NameSpaceElement.java

/* (c) 2014 Open Source Geospatial Foundation - all rights reserved
 * (c) 2001 - 2013 OpenPlans
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.wfs.xml;


/**
 * NameSpaceElement purpose.
 * <p>
 * NameSpaceElement sub classes will represent a particular element
 * found within a particular namespace. Most of the methods below
 * should return constants to improve performance.
 * </p>
 *
 * @author dzwiers, Refractions Research, Inc.
 * @author $Author: dmzwiers $ (last modification)
 * @version $Id$
 */
public abstract class NameSpaceElement {
    /** the namespace prefix to use for qualification*/
    protected final String prefix;

    /**
     * NameSpaceElement constructor.
     * <p>
     * Creates an instance of this NameSpaceElement.
     * </p>
     * <p>
     * The prefix is to be used for the qualification routines.
     * If the prefix passed is null, then qualified names will be
     * null unless they have a prefix specified.
     * </p>
     * @param prefix The prefix to use for qualification.
     */
    public NameSpaceElement(String prefix) {
        this.prefix = prefix;
    }

    /**
     * NameSpaceElement constructor.
     * <p>
     * Creates an instance of this NameSpaceElement.
     * </p>
     * <p>
     * The prefix is to be used for the qualification routines is set to null.
     * the qualified names of the elements will be null
     * </p>
     */
    public NameSpaceElement() {
        this.prefix = null;
    }

    /**
     * getTypeDefName purpose.
     * <p>
     * This will return the name of the definition of the element.
     * This method is useful when defining a new type and wish to
     * extend an existing defined type, such as
     * <code>gml:AbstractFeatureType</code>.
     * </p>
     * <p>
     * <code>
     * <xs:complexType name="Lines_Type">
     *   <xs:complexContent>
     *     <xs:extension base="gml:AbstractFeatureType">
     *      <xs:sequence>
     *        <xs:element name="id" type="xs:string"/>
     *      <xs:element ref="gml:lineStringProperty" minOccurs="0"/>
     *     </xs:sequence>
     *    </xs:extension>
     *   </xs:complexContent>
     * </xs:complexType>
     * </code>
     * </p>
     * @return The type def. name, for the above example AbstractFeatureType.
     */
    public abstract String getTypeDefName();

    /**
     * getTypeDefName purpose.
     * <p>
     * This will return the name of the element.
     * This method is useful when defining a new element and wish to
     * extend an existing element, such as <code>xs:string</code>.
     * </p>
     * <p>
     * <code>
     * <xs:element name="id" type="xs:string"/>
     * <xs:element ref="gml:lineStringProperty" minOccurs="0"/>
     * </code>
     * </p>
     * @return The element name, for the above example string or lineStringProperty.
     */
    public abstract String getTypeRefName();

    /**
     * getQualifiedTypeDefName purpose.
     * <p>
     * Returns a qualified type definition name <code>prefix:definition name</code>.
     * </p>
     * @return the name if the default prefix is non null, null otherwise
     * @see #getTypeDefName()
     */
    public abstract String getQualifiedTypeDefName();

    /**
     * getQualifiedTypeRefName purpose.
     * <p>
     * Returns a qualified type reference name <code>prefix:reference name</code>.
     * </p>
     * @return the name if the default prefix is non null, null otherwise
     * @see #getTypeRefName()
     */
    public abstract String getQualifiedTypeRefName();

    /**
     * getQualifiedTypeDefName purpose.
     * <p>
     * Returns a qualified type definition name <code>prefix:definition name</code> with the specified prefix.
     * </p>
     * @param prefix The prefix to use for qualification.
     * @return the name if either the specified or default prefix is non null, null otherwise
     * @see #getTypeDefName()
     */
    public abstract String getQualifiedTypeDefName(String prefix);

    /**
     * getQualifiedTypeRefName purpose.
     * <p>
     * Returns a qualified type reference name <code>prefix:reference name</code> with the specified prefix.
     * </p>
     * @param prefix The prefix to use for qualification.
     * @return the name if either the specified or default prefix is non null, null otherwise
     * @see #getTypeRefName()
     */
    public abstract String getQualifiedTypeRefName(String prefix);

    /**
     * getJavaClass purpose.
     * <p>
     * Returns an instance of the Class object which would best represent this element.
     * </p>
     * <p>
     * for example an element of type xs:int would return <code>Integer.class</code>.
     * </p>
     * @return Class instance of the Class object which would best represent this element.
     */
    public abstract Class<?> getJavaClass();

    /**
     * This is a bit of a hack, so that GeoServer can generate with the best
     * (default) xml mappings for each Java class.  This should be implemented
     * the other way around, with a nice lookup table to get the one and only
     * default.  But this is far easier to implement, as we just add this
     * method set to true for the namespace element classes we like best.  If
     * for some reason we set two NSE's that map to the same java class to true
     * then things will behave randomly, which is why this is a bit of a hack.
     * Apologies, it's late, and I need to finish my docs.
     */
    public boolean isDefault() {
        return false;
    }

    /* (non-Javadoc)
         * @see java.lang.Object#toString()
         */
    public String toString() {
        return getQualifiedTypeDefName(prefix);
    }

    public abstract boolean isAbstract();
}