org.arrow.model.gateway.impl.ExclusiveGateway.java Source code

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Here is the source code for org.arrow.model.gateway.impl.ExclusiveGateway.java

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/*
 * Copyright 2014 Christian Weber
 *
 * 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.arrow.model.gateway.impl;

import org.springframework.data.neo4j.annotation.NodeEntity;
import org.springframework.expression.Expression;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.expression.spel.support.StandardEvaluationContext;
import org.arrow.model.gateway.AbstractGateway;
import org.arrow.model.transition.Flow;
import org.arrow.model.transition.impl.ConditionExpression;
import org.arrow.model.transition.impl.SequenceFlow;
import org.arrow.runtime.execution.service.ExecutionDataService;
import org.arrow.runtime.message.EventMessage;
import org.arrow.runtime.execution.Execution;
import org.arrow.runtime.execution.State;
import org.arrow.runtime.execution.service.ExecutionService;
import org.arrow.runtime.message.infrastructure.TokenEventMessage;

import java.util.Arrays;
import java.util.List;

import static org.springframework.util.Assert.notNull;
import static org.arrow.runtime.message.infrastructure.TokenEventMessage.TokenAction.CONSUME;

@NodeEntity
public class ExclusiveGateway extends AbstractGateway {

    @Override
    public List<EventMessage> fork(Execution execution, ExecutionService service) {

        ExpressionParser parser = new SpelExpressionParser();

        for (Flow flow : getOutgoingFlows()) {

            // handle multiple outgoing flows
            ConditionExpression ce = ((SequenceFlow) flow).getConditionExpression();

            if (ce == null) {
                continue;
            }

            StandardEvaluationContext context = new StandardEvaluationContext();
            context.setVariables(execution.getVariables());

            Expression expr = parser.parseExpression(ce.getCondition());
            Boolean result = expr.getValue(context, Boolean.class);

            if ((result != null) && (result)) {
                flow.enableRelation(execution);
                break;
            }
        }

        // mark gateway as finished
        execution.setState(State.SUCCESS);
        finish(execution, service);

        return Arrays.asList();
    }

    public JoinResult join(Execution execution, ExecutionService service) {
        return new JoinResult(true);
    }

}