package org.apache.turbine.services.template;
/*
* 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.
*/
import java.io.File;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.fulcrum.factory.FactoryException;
import org.apache.fulcrum.factory.FactoryService;
import org.apache.turbine.Turbine;
import org.apache.turbine.TurbineConstants;
import org.apache.turbine.modules.Layout;
import org.apache.turbine.modules.Loader;
import org.apache.turbine.modules.Navigation;
import org.apache.turbine.modules.Page;
import org.apache.turbine.modules.Screen;
import org.apache.turbine.services.InitializationException;
import org.apache.turbine.services.TurbineBaseService;
import org.apache.turbine.services.TurbineServices;
import org.apache.turbine.services.assemblerbroker.AssemblerBrokerService;
import org.apache.turbine.services.servlet.TurbineServlet;
import org.apache.turbine.services.template.mapper.BaseTemplateMapper;
import org.apache.turbine.services.template.mapper.ClassMapper;
import org.apache.turbine.services.template.mapper.DirectMapper;
import org.apache.turbine.services.template.mapper.DirectTemplateMapper;
import org.apache.turbine.services.template.mapper.LayoutTemplateMapper;
import org.apache.turbine.services.template.mapper.Mapper;
import org.apache.turbine.services.template.mapper.ScreenTemplateMapper;
import org.apache.turbine.util.RunData;
import org.apache.turbine.util.uri.URIConstants;
/**
* This service provides a method for mapping templates to their
* appropriate Screens or Navigations. It also allows templates to
* define a layout/navigations/screen modularization within the
* template structure. It also performs caching if turned on in the
* properties file.
*
* This service is not bound to a specific templating engine but we
* will use the Velocity templating engine for the examples. It is
* available by using the VelocityService.
*
* This assumes the following properties in the Turbine configuration:
*
* <pre>
* # Register the VelocityService for the "vm" extension.
* services.VelocityService.template.extension=vm
*
* # Default Java class for rendering a Page in this service
* # (must be found on the class path (org.apache.turbine.modules.page.VelocityPage))
* services.VelocityService.default.page = VelocityPage
*
* # Default Java class for rendering a Screen in this service
* # (must be found on the class path (org.apache.turbine.modules.screen.VelocityScreen))
* services.VelocityService.default.screen=VelocityScreen
*
* # Default Java class for rendering a Layout in this service
* # (must be found on the class path (org.apache.turbine.modules.layout.VelocityOnlyLayout))
* services.VelocityService.default.layout = VelocityOnlyLayout
*
* # Default Java class for rendering a Navigation in this service
* # (must be found on the class path (org.apache.turbine.modules.navigation.VelocityNavigation))
* services.VelocityService.default.navigation=VelocityNavigation
*
* # Default Template Name to be used as Layout. If nothing else is
* # found, return this as the default name for a layout
* services.VelocityService.default.layout.template = Default.vm
* </pre>
* If you want to render a template, a search path is used to find
* a Java class which might provide information for the context of
* this template.
*
* If you request e.g. the template screen
*
* about,directions,Driving.vm
*
* then the following class names are searched (on the module search
* path):
*
* 1. about.directions.Driving <- direct matching the template to the class name
* 2. about.directions.Default <- matching the package, class name is Default
* 3. about.Default <- stepping up in the package hierarchy, looking for Default
* 4. Default <- Class called "Default" without package
* 5. VelocityScreen <- The class configured by the Service (VelocityService) to
*
* And if you have the following module packages configured:
*
* module.packages = org.apache.turbine.modules, com.mycorp.modules
*
* then the class loader will look for
*
* org.apache.turbine.modules.screens.about.directions.Driving
* com.mycorp.modules.screens.about.directions.Driving
* org.apache.turbine.modules.screens.about.directions.Default
* com.mycorp.modules.screens.about.directions.Default
* org.apache.turbine.modules.screens.about.Default
* com.mycorp.modules.screens.about.Default
* org.apache.turbine.modules.screens.Default
* com.mycorp.modules.screens.Default
* org.apache.turbine.modules.screens.VelocityScreen
* com.mycorp.modules.screens.VelocityScreen
*
* Most of the times, you don't have any backing Java class for a
* template screen, so the first match will be
* org.apache.turbine.modules.screens.VelocityScreen
* which then renders your screen.
*
* Please note, that your Screen Template (Driving.vm) must exist!
* If it does not exist, the Template Service will report an error.
*
* Once the screen is found, the template service will look for
* the Layout and Navigation templates of your Screen. Here, the
* template service looks for matching template names!
*
* Consider our example: about,directions,Driving.vm (Screen Name)
*
* Now the template service will look for the following Navigation
* and Layout templates:
*
* 1. about,directions,Driving.vm <- exact match
* 2. about,directions,Default.vm <- package match, Default name
* 3. about,Default.vm <- stepping up in the hierarchy
* 4. Default.vm <- The name configured as default.layout.template
* in the Velocity service.
*
* And now Hennings' two golden rules for using templates:
*
* Many examples and docs from older Turbine code show template pathes
* with a slashes. Repeat after me: "TEMPLATE NAMES NEVER CONTAIN SLASHES!"
*
* Many examples and docs from older Turbine code show templates that start
* with "/". This is not only a violation of the rule above but actively breaks
* things like loading templates from a jar with the velocity jar loader. Repeat
* after me: "TEMPLATE NAMES ARE NOT PATHES. THEY'RE NOT ABSOLUTE AND HAVE NO
* LEADING /".
*
* If you now wonder how a template name is mapped to a file name: This is
* scope of the templating engine. Velocity e.g. has this wonderful option to
* load templates from jar archives. There is no single file but you tell
* velocity "get about,directions,Driving.vm" and it returns the rendered
* template. This is not the job of the Templating Service but of the Template
* rendering services like VelocityService.
*
* @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
* @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
* @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
* @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
* @author <a href="mailto:ilkka.priha@simsoft.fi">Ilkka Priha</a>
* @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
* @version $Id: TurbineTemplateService.java 1078552 2011-03-06 19:58:46Z tv $
*/
public class TurbineTemplateService
extends TurbineBaseService
implements TemplateService
{
/** Logging */
private static Log log = LogFactory.getLog(TurbineTemplateService.class);
/** Represents Page Objects */
public static final int PAGE_KEY = 0;
/** Represents Screen Objects */
public static final int SCREEN_KEY = 1;
/** Represents Layout Objects */
public static final int LAYOUT_KEY = 2;
/** Represents Navigation Objects */
public static final int NAVIGATION_KEY = 3;
/** Represents Layout Template Objects */
public static final int LAYOUT_TEMPLATE_KEY = 4;
/** Represents Layout Template Objects */
public static final String LAYOUT_TEMPLATE_NAME = "layout.template";
/** Represents Screen Template Objects */
public static final int SCREEN_TEMPLATE_KEY = 5;
/** Represents Screen Template Objects */
public static final String SCREEN_TEMPLATE_NAME = "screen.template";
/** Represents Navigation Template Objects */
public static final int NAVIGATION_TEMPLATE_KEY = 6;
/** Represents Navigation Template Objects */
public static final String NAVIGATION_TEMPLATE_NAME = "navigation.template";
/** Number of different Template Types that we know of */
public static final int TEMPLATE_TYPES = 7;
/** Here we register the mapper objects for our various object types */
private Mapper [] mapperRegistry = null;
/**
* The default file extension used as a registry key when a
* template's file extension cannot be determined.
*
* @deprecated. Use TemplateService.DEFAULT_EXTENSION_VALUE.
*/
protected static final String NO_FILE_EXT = TemplateService.DEFAULT_EXTENSION_VALUE;
/** Flag set if cache is to be used. */
private boolean useCache = false;
/** Default extension for templates. */
private String defaultExtension;
/** Default template without the default extension. */
private String defaultTemplate;
/**
* The mappings of template file extensions to {@link
* org.apache.turbine.services.template.TemplateEngineService}
* implementations. Implementing template engines can locate
* templates within the capability of any resource loaders they
* may possess, and other template engines are stuck with file
* based template hierarchy only.
*/
private Map<String, TemplateEngineService> templateEngineRegistry = null;
/**
* C'tor
*/
public TurbineTemplateService()
{
// empty
}
/**
* Called the first time the Service is used.
*
* @exception InitializationException Something went wrong when
* setting up the Template Service.
*/
@Override
public void init()
throws InitializationException
{
// Get the configuration for the template service.
Configuration config = getConfiguration();
// Get the default extension to use if nothing else is applicable.
defaultExtension = config.getString(TemplateService.DEFAULT_EXTENSION_KEY,
TemplateService.DEFAULT_EXTENSION_VALUE);
defaultTemplate = config.getString(TemplateService.DEFAULT_TEMPLATE_KEY,
TemplateService.DEFAULT_TEMPLATE_VALUE);
// Check to see if we are going to be caching modules.
// Aaargh, who moved this _out_ of the TemplateService package?
useCache = Turbine.getConfiguration().getBoolean(TurbineConstants.MODULE_CACHE_KEY,
TurbineConstants.MODULE_CACHE_DEFAULT);
log.debug("Default Extension: " + defaultExtension);
log.debug("Default Template: " + defaultTemplate);
log.debug("Use Caching: " + useCache);
templateEngineRegistry = Collections.synchronizedMap(new HashMap<String, TemplateEngineService>());
initMapper(config);
setInit(true);
}
/**
* Returns true if the Template Service has caching activated
*
* @return true if Caching is active.
*/
public boolean isCaching()
{
return useCache;
}
/**
* Get the default template name extension specified
* in the template service properties. If no extension
* is defined, return the empty string.
*
* @return The default extension.
*/
public String getDefaultExtension()
{
return StringUtils.isNotEmpty(defaultExtension) ? defaultExtension : "";
}
/**
* Return Extension for a supplied template
*
* @param template The template name
*
* @return extension The extension for the supplied template
*/
public String getExtension(String template)
{
if (StringUtils.isEmpty(template))
{
return getDefaultExtension();
}
int dotIndex = template.indexOf(EXTENSION_SEPARATOR);
return (dotIndex < 0) ? getDefaultExtension() : template.substring(dotIndex + 1);
}
/**
* Returns the Default Template Name with the Default Extension.
* If the extension is unset, return only the template name
*
* @return The default template Name
*/
public String getDefaultTemplate()
{
StringBuffer sb = new StringBuffer();
sb.append(defaultTemplate);
if (StringUtils.isNotEmpty(defaultExtension))
{
sb.append(EXTENSION_SEPARATOR);
sb.append(getDefaultExtension());
}
return sb.toString();
}
/**
* Get the default page module name of the template engine
* service corresponding to the default template name extension.
*
* @return The default page module name.
*/
public String getDefaultPage()
{
return getDefaultPageName(getDefaultTemplate());
}
/**
* Get the default screen module name of the template engine
* service corresponding to the default template name extension.
*
* @return The default screen module name.
*/
public String getDefaultScreen()
{
return getDefaultScreenName(getDefaultTemplate());
}
/**
* Get the default layout module name of the template engine
* service corresponding to the default template name extension.
*
* @return The default layout module name.
*/
public String getDefaultLayout()
{
return getDefaultLayoutName(getDefaultTemplate());
}
/**
* Get the default navigation module name of the template engine
* service corresponding to the default template name extension.
*
* @return The default navigation module name.
*/
public String getDefaultNavigation()
{
return getDefaultNavigationName(getDefaultTemplate());
}
/**
* Get the default layout template name of the template engine
* service corresponding to the default template name extension.
*
* @return The default layout template name.
*/
public String getDefaultLayoutTemplate()
{
return getDefaultLayoutTemplateName(getDefaultTemplate());
}
/**
* Get the default page module name of the template engine
* service corresponding to the template name extension of
* the named template.
*
* @param template The template name.
* @return The default page module name.
*/
public String getDefaultPageName(String template)
{
return (mapperRegistry[PAGE_KEY]).getDefaultName(template);
}
/**
* Get the default screen module name of the template engine
* service corresponding to the template name extension of
* the named template.
*
* @param template The template name.
* @return The default screen module name.
*/
public String getDefaultScreenName(String template)
{
return (mapperRegistry[SCREEN_KEY]).getDefaultName(template);
}
/**
* Get the default layout module name of the template engine
* service corresponding to the template name extension of
* the named template.
*
* @param template The template name.
* @return The default layout module name.
*/
public String getDefaultLayoutName(String template)
{
return (mapperRegistry[LAYOUT_KEY]).getDefaultName(template);
}
/**
* Get the default navigation module name of the template engine
* service corresponding to the template name extension of
* the named template.
*
* @param template The template name.
* @return The default navigation module name.
*/
public String getDefaultNavigationName(String template)
{
return (mapperRegistry[NAVIGATION_KEY]).getDefaultName(template);
}
/**
* Get the default layout template name of the template engine
* service corresponding to the template name extension of
* the named template.
*
* @param template The template name.
* @return The default layout template name.
*/
public String getDefaultLayoutTemplateName(String template)
{
return (mapperRegistry[LAYOUT_TEMPLATE_KEY]).getDefaultName(template);
}
/**
* Find the default page module name for the given request.
*
* @param data The encapsulation of the request to retrieve the
* default page for.
* @return The default page module name.
*/
public String getDefaultPageName(RunData data)
{
String template = data.getParameters().get(URIConstants.CGI_TEMPLATE_PARAM);
return (template != null) ?
getDefaultPageName(template) : getDefaultPage();
}
/**
* Find the default layout module name for the given request.
*
* @param data The encapsulation of the request to retrieve the
* default layout for.
* @return The default layout module name.
*/
public String getDefaultLayoutName(RunData data)
{
String template = data.getParameters().get(URIConstants.CGI_TEMPLATE_PARAM);
return (template != null) ?
getDefaultLayoutName(template) : getDefaultLayout();
}
/**
* Locate and return the name of the screen module to be used
* with the named screen template.
*
* @param template The screen template name.
* @return The found screen module name.
* @exception Exception, a generic exception.
*/
public String getScreenName(String template)
throws Exception
{
return (mapperRegistry[SCREEN_KEY]).getMappedName(template);
}
/**
* Locate and return the name of the layout module to be used
* with the named layout template.
*
* @param template The layout template name.
* @return The found layout module name.
* @exception Exception, a generic exception.
*/
public String getLayoutName(String template)
throws Exception
{
return (mapperRegistry[LAYOUT_KEY]).getMappedName(template);
}
/**
* Locate and return the name of the navigation module to be used
* with the named navigation template.
*
* @param template The navigation template name.
* @return The found navigation module name.
* @exception Exception, a generic exception.
*/
public String getNavigationName(String template)
throws Exception
{
return (mapperRegistry[NAVIGATION_KEY]).getMappedName(template);
}
/**
* Locate and return the name of the screen template corresponding
* to the given template name parameter. This might return null if
* the screen is not found!
*
* @param template The template name parameter.
* @return The found screen template name.
* @exception Exception, a generic exception.
*/
public String getScreenTemplateName(String template)
throws Exception
{
return (mapperRegistry[SCREEN_TEMPLATE_KEY]).getMappedName(template);
}
/**
* Locate and return the name of the layout template corresponding
* to the given screen template name parameter.
*
* @param template The template name parameter.
* @return The found screen template name.
* @exception Exception, a generic exception.
*/
public String getLayoutTemplateName(String template)
throws Exception
{
return (mapperRegistry[LAYOUT_TEMPLATE_KEY]).getMappedName(template);
}
/**
* Locate and return the name of the navigation template corresponding
* to the given template name parameter. This might return null if
* the navigation is not found!
*
* @param template The template name parameter.
* @return The found navigation template name.
* @exception Exception, a generic exception.
*/
public String getNavigationTemplateName(String template)
throws Exception
{
return (mapperRegistry[NAVIGATION_TEMPLATE_KEY]).getMappedName(template);
}
/**
* Translates the supplied template paths into their Turbine-canonical
* equivalent (probably absolute paths). This is used if the templating
* engine (e.g. JSP) does not provide any means to load a page but
* the page path is passed to the servlet container.
*
* @param templatePaths An array of template paths.
* @return An array of translated template paths.
* @deprecated Each template engine service should know how to translate
* a request onto a file.
*/
@Deprecated
public String[] translateTemplatePaths(String[] templatePaths)
{
for (int i = 0; i < templatePaths.length; i++)
{
templatePaths[i] = TurbineServlet.getRealPath(templatePaths[i]);
}
return templatePaths;
}
/**
* Delegates to the appropriate {@link
* org.apache.turbine.services.template.TemplateEngineService} to
* check the existance of the specified template.
*
* @param template The template to check for the existance of.
* @param templatePaths The paths to check for the template.
* @deprecated Use templateExists from the various Templating Engines
*/
@Deprecated
public boolean templateExists(String template,
String[] templatePaths)
{
for (int i = 0; i < templatePaths.length; i++)
{
if (new File(templatePaths[i], template).exists())
{
return true;
}
}
return false;
}
/**
* Registers the provided template engine for use by the
* <code>TemplateService</code>.
*
* @param service The <code>TemplateEngineService</code> to register.
*/
public synchronized void registerTemplateEngineService(TemplateEngineService service)
{
String[] exts = service.getAssociatedFileExtensions();
for (int i = 0; i < exts.length; i++)
{
templateEngineRegistry.put(exts[i], service);
}
}
/**
* The {@link org.apache.turbine.services.template.TemplateEngineService}
* associated with the specified template's file extension.
*
* @param template The template name.
* @return The template engine service.
*/
public TemplateEngineService getTemplateEngineService(String template)
{
return templateEngineRegistry.get(getExtension(template));
}
/**
* Register a template Mapper to the service. This Mapper
* performs the template mapping and searching for a specific
* object type which is managed by the TemplateService.
*
* @param templateKey One of the _KEY constants for the Template object types.
* @param mapper An object which implements the Mapper interface.
*/
private void registerMapper(int templateKey, Mapper mapper)
{
mapper.init();
mapperRegistry[templateKey] = mapper;
}
/**
* Load and configure the Template mappers for
* the Template Service.
*
* @param conf The current configuration object.
* @throws InitializationException A problem occured trying to set up the mappers.
*/
private void initMapper(Configuration conf)
throws InitializationException
{
// Create a registry with the number of Template Types managed by this service.
// We could use a List object here and extend the number of managed objects
// dynamically. However, by using an Object Array, we get much more performance
// out of the Template Service.
mapperRegistry = new Mapper[TEMPLATE_TYPES];
String [] mapperNames = new String [] {
Page.NAME, Screen.NAME, Layout.NAME, Navigation.NAME,
LAYOUT_TEMPLATE_NAME, SCREEN_TEMPLATE_NAME, NAVIGATION_TEMPLATE_NAME
};
String [] mapperKeys = new String [] {
Page.NAME, Screen.NAME, Layout.NAME, Navigation.NAME,
Layout.NAME, Screen.NAME, Navigation.NAME
};
String [] mapperClasses = new String [] {
DirectMapper.class.getName(),
ClassMapper.class.getName(),
ClassMapper.class.getName(),
ClassMapper.class.getName(),
LayoutTemplateMapper.class.getName(),
ScreenTemplateMapper.class.getName(),
DirectTemplateMapper.class.getName()
};
AssemblerBrokerService ab = (AssemblerBrokerService)TurbineServices.getInstance()
.getService(AssemblerBrokerService.SERVICE_NAME);
int [] mapperCacheSize = new int [mapperKeys.length];
Loader [] mapperLoader = new Loader [mapperKeys.length];
for (int i = 0; i < mapperKeys.length; i++)
{
mapperLoader[i] = ab.getLoader(mapperKeys[i]);
mapperCacheSize[i] = (mapperLoader[i] != null) ? mapperLoader[i].getCacheSize() : 0;
}
// HACK: to achieve the same behaviour as before
mapperLoader[LAYOUT_TEMPLATE_KEY] = null;
mapperLoader[SCREEN_TEMPLATE_KEY] = null;
mapperLoader[NAVIGATION_TEMPLATE_KEY] = null;
String [] mapperDefaultProperty = new String [] {
TemplateEngineService.DEFAULT_PAGE,
TemplateEngineService.DEFAULT_SCREEN,
TemplateEngineService.DEFAULT_LAYOUT,
TemplateEngineService.DEFAULT_NAVIGATION,
TemplateEngineService.DEFAULT_LAYOUT_TEMPLATE,
TemplateEngineService.DEFAULT_SCREEN_TEMPLATE,
TemplateEngineService.DEFAULT_NAVIGATION_TEMPLATE
};
char [] mapperSeparator = new char [] { '.', '.', '.', '.', '/', '/', '/' };
String [] mapperPrefix = new String [] {
null, null, null, null,
Layout.PREFIX,
Screen.PREFIX,
Navigation.PREFIX };
for (int i = 0; i < TEMPLATE_TYPES; i++)
{
StringBuffer mapperProperty = new StringBuffer();
mapperProperty.append("mapper.");
mapperProperty.append(mapperNames[i]);
mapperProperty.append(".class");
String mapperClass =
conf.getString(mapperProperty.toString(), mapperClasses[i]);
log.info("Using " + mapperClass + " to map " + mapperNames[i] + " elements");
Mapper tm = null;
try
{
FactoryService factory = (FactoryService)TurbineServices.getInstance().getService(FactoryService.ROLE);
tm = (Mapper) factory.getInstance(mapperClass);
}
catch (FactoryException e)
{
throw new InitializationException("", e);
}
tm.setUseCache(useCache);
tm.setCacheSize(mapperCacheSize[i]);
tm.setDefaultProperty(mapperDefaultProperty[i]);
tm.setSeparator(mapperSeparator[i]);
if ((mapperLoader[i] != null) && (tm instanceof ClassMapper))
{
((ClassMapper) tm).setLoader(mapperLoader[i]);
}
if ((mapperPrefix[i] != null) && (tm instanceof BaseTemplateMapper))
{
((BaseTemplateMapper) tm).setPrefix(mapperPrefix[i]);
}
registerMapper(i, tm);
}
}
}