com.google.javascript.jscomp.JsMessageExtractor Maven / Gradle / Ivy
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/*
* Copyright 2004 The Closure Compiler Authors.
*
* 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.javascript.jscomp;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
/**
* Extracts messages and message comments from JS code.
*
* Uses a special prefix (e.g. {@code MSG_}) to determine which variables
* are messages. Here are the recognized formats:
*
*
* var MSG_FOO = "foo";
* var MSG_FOO_HELP = "this message is used for foo";
*
*
*
* var MSG_BAR = function(a, b) {
* return a + " bar " + b;
* }
* var MSG_BAR_HELP = "the bar message";
*
*
*
This class enforces the policy that message variable names must be unique
* across all JS files.
*/
@GwtIncompatible("JsMessage.Builder")
public final class JsMessageExtractor {
private final JsMessage.Style style;
private final JsMessage.IdGenerator idGenerator;
private final CompilerOptions options;
private final boolean extractExternalMessages;
public JsMessageExtractor(
JsMessage.IdGenerator idGenerator,
JsMessage.Style style) {
this(idGenerator, style, new CompilerOptions(), false /* extractExternalMessages */);
}
public JsMessageExtractor(
JsMessage.IdGenerator idGenerator,
JsMessage.Style style,
CompilerOptions options,
boolean extractExternalMessages) {
this.idGenerator = idGenerator;
this.style = style;
this.options = options;
this.extractExternalMessages = extractExternalMessages;
}
/**
* Visitor that collects messages.
*/
private class ExtractMessagesVisitor extends JsMessageVisitor {
// We use List here as we want to preserve insertion-order for found
// messages.
// Take into account that messages with the same id could be present in the
// result list. Message could have the same id only in case if they are
// unnamed and have the same text but located in different source files.
private final List messages = new ArrayList<>();
private ExtractMessagesVisitor(AbstractCompiler compiler) {
super(compiler, true, style, idGenerator);
}
@Override
protected void processJsMessage(JsMessage message,
JsMessageDefinition definition) {
if (extractExternalMessages || !message.isExternal()) {
messages.add(message);
}
}
/**
* Returns extracted messages.
*
* @return collection of JsMessage objects that was found in js sources.
*/
public Collection getMessages() {
return messages;
}
}
/**
* Extracts JS messages from JavaScript code.
*/
public Collection extractMessages(SourceFile... inputs)
throws IOException {
return extractMessages(ImmutableList.copyOf(inputs));
}
/**
* Extracts JS messages from JavaScript code.
*
* @param inputs the JavaScript source code inputs
* @return the extracted messages collection
* @throws RuntimeException if there are problems parsing the JS code or the
* JS messages, or if two messages have the same key
*/
public Collection extractMessages(Iterable inputs) {
final Compiler compiler = new Compiler();
compiler.init(
ImmutableList.of(),
ImmutableList.copyOf(inputs),
options);
compiler.runInCompilerThread(
() -> {
compiler.parseInputs();
return null;
});
ExtractMessagesVisitor extractCompilerPass =
new ExtractMessagesVisitor(compiler);
if (compiler.getErrors().isEmpty()) {
extractCompilerPass.process(null, compiler.getRoot());
}
ImmutableList errors = compiler.getErrors();
// Check for errors.
if (!errors.isEmpty()) {
StringBuilder msg = new StringBuilder("JSCompiler errors\n");
MessageFormatter formatter = new LightweightMessageFormatter(compiler);
for (JSError e : errors) {
msg.append(formatter.formatError(e));
}
throw new RuntimeException(msg.toString());
}
return extractCompilerPass.getMessages();
}
}