MONDRIAN: added "DynamicSchemaProcessor" so that a schema can be modi…

…fied at runtime.

[git-p4: depot-paths = "//open/mondrian/": change = 2805]

src/main/mondrian/rolap/DynamicSchemaProcessor.java

@@ -0,0 +1,27 @@
+/*
+//$Id$
+//This software is subject to the terms of the Common Public License
+//Agreement, available at the following URL:
+//http://www.opensource.org/licenses/cpl.html.
+//Copyright (C) 2004-2004 TONBELLER AG
+//All Rights Reserved.
+//You must accept the terms of that agreement to use this software.
+*/
+package mondrian.rolap;
+
+import java.net.URL;
+
+/**
+ * A dynamic schema processor is used to dynamically change
+ * a Mondrian schema at runtime.
+ */
+public interface DynamicSchemaProcessor{
+
+	/**
+	 * modify a Mondrian schema
+	 * @param schemaUrl - the catalog URL
+	 * @return the modified schema 
+	 */
+	public String processSchema(URL schemaUrl) throws Exception ;
+
+} // DynamicSchemaProcessor

src/main/mondrian/rolap/RolapConnectionProperties.java

@@ -23,7 +23,7 @@ public class RolapConnectionProperties extends EnumeratedValues {
     private RolapConnectionProperties() {
 		super(new String[] {
 			Provider, Jdbc, JdbcDrivers, JdbcUser, JdbcPassword, Catalog,
-			CatalogContent, CatalogName, DataSource, PoolNeeded, Role});
+			CatalogContent, CatalogName, DataSource, PoolNeeded, Role, DynamicSchemaProcessor});
 	}
 	/**
 	 * @{value} must equal <code>"Mondrian"</code>.
@@ -98,6 +98,13 @@ private RolapConnectionProperties() {
      * after removing this prefix. This allows you to specify connection properties without a URL.
      */
     public static final String JdbcPropertyPrefix = "jdbc.";
+    /**
+     * The name of a class implementing mondrian.rolap.DynamicSchemaProcessor.
+     * A dynamic schema prozessor is called at runtime in order to modify the
+     * schema content.
+     */
+    public static final String DynamicSchemaProcessor = "DynamicSchemaProcessor";
+
 }
 
 // End RolapConnectionProperties.java

src/main/mondrian/rolap/RolapSchema.java

@@ -90,8 +90,22 @@ private RolapSchema(String catalogName, Util.PropertyList connectInfo) {
 			String schema = connectInfo.get(RolapConnectionProperties.CatalogContent);
 			final DOMWrapper def;
 			if (schema == null) {
+				String dynProcName = connectInfo.get(RolapConnectionProperties.DynamicSchemaProcessor);
 				java.net.URL url = new java.net.URL(catalogName);
+				if ( dynProcName != null && dynProcName.length() >0 ) {
+					try {
+						Class clazz = Class.forName(dynProcName);
+						Constructor ctor = clazz.getConstructor(new Class[0]);
+						DynamicSchemaProcessor dynProc =
+							(DynamicSchemaProcessor) ctor.newInstance(new Object[0]);
+						schema = dynProc.processSchema(url);
+					} catch (Exception e) {
+						throw Util.newError(e, "loading DynamicSchemaProcessor " + dynProcName);
+					}
+					def = xmlParser.parse(schema);
+				} else {
 				def = xmlParser.parse(url);
+				}
 			} else {
 				def = xmlParser.parse(schema);
 			}
@@ -296,18 +310,18 @@ static Pool instance() {
 		synchronized RolapSchema get(
 				String catalogName, String jdbcConnectString,
 				String jdbcUser, String dataSource, Util.PropertyList connectInfo) {
+			// if a schema will be dynamically processed, caching is not possible
+			// a "http" URL schema is assumed to be dynamic and will not be cached either
+			String dynProc = connectInfo.get(RolapConnectionProperties.DynamicSchemaProcessor);
+			if ( (dynProc != null && dynProc.length() == 0) || catalogName.toLowerCase().startsWith("http")  ) {
+				// no caching
+				return new RolapSchema(catalogName, connectInfo);
+			}
 			final String key = makeKey(catalogName, jdbcConnectString, jdbcUser, dataSource);
 			RolapSchema schema = (RolapSchema) mapUrlToSchema.get(key);
 			if (schema == null) {
 				schema = new RolapSchema(catalogName, connectInfo);
-				// do not chache the schema, if it dynamic
-				//  .i.e created from an http URL.
-				if (!catalogName.toLowerCase().startsWith("http"))
 					mapUrlToSchema.put(key, schema);
-				// Must create RolapConnection after we add to map, otherwise
-				// we will loop.
-				// no, this is redundant - its set in the ctor of RolapSchema
-				// schema.internalConnection = new RolapConnection(connectInfo, schema);
 			}
 			return schema;
 		}