org.openmrs.api.db.hibernate.ImmutableEntityInterceptor.java Source code

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Here is the source code for org.openmrs.api.db.hibernate.ImmutableEntityInterceptor.java

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/**
 * This Source Code Form is subject to the terms of the Mozilla Public License,
 * v. 2.0. If a copy of the MPL was not distributed with this file, You can
 * obtain one at http://mozilla.org/MPL/2.0/. OpenMRS is also distributed under
 * the terms of the Healthcare Disclaimer located at http://openmrs.org/license.
 *
 * Copyright (C) OpenMRS Inc. OpenMRS is a registered trademark and the OpenMRS
 * graphic logo is a trademark of OpenMRS Inc.
 */
package org.openmrs.api.db.hibernate;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.lang.ArrayUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.EmptyInterceptor;
import org.hibernate.type.Type;
import org.openmrs.Retireable;
import org.openmrs.Voidable;
import org.openmrs.api.APIException;
import org.openmrs.util.OpenmrsUtil;

/**
 * Superclass for all Interceptors that would like to ensure that changes to immutable entities of
 * specific types don't get persisted to the database, more granularity of the immutable properties
 * is also supported so as to allow editing some properties while not for others
 * 
 * <pre>
 * <b>NOTE:</b> Subclasses MUST not make any changes to the persistent object because they get 
 * called last, if they make any changes other interceptors would never know about them.
 * </pre>
 * 
 * @since 1.10
 */
public abstract class ImmutableEntityInterceptor extends EmptyInterceptor {

    private static final Log log = LogFactory.getLog(ImmutableEntityInterceptor.class);

    /**
     * Returns the class handled by the interceptor
     */
    protected abstract Class<?> getSupportedType();

    /**
     * Subclasses can override this to return fields that are allowed to be edited, returning null
     * or an empty array implies the entity is immutable
     * 
     * @return an array of properties
     */
    protected String[] getMutablePropertyNames() {
        return null;
    }

    /**
     * Subclasses can override this to specify whether voided or retired items are mutable
     * 
     * @return true if voided or retired objects are mutable otherwise false means they are
     *         immutable
     */
    protected boolean ignoreVoidedOrRetiredObjects() {
        return false;
    }

    /**
     * @see org.hibernate.EmptyInterceptor#onFlushDirty(Object, java.io.Serializable, Object[],
     *      Object[], String[], org.hibernate.type.Type[])
     * @should fail if an entity has a changed property
     * @should pass if an entity has changes for an allowed mutable property
     * @should pass if the edited object is voided or retired and ignore is set to true
     * @should fail if the edited object is voided or retired and ignore is set to false
     */
    @Override
    public boolean onFlushDirty(Object entity, Serializable id, Object[] currentState, Object[] previousState,
            String[] propertyNames, Type[] types) {

        if (getSupportedType().isAssignableFrom(entity.getClass())) {
            List<String> changedProperties = null;
            for (int i = 0; i < propertyNames.length; i++) {
                String property = propertyNames[i];
                if (ArrayUtils.contains(getMutablePropertyNames(), property)) {
                    continue;
                }

                boolean isVoidedOrRetired = false;
                if (Voidable.class.isAssignableFrom(entity.getClass())) {
                    isVoidedOrRetired = ((Voidable) entity).isVoided();
                } else if (Retireable.class.isAssignableFrom(entity.getClass())) {
                    isVoidedOrRetired = ((Retireable) entity).isRetired();
                }
                if (isVoidedOrRetired && ignoreVoidedOrRetiredObjects()) {
                    continue;
                }

                Object previousValue = (previousState != null) ? previousState[i] : null;
                Object currentValue = (currentState != null) ? currentState[i] : null;
                if (!OpenmrsUtil.nullSafeEquals(currentValue, previousValue)) {
                    if (changedProperties == null) {
                        changedProperties = new ArrayList<String>();
                    }
                    changedProperties.add(property);
                }
            }
            if (CollectionUtils.isNotEmpty(changedProperties)) {
                if (log.isDebugEnabled()) {
                    log.debug("The following fields cannot be changed for " + getSupportedType() + ":"
                            + changedProperties);
                }
                throw new APIException("editing.fields.not.allowed",
                        new Object[] { getSupportedType().getSimpleName() });
            }
        }

        return super.onFlushDirty(entity, id, currentState, previousState, propertyNames, types);
    }
}