AbstractSchemaModel.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.mappingsmodel.schema;

import java.util.Iterator;

import org.apache.xerces.xs.XSObject;
import org.eclipse.persistence.tools.workbench.mappingsmodel.MWModel;
import org.eclipse.persistence.tools.workbench.mappingsmodel.handles.QName;
import org.eclipse.persistence.tools.workbench.utility.iterators.NullIterator;


public abstract class AbstractSchemaModel
    extends MWModel
    implements MWSchemaModel
{
    // **************** Variables *********************************************

    /** Used to prevent infinite loops in reload cycle */
    private boolean reloadInProgress;


    // **************** Constructors ******************************************

    /** Default Constructor - Toplink Use Only */
    protected AbstractSchemaModel() {
        super();
    }

    AbstractSchemaModel(MWModel parent) {
        super(parent);
    }


    // **************** Public ************************************************

    /**
     * Do NOT override this method.
     * Every schema model object (except Namespace) should have a schema model parent.
     */
    public final AbstractSchemaModel getSchemaModelParent() {
        //use instanceof instead of catching ClassCastException
        //for performance reasons while importing a schema
        if (getParent() instanceof AbstractSchemaModel) {
            return (AbstractSchemaModel) this.getParent();
        }
        return null;
    }


    // **************** MWSchemaModel contract ********************************

    /**
     * Do NOT override this method.
     * Every schema object should be able to return its schema.
     */
    public final MWXmlSchema getSchema() {
        return this.getParentNamespace().getSchema();
    }

    /**
     * Do NOT override this method.
     * Every schema object should be able to return its parent namespace.
     */
    public final MWNamespace getParentNamespace() {
        if (this.getSchemaModelParent() == null) {
            try {
                return (MWNamespace) this.getParent();
            } catch (ClassCastException ex) {
                throw new IllegalStateException("This object is missing a parent namespace: " + this.toString());
            }
        } else {
            return this.getSchemaModelParent().getParentNamespace();
        }
    }

    /** default implementation */
    public Iterator structuralComponents() {
        return NullIterator.instance();
    }

    /** default implementation */
    public Iterator descriptorContextComponents() {
        return NullIterator.instance();
    }

    /** default implementation */
    public Iterator xpathComponents() {
        return NullIterator.instance();
    }

    public MWNamedSchemaComponent parentNamedComponent() {
        MWSchemaModel parent = this.getSchemaModelParent();

        if (parent == null) {
            return null;
        }
        else {
            MWNamedSchemaComponent namedParent;

            try {
                namedParent = (MWNamedSchemaComponent) parent;
            }
            catch (ClassCastException cce) {
                return parent.parentNamedComponent();
            }

            return (namedParent.getName() == null) ? namedParent.parentNamedComponent() : namedParent;
        }
    }

    MWXpathableSchemaComponent parentXPathableComponent() {
        try {
            return (MWXpathableSchemaComponent) this.parentNamedComponent();
        }
        catch (ClassCastException cce) {
            return null;
        }
    }

    /** default implementation */
    public MWNamedSchemaComponent nestedNamedComponent(QName qName) {
        if (qName.getComponentType() == QName.ATTRIBUTE_TYPE) {
            return this.nestedAttribute(qName.getNamespaceURI(), qName.getLocalName());
        }
        else if (qName.getComponentType() == QName.ELEMENT_TYPE) {
            return this.nestedElement(qName.getNamespaceURI(), qName.getLocalName());
        }
        else {
            return null;
        }
    }

    /** default implementation */
    public MWAttributeDeclaration nestedAttribute(String namespaceUrl, String attributeName) {
        return null;
    }

    /** default implementation */
    public MWElementDeclaration nestedElement(String namespaceUrl, String elementName) {
        return null;
    }

    /** default implementation */
    public int totalElementCount() {
        return 0;
    }


    // **************** SchemaModel contract **********************************

    public final void reload(XSObject schemaObject) {
        if (this.reloadInProgress) {
            return;
        }

        this.reloadInProgress = true;
        this.reloadInternal(schemaObject);
        this.reloadInProgress = false;
        this.fireStateChanged();
    }

    protected void reloadInternal(XSObject schemaObject) {
        // subclasses must call super.reloadInternal(XSDNode)
        // no op
    }

    public void resolveReferences() {
        // subclasses must call super.resolveReferences()
        // no op
    }
}