNOWN,
Collections.singletonList(new ExpressionStmt(
(Expression) QuasiBuilder.substV(
"IMPORTS___./*@synthetic*/htmlEmitter___"
+ "./*@synthetic*/emitStatic(@html)",
"html", renderDomAsJsStringLiteral(node)))))));
}
private static StringLiteral renderDomAsJsStringLiteral(Node node) {
StringBuilder stringBuilder = new StringBuilder();
TokenConsumer tc = new Concatenator(stringBuilder);
Nodes.render(node, new RenderContext(tc));
return StringLiteral.valueOf(Nodes.getFilePositionFor(node), stringBuilder);
}
private static boolean hasContent(Node n) {
switch (n.getNodeType()) {
case Node.DOCUMENT_FRAGMENT_NODE:
for (Node c : Nodes.childrenOf(n)) {
if (hasContent(c)) { return true; }
}
return false;
case Node.COMMENT_NODE: return false;
case Node.TEXT_NODE:
return n.getNodeValue().length() != 0;
default:
return true;
}
}
}