org.flowable.engine.delegate.variable.VariableAggregator Maven / Gradle / Ivy
/* 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 org.flowable.engine.delegate.variable;
import java.util.List;
import org.flowable.engine.delegate.DelegateExecution;
import org.flowable.variable.api.persistence.entity.VariableInstance;
/**
* An interface that can be used to aggregate multiple variables into a single one based on an aggregation definition.
*
* @author Filip Hrisafov
*/
public interface VariableAggregator {
/**
* Create a single variable value based on the provided aggregation definition.
*
* This is called after a single child multi instance execution is completed, or an overview for a child multi instance execution is needed.
*
* @param execution the delegate execution from where we need to get data from
* @param context the aggregation context
* @return the value for the aggregated variable
*/
Object aggregateSingleVariable(DelegateExecution execution, VariableAggregatorContext context);
/**
* Aggregated the provided variable instances into one variable value.
*
* This is called when a multi instance execution and all its children is complete, or an overview for a multi instance execution is needed.
*
* @param execution the delegated execution for which we need to do the aggregation
* @param instances the variable values that should be aggregated (these variables are created based on the value from {@link #aggregateSingleVariable(DelegateExecution, VariableAggregatorContext)})
* @param context the aggregation context
* @return the aggregated value
*/
Object aggregateMultiVariables(DelegateExecution execution, List instances, VariableAggregatorContext context);
}