com.deliveredtechnologies.rulebook.model.RuleBook 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.model;

import com.deliveredtechnologies.rulebook.FactMap;
import com.deliveredtechnologies.rulebook.NameValueReferableMap;
import com.deliveredtechnologies.rulebook.Result;

import java.util.Optional;

/**
 * The RuleBook interface for defining objects that handle the behavior of rules chained together.
 * @param  the Result type
 */
public interface RuleBook {
  /**
   * Add a Rule.
   * @param rule  the Rule to add to the RuleBook
   */
  void addRule(Rule rule);

  /**
   * Run the RuleBook given the facts supplied.
   * @param facts the facts to be applied to the execution of the RuleBook
   */
  void run(NameValueReferableMap facts);

  /**
   * Set the default Result value; this should be set for RuleBooks that are expected to produce a Result.
   * @param result  the default Result value
   */
  void setDefaultResult(T result);

  /**
   * Get the Result of the RuleBook.
   * @return  the Result of the RuleBook
   */
  Optional> getResult();

  /**
   * The defineRules method can be optionally implemented to define rules in a either a completely
   * custom RuleBook or in a RuleBook that extends (subclasses) an existing RuleBook implementation.
   */
  default void defineRules() { }

  /**
   * The hasRules() method returns true if any Rules have been defined in the RuleBook.
   * @return  true if any Rules have been defined in the RuleBook, otherwise false.
   */
  boolean hasRules();
}