/*
* Copyright 2012-present Facebook, 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.facebook.buck.cli;
import com.google.common.collect.Sets;
import java.lang.reflect.Field;
import java.util.Set;
import org.kohsuke.args4j.Argument;
import org.kohsuke.args4j.ClassParser;
import org.kohsuke.args4j.CmdLineException;
import org.kohsuke.args4j.CmdLineParser;
import org.kohsuke.args4j.IllegalAnnotationError;
import org.kohsuke.args4j.Option;
import org.kohsuke.args4j.spi.Setters;
/**
* {@link CmdLineParser} with nested options via the {@link AdditionalOptions} annotation.
*
* <p>Fields annotated with it should be of classes which have a default constructor, and will be
* automatically instantiated.
*/
public class AdditionalOptionsCmdLineParser extends CmdLineParser {
/**
* Creates a new command line owner that parses arguments/options and set them into the given
* object.
*
* @param bean instance of a class annotated by {@link Option}, {@link Argument} and {@link
* AdditionalOptions}. This object will receive values. If this is null, the processing will
* be skipped, which is useful if you'd like to feed metadata from other sources.
* @throws IllegalAnnotationError if the option bean class is using args4j annotations
* incorrectly.
* @see CmdLineParser#CmdLineParser(Object)
*/
public AdditionalOptionsCmdLineParser(Object bean) {
super(bean);
Set<Class<?>> visited = Sets.newHashSet();
parseAdditionalOptions(new ClassParser(), bean, visited);
}
@SuppressWarnings("unchecked")
private void parseAdditionalOptions(ClassParser classParser, Object bean, Set<Class<?>> visited) {
// The top-level bean was already parsed by the superclass constructor,
// so an empty visited set means we're parsing the top-level bean.
if (!visited.isEmpty()) {
classParser.parse(bean, this); // 'Parse' the class of the bean looking for annotations.
}
Class<?> beanClass = bean.getClass();
if (visited.contains(beanClass)) {
throw new IllegalAnnotationError(beanClass.getCanonicalName() + " used more than once.");
} else {
visited.add(beanClass);
}
for (Field f : beanClass.getDeclaredFields()) {
if (f.isAnnotationPresent(AdditionalOptions.class)) {
try {
// TODO(vlada): nicer to do this lazily in parseArgument()
Object fieldValue = f.getType().newInstance();
Setters.create(f, bean).addValue(fieldValue);
parseAdditionalOptions(classParser, fieldValue, visited);
} catch (CmdLineException | IllegalAccessException | InstantiationException e) {
throw new RuntimeException(e);
}
}
}
}
}