Code tweaks and new EqualsExpression
diff --git a/bundles/org.eclipse.core.expressions/buildnotes_core-expressions.html b/bundles/org.eclipse.core.expressions/buildnotes_core-expressions.html
index 2c1be16..38461b1 100644
--- a/bundles/org.eclipse.core.expressions/buildnotes_core-expressions.html
+++ b/bundles/org.eclipse.core.expressions/buildnotes_core-expressions.html
@@ -12,9 +12,32 @@
<h1>
Eclipse Platform Build Notes <br>
Core Expressions</h1>
-March 16, 2004
-<h3>Problem Reports Fixed</h3>
-<h3>Implemenation Changes</h3>
+<h3>March 23, 2004</h3>
+<h4>Problem Reports Fixed</h4>
+<h4>Implemenation Changes</h4>
+<ul>
+ <li>removed the constructor public EvaluationContext(IEvaluationContext parent, Object defaultVariable,
+ Object selection). Instead of calling this constructor, the following code has to be written:
+ <pre>
+ EvaluationContext evalContext= new EvaluationContext(null, cunit);
+ evalContext.addVariable("selection", cunit); //$NON-NLS-1$
+ </pre>
+ </li>
+ <li> removed the two string constants:
+ <pre>
+ public static final String SYSTEM= "System"; //$NON-NLS-1$
+ public static final String SELECTION= "selection"; //$NON-NLS-1$
+ </pre>
+ </li>
+ <li>added support for custom variable resolver (see new class IVariableResolver). So there is no need
+ to subclass EvaluationContext anymore to add your own resolving strategy.
+ </li>
+ <li>added support for an equals expression. </li>
+</ul>
+
+<h3>March 16, 2004</h3>
+<h4>Problem Reports Fixed</h4>
+<h4>Implemenation Changes</h4>
The adapt expression now uses the new IAdapterManager API hasAdapter(Object, String) and
getAdapter(Object, String). This ensures that the right class loader is used to convert
the string representing a type into a corresponding Class. However, this change now requires
diff --git a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/EvaluationContext.java b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/EvaluationContext.java
index fd7b5d6..4c78456 100644
--- a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/EvaluationContext.java
+++ b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/EvaluationContext.java
@@ -32,6 +32,7 @@
private IEvaluationContext fParent;
private Object fDefaultVariable;
private Map/*<String, Object>*/ fVariables;
+ private IVariableResolver[] fVariableResolvers;
/**
* Create a new evaluation context with the given parent and default
@@ -47,20 +48,22 @@
}
/**
- * Create a new evaluation context with the given parent, default
- * variable and the variable stored under the name selection.
+ * Create a new evaluation context with the given parent and default
+ * variable.
*
* @param parent the parent context. Can be <code>null</code>.
* @param defaultVariable the default variable
- * @param selection the variable stored under the name selection. Can
- * be <code>null</code>
+ * @param resolvers an array of <code>IVariableResolvers</code> to
+ * resolve additional variables.
+ *
+ * @see #resolveVariable(String, Object[])
*/
- public EvaluationContext(IEvaluationContext parent, Object defaultVariable, Object selection) {
+ public EvaluationContext(IEvaluationContext parent, Object defaultVariable, IVariableResolver[] resolvers) {
Assert.isNotNull(defaultVariable);
+ Assert.isNotNull(resolvers);
fParent= parent;
fDefaultVariable= defaultVariable;
- if (selection != null)
- addVariable(SELECTION, selection);
+ fVariableResolvers= resolvers;
}
/**
@@ -125,8 +128,6 @@
/**
* {@inheritDoc}
- *
- * Subclasses may extend this method to resolve specific variables.
*/
public Object resolveVariable(String name, Object[] args) throws CoreException {
if (PLUGIN_DESCRIPTOR.equals(name)) {
@@ -142,6 +143,14 @@
ExpressionMessages.getString("VariablePool.resolveVariable.arguments.not_a_string"))); //$NON-NLS-1$
return Platform.getPluginRegistry().getPluginDescriptor((String)(args[0]));
}
+ if (fVariableResolvers != null && fVariableResolvers.length > 0) {
+ for (int i= 0; i < fVariableResolvers.length; i++) {
+ IVariableResolver resolver= fVariableResolvers[i];
+ Object variable= resolver.resolve(name, args);
+ if (variable != null)
+ return variable;
+ }
+ }
if (fParent != null)
return fParent.resolveVariable(name, args);
return null;
diff --git a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/ExpressionTagNames.java b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/ExpressionTagNames.java
index 1568067..7a33fb9 100644
--- a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/ExpressionTagNames.java
+++ b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/ExpressionTagNames.java
@@ -52,5 +52,8 @@
public static final String RESOLVE= "resolve"; //$NON-NLS-1$
/** The tag name of the systemTest expression (value: <code>systemTest</code>) */
- public static final String SYSTEM_TEST= "systemTest"; //$NON-NLS-1$
+ public static final String SYSTEM_TEST= "systemTest"; //$NON-NLS-1$
+
+ /** The tag name of the equals expression (value: <code>equals</code>) */
+ public static final String EQUALS= "equals"; //$NON-NLS-1$
}
diff --git a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/IEvaluationContext.java b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/IEvaluationContext.java
index 617077f..9ca49de 100644
--- a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/IEvaluationContext.java
+++ b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/IEvaluationContext.java
@@ -30,12 +30,6 @@
/** Variable name to denote a plug-in descriptor */
public static final String PLUGIN_DESCRIPTOR= "pluginDescriptor"; //$NON-NLS-1$
- /** Variable name to denote the current selection of elements */
- public static final String SELECTION= "selection"; //$NON-NLS-1$
-
- /** Variable name to denote the java.lang.System class */
- public static final String SYSTEM= "System"; //$NON-NLS-1$
-
/**
* Returns the parent context or <code>null</code> if
* this is the root of the evaluation context hierarchy.
diff --git a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/IVariableResolver.java b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/IVariableResolver.java
new file mode 100644
index 0000000..7eb727c
--- /dev/null
+++ b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/expressions/IVariableResolver.java
@@ -0,0 +1,39 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2004 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.core.expressions;
+
+import org.eclipse.core.runtime.CoreException;
+
+/**
+ * A variable resolver can be used to add additional variable resolving
+ * stategies to a {@link EvaluationContext}.
+ *
+ * @since 3.0
+ *
+ * @see org.eclipse.core.expressions.EvaluationContext#resolveVariable(String, Object[])
+ */
+public interface IVariableResolver {
+
+ /**
+ * Resolves a variable for the given name and arguments. The
+ * handler is allowed to return <code>null</code> to indicate
+ * that it is not able to resolve the requested variable.
+ *
+ * @param name the variable to resolve
+ * @param args an object array of arguments used to resolve the
+ * variable
+ * @return the variable's value or <code>null</code> if no variable
+ * could be resolved
+ * @exception CoreException if an errors occurs while resolving
+ * the variable
+ */
+ public Object resolve(String name, Object[] args) throws CoreException;
+}
diff --git a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/EqualsExpression.java b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/EqualsExpression.java
new file mode 100644
index 0000000..32e5a5e
--- /dev/null
+++ b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/EqualsExpression.java
@@ -0,0 +1,39 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2004 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.core.internal.expressions;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IConfigurationElement;
+
+import org.eclipse.core.expressions.EvaluationResult;
+import org.eclipse.core.expressions.Expression;
+import org.eclipse.core.expressions.IEvaluationContext;
+
+public class EqualsExpression extends Expression {
+
+ private Object fExpectedValue;
+
+ public EqualsExpression(Object expectedValue) {
+ Assert.isNotNull(expectedValue);
+ fExpectedValue= expectedValue;
+ }
+
+ public EqualsExpression(IConfigurationElement element) throws CoreException {
+ String value= element.getAttribute(ATT_VALUE);
+ Expressions.checkAttribute(ATT_VALUE, value);
+ fExpectedValue= Expressions.convertArgument(value);
+ }
+
+ public EvaluationResult evaluate(IEvaluationContext context) throws CoreException {
+ Object element= context.getDefaultVariable();
+ return EvaluationResult.valueOf(element.equals(fExpectedValue));
+ }
+}
diff --git a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/StandardElementHandler.java b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/StandardElementHandler.java
index bb733df..2c34fc5 100644
--- a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/StandardElementHandler.java
+++ b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/StandardElementHandler.java
@@ -63,6 +63,8 @@
EnablementExpression result= new EnablementExpression(element);
processChildren(converter, element, result);
return result;
+ } else if (ExpressionTagNames.EQUALS.equals(name)) {
+ return new EqualsExpression(element);
}
return null;
}
diff --git a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/TestExpression.java b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/TestExpression.java
index a501319..118f7b2 100644
--- a/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/TestExpression.java
+++ b/bundles/org.eclipse.core.expressions/src/org/eclipse/core/internal/expressions/TestExpression.java
@@ -40,7 +40,7 @@
fNamespace= property.substring(0, pos);
fProperty= property.substring(pos + 1);
fArgs= Expressions.getArguments(element, ATT_ARGS);
- fExpectedValue= element.getAttribute(ATT_VALUE);
+ fExpectedValue= Expressions.convertArgument(element.getAttribute(ATT_VALUE));
}
public EvaluationResult evaluate(IEvaluationContext context) throws CoreException {
diff --git a/tests/org.eclipse.core.expressions.tests/src/org/eclipse/core/internal/expressions/tests/ExpressionTests.java b/tests/org.eclipse.core.expressions.tests/src/org/eclipse/core/internal/expressions/tests/ExpressionTests.java
index 75a0ae2..bef619b 100644
--- a/tests/org.eclipse.core.expressions.tests/src/org/eclipse/core/internal/expressions/tests/ExpressionTests.java
+++ b/tests/org.eclipse.core.expressions.tests/src/org/eclipse/core/internal/expressions/tests/ExpressionTests.java
@@ -14,12 +14,15 @@
import junit.framework.TestCase;
import junit.framework.TestSuite;
+import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPluginDescriptor;
import org.eclipse.core.expressions.EvaluationContext;
import org.eclipse.core.expressions.EvaluationResult;
import org.eclipse.core.expressions.IEvaluationContext;
+import org.eclipse.core.expressions.IVariableResolver;
import org.eclipse.core.internal.expressions.AdaptExpression;
+import org.eclipse.core.internal.expressions.EqualsExpression;
import org.eclipse.core.internal.expressions.Expressions;
import org.eclipse.core.internal.expressions.InstanceofExpression;
import org.eclipse.core.internal.expressions.SystemTestExpression;
@@ -36,6 +39,7 @@
assertEquals("", Expressions.convertArgument(""));
assertEquals("", Expressions.convertArgument("''"));
assertEquals("eclipse", Expressions.convertArgument("eclipse"));
+ assertEquals("eclipse", Expressions.convertArgument("'eclipse'"));
assertEquals("true", Expressions.convertArgument("'true'"));
assertEquals("1.7", Expressions.convertArgument("'1.7'"));
assertEquals("007", Expressions.convertArgument("'007'"));
@@ -114,4 +118,32 @@
EvaluationResult result= expression.evaluate(new EvaluationContext(null, new Adaptee()));
assertTrue(result == EvaluationResult.FALSE);
}
+
+ public void testVariableResolver() throws Exception {
+ final Object result= new Object();
+ IVariableResolver resolver= new IVariableResolver() {
+ public Object resolve(String name, Object[] args) throws CoreException {
+ assertEquals("variable", name);
+ assertEquals("arg1", args[0]);
+ assertEquals(Boolean.TRUE, args[1]);
+ return result;
+ }
+ };
+ EvaluationContext context= new EvaluationContext(null, new Object(), new IVariableResolver[] { resolver });
+ assertTrue(result == context.resolveVariable("variable", new Object[] {"arg1", Boolean.TRUE}));
+ }
+
+ public void testEqualsExpression() throws Exception {
+ EqualsExpression exp= new EqualsExpression("name");
+ EvaluationContext context= new EvaluationContext(null, "name");
+ assertTrue(EvaluationResult.TRUE == exp.evaluate(context));
+
+ exp= new EqualsExpression(Boolean.TRUE);
+ context= new EvaluationContext(null, Boolean.TRUE);
+ assertTrue(EvaluationResult.TRUE == exp.evaluate(context));
+
+ exp= new EqualsExpression("name");
+ context= new EvaluationContext(null, Boolean.TRUE);
+ assertTrue(EvaluationResult.FALSE == exp.evaluate(context));
+ }
}
