IN PROGRESS - issue SWF-550: Allow FlowModels to be marked abstract

http://jira.springframework.org/browse/SWF-550

spring-webflow/src/main/java/org/springframework/webflow/engine/builder/model/FlowModelFlowBuilder.java

@@ -112,6 +112,9 @@ public class FlowModelFlowBuilder extends AbstractFlowBuilder {
 	 */
 	protected void doInit() throws FlowBuilderException {
 		flowModel = flowModelHolder.getFlowModel();
+		if ("true".equals(flowModel.getAbstract())) {
+			throw new FlowBuilderException("Abstract flow models cannot be instantiated.");
+		}
 		initLocalFlowContext();
 	}
 

spring-webflow/src/main/java/org/springframework/webflow/engine/model/FlowModel.java

@@ -47,6 +47,7 @@ import org.springframework.util.StringUtils;
  */
 public class FlowModel extends AbstractModel {
 	// private String id;
+	private String abztract;
 	private String parent;
 	private String startStateId;
 	private LinkedList attributes;
@@ -94,6 +95,24 @@ public class FlowModel extends AbstractModel {
 		setBeanImports(merge(getBeanImports(), flow.getBeanImports()));
 	}
 
+	/**
+	 * @return the abstract
+	 */
+	public String getAbstract() {
+		return abztract;
+	}
+
+	/**
+	 * @param abztract the abstract to set
+	 */
+	public void setAbstract(String abztract) {
+		if (StringUtils.hasText(abztract)) {
+			this.abztract = abztract;
+		} else {
+			this.abztract = null;
+		}
+	}
+
 	/**
 	 * @return the parent
 	 */

spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/xml/XmlFlowModelBuilder.java

@@ -220,6 +220,7 @@ public class XmlFlowModelBuilder implements FlowModelBuilder {
 
 	private FlowModel parseFlow(Element element) {
 		FlowModel flow = new FlowModel();
+		flow.setAbstract(element.getAttribute("abstract"));
 		flow.setParent(element.getAttribute("parent"));
 		flow.setStartStateId(element.getAttribute("start-state"));
 		flow.addAttributes(parseAttributes(element));

spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/xml/spring-webflow-2.0.xsd

@@ -1012,6 +1012,15 @@ For example:
 					<xsd:documentation>
 						<![CDATA[
 The starting point of this flow.  If not specified, the start state is the first state defined in this document.
+]]>
+					</xsd:documentation>
+				</xsd:annotation>
+			</xsd:attribute>
+			<xsd:attribute name="abstract" type="xsd:boolean">
+				<xsd:annotation>
+					<xsd:documentation>
+						<![CDATA[
+Marks a flow model as abstract, preventing it from instantiating as a flow definition.
 ]]>
 					</xsd:documentation>
 				</xsd:annotation>

spring-webflow/src/test/java/org/springframework/webflow/engine/builder/model/FlowModelFlowBuilderTests.java

@@ -326,6 +326,16 @@ public class FlowModelFlowBuilderTests extends TestCase {
 		assertEquals("end", flow.getStartState().getId());
 	}
 
+	public void testAbstractFlow() {
+		model.setAbstract("true");
+		try {
+			getFlow(model);
+			fail("FlowBuilderException expected");
+		} catch (FlowBuilderException e) {
+			// we want this
+		}
+	}
+
 	private Flow getFlow(FlowModel model) {
 		FlowModelHolder holder = new StaticFlowModelHolder(model);
 		FlowModelFlowBuilder builder = new FlowModelFlowBuilder(holder);