package com.github.jknack.mwa.wro4j;
import static com.google.common.base.Preconditions.checkNotNull;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Collections;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.context.ServletContextAware;
import org.springframework.web.servlet.ModelAndView;
import ro.isdc.wro.config.Context;
import ro.isdc.wro.manager.WroManager;
import ro.isdc.wro.manager.factory.BaseWroManagerFactory;
import ro.isdc.wro.model.WroModel;
import ro.isdc.wro.model.factory.WroModelFactory;
import ro.isdc.wro.model.group.Group;
import ro.isdc.wro.model.group.InvalidGroupNameException;
import ro.isdc.wro.model.group.processor.Injector;
import ro.isdc.wro.model.group.processor.InjectorBuilder;
import com.github.jknack.mwa.mvc.AbstractModelContribution;
import com.github.jknack.mwa.mvc.ModelContribution;
/**
* Base class for {@link ModelContribution} based on Wro4j.
*
* @author edgar.espina
* @since 0.1.0
*/
public abstract class WroContribution extends AbstractModelContribution
implements ServletContextAware {
/**
* A {@link FilterConfig} for wro filter.
*
* @author edgar.espina
* @since 0.1.2
*/
static final class WroFilterConfig implements FilterConfig {
/**
* The servlet's context.
*/
private ServletContext servletContext;
/**
* Creates a new {@link WroFilterConfig}.
*
* @param servletContext The servlet's context.
*/
public WroFilterConfig(final ServletContext servletContext) {
this.servletContext = servletContext;
}
/**
* {@inheritDoc}
*/
@Override
public String getFilterName() {
return "wroFilter";
}
/**
* {@inheritDoc}
*/
@Override
public ServletContext getServletContext() {
return servletContext;
}
/**
* {@inheritDoc}
*/
@Override
public String getInitParameter(final String name) {
return null;
}
/**
* {@inheritDoc}
*/
@Override
public Enumeration<String> getInitParameterNames() {
return null;
}
}
/**
* The default group name, if the candidate group cannot be found.
*/
public static final String DEFAULT_GROUP = "defaults";
/**
* The {@link WroModel} factory.
*/
private BaseWroManagerFactory wroManagerFactory;
/**
* A clear cache flag.
*/
protected final String version = new SimpleDateFormat("yyyyMMdd.hhmmss")
.format(new Date());
/**
* The wro filter config.
*/
private FilterConfig wroConfig;
/**
* Creates a new {@link WroContribution}.
*
* @param wroManagerFactory The {@link WroModelFactory}. Required.
*/
public WroContribution(final BaseWroManagerFactory wroManagerFactory) {
this.wroManagerFactory =
checkNotNull(wroManagerFactory, "The wroManagerFactory is required.");
}
/**
* The {@link WroModel} from wro.xml.
*
* @param request The HTTP request.
* @param response The HTTP response.
* @return The {@link WroModel} from wro.xml.
*/
private Map<String, Group> lookupGroups(final HttpServletRequest request,
final HttpServletResponse response) {
try {
Context.set(Context.webContext(request, response, wroConfig));
// TODO: Add a cache for no-dev.
Injector injector = InjectorBuilder.create(wroManagerFactory).build();
WroManager manager = wroManagerFactory.create();
WroModelFactory modelFactory = manager.getModelFactory();
injector.inject(modelFactory);
WroModel model = modelFactory.create();
Map<String, Group> groups = new HashMap<String, Group>();
for (Group group : model.getGroups()) {
groups.put(group.getName(), group);
}
return groups;
} finally {
Context.unset();
}
}
/**
* {@inheritDoc}
*/
@Override
public final void contribute(final HttpServletRequest request,
final HttpServletResponse response, final ModelAndView modelAndView)
throws IOException {
try {
Map<String, Group> groups = lookupGroups(request, response);
String candidate = defaultGroup(modelAndView);
Group group = groups.remove(candidate);
if (group == null) {
group = groups.remove("defaults");
}
if (group == null) {
throw new InvalidGroupNameException("'" + candidate
+ "'. Available groups are: " + groups.keySet());
}
doContribution(group, modelAndView, groups);
} catch (InvalidGroupNameException ex) {
modelAndView.addObject(varName(), "");
modelAndView.addObject(resourcesVarName(), Collections.emptyList());
logger.error("Groups not found: " + ex.getMessage(), ex);
}
}
/**
* Extract the default group name from the model.
*
* @param modelAndView The model and view.
* @return The group's name.
*/
protected String defaultGroup(final ModelAndView modelAndView) {
return modelAndView.getViewName();
}
/**
* Add wro contribution to the model.
*
* @param group The group behind the view.
* @param modelAndView The model and view.
* @param additionalGroups Additional groups, defined by
* {@link #additionalGroups()}.
* @throws IOException If something goes wrong.
*/
protected abstract void doContribution(final Group group,
final ModelAndView modelAndView, Map<String, Group> additionalGroups)
throws IOException;
/**
* The name of the model attribute.
*
* @return The name of the model attribute.
*/
protected abstract String varName();
/**
* The name of the model attribute.
*
* @return The name of the model attribute.
*/
protected abstract String resourcesVarName();
@Override
public void setServletContext(final ServletContext servletContext) {
super.setServletContext(servletContext);
wroConfig = new WroFilterConfig(servletContext);
}
/**
* Generate a script element for the javascript URI.
*
* @param uri The javascript URI.
* @return A script HTML element.
*/
protected String script(final String uri) {
String script = "<script type=\"text/javascript\" src=\"%s\"></script>\n";
return String.format(script, normalizePath(uri));
}
/**
* Check if the path start with the servlet context. If not the servlet
* context is prepend to the URI.
*
* @param uri A URI.
* @return A URI with the servlet context.
*/
protected String normalizePath(final String uri) {
String contextPath = contextPath();
if (uri.startsWith(contextPath)) {
return uri;
}
return contextPath + (uri.startsWith("/") ? uri : "/" + uri);
}
/**
* Generate a link element for the css URI.
*
* @param uri The css URI.
* @return A link HTML element.
*/
protected String link(final String uri) {
String link = "<link rel=\"stylesheet\" text=\"text/css\" href=\"%s\">\n";
return String.format(link, normalizePath(uri));
}
}