cayenne/src/main/java/org/apache/cayenne/map/PathComponent.java

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package org.apache.cayenne.map;

/**
 * A component in a path chain.
 * 
 * @since 3.0
 */
public interface PathComponent<A extends Attribute, R extends Relationship> {

    A getAttribute();

    R getRelationship();

    String getName();

    /**
     * Returns a joint type of this path component in the expression. Attributes always
     * return undefined type, while relationships may be outer or inner joins.
     */
    JoinType getJoinType();

    boolean isLast();

    /**
     * Returns true if this component is an alias for a different path. Only the first
     * path component can be an alias. Aliased path can be obtained by calling
     * {@link #getAliasedPath()}.
     */
    boolean isAlias();

    /**
     * Returns an aliased path or null if this component is not an alias.
     */
    Iterable<PathComponent<A, R>> getAliasedPath();
}