GwtNodeBootstrap.java

/*
 * Copyright 2011 Chad Retz
 * 
 * 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.gwtnode.core;

import org.gwtnode.core.node.event.ParameterlessEventHandler;
import org.gwtnode.core.node.process.Process;
import org.gwtnode.core.node.util.Util;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JsArrayString;

/**
 * Base class for bootstrapping into a node.js program. It is
 * recommended that this class is extended and {@link #main(String...)}
 * implemented to begin a node.js program.
 * 
 * @author Chad Retz
 */
public abstract class GwtNodeBootstrap implements EntryPoint {
    
    @Override
    public final void onModuleLoad() {
        Process.get().nextTick(new ParameterlessEventHandler() {
        @Override
        public void onEvent() {
            //grab the arguments
            JsArrayString nativeArgs = Process.get().argv();
            //well, the best I can do right now is find the arguments
            //    after the .js argument
            //TODO: be smarter than this
            int jsArgIndex;
            for (jsArgIndex = 0; jsArgIndex < nativeArgs.length(); jsArgIndex++) {
                if (nativeArgs.get(jsArgIndex).endsWith(".js")) {
                    break;
                }
            }
            //make the final native string array
            String[] args;
            if (jsArgIndex == nativeArgs.length()) {
                Util.get().log("Unable to find argument ending with .js");
                args = new String[0];
            } else {
                args = new String[nativeArgs.length() - jsArgIndex - 1];
                for (int i = 0; i < args.length; i++) {
                    args[i] = nativeArgs.get(jsArgIndex + i + 1);
                }
            }
            //call the main method
            Runner runner = GWT.create(Runner.class);
            runner.run(GwtNodeBootstrap.this, new Closure<Integer>() {
                @Override
                public void call(Integer result) {
                    if (result != null) {
                        Process.get().exit(result);
                    }
                }
            }, args);
        }});
    }
    
    /**
     * Entry point for the application. The arguments are all the arguments
     * after the .js file is located (by its file extension) in the original 
     * arguments. To get the full, original argument list, use {@link Process#argv()}.
     * 
     * @param args
     * @return Return null to NOT call {@link Process#exit(int)}
     */
    public abstract Integer main(String... args);
}