RuleManager.java

/*
 * Copyright 2017 Red Hat, Inc. and/or its affiliates.
 *
 * 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.kie.workbench.common.stunner.core.rule;

import org.kie.workbench.common.stunner.core.registry.rule.RuleHandlerRegistry;

/**
 * Main entry point for evaluating a set of rules in a
 * certain context.
 * <p>
 * It does:
 * - It provides a rule handler registry instance that
 * is populated with all available evaluation handlers.
 * - Evaluates each of the rules in the rule set with each of the
 * registered evaluation handlers for the given context type.
 * - If no rules are present in the rule set (for any context - an empty rule set),
 * it does not produce any rule violations.
 * - If no rules are present in the rule set for the given context, it depends on the context
 * type if produce any rule violations.
 * @See {@link Rule}
 * @See {@link RuleEvaluationContext}
 * @See {@link RuleEvaluationHandler}
 */
public interface RuleManager {

    /**
     * Provides a rule handler registry that contains
     * all available rule & extension handlers present.
     */
    RuleHandlerRegistry registry();

    /**
     * Evaluates if a given set of rules are allowed
     * for the given context.
     * @param ruleSet The set of rules to evaluate for the context.
     * @param context The rule evaluation context.
     * @return - If no rules are present in the rule set (for any context - an empty rule set),
     * it does not produce any rule violations.
     * - If no rules are present in the rule set for the given context, it depends on the context
     * type if produce any rule violations.
     */
    RuleViolations evaluate(final RuleSet ruleSet,
                            final RuleEvaluationContext context);
}