EL functions library
Here are few additional EL functions I couldn't live without.
(Might be they could be included into Seam code base)
package org.el.func;
import java.lang.reflect.InvocationTargetException;
import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.Date;
import org.apache.commons.beanutils.PropertyUtils;
import org.jboss.seam.Entity;
import org.jboss.seam.core.Expressions;
public class SeamFunc {
public static Object getId(Object bean) {
Class<?> clazz = bean.getClass();
if (!clazz.isAnnotationPresent(javax.persistence.Entity.class)) {
// this better be instrumented proxy class
clazz = clazz.getSuperclass();
}
return Entity.forClass(clazz).getIdentifier(bean);
}
public static String toString(Object obj) {
return "" + obj;
}
public static Object[] toArray(Collection<Object> collect) {
if (collect == null) {
return null;
} else {
return collect.toArray();
}
}
public static int size(Collection<Object> collect) {
if (collect == null) {
return 0;
} else {
return collect.size();
}
}
public static boolean isBlank(String str) {
if (str == null) {
return true;
} else {
return "".equals(str.trim());
}
}
public static String trunc(String str, int len) {
if (str == null) {
return null;
} else {
return str.substring(0, len);
}
}
public static String concat(String... strings) {
StringBuilder buff = new StringBuilder();
if (strings != null) {
for (String str : strings) {
buff.append(str);
}
}
return buff.toString();
}
public static boolean matches(String str, String regex) {
if (str == null) {
return false;
} else {
return str.matches(regex);
}
}
public static String formatDate(Date date, String pattern) {
if (date == null) {
return null;
}
else {
return new SimpleDateFormat(pattern).format(date);
}
}
public static String getProperty(String propName) {
return System.getProperty(propName);
}
public static String getEnv(String varName) {
return System.getenv(varName);
}
public static Object getBeanProperty(Object bean, String propName) {
Object obj = null;
try {
obj = PropertyUtils.getProperty(bean, propName);
} catch (IllegalAccessException ex) {
throw new RuntimeException(ex);
} catch (InvocationTargetException ex) {
throw new RuntimeException(ex);
} catch (NoSuchMethodException ex) {
throw new RuntimeException(ex);
}
return obj;
}
public static Object evalEl(String expression) {
String framedExpr = "#{" + expression + "}";
Object value = Expressions.instance().createValueBinding(framedExpr).getValue();
return value;
}
}
/**
* Licensed under the Common Development and Distribution License,
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.sun.com/cddl/
*
* 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.el.func;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.Map;
import javax.faces.FacesException;
import com.sun.facelets.tag.TagConfig;
import com.sun.facelets.tag.TagHandler;
import com.sun.facelets.tag.TagLibrary;
public class FnLibrary implements TagLibrary {
public final static String Namespace = "http://org.el.func/func";
private final Map<String, Method> fns = new HashMap<String, Method>();
public FnLibrary() {
super();
try {
Method[] methods = SeamFunc.class.getMethods();
putMethods(methods);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
private void putMethods(Method[] methods) {
for (int i = 0; i < methods.length; i++) {
if (Modifier.isStatic(methods.getModifiers())) {
fns.put(methods.getName(), methods);
}
}
}
public boolean containsNamespace(String ns) {
return Namespace.equals(ns);
}
public boolean containsTagHandler(String ns, String localName) {
return false;
}
public TagHandler createTagHandler(String ns, String localName,
TagConfig tag) throws FacesException {
return null;
}
public boolean containsFunction(String ns, String name) {
if (Namespace.equals(ns)) {
return this.fns.containsKey(name);
}
return false;
}
public Method createFunction(String ns, String name) {
if (Namespace.equals(ns)) {
return (Method) this.fns.get(name);
}
return null;
}
public static void main(String[] argv) {
FnLibrary lib = new FnLibrary();
System.out.println(lib.containsFunction(FnLibrary.Namespace, "isBlank"));
}
}
META-INF/elfunc.taglib.xml
<facelet-taglib> <library-class>org.el.func.FnLibrary</library-class> </facelet-taglib>
