org.jeasy.rules.jexl.JexlRule Maven / Gradle / Ivy

Go to download
/*
 * The MIT License
 *
 *  Copyright (c) 2022, Mahmoud Ben Hassine ([email protected])
 *
 *  Permission is hereby granted, free of charge, to any person obtaining a copy
 *  of this software and associated documentation files (the "Software"), to deal
 *  in the Software without restriction, including without limitation the rights
 *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *  copies of the Software, and to permit persons to whom the Software is
 *  furnished to do so, subject to the following conditions:
 *
 *  The above copyright notice and this permission notice shall be included in
 *  all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *  THE SOFTWARE.
 */
package org.jeasy.rules.jexl;

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import org.apache.commons.jexl3.JexlBuilder;
import org.apache.commons.jexl3.JexlEngine;
import org.apache.commons.jexl3.introspection.JexlPermissions;
import org.jeasy.rules.api.Action;
import org.jeasy.rules.api.Condition;
import org.jeasy.rules.api.Facts;
import org.jeasy.rules.api.Rule;
import org.jeasy.rules.core.BasicRule;

/**
 * @author Lauri Kimmel
 * @author Mahmoud Ben Hassine
 */
public class JexlRule extends BasicRule {

  static final JexlEngine DEFAULT_JEXL = new JexlBuilder().permissions(JexlPermissions.UNRESTRICTED).safe(false).create();

  private Condition condition = Condition.FALSE;
  private final List actions = new ArrayList<>();
  private final JexlEngine jexl;

  public JexlRule() {
    this(DEFAULT_JEXL);
  }

  public JexlRule(JexlEngine jexl) {
    super(Rule.DEFAULT_NAME, Rule.DEFAULT_DESCRIPTION, Rule.DEFAULT_PRIORITY);
    this.jexl = Objects.requireNonNull(jexl, "jexl cannot be null");
  }

  public JexlRule name(String name) {
    this.name = Objects.requireNonNull(name, "name cannot be null");
    return this;
  }

  public JexlRule description(String description) {
    this.description = Objects.requireNonNull(description, "description cannot be null");
    return this;
  }

  public JexlRule priority(int priority) {
    this.priority = priority;
    return this;
  }

  public JexlRule when(String condition) {
    Objects.requireNonNull(condition, "condition cannot be null");
    this.condition = new JexlCondition(condition, jexl);
    return this;
  }

  public JexlRule then(String action) {
    Objects.requireNonNull(action, "action cannot be null");
    this.actions.add(new JexlAction(action, jexl));
    return this;
  }

  @Override
  public boolean evaluate(Facts facts) {
    Objects.requireNonNull(facts, "facts cannot be null");
    return condition.evaluate(facts);
  }

  @Override
  public void execute(Facts facts) throws Exception {
    Objects.requireNonNull(facts, "facts cannot be null");
    for (Action action : actions) {
      action.execute(facts);
    }
  }
}