| // Copyright 2004 The Apache Software Foundation |
| // |
| // 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.apache.tapestry.spec; |
| |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.tapestry.ApplicationRuntimeException; |
| import org.apache.tapestry.IResourceResolver; |
| import org.apache.tapestry.Tapestry; |
| import org.apache.tapestry.util.prop.OgnlUtils; |
| |
| /** |
| * Defines an "extension", which is much like a helper bean, but |
| * is part of a library or application specification (and has the same |
| * lifecycle as the application). |
| * |
| * @author Howard Lewis Ship |
| * @version $Id$ |
| * @since 2.2 |
| * |
| **/ |
| |
| public class ExtensionSpecification |
| extends LocatablePropertyHolder |
| implements IExtensionSpecification |
| { |
| private static final Log LOG = LogFactory.getLog(ExtensionSpecification.class); |
| |
| private String _className; |
| protected Map _configuration = new HashMap(); |
| private boolean _immediate; |
| |
| public String getClassName() |
| { |
| return _className; |
| } |
| |
| public void setClassName(String className) |
| { |
| _className = className; |
| } |
| |
| public void addConfiguration(String propertyName, Object value) |
| { |
| if (_configuration.containsKey(propertyName)) |
| throw new IllegalArgumentException( |
| Tapestry.format( |
| "ExtensionSpecification.duplicate-property", |
| this, |
| propertyName)); |
| |
| _configuration.put(propertyName, value); |
| } |
| |
| /** |
| * Returns an immutable Map of the configuration; keyed on property name, |
| * with values as properties to assign. |
| * |
| **/ |
| |
| public Map getConfiguration() |
| { |
| return Collections.unmodifiableMap(_configuration); |
| } |
| |
| /** |
| * Invoked to instantiate an instance of the extension and return it. |
| * It also configures properties of the extension. |
| * |
| **/ |
| |
| public Object instantiateExtension(IResourceResolver resolver) |
| { |
| if (LOG.isDebugEnabled()) |
| LOG.debug("Instantiating extension class " + _className + "."); |
| Class extensionClass = null; |
| Object result = null; |
| |
| try |
| { |
| extensionClass = resolver.findClass(_className); |
| } |
| catch (Exception ex) |
| { |
| throw new ApplicationRuntimeException( |
| Tapestry.format("ExtensionSpecification.bad-class", _className), |
| getLocation(), |
| ex); |
| } |
| |
| result = instantiateInstance(extensionClass, result); |
| |
| initializeProperties(resolver, result); |
| |
| return result; |
| } |
| |
| private void initializeProperties(IResourceResolver resolver, Object extension) |
| { |
| if (_configuration.isEmpty()) |
| return; |
| |
| Iterator i = _configuration.entrySet().iterator(); |
| while (i.hasNext()) |
| { |
| Map.Entry entry = (Map.Entry) i.next(); |
| |
| String propertyName = (String) entry.getKey(); |
| |
| OgnlUtils.set(propertyName, resolver, extension, entry.getValue()); |
| } |
| } |
| |
| private Object instantiateInstance(Class extensionClass, Object result) |
| { |
| try |
| { |
| result = extensionClass.newInstance(); |
| } |
| catch (Exception ex) |
| { |
| throw new ApplicationRuntimeException(ex.getMessage(), getLocation(), ex); |
| } |
| |
| return result; |
| } |
| |
| public String toString() |
| { |
| StringBuffer buffer = new StringBuffer("ExtensionSpecification@"); |
| buffer.append(Integer.toHexString(hashCode())); |
| buffer.append('['); |
| buffer.append(_className); |
| |
| if (_configuration != null) |
| { |
| buffer.append(' '); |
| buffer.append(_configuration); |
| } |
| |
| buffer.append(']'); |
| |
| return buffer.toString(); |
| } |
| |
| /** |
| * Returns true if the extensions should be instantiated |
| * immediately after the containing |
| * {@link org.apache.tapestry.spec.LibrarySpecification} |
| * if parsed. Non-immediate extensions are instantiated |
| * only as needed. |
| * |
| **/ |
| |
| public boolean isImmediate() |
| { |
| return _immediate; |
| } |
| |
| public void setImmediate(boolean immediate) |
| { |
| _immediate = immediate; |
| } |
| |
| } |