[333617] ModuleFactory extension point should contain enablement expression

2 files changed, 62 insertions, 8 deletions

diff --git a/plugins/org.eclipse.wst.server.core/servercore/org/eclipse/wst/server/core/ServerUtil.java b/plugins/org.eclipse.wst.server.core/servercore/org/eclipse/wst/server/core/ServerUtil.java
index 51b30c85e..d01415b52 100644
--- a/plugins/org.eclipse.wst.server.core/servercore/org/eclipse/wst/server/core/ServerUtil.java
+++ b/plugins/org.eclipse.wst.server.core/servercore/org/eclipse/wst/server/core/ServerUtil.java
@@ -1,5 +1,5 @@
 /**********************************************************************
- * Copyright (c) 2003, 2010 IBM Corporation and others.
+ * Copyright (c) 2003, 2011 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -91,13 +91,16 @@ public class ServerUtil {
 		List<IModule> list = new ArrayList<IModule>();
 		
 		ModuleFactory[] factories = ServerPlugin.getModuleFactories();
+
 		if (factories != null) {
 			for (ModuleFactory factory : factories) {
-				IModule[] modules = factory.getModules(project, null);
-				if (modules != null) {
-					for (IModule module : modules) {
-						if (!list.contains(module))
-							list.add(module);
+				if (factory.isEnabled(project, null)){
+					IModule[] modules = factory.getModules(project, null);
+					if (modules != null) {
+						for (IModule module : modules) {
+							if (!list.contains(module))
+								list.add(module);
+						}
 					}
 				}
 			}
diff --git a/plugins/org.eclipse.wst.server.core/servercore/org/eclipse/wst/server/core/internal/ModuleFactory.java b/plugins/org.eclipse.wst.server.core/servercore/org/eclipse/wst/server/core/internal/ModuleFactory.java
index 0e07791fb..9b9790429 100644
--- a/plugins/org.eclipse.wst.server.core/servercore/org/eclipse/wst/server/core/internal/ModuleFactory.java
+++ b/plugins/org.eclipse.wst.server.core/servercore/org/eclipse/wst/server/core/internal/ModuleFactory.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2003, 2007 IBM Corporation and others.
+ * Copyright (c) 2003, 2011 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -13,10 +13,11 @@ package org.eclipse.wst.server.core.internal;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.eclipse.core.expressions.*;
 import org.eclipse.core.resources.IProject;
+import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IProgressMonitor;
-
 import org.eclipse.wst.server.core.IModule;
 import org.eclipse.wst.server.core.IModuleType;
 import org.eclipse.wst.server.core.model.InternalInitializer;
@@ -28,6 +29,7 @@ public class ModuleFactory implements IOrdered {
 	private IConfigurationElement element;
 	public ModuleFactoryDelegate delegate;
 	private List<IModuleType> moduleTypes;
+	private Expression fContextualLaunchExpr = null;
 
 	/**
 	 * ModuleFactory constructor comment.
@@ -137,6 +139,55 @@ public class ModuleFactory implements IOrdered {
 			return new IModule[0];
 		}
 	}
+	
+	/**
+	 * Returns an expression that represents the enablement logic for the
+	 * contextual project of this module factory <code>null</code> if none.
+	 * @return an evaluatable expression or <code>null</code>
+	 * @throws CoreException if the configuration element can't be
+	 *  converted. Reasons include: (a) no handler is available to
+	 *  cope with a certain configuration element or (b) the XML
+	 *  expression tree is malformed.
+	 */
+	protected Expression getContextualLaunchEnablementExpression() throws CoreException {
+		if (fContextualLaunchExpr == null) {
+			IConfigurationElement[] elements = element.getChildren(ExpressionTagNames.ENABLEMENT);
+			IConfigurationElement enablement = (elements != null && elements.length > 0) ? elements[0] : null; 
+
+			if (enablement != null)
+				fContextualLaunchExpr = ExpressionConverter.getDefault().perform(enablement);
+		}
+		return fContextualLaunchExpr;
+	}
+	
+	/**
+	 * Evaluate the given expression within the given context and return
+	 * the result. Returns <code>true</code> if result is either TRUE or NOT_LOADED.
+	 * This allows optimistic inclusion before plugins are loaded.
+	 * Returns <code>true</code> if exp is <code>null</code>.
+	 * 
+	 * @param exp the enablement expression to evaluate or <code>null</code>
+	 * @param context the context of the evaluation. 
+	 * @return the result of evaluating the expression
+	 * @throws CoreException
+	 */
+	protected boolean evalEnablementExpression(IEvaluationContext context, Expression exp) throws CoreException {
+		// for compatibility with the current behaviour, if the exp == null we return true. Meaning that the factory doesn't
+		// implement an expression and should be enabled for all cases.
+		return (exp != null) ? ((exp.evaluate(context)) != EvaluationResult.FALSE) : true;
+	}
+	
+	public boolean isEnabled(IProject project, IProgressMonitor monitor) {
+		try {
+			IEvaluationContext context = new EvaluationContext(null, project);
+			context.addVariable("project", project);
+			
+			return evalEnablementExpression(context, getContextualLaunchEnablementExpression());
+		} catch (Throwable t) {
+			Trace.trace(Trace.SEVERE, "Error calling delegate " + toString(), t);
+			return false;
+		}
+	}
 
 	/*
 	 * @see ModuleFactoryDelegate#findModule(String)