| /* |
| * $Id$ |
| * |
| * 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.tiles.template; |
| |
| import java.io.IOException; |
| import java.io.Writer; |
| import java.util.Deque; |
| |
| import org.apache.tiles.Attribute; |
| import org.apache.tiles.TilesContainer; |
| import org.apache.tiles.access.TilesAccess; |
| import org.apache.tiles.autotag.core.runtime.ModelBody; |
| import org.apache.tiles.autotag.core.runtime.annotation.Parameter; |
| import org.apache.tiles.request.Request; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * <p> |
| * <strong> Render the value of the specified template attribute to the current |
| * Writer</strong> |
| * </p> |
| * |
| * <p> |
| * Retrieve the value of the specified template attribute property, and render |
| * it to the current Writer as a String. The usual toString() conversions is |
| * applied on found value. |
| * </p> |
| * |
| * @version $Rev$ $Date$ |
| * @since 2.2.0 |
| */ |
| public class GetAsStringModel { |
| |
| /** |
| * The logging object. |
| */ |
| private Logger log = LoggerFactory.getLogger(getClass()); |
| |
| /** |
| * The attribute resolver to use. |
| */ |
| private AttributeResolver attributeResolver; |
| |
| /** |
| * Constructor that uses the defaut attribute resolver. |
| * |
| * @since 3.0.0 |
| */ |
| public GetAsStringModel() { |
| this(new DefaultAttributeResolver()); |
| } |
| |
| /** |
| * Constructor. |
| * |
| * @param attributeResolver The attribute resolver to use. |
| * @since 2.2.0 |
| */ |
| public GetAsStringModel(AttributeResolver attributeResolver) { |
| this.attributeResolver = attributeResolver; |
| } |
| |
| /** |
| * Executes the operation. |
| * @param ignore If <code>true</code>, if an exception happens during |
| * rendering, of if the attribute is null, the problem will be ignored. |
| * @param preparer The preparer to invoke before rendering the attribute. |
| * @param role A comma-separated list of roles. If present, the attribute |
| * will be rendered only if the current user belongs to one of the roles. |
| * @param defaultValue The default value of the attribute. To use only if |
| * the attribute was not computed. |
| * @param defaultValueRole The default comma-separated list of roles. To use |
| * only if the attribute was not computed. |
| * @param defaultValueType The default type of the attribute. To use only if |
| * the attribute was not computed. |
| * @param name The name of the attribute. |
| * @param value The attribute to use immediately, if not null. |
| * @param request The request. |
| * @param modelBody The body. |
| * @throws IOException If an I/O error happens during rendering. |
| * @since 2.2.0 |
| */ |
| public void execute(boolean ignore, String preparer, String role, |
| Object defaultValue, String defaultValueRole, |
| String defaultValueType, @Parameter(required = true) String name, |
| Attribute value, Request request, ModelBody modelBody) |
| throws IOException { |
| TilesContainer container = TilesAccess.getCurrentContainer(request); |
| Deque<Object> composeStack = ComposeStackUtil.getComposeStack(request); |
| Attribute attribute = resolveAttribute(container, ignore, preparer, |
| role, defaultValue, defaultValueRole, defaultValueType, name, |
| value, request); |
| if (attribute != null) { |
| composeStack.push(attribute); |
| } |
| modelBody.evaluateWithoutWriting(); |
| container = TilesAccess.getCurrentContainer(request); |
| Writer writer = request.getWriter(); |
| if (attribute != null) { |
| attribute = (Attribute) composeStack.pop(); |
| } |
| renderAttribute(attribute, container, writer, ignore, request); |
| } |
| |
| /** |
| * Resolves the attribute. and starts the context. |
| * |
| * @param container The Tiles container to use. |
| * @param ignore If <code>true</code>, if an exception happens during |
| * rendering, of if the attribute is null, the problem will be ignored. |
| * @param preparer The preparer to invoke before rendering the attribute. |
| * @param role A comma-separated list of roles. If present, the attribute |
| * will be rendered only if the current user belongs to one of the roles. |
| * @param defaultValue The default value of the attribute. To use only if |
| * the attribute was not computed. |
| * @param defaultValueRole The default comma-separated list of roles. To use |
| * only if the attribute was not computed. |
| * @param defaultValueType The default type of the attribute. To use only if |
| * the attribute was not computed. |
| * @param name The name of the attribute. |
| * @param value The attribute to use immediately, if not null. |
| * @param request The request. |
| * @return The resolved attribute. |
| */ |
| private Attribute resolveAttribute(TilesContainer container, |
| boolean ignore, String preparer, String role, Object defaultValue, |
| String defaultValueRole, String defaultValueType, String name, |
| Attribute value, Request request) { |
| if (preparer != null) { |
| container.prepare(preparer, request); |
| } |
| Attribute attribute = attributeResolver.computeAttribute(container, |
| value, name, role, ignore, defaultValue, defaultValueRole, |
| defaultValueType, request); |
| container.startContext(request); |
| return attribute; |
| } |
| |
| /** |
| * Renders the attribute as a string. |
| * |
| * @param attribute The attribute to use, previously resolved. |
| * @param container The Tiles container to use. |
| * @param writer The writer into which the attribute will be written. |
| * @param ignore If <code>true</code>, if an exception happens during |
| * rendering, of if the attribute is null, the problem will be ignored. |
| * @param request The request. |
| * @throws IOException If an I/O error happens during rendering. |
| */ |
| private void renderAttribute(Attribute attribute, TilesContainer container, |
| Writer writer, boolean ignore, Request request) |
| throws IOException { |
| try { |
| if (attribute == null && ignore) { |
| return; |
| } |
| Object value = container.evaluate(attribute, request); |
| if(value != null) { |
| writer.write(value.toString()); |
| } |
| } catch (IOException e) { |
| if (!ignore) { |
| throw e; |
| } else if (log.isDebugEnabled()) { |
| log.debug("Ignoring exception", e); |
| } |
| } catch (RuntimeException e) { |
| if (!ignore) { |
| throw e; |
| } else if (log.isDebugEnabled()) { |
| log.debug("Ignoring exception", e); |
| } |
| } finally { |
| container.endContext(request); |
| } |
| } |
| } |