PersistenceStrategy.java

/**
 *
 * Copyright 2010, Lawrence McAlpin.
 *
 *
 *  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 play.modules.scaffold.entity;

import java.lang.reflect.Field;
import java.util.List;

import play.modules.scaffold.ScaffoldingException;
import play.modules.scaffold.strategy.JpaViewScaffoldingStrategy;
import play.modules.scaffold.strategy.SienaViewScaffoldingStrategy;
import play.modules.scaffold.strategy.ViewScaffoldingStrategy;
import play.modules.scaffold.utils.Classes;
import play.modules.scaffold.utils.Fields;

public enum PersistenceStrategy {
    PLAY_JPA, PURE_JPA, SIENA;

    public ViewScaffoldingStrategy getViewScaffoldingStrategy() {
        switch (this) {
        case PLAY_JPA:
            return new JpaViewScaffoldingStrategy();
        case PURE_JPA:
            return new JpaViewScaffoldingStrategy();
        case SIENA:
            return new SienaViewScaffoldingStrategy();
        }
        return null;
    }

    public boolean isId(Field field) {
        List<String> annotations = Fields.annotationNames(field);
        switch (this) {
        case PLAY_JPA:
            return (annotations.contains("javax.persistence.Id"));
        case PURE_JPA:
            return (annotations.contains("javax.persistence.Id"));
        case SIENA:
            return (annotations.contains("siena.Id"));
        }
        return false;

    }

    // Determine whether this is a play.db.jpa.Model model or an alternative
    // model, such as a siena.Model. Since we can't be sure that alternative
    // model support classes, such as siena.Model, are available on the
    // classpath, we determine all superclasses for our model, and compile
    // a List of class names that our model is descended from.
    //
    // Then, we simply see if the class name for our database support class is
    // in that list.
    public static PersistenceStrategy forModel(Class<?> clazz) {
        List<String> superclasses = Classes.superclasses(clazz);
        List<String> annotations = Classes.annotations(clazz);
        if (superclasses.contains("play.db.jpa.Model")) {
            return PersistenceStrategy.PLAY_JPA;
        }
        if (annotations.contains("javax.persistence.Entity")) {
            return PersistenceStrategy.PURE_JPA;
        }
        if (superclasses.contains("siena.Model")) {
            return PersistenceStrategy.SIENA;
        }
        return null;
    }

    public static PersistenceStrategy forEmbeddable(Class<?> clazz) {
        List<String> annotations = Classes.annotations(clazz);
        if (annotations.contains("javax.persistence.Embeddable"))
            return PersistenceStrategy.PURE_JPA;
        return null;
    }

    public boolean getUsesPlayModelSupport() {
        if (this == PersistenceStrategy.PURE_JPA)
            return false;
        return true;
    }
}