/*
* RapidMiner
*
* Copyright (C) 2001-2011 by Rapid-I and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapid-i.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.operator.ports.metadata;
import com.rapidminer.operator.ports.InputPort;
/** A simple precondition of an {@link InputPort}. In an early design phase, preconditions
* used to be special {@link MDTransformationRule}s rules, but having them separately
* attached to the input ports has advantages for GUI design and auto-wiring processes.
*
* @author Simon Fischer
* */
public interface Precondition {
/** Checks whether the precondition is satisfied, registering a {@link MetaDataError} with the input port if not.
*
* @param metaData the delivered meta data. Note that this may differ from the meta data currently assigned to the
* input port for which this Precondition was created, e.g. for a ClooectionPrecondition.
* */
public void check(MetaData metaData);
/** Returns a human readable description. */
public String getDescription();
/** Returns true if the given object is compatible with this precondition. */
public boolean isCompatible(MetaData input, CompatibilityLevel level);
/** Assume that the precondition is satisfied, i.e., artificially generate
* compatible meta data at the input port. This method is used to check what
* output would be generated if the input was correctly delivered. */
public void assumeSatisfied();
/** Returns the meta data required by this precondition. */
public MetaData getExpectedMetaData();
}