libraries/rest-server/src/main/java/org/apache/zest/library/rest/server/api/constraint/InteractionValidation.java

/**
 *
 * Copyright 2009-2011 Rickard Öberg AB
 *
 * 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.apache.zest.library.rest.server.api.constraint;

/**
 * Interface that resources can implement to achieve custom validation
 * of whether an interaction is valid or not.
 * <p>
 * If the logic only applies for one
 * method it is usually better to use this instead of creating a new annotation for it.
 * </p>
 * <p>
 * This is triggered by annotating the method that should be validated like so:
 * </p>
 * <pre><code>
 *
 * &#64;RequiresValid("xyz") public void xyz()
 * {...}
 *
 * </code></pre>
 * <p>
 * This causes isValid("xyz") to be called. The isValid()
 * method can use the name to determine which set of logic is to be applied. Typically the provided
 * string will correspond to the name of the interaction, but this is not strictly necessary. It is
 * possible to combine several annotations on one method, if desired:
 * </p>
 * <pre><code>
 *
 * &#64;RequiresValid("allowed") &#64;RequiresValid("officehours")
 * public void xyz()
 * {...}
 * </code></pre>
 * <p>
 * The validation occurs both when a Resource is computed for the resource as a whole, and when an actual
 * invocation of an interaction is made.
 * </p>
 */
public interface InteractionValidation
{
    boolean isValid( String name );
}