/**
* 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.Collection;
import org.apache.commons.lang3.StringUtils;
import org.structr.common.error.FrameworkException;
import org.structr.schema.action.ActionContext;
import org.structr.schema.action.Function;
/**
*
*/
public class EmptyFunction extends Function<Object, Object> {
public static final String ERROR_MESSAGE_EMPTY = "Usage: ${empty(string|array|collection)}. Example: ${if(empty(possibleEmptyString), \"empty\", \"non-empty\")}";
@Override
public String getName() {
return "empty()";
}
@Override
public Object apply(final ActionContext ctx, final Object caller, final Object[] sources) throws FrameworkException {
if (sources == null) {
logParameterError(caller, sources, ctx.isJavaScriptContext());
return usage(ctx.isJavaScriptContext());
}
if (sources.length == 0 || sources[0] == null || StringUtils.isEmpty(sources[0].toString())) {
return true;
} else if (sources[0] instanceof Collection) {
return ((Collection) sources[0]).isEmpty();
} else if (sources[0].getClass().isArray()) {
return (((Object[]) sources[0]).length == 0);
} else {
return false;
}
}
@Override
public String usage(boolean inJavaScriptContext) {
return ERROR_MESSAGE_EMPTY;
}
@Override
public String shortDescription() {
return "Returns true if the given string or collection is null or empty";
}
}