/**
* Copyright 2009 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 org.waveprotocol.wave.client.common.util;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.JsArrayString;
import org.waveprotocol.wave.model.util.Preconditions;
import java.util.ArrayList;
import java.util.List;
/**
* GWT/JS implementation of the regular expression interface. Uses JSNI
* to call JS methods.
*
*/
public class JsRegExp implements RegExp {
private final JavaScriptObject regExp;
/**
* Compiles a javascript regular expression. Returns null if the pattern
* failed to compile.
*/
private static native JavaScriptObject compileRegExp(String pattern, String flags) /*-{
try {
return new RegExp(pattern, flags);
} catch (e) {
}
return null;
}-*/;
private static native boolean test(JavaScriptObject regExp, String test) /*-{
return regExp.test(test);
}-*/;
private static native JsArrayString matches(JavaScriptObject regExp, String test) /*-{
return test.match(regExp);
}-*/;
/**
* Creates a local matching regular expression. Throws an
* {@link IllegalArgumentException} if a bad pattern is given.
*
* @param pattern the pattern to match against.
* @return JS regular expression object.
*/
public static JsRegExp createLocal(String pattern) {
JavaScriptObject jso = compileRegExp(pattern, "");
Preconditions.checkArgument(jso != null, "Bad regex pattern");
return new JsRegExp(jso);
}
/**
* Creates a global matching regular expression. Throws an
* {@link IllegalArgumentException} if a bad pattern is given.
*
* @param pattern the pattern to match against.
* @return JS regular expression object.
*/
public static JsRegExp createGlobal(String pattern) {
JavaScriptObject jso = compileRegExp(pattern, "g");
Preconditions.checkArgument(jso != null, "Bad regex pattern");
return new JsRegExp(jso);
}
/**
* Tests whether a given pattern is valid or not.
*
* @param pattern the pattern to match against.
* @return true if the pattern is valid.
*/
public static boolean isValidPattern(String pattern) {
JavaScriptObject jso = compileRegExp(pattern, "");
return jso != null;
}
private JsRegExp(JavaScriptObject regExp) {
this.regExp = regExp;
}
@Override
public boolean test(String test) {
return test(regExp, test);
}
@Override
public List<String> getMatches(String test) {
JsArrayString matches = matches(regExp, test);
if (matches != null && matches.length() > 0) {
List<String> result = new ArrayList<String>(matches.length());
for (int i = 0; i < matches.length(); ++i) {
result.add(matches.get(i));
}
return result;
}
return new ArrayList<String>();
}
}