/**
* Copyright (C) 2010-2017 Structr GmbH
*
* This file is part of Structr <http://structr.org>.
*
* Structr is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* Structr is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Structr. If not, see <http://www.gnu.org/licenses/>.
*/
package org.structr.core.function;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.structr.common.error.FrameworkException;
import org.structr.schema.action.ActionContext;
import org.structr.schema.action.Function;
/**
*
*/
public class MergeFunction extends Function<Object, Object> {
public static final String ERROR_MESSAGE_MERGE = "Usage: ${merge(list1, list2, list3, ...)}. Example: ${merge(this.children, this.siblings)}";
@Override
public String getName() {
return "merge()";
}
@Override
public Object apply(final ActionContext ctx, final Object caller, final Object[] sources) throws FrameworkException {
final List list = new ArrayList();
for (final Object source : sources) {
if (source instanceof Collection) {
// filter null objects
for (Object obj : (Collection)source) {
if (obj != null) {
list.add(obj);
}
}
} else if (source != null) {
list.add(source);
}
}
return list;
}
@Override
public String usage(boolean inJavaScriptContext) {
return ERROR_MESSAGE_MERGE;
}
@Override
public String shortDescription() {
return "Merges the given collections / objects into a single collection";
}
}