/*
* Copyright 2010-2013, CloudBees 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.cloudbees.sdk.cli;
import com.cloudbees.sdk.AbortException;
import org.kohsuke.args4j.Argument;
import org.kohsuke.args4j.ClassParser;
import org.kohsuke.args4j.CmdLineException;
import org.kohsuke.args4j.CmdLineParser;
import org.kohsuke.args4j.ExampleMode;
import org.kohsuke.args4j.Option;
import org.kohsuke.args4j.spi.OptionHandler;
import javax.inject.Inject;
import java.lang.reflect.Field;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* Partial implementation of {@link ACommand} that provides more integration
* between argument parsing and dependency injections.
*
* <p>
* To encourage commonality between various commands and simplify the development of new commands,
* this subtype handles argument processing via <a href="http://args4j.kohsuke.org/">args4j</a>.
* Primarily this means you'll be defining your command line options as annotated fields or setter
* methods on subtypes. See {@link Option} and {@link Argument} for more details.
*
* <p>
* In addition to annotating setters and fields, the argument parsing code also looks for any
* {@linkplain Inject injected} fields whose type has {@link HasOptions} marker interface.
* There are several injectable option fragment components (such as {@link Verbose}) that contains
* this marker interface, and whatever options that these components define also becomes a part of
* the recognizable options.
*
* <p>
* By sharing and reusing such option fragment components, users will see consistent user interfaces
* and command developers are freed from lower-level option parsing.
*
* @author Kohsuke Kawaguchi
*/
public abstract class AbstractCommand extends ACommand {
@Inject
Verbose verbose;
public abstract int main() throws Exception;
@Override
public int run(List<String> args) throws Exception {
CmdLineParser p = createParser();
try {
p.parseArgument(args.subList(1,args.size()));
return main();
} catch (AbortException e) {
System.err.println(e.getMessage());
return 1;
} catch (CmdLineException e) {
System.err.println(e.getMessage());
System.err.println("Usage: bees "+args.get(0)+" "+p.printExample(ExampleMode.REQUIRED));
p.printUsage(System.err);
return 1;
}
}
protected CmdLineParser createParser() {
CmdLineParser p = new CmdLineParser(this);
Set<Object> collected = new HashSet<Object>();
collected.add(this);
// if any injected component define options, include them
collectComponentsWithOptions(p, this, collected);
return p;
}
/**
* Recursively visits object graph, finds all {@link HasOptions} components,
* and adds them all to the parser.
*/
private void collectComponentsWithOptions(CmdLineParser p, Object o, Set<Object> collected) {
for (Class c = o.getClass(); c!=null; c=c.getSuperclass()) {
for (Field f : c.getDeclaredFields()) {
if (f.isAnnotationPresent(Inject.class) && HasOptions.class.isAssignableFrom(f.getType())) {
try {
f.setAccessible(true);
Object child = f.get(o);
if (child!=null && collected.add(child)) {
new ClassParser().parse(child,p);
collectComponentsWithOptions(p,child,collected);
}
} catch (IllegalAccessException e) {
throw new Error(e);
}
}
}
}
}
@Override
public void printHelp(List<String> args) {
CmdLineParser p = createParser();
if (getUsageMessage() != null)
System.err.println("Usage: bees "+args.get(0)+" "+getUsageMessage());
else {
System.err.print("Usage: bees "+args.get(0)+p.printExample(ExampleMode.REQUIRED));
for (OptionHandler optionHandler: p.getArguments()) {
if (optionHandler.option.required())
System.err.print(" " + optionHandler.getMetaVariable(null));
else
System.err.print(" [" + optionHandler.getMetaVariable(null) + "]");
}
System.err.println();
}
p.printUsage(System.err);
}
protected String getUsageMessage() {
return null;
}
}