/*******************************************************************************
* 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.handles;
import org.eclipse.persistence.tools.workbench.mappingsmodel.MWModel;
import org.eclipse.persistence.tools.workbench.mappingsmodel.db.MWColumn;
import org.eclipse.persistence.tools.workbench.mappingsmodel.db.MWTable;
import org.eclipse.persistence.tools.workbench.utility.node.Node;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.mappings.OneToOneMapping;
import org.eclipse.persistence.oxm.XMLDescriptor;
/**
* MWColumnHandle is used to isolate the painful bits of code
* necessary to correctly handle references to MWColumns.
* Since a MWColumn is nested within the XML file
* for a MWTable, we need to store a reference to a particular
* column as a pair of instance variables:
* - the name of the containing table
* - the name of the column
*
* This causes no end of pain when dealing with TopLink, property
* change listeners, backward-compatibility, etc.
*/
public final class MWColumnHandle extends MWHandle {
/**
* This is the actual column.
* It is built from the table and column names, below.
*/
private volatile MWColumn column;
/**
* The table and column names are transient. They
* are used only to hold their values until postProjectBuild()
* is called and we can resolve the actual column.
* We do not keep these in synch with the column itself because
* we cannot know when the column has been renamed etc.
*/
private volatile String columnTableName;
private volatile String columnName;
// ********** constructors **********
/**
* default constructor - for TopLink use only
*/
private MWColumnHandle() {
super();
}
public MWColumnHandle(MWModel parent, NodeReferenceScrubber scrubber) {
super(parent, scrubber);
}
public MWColumnHandle(MWModel parent, MWColumn column, NodeReferenceScrubber scrubber) {
super(parent, scrubber);
this.column = column;
}
// ********** instance methods **********
public MWColumn getColumn() {
return this.column;
}
public void setColumn(MWColumn column) {
this.column = column;
}
protected Node node() {
return this.getColumn();
}
/**
* Override to delegate comparison to the column itself.
* If the handles being compared are in a collection that is being sorted,
* NEITHER column should be null.
*/
public int compareTo(Object o) {
return this.column.compareTo(((MWColumnHandle) o).column);
}
public void toString(StringBuffer sb) {
if (this.column == null) {
sb.append("null");
} else {
this.column.toString(sb);
}
}
public MWColumnHandle setScrubber(NodeReferenceScrubber scrubber) {
this.setScrubberInternal(scrubber);
return this;
}
public void resolveColumnHandles() {
super.resolveColumnHandles();
if (this.columnTableName != null && this.columnName != null) {
MWTable table = this.getDatabase().tableNamed(this.columnTableName);
if (table != null) {
this.column = table.columnNamed(this.columnName);
}
}
// Ensure columnTableName and columnName are not used by setting them to null....
// If the XML is corrupt and only one of these attributes is populated,
// this will cause the populated attribute to be cleared out if the
// objects are rewritten.
this.columnTableName = null;
this.columnName = null;
}
// ********** TopLink methods **********
public static XMLDescriptor buildDescriptor() {
XMLDescriptor descriptor = new XMLDescriptor();
descriptor.setJavaClass(MWColumnHandle.class);
descriptor.addDirectMapping("columnTableName", "getColumnTableNameForTopLink", "setColumnTableNameForTopLink", "column-table-name/text()");
descriptor.addDirectMapping("columnName", "getColumnNameForTopLink", "setColumnNameForTopLink", "column-name/text()");
return descriptor;
}
private String getColumnTableNameForTopLink(){
return (this.column == null) ? null : this.column.getTable().getName();
}
private void setColumnTableNameForTopLink(String columnTableName){
this.columnTableName = columnTableName;
}
private String getColumnNameForTopLink() {
return (this.column == null) ? null : this.column.getName();
}
private void setColumnNameForTopLink(String columnName) {
this.columnName = columnName;
}
}