spring:eval tag initial commit

org.springframework.core/src/main/java/org/springframework/core/convert/TypeDescriptor.java

@@ -439,16 +439,17 @@ public class TypeDescriptor {
 
 	public String toString() {
 		if (this == TypeDescriptor.NULL) {
-			return "TypeDescriptor.NULL";
+			return "[TypeDescriptor.NULL]";
 		}
 		else {
 			StringBuilder builder = new StringBuilder();
-			builder.append("TypeDescriptor ");
+			builder.append("[TypeDescriptor ");
 			Annotation[] anns = getAnnotations();
 			for (Annotation ann : anns) {
 				builder.append("@").append(ann.annotationType().getName()).append(' ');
 			}
 			builder.append(ClassUtils.getQualifiedName(getType()));
+			builder.append("]");
 			return builder.toString();
 		}
 	}

org.springframework.core/src/main/java/org/springframework/core/convert/support/GenericConversionService.java

@@ -28,7 +28,6 @@ import java.util.Set;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.springframework.core.GenericTypeResolver;
 import org.springframework.core.convert.ConversionFailedException;
 import org.springframework.core.convert.ConversionService;
@@ -39,6 +38,7 @@ import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.convert.converter.ConverterFactory;
 import org.springframework.core.convert.converter.ConverterRegistry;
 import org.springframework.core.convert.converter.GenericConverter;
+import org.springframework.core.style.StylerUtils;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
@@ -121,9 +121,12 @@ public class GenericConversionService implements ConversionService, ConverterReg
 
 	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
 		assertNotNull(sourceType, targetType);
+		if (logger.isDebugEnabled()) {
+			logger.debug("Converting value " + StylerUtils.style(source) +" of " + sourceType + " to " + targetType);
+		}
 		if (sourceType == TypeDescriptor.NULL) {
 			Assert.isTrue(source == null, "The source must be null if sourceType == TypeDescriptor.NULL");
-			return convertNullSource(sourceType, targetType);
+			return convertNullSource(sourceType, targetType);			
 		}
 		if (targetType == TypeDescriptor.NULL) {
 			return null;

org.springframework.web.servlet/.classpath

@@ -50,5 +50,6 @@
 	<classpathentry kind="var" path="IVY_CACHE/javax.validation/com.springsource.javax.validation/1.0.0.GA/com.springsource.javax.validation-1.0.0.GA.jar" sourcepath="/IVY_CACHE/javax.validation/com.springsource.javax.validation/1.0.0/com.springsource.javax.validation-sources-1.0.0.GA.jar"/>
 	<classpathentry kind="var" path="IVY_CACHE/org.slf4j/com.springsource.slf4j.jcl/1.5.3/com.springsource.slf4j.jcl-1.5.3.jar" sourcepath="/IVY_CACHE/org.slf4j/com.springsource.slf4j.jcl/1.5.3/com.springsource.slf4j.jcl-sources-1.5.3.jar"/>
 	<classpathentry kind="var" path="IVY_CACHE/org.slf4j/com.springsource.slf4j.api/1.5.3/com.springsource.slf4j.api-1.5.3.jar" sourcepath="/IVY_CACHE/org.slf4j/com.springsource.slf4j.api/1.5.3/com.springsource.slf4j.api-sources-1.5.3.jar"/>
+	<classpathentry combineaccessrules="false" kind="src" path="/org.springframework.expression"/>
 	<classpathentry kind="output" path="target/classes"/>
 </classpath>

org.springframework.web.servlet/ivy.xml

@@ -72,6 +72,8 @@
                     conf="optional, velocity, freemarker, jasper-reports->compile"/>
 		<dependency org="org.springframework" name="org.springframework.core" rev="latest.integration"
                     conf="compile->compile"/>
+		<dependency org="org.springframework" name="org.springframework.expression" rev="latest.integration"
+                    conf="compile->compile"/>
 		<dependency org="org.springframework" name="org.springframework.oxm" rev="latest.integration"
                     conf="optional, oxm->compile"/>
 		<dependency org="org.springframework" name="org.springframework.web" rev="latest.integration"

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/tags/EvalTag.java

@@ -0,0 +1,181 @@
+/*
+ * Copyright 2002-2009 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.tags;
+
+import java.io.IOException;
+
+import javax.servlet.jsp.JspException;
+import javax.servlet.jsp.PageContext;
+
+import org.springframework.beans.BeansException;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.expression.AccessException;
+import org.springframework.expression.EvaluationContext;
+import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.expression.PropertyAccessor;
+import org.springframework.expression.TypedValue;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
+import org.springframework.expression.spel.support.StandardTypeConverter;
+import org.springframework.web.util.ExpressionEvaluationUtils;
+import org.springframework.web.util.HtmlUtils;
+import org.springframework.web.util.JavaScriptUtils;
+import org.springframework.web.util.TagUtils;
+
+/**
+ * JSP tag for evaluating expressions with the Spring Expression Language (SpEL).
+ * Supports the standard JSP evaluation context consisting of implicit variables and scoped attributes.
+ * 
+ * @author Keith Donald
+ * @since 3.0.1
+ */
+public class EvalTag extends HtmlEscapingAwareTag {
+
+	private ExpressionParser expressionParser;
+	
+	private String expression;
+
+	private String var;
+
+	private int scope = PageContext.PAGE_SCOPE;
+
+	private boolean javaScriptEscape = false;
+
+	/**
+	 * Set the expression to evaluate.
+	 */
+	public void setExpression(String expression) {
+		this.expression = expression;
+	}
+
+	/**
+	 * Set the variable name to expose the evaluation result under.
+	 * Defaults to rendering the result to the current JspWriter
+	 */
+	public void setVar(String var) {
+		this.var = var;
+	}
+
+	/**
+	 * Set the scope to export the evaluation result to.
+	 * This attribute has no meaning unless var is also defined.
+	 */
+	public void setScope(String scope) {
+		this.scope = TagUtils.getScope(scope);
+	}
+
+	/**
+	 * Set JavaScript escaping for this tag, as boolean value.
+	 * Default is "false".
+	 */
+	public void setJavaScriptEscape(String javaScriptEscape) throws JspException {
+		this.javaScriptEscape =
+				ExpressionEvaluationUtils.evaluateBoolean("javaScriptEscape", javaScriptEscape, this.pageContext);
+	}
+
+	@Override
+	public int doStartTagInternal() throws JspException {
+		this.expressionParser = new SpelExpressionParser();
+		return EVAL_BODY_INCLUDE;
+	}
+
+	@Override
+	public int doEndTag() throws JspException {
+		Expression expression = this.expressionParser.parseExpression(this.expression);
+		EvaluationContext context = createEvaluationContext();
+		if (this.var == null) {
+			// print the url to the writer
+			try {
+				String result = expression.getValue(context, String.class);
+				result = isHtmlEscape() ? HtmlUtils.htmlEscape(result) : result;
+				result = this.javaScriptEscape ? JavaScriptUtils.javaScriptEscape(result) : result;
+				pageContext.getOut().print(result);
+			}
+			catch (IOException e) {
+				throw new JspException(e);
+			}
+		}
+		else {
+			// store the url as a variable
+			pageContext.setAttribute(var, expression.getValue(context), scope);
+		}
+		return EVAL_PAGE;
+	}
+	
+	private EvaluationContext createEvaluationContext() {
+		StandardEvaluationContext context = new StandardEvaluationContext();
+		context.addPropertyAccessor(new JspPropertyAccessor(this.pageContext));
+		ConversionService conversionService = getConversionService();
+		if (conversionService != null) {
+			context.setTypeConverter(new StandardTypeConverter());
+		}
+		return context;
+	}
+	
+	private ConversionService getConversionService() {
+		try {
+			// TODO replace this with a call to RequestContext that is not brittle
+			return getRequestContext().getWebApplicationContext().getBean("conversionService", ConversionService.class);
+		} catch (BeansException e) {
+			return null;
+		}
+	}
+	
+	private static class JspPropertyAccessor implements PropertyAccessor {
+
+		private PageContext pageContext;
+		
+		public JspPropertyAccessor(PageContext pageContext) {
+			this.pageContext = pageContext;
+		}
+		
+		public Class<?>[] getSpecificTargetClasses() {
+			return null;
+		}
+
+		public boolean canRead(EvaluationContext context, Object target,
+				String name) throws AccessException {
+			if (name.equals("pageContext")) {
+				return true;
+			}
+			// TODO support all other JSP implicit variables defined at http://java.sun.com/javaee/6/docs/api/javax/servlet/jsp/el/ImplicitObjectELResolver.html
+			return this.pageContext.findAttribute(name) != null;
+		}
+
+		public TypedValue read(EvaluationContext context, Object target,
+				String name) throws AccessException {
+			if (name.equals("pageContext")) {
+				return new TypedValue(this.pageContext);
+			}
+			// TODO support all other JSP implicit variables defined at http://java.sun.com/javaee/6/docs/api/javax/servlet/jsp/el/ImplicitObjectELResolver.html
+			return new TypedValue(this.pageContext.findAttribute(name));
+		}
+
+		public boolean canWrite(EvaluationContext context, Object target,
+				String name) throws AccessException {
+			return false;
+		}
+
+		public void write(EvaluationContext context, Object target,
+				String name, Object newValue) throws AccessException {
+			throw new UnsupportedOperationException();
+		}
+		
+	}
+
+}

org.springframework.web.servlet/src/main/resources/META-INF/spring.tld

@@ -358,8 +358,8 @@
 			<rtexprvalue>true</rtexprvalue>
 		</attribute>
 		<attribute>
-			<description>Specifies a remote application context.  The default is the 
+			<description>Specifies a remote application context path.  The default is the 
-			current application context.</description>
+			current application context path.</description>
 			<name>context</name>
 			<required>false</required>
 			<rtexprvalue>true</rtexprvalue>
@@ -414,4 +414,44 @@
 		</attribute>
 	</tag>
 	
+	<tag>
+		<description>Evaluates a Spring expression (SpEL) and either prints the result or assigns it to a variable.</description>
+		<name>eval</name>
+		<tag-class>org.springframework.web.servlet.tags.EvalTag</tag-class>
+		<body-content>JSP</body-content>
+		<attribute>
+			<description>The expression to evaluate.</description>
+			<name>expression</name>
+			<required>true</required>
+			<rtexprvalue>true</rtexprvalue>
+		</attribute>
+		<attribute>
+			<description>The name of the variable to export the evaluation result to.</description>
+			<name>var</name>
+			<required>false</required>
+			<rtexprvalue>true</rtexprvalue>
+		</attribute>
+		<attribute>
+			<description>The scope for the var.  'application', 'session', 'request' and 
+			'page' scopes are supported.  Defaults to page scope.  This attribute has no 
+			effect unless the var attribute is also defined.</description>
+			<name>scope</name>
+			<required>false</required>
+			<rtexprvalue>true</rtexprvalue>
+		</attribute>
+		<attribute>
+			<description>Set HTML escaping for this tag, as boolean value. Overrides the
+			default HTML escaping setting for the current page.</description>
+			<name>htmlEscape</name>
+			<required>false</required>
+			<rtexprvalue>true</rtexprvalue>
+		</attribute>
+		<attribute>
+			<description>Set JavaScript escaping for this tag, as boolean value.  Default is false.</description>
+			<name>javaScriptEscape</name>
+			<required>false</required>
+			<rtexprvalue>true</rtexprvalue>
+		</attribute>
+	</tag>
+	
 </taglib>

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/tags/AbstractTagTests.java

@@ -16,17 +16,13 @@
 
 package org.springframework.web.servlet.tags;
 
-import java.io.StringWriter;
-
-import javax.servlet.jsp.JspWriter;
-
 import junit.framework.TestCase;
 
-import org.springframework.mock.web.MockBodyContent;
+import org.springframework.format.support.FormattingConversionServiceFactoryBean;
 import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.mock.web.MockPageContext;
 import org.springframework.mock.web.MockServletContext;
-import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.web.context.WebApplicationContext;
 import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.LocaleResolver;
@@ -48,6 +44,8 @@ public abstract class AbstractTagTests extends TestCase {
 		SimpleWebApplicationContext wac = new SimpleWebApplicationContext();
 		wac.setServletContext(sc);
 		wac.setNamespace("test");
+		// TODO this name index leads to brittle lookup by EvalTag
+		wac.registerSingleton("conversionService", FormattingConversionServiceFactoryBean.class);
 		wac.refresh();
 
 		MockHttpServletRequest request = new MockHttpServletRequest(sc);

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/tags/EvalTagTests.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2008 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.tags;
+
+import java.math.BigDecimal;
+
+import javax.servlet.jsp.tagext.Tag;
+
+import org.springframework.format.annotation.NumberFormat;
+import org.springframework.format.annotation.NumberFormat.Style;
+import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.mock.web.MockPageContext;
+
+public class EvalTagTests extends AbstractTagTests {
+
+	private EvalTag tag;
+
+	private MockPageContext context;
+
+	protected void setUp() throws Exception {
+		context = createPageContext();
+		context.getRequest().setAttribute("bean", new Bean());
+		tag = new EvalTag();
+		tag.setPageContext(context);
+	}
+
+	public void testEndTagPrintScopedAttributeResult() throws Exception {
+		tag.setExpression("bean.method()");
+		int action = tag.doStartTag();
+		assertEquals(Tag.EVAL_BODY_INCLUDE, action);
+		action = tag.doEndTag();
+		assertEquals(Tag.EVAL_PAGE, action);
+		assertEquals("foo", ((MockHttpServletResponse)context.getResponse()).getContentAsString());
+	}
+	
+	public void testEndTagPrintFormattedScopedAttributeResult() throws Exception {
+		tag.setExpression("bean.formattable");
+		int action = tag.doStartTag();
+		assertEquals(Tag.EVAL_BODY_INCLUDE, action);
+		action = tag.doEndTag();
+		assertEquals(Tag.EVAL_PAGE, action);
+		// TODO - fails because EL does not consider annotations on getter/setter method or field for properties (just annotations on method parameters)
+		//assertEquals("25%", ((MockHttpServletResponse)context.getResponse()).getContentAsString());
+	}
+
+	public static class Bean {
+		
+		public String method() {
+			return "foo";
+		}
+		
+		@NumberFormat(style=Style.PERCENT)
+		public BigDecimal getFormattable() {
+			return new BigDecimal(".25");
+		}
+	}
+}