| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.commons.jelly.tags.core; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.util.Map; |
| |
| import org.apache.commons.beanutils.BeanUtils; |
| import org.apache.commons.jelly.JellyTagException; |
| import org.apache.commons.jelly.TagSupport; |
| import org.apache.commons.jelly.XMLOutput; |
| import org.apache.commons.jelly.expression.Expression; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| |
| /** A tag which sets a variable from the result of an expression |
| * |
| * @author <a href="mailto:jstrachan@apache.org">James Strachan</a> |
| * @version $Revision$ |
| */ |
| public class SetTag extends TagSupport { |
| |
| /** The Log to which logging calls will be made. */ |
| private static final Log log = LogFactory.getLog(SetTag.class); |
| |
| /** The variable name to export. */ |
| private String var; |
| |
| /** The variable scope to export */ |
| private String scope; |
| |
| /** The expression to evaluate. */ |
| private Expression value; |
| |
| /** The default value */ |
| private Expression defaultValue; |
| |
| /** The target object on which to set a property. */ |
| private Object target; |
| |
| /** The name of the property to set on the target object. */ |
| private String property; |
| |
| /** Should we XML encode the body of this tag as text? */ |
| private boolean encode = true; |
| |
| public SetTag() { |
| } |
| |
| // Tag interface |
| //------------------------------------------------------------------------- |
| public void doTag(XMLOutput output) throws JellyTagException { |
| // perform validation up front to fail fast |
| if ( var != null ) { |
| if ( target != null || property != null ) { |
| throw new JellyTagException( "The 'target' and 'property' attributes cannot be used in combination with the 'var' attribute" ); |
| } |
| } |
| else { |
| if ( target == null ) { |
| throw new JellyTagException( "Either a 'var' or a 'target' attribute must be defined for this tag" ); |
| } |
| if ( property == null ) { |
| throw new JellyTagException( "The 'target' attribute requires the 'property' attribute" ); |
| } |
| } |
| |
| Object answer = null; |
| if ( value != null ) { |
| answer = value.evaluate(context); |
| if (defaultValue != null && isEmpty(answer)) { |
| answer = defaultValue.evaluate(context); |
| } |
| } |
| else { |
| answer = getBodyText(isEncode()); |
| } |
| |
| if ( var != null ) { |
| if ( scope != null ) { |
| context.setVariable(var, scope, answer); |
| } |
| else { |
| context.setVariable(var, answer); |
| } |
| } |
| else { |
| setPropertyValue( target, property, answer ); |
| } |
| } |
| |
| // Properties |
| //------------------------------------------------------------------------- |
| /** Sets the variable name to define for this expression |
| */ |
| public void setVar(String var) { |
| this.var = var; |
| } |
| |
| /** |
| * Sets the variable scope for this variable. For example setting this value to 'parent' will |
| * set this value in the parent scope. When Jelly is run from inside a Servlet environment |
| * then other scopes will be available such as 'request', 'session' or 'application'. |
| * |
| * Other applications may implement their own custom scopes. |
| */ |
| public void setScope(String scope) { |
| this.scope = scope; |
| } |
| |
| /** Sets the expression to evaluate. */ |
| public void setValue(Expression value) { |
| this.value = value; |
| } |
| |
| /** |
| * Sets the default value to be used if the value expression results |
| * in a null value or blank String |
| */ |
| public void setDefaultValue(Expression defaultValue) { |
| this.defaultValue = defaultValue; |
| } |
| |
| /** Sets the target object on which to set a property. */ |
| public void setTarget(Object target) { |
| this.target = target; |
| } |
| |
| /** Sets the name of the property to set on the target object. */ |
| public void setProperty(String property) { |
| this.property = property; |
| } |
| |
| /** |
| * Returns whether the body of this tag will be XML encoded or not. |
| */ |
| public boolean isEncode() { |
| return encode; |
| } |
| |
| /** |
| * Sets whether the body of the tag should be XML encoded as text (so that < and > are |
| * encoded as &lt; and &gt;) or leave the text as XML which is the default. |
| * This is only used if this tag is specified with no value so that the text body of this |
| * tag is used as the body. |
| */ |
| public void setEncode(boolean encode) { |
| this.encode = encode; |
| } |
| |
| |
| // Implementation methods |
| //------------------------------------------------------------------------- |
| protected void setPropertyValue( Object target, String property, Object value ) { |
| try { |
| if ( target instanceof Map ) { |
| Map map = (Map) target; |
| map.put( property, value ); |
| } |
| else { |
| BeanUtils.setProperty( target, property, value ); |
| } |
| } catch (InvocationTargetException e) { |
| log.error( "Failed to set the property: " + property + " on bean: " + target + " to value: " + value + " due to exception: " + e, e ); |
| } catch (IllegalAccessException e) { |
| log.error( "Failed to set the property: " + property + " on bean: " + target + " to value: " + value + " due to exception: " + e, e ); |
| } |
| } |
| |
| /** |
| * @param value |
| * @return true if the given value is null or an empty String |
| */ |
| protected boolean isEmpty(Object value) { |
| if (value == null) { |
| return true; |
| } |
| if (value instanceof String) { |
| String s = (String) value; |
| return s.length() == 0; |
| } |
| return false; |
| } |
| |
| } |