com.deliveredtechnologies.rulebook.lang.WhenRuleBuilder Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of rulebook-core Show documentation

A simple and intuitive rules abstraction for Java

There is a newer version: 0.12

package com.deliveredtechnologies.rulebook.lang;

import com.deliveredtechnologies.rulebook.FactMap;
import com.deliveredtechnologies.rulebook.NameValueReferableTypeConvertibleMap;
import com.deliveredtechnologies.rulebook.Result;
import com.deliveredtechnologies.rulebook.model.Rule;

import java.util.function.BiConsumer;
import java.util.function.Consumer;
import java.util.function.Predicate;

/**
 * Builds the portion of a Rule that is available in the languate on 'when'.
 */
public class WhenRuleBuilder {

  private Rule _rule;

  WhenRuleBuilder(Rule rule, Predicate> condition) {
    _rule = rule;
    _rule.setCondition(condition);
  }

  /**
   * Adds a using constraint in the Rule that restricts the facts supplied to the subsequent 'then' action.
   * @param factNames the fact names to be supplied to the subsequent 'then' action
   * @return          a builder the allows for the Rule to be built following the 'using' statement
   */
  public UsingRuleBuilder using(String... factNames) {
    return new UsingRuleBuilder(_rule, factNames);
  }

  /**
   * Adds a then action into the Rule.
   * @param action  an action that the rule will execute based on the condition
   * @return        a builder that allows for the Rule to be built following the 'then' statement
   */
  public ThenRuleBuilder then(Consumer> action) {
    return new ThenRuleBuilder(_rule, action);
  }

  /**
   * Addds a then action into the Rule.
   * @param action  an action that the rule will execute based on the condition; accepts facts and the result
   * @return        a builder that allows for the Rule to be built following the 'then' statement
   */
  public ThenRuleBuilder then(BiConsumer, Result> action) {
    return new ThenRuleBuilder(_rule, action);
  }
}