INT-547 The 'selector' element is now supported at top level.

org.springframework.integration/src/main/java/org/springframework/integration/config/xml/IntegrationNamespaceHandler.java

@@ -50,6 +50,7 @@ public class IntegrationNamespaceHandler extends AbstractIntegrationNamespaceHan
 		registerBeanDefinitionParser("delayer", new DelayerParser());
 		registerBeanDefinitionParser("bridge", new BridgeParser());
 		registerBeanDefinitionParser("chain", new ChainParser());
+		registerBeanDefinitionParser("selector", new SelectorParser());
 		registerBeanDefinitionParser("selector-chain", new SelectorChainParser());
 		registerBeanDefinitionParser("poller", new PollerParser());
 		registerBeanDefinitionParser("annotation-config", new AnnotationConfigParser());

org.springframework.integration/src/main/java/org/springframework/integration/config/xml/SelectorParser.java

@@ -0,0 +1,60 @@
+/*
+ * 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.integration.config.xml;
+
+import org.w3c.dom.Element;
+
+import org.springframework.beans.factory.config.RuntimeBeanReference;
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser;
+import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.util.StringUtils;
+
+/**
+ * Parser for a top-level <selector/> element.
+ * 
+ * @author Mark Fisher
+ * @since 2.0
+ */
+public class SelectorParser extends AbstractSingleBeanDefinitionParser {
+
+	@Override
+	protected String getBeanClassName(Element element) {
+		return IntegrationNamespaceUtils.BASE_PACKAGE + ".filter.MethodInvokingSelector";
+	}
+
+	public void doParse(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) {
+		String id = element.getAttribute("id");
+		if (!StringUtils.hasText(id)) {
+			parserContext.getReaderContext().error(
+					"The 'id' attribute is required for a selector.", element);
+		}
+		String ref = element.getAttribute("ref");
+		if (!StringUtils.hasText(ref)) {
+			parserContext.getReaderContext().error(
+					"The 'ref' attribute is required for selector '" + id + "'.", element);
+		}
+		String method = element.getAttribute("method");
+		if (!StringUtils.hasText(method)) {
+			parserContext.getReaderContext().error(
+					"The 'method' attribute is required for selector '" + id + "'.", element);
+		}		
+		builder.addConstructorArgValue(new RuntimeBeanReference(ref));
+		builder.addConstructorArgValue(method);
+	}
+
+}

org.springframework.integration/src/main/resources/org/springframework/integration/config/xml/spring-integration-2.0.xsd

@@ -814,7 +814,7 @@
 				</xsd:documentation>
 			</xsd:annotation>
 			<xsd:choice minOccurs="0" maxOccurs="unbounded">
-				<xsd:element ref="selector" />
+				<xsd:element name="selector" type="selectorType" />
 				<xsd:element ref="selector-chain" />
 			</xsd:choice>
 			<xsd:attribute name="id" type="xsd:ID" />
@@ -838,20 +838,25 @@
 
 	<xsd:element name="selector">
 		<xsd:complexType>
-			<xsd:annotation>
-				<xsd:documentation>
-					Provides a MessageSelector reference. If a method
-					attribute is set the
-					referred bean doesn't need to implement the
-					MessageSelector
-					interface.
-				</xsd:documentation>
-			</xsd:annotation>
-			<xsd:attribute name="ref" type="xsd:string" use="required" />
-			<xsd:attribute name="method" type="xsd:string" use="optional" />
+			<xsd:complexContent>
+				<xsd:extension base="selectorType">
+					<xsd:attribute name="id" type="xsd:string" use="required" />
+				</xsd:extension>
+			</xsd:complexContent>
 		</xsd:complexType>
 	</xsd:element>
 
+	<xsd:complexType name="selectorType">
+		<xsd:annotation>
+			<xsd:documentation>
+	Provides a MessageSelector reference. If a method attribute is set the
+	referred bean doesn't need to implement the MessageSelector interface.
+			</xsd:documentation>
+		</xsd:annotation>
+		<xsd:attribute name="ref" type="xsd:string" use="required" />
+		<xsd:attribute name="method" type="xsd:string" use="optional" />
+	</xsd:complexType>
+
 	<xsd:element name="header-enricher">
 		<xsd:annotation>
 			<xsd:documentation>