| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. 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. For additional information regarding |
| * copyright in this work, please see the NOTICE file in the top level |
| * directory of this distribution. |
| */ |
| |
| package org.apache.roller.weblogger.ui.rendering.velocity; |
| |
| import java.io.StringWriter; |
| import java.io.Writer; |
| import java.util.Map; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.roller.util.RollerConstants; |
| import org.apache.roller.weblogger.pojos.Template; |
| import org.apache.roller.weblogger.ui.rendering.Renderer; |
| import org.apache.roller.weblogger.ui.rendering.RenderingException; |
| import org.apache.roller.weblogger.ui.rendering.mobile.MobileDeviceRepository; |
| import org.apache.roller.weblogger.ui.rendering.model.UtilitiesModel; |
| import org.apache.velocity.VelocityContext; |
| import org.apache.velocity.context.Context; |
| import org.apache.velocity.exception.MethodInvocationException; |
| import org.apache.velocity.exception.ParseErrorException; |
| import org.apache.velocity.exception.ResourceNotFoundException; |
| import org.apache.velocity.exception.VelocityException; |
| |
| /** |
| * Renderer that renders using the Velocity template engine. |
| */ |
| public class VelocityRenderer implements Renderer { |
| |
| private static Log log = LogFactory.getLog(VelocityRenderer.class); |
| |
| // the original template we are supposed to render |
| private Template renderTemplate = null; |
| private MobileDeviceRepository.DeviceType deviceType = null; |
| |
| // the velocity templates |
| private org.apache.velocity.Template velocityTemplate = null; |
| private org.apache.velocity.Template velocityDecorator = null; |
| |
| // a possible exception |
| private Exception velocityException = null; |
| |
| public VelocityRenderer(Template template, |
| MobileDeviceRepository.DeviceType deviceType) throws Exception { |
| |
| // the Template we are supposed to render |
| this.renderTemplate = template; |
| this.deviceType = deviceType; |
| |
| try { |
| // make sure that we can locate the template |
| // if we can't then this will throw an exception |
| velocityTemplate = RollerVelocity.getTemplate(template.getId(), |
| deviceType, "UTF-8"); |
| |
| } catch (ResourceNotFoundException ex) { |
| // velocity couldn't find the resource so lets log a warning |
| log.warn("Error creating renderer for " + template.getId() |
| + " due to [" + ex.getMessage() + "]"); |
| |
| // then just rethrow so that the caller knows this instantiation |
| // failed |
| throw ex; |
| |
| } catch (ParseErrorException ex) { |
| // in the case of a parsing error we want to render an |
| // error page instead so the user knows what was wrong |
| velocityException = ex; |
| |
| // need to lookup error page template |
| velocityTemplate = RollerVelocity.getTemplate("error-page.vm", |
| deviceType); |
| |
| } catch (MethodInvocationException ex) { |
| |
| // in the case of a invocation error we want to render an |
| // error page instead so the user knows what was wrong |
| velocityException = ex; |
| |
| // need to lookup error page template |
| velocityTemplate = RollerVelocity.getTemplate("error-page.vm", |
| deviceType); |
| |
| } catch (VelocityException ex) { |
| |
| // in the case of a parsing error including a macro we want to |
| // render an error page instead so the user knows what was wrong |
| velocityException = ex; |
| |
| // need to lookup error page template |
| velocityTemplate = RollerVelocity.getTemplate("error-page.vm", |
| deviceType); |
| |
| } catch (Exception ex) { |
| // some kind of generic/unknown exception, dump it to the logs |
| log.error( |
| "Unknown exception creating renderer for " |
| + template.getId(), ex); |
| |
| // throw if back to the caller |
| throw ex; |
| } |
| } |
| |
| /** |
| * @see org.apache.roller.weblogger.ui.rendering.Renderer#render(java.util.Map, |
| * java.io.Writer) |
| */ |
| public void render(Map<String, Object> model, Writer out) |
| throws RenderingException { |
| |
| try { |
| |
| if (velocityException != null) { |
| |
| // Render exception |
| renderException(model, out, null); |
| |
| // and we're done |
| return; |
| } |
| |
| long startTime = System.currentTimeMillis(); |
| |
| // convert model to Velocity Context |
| Context ctx = new VelocityContext(model); |
| |
| if (velocityDecorator != null) { |
| |
| /** |
| * We only allow decorating once, so the process isn't fully |
| * recursive. This is just to keep it simple. |
| */ |
| |
| // render base template to a temporary StringWriter |
| StringWriter sw = new StringWriter(); |
| velocityTemplate.merge(ctx, sw); |
| |
| // put rendered template into context |
| ctx.put("decorator_body", sw.toString()); |
| |
| log.debug("Applying decorator " + velocityDecorator.getName()); |
| |
| // now render decorator to our output writer |
| velocityDecorator.merge(ctx, out); |
| |
| } else { |
| |
| // no decorator, so just merge template to our output writer |
| velocityTemplate.merge(ctx, out); |
| } |
| |
| long endTime = System.currentTimeMillis(); |
| long renderTime = (endTime - startTime) / RollerConstants.SEC_IN_MS; |
| |
| log.debug("Rendered [" + renderTemplate.getId() + "] in " |
| + renderTime + " secs"); |
| |
| } catch (ParseErrorException ex) { |
| |
| // in the case of a parsing error including a page we want to render |
| // an error on the page instead so the user knows what was wrong |
| velocityException = ex; |
| |
| // need to lookup parse error template |
| renderException(model, out, "error-parse.vm"); |
| |
| } catch (MethodInvocationException ex) { |
| |
| // in the case of a parsing error including a page we want to render |
| // an error on the page instead so the user knows what was wrong |
| velocityException = ex; |
| |
| // need to lookup parse error template |
| renderException(model, out, "error-parse.vm"); |
| |
| } catch (VelocityException ex) { |
| |
| // in the case of a parsing error including a macro we want to |
| // render an error page instead so the user knows what was wrong |
| velocityException = ex; |
| |
| // need to lookup parse error template |
| renderException(model, out, "error-parse.vm"); |
| |
| } catch (Exception ex) { |
| // wrap and rethrow so caller can deal with it |
| throw new RenderingException("Error during rendering", ex); |
| } |
| } |
| |
| /** |
| * Render Velocity Exception. |
| * |
| * @param model |
| * the model |
| * @param out |
| * the out |
| * @param template |
| * the template. Null if using existing template name |
| * |
| * @throws RenderingException |
| * the rendering exception |
| */ |
| private void renderException(Map<String, Object> model, Writer out, |
| String template) throws RenderingException { |
| |
| try { |
| |
| if (template != null) { |
| // need to lookup error page template |
| velocityTemplate = RollerVelocity.getTemplate(template, |
| deviceType); |
| } |
| |
| Context ctx = new VelocityContext(model); |
| ctx.put("exception", velocityException); |
| ctx.put("exceptionSource", renderTemplate.getId()); |
| ctx.put("exceptionDevice", deviceType); |
| ctx.put("utils", new UtilitiesModel()); |
| |
| // render output to Writer |
| velocityTemplate.merge(ctx, out); |
| |
| } catch (Exception e) { |
| // wrap and rethrow so caller can deal with it |
| throw new RenderingException("Error during rendering", e); |
| } |
| |
| } |
| |
| } |