GData html render preview: LUCENE-660

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@433051 13f79535-47bb-0310-9956-ffa450edef68

contrib/gdata-server/src/java/org/apache/lucene/gdata/server/GDataRequest.java

@@ -58,6 +58,7 @@ public class GDataRequest {
     private static final String RESPONSE_FORMAT_PARAMETER = "alt";
 
     private static final String RESPONSE_FORMAT_PARAMETER_RSS = "rss";
+    private static final String RESPONSE_FORMAT_PARAMETER_HTML = "html";
 
     private static final int DEFAULT_ITEMS_PER_PAGE = 25;
 
@@ -276,6 +277,8 @@ public class GDataRequest {
             return;
         if (formatParameter.equalsIgnoreCase(RESPONSE_FORMAT_PARAMETER_RSS))
             this.responseFormat = OutputFormat.RSS;
+        if (formatParameter.equalsIgnoreCase(RESPONSE_FORMAT_PARAMETER_HTML))
+            this.responseFormat = OutputFormat.HTML;
 
     }
 
@@ -439,7 +442,11 @@ public class GDataRequest {
         /**
          * Output format RSS
          */
-        RSS
+        RSS,
+        /**
+         * Output format html if user defined xsl style sheet is present 
+         */
+        HTML
     }
 
     /**

contrib/gdata-server/src/java/org/apache/lucene/gdata/server/GDataResponse.java

@@ -17,14 +17,23 @@
 package org.apache.lucene.gdata.server;
 
 import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
 import java.io.Writer;
 import java.util.Date;
 
 import javax.servlet.http.HttpServletResponse;
+import javax.xml.transform.Source;
+import javax.xml.transform.Templates;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.stream.StreamResult;
+import javax.xml.transform.stream.StreamSource;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.lucene.gdata.server.GDataRequest.OutputFormat;
+import org.apache.lucene.gdata.server.registry.ProvidedService;
 import org.apache.lucene.gdata.utils.DateFormater;
 
 import com.google.gdata.data.BaseEntry;
@@ -104,7 +113,7 @@ public class GDataResponse {
     public static final int UNAUTHORIZED = HttpServletResponse.SC_UNAUTHORIZED;
     
     
-    private static final Log LOG = LogFactory.getLog(GDataResponse.class);
+    static final Log LOG = LogFactory.getLog(GDataResponse.class);
     private int error;
 
     private boolean isError = false;
@@ -119,11 +128,6 @@ public class GDataResponse {
 
     protected static final String XMLMIME_RSS = "text/xml";
 
-    private static final String DEFAUL_NAMESPACE_URI = "http://www.w3.org/2005/Atom";
-
-    private static final Namespace DEFAULT_NAMESPACE = new Namespace("",
-            DEFAUL_NAMESPACE_URI);
-
     private static final String HEADER_LASTMODIFIED = "Last-Modified";
 
     /**
@@ -188,33 +192,26 @@ public class GDataResponse {
      * 
      * @param feed -
      *            the feed to respond to the client
-     * @param profile -
+     * @param service - the service to render the feed
-     *            the extension profile for the feed to write
+     * 
      * @throws IOException -
      *             if an I/O exception occurs, often caused by an already
      *             closed Writer or OutputStream
      * 
      */
-    public void sendResponse(BaseFeed feed, ExtensionProfile profile)
+    public void sendResponse(final BaseFeed feed, final ProvidedService service)
             throws IOException {
         if (feed == null)
             throw new IllegalArgumentException("feed must not be null");
-        if (profile == null)
+        if (service == null)
             throw new IllegalArgumentException(
-                    "extension profile must not be null");
+                    "provided service must not be null");
         DateTime time = feed.getUpdated();
         if (time != null)
             setLastModifiedHeader(time.getValue());
-        XmlWriter writer = createWriter();
+        FormatWriter writer = FormatWriter.getFormatWriter(this,service);
-        
+        writer.generateOutputFormat(feed,this.response);
-        if (this.outputFormat.equals(OutputFormat.ATOM)) {
+
-            this.response.setContentType(XMLMIME_ATOM);
-            feed.generateAtom(writer, profile);
-        } else {
-            this.response.setContentType(XMLMIME_RSS);
-            feed.generateRss(writer, profile);
-        }
-        writer.close();
     }
 
     /**
@@ -226,38 +223,27 @@ public class GDataResponse {
      * 
      * @param entry -
      *            the modified / created entry to send
-     * @param profile -
+     * @param service - the service to render the feed
-     *            the entries extension profile
      * @throws IOException -
      *             if an I/O exception occurs, often caused by an already
      *             closed Writer or OutputStream
      */
-    public void sendResponse(BaseEntry entry, ExtensionProfile profile)
+    public void sendResponse(BaseEntry entry, ProvidedService service)
             throws IOException {
         if (entry == null)
             throw new IllegalArgumentException("entry must not be null");
-        if (profile == null)
+        if (service == null)
             throw new IllegalArgumentException(
-                    "extension profile must not be null");
+                    "service must not be null");
         DateTime time = entry.getUpdated();
         if (time != null)
             setLastModifiedHeader(time.getValue());
-        XmlWriter writer = createWriter();
+        FormatWriter writer = FormatWriter.getFormatWriter(this,service);
-        if (this.outputFormat.equals(OutputFormat.ATOM))
+        writer.generateOutputFormat(entry,this.response);
-            entry.generateAtom(writer, profile);
+
-        else
-            entry.generateRss(writer, profile);
-        writer.close();
         
     }
 
-    private XmlWriter createWriter() throws IOException {
-        XmlWriter writer = new XmlWriter(getWriter(), this.encoding);
-        // set the default namespace to Atom if Atom is the response format
-        if (this.outputFormat.equals(OutputFormat.ATOM))
-            writer.setDefaultNamespace(DEFAULT_NAMESPACE);
-        return writer;
-    }
 
     /**
      * This encoding will be used to encode the xml representation of feed or
@@ -326,4 +312,138 @@ public class GDataResponse {
         this.response.setStatus(status);
     }
 
+    private static abstract class FormatWriter{
+        
+        static FormatWriter getFormatWriter(final GDataResponse response, final ProvidedService service ){
+            OutputFormat format = response.getOutputFormat();
+            if(format == OutputFormat.HTML){
+                return new HTMLFormatWriter(service);
+            }
+            return new SyndicateFormatWriter(service,format,response.getEncoding());
+        }
+        
+        abstract void generateOutputFormat(final BaseFeed feed, final HttpServletResponse response) throws IOException;
+        abstract void generateOutputFormat(final BaseEntry entry, final HttpServletResponse response) throws IOException;
+        
+        private static class HTMLFormatWriter extends FormatWriter{
+            private static final String CONTENT_TYPE = "text/html";
+            private final ProvidedService service;
+            
+            HTMLFormatWriter(final ProvidedService service){
+                this.service = service;
+            }
+            @Override
+            void generateOutputFormat(BaseFeed feed, final HttpServletResponse response) throws IOException {
+                Templates template = this.service.getTransformTemplate();
+                response.setContentType(CONTENT_TYPE);
+                if(template == null){
+                    sendNotAvailable(response);
+                    return;
+                }
+                StringWriter writer = new StringWriter();
+                XmlWriter xmlWriter = new XmlWriter(writer);
+                feed.generateAtom(xmlWriter,this.service.getExtensionProfile());
+                try {
+                    writeHtml(template,response.getWriter(),writer);
+                } catch (TransformerException e) {
+                 LOG.error("Can not transform feed for service "+this.service.getName(),e);
+                 sendNotAvailable(response);
+                    
+                }
+            }
+
+            @Override
+            void generateOutputFormat(BaseEntry entry, final HttpServletResponse response)  throws IOException{
+                Templates template = this.service.getTransformTemplate();
+                response.setContentType(CONTENT_TYPE);
+                if(template == null){
+                    sendNotAvailable(response);
+                    return;
+                }
+                StringWriter writer = new StringWriter();
+                XmlWriter xmlWriter = new XmlWriter(writer);
+                entry.generateAtom(xmlWriter,this.service.getExtensionProfile());
+                try {
+                    writeHtml(template,response.getWriter(),writer);
+                } catch (TransformerException e) {
+                 LOG.error("Can not transform feed for service "+this.service.getName(),e);
+                 sendNotAvailable(response);
+                    
+                }
+
+            }
+            
+            private void writeHtml(final Templates template, final Writer writer, final StringWriter source ) throws TransformerException{
+                Transformer transformer = template.newTransformer();
+                Source tranformSource = new StreamSource(new StringReader(source.toString())); 
+                transformer.transform(tranformSource,new StreamResult(writer));
+            }
+            
+            private void sendNotAvailable(final HttpServletResponse response) throws IOException{
+                response.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE, "No transformation stylesheet available");
+            }
+            
+        }
+        private static class SyndicateFormatWriter extends FormatWriter{
+            private static final String DEFAUL_NAMESPACE_URI = "http://www.w3.org/2005/Atom";
+
+            private static final Namespace DEFAULT_NAMESPACE = new Namespace("",
+                    DEFAUL_NAMESPACE_URI);
+            private final ProvidedService service;
+            private final String encoding;
+            private final OutputFormat format;
+            
+            SyndicateFormatWriter(final ProvidedService service,final OutputFormat format, String encoding){
+                this.service = service;
+                this.format = format;
+                this.encoding = encoding;
+                
+            }
+            @Override
+            void generateOutputFormat(final BaseFeed feed, final HttpServletResponse response) throws IOException {
+                XmlWriter writer = null;
+                try{
+                 writer = createWriter(response.getWriter());
+                if (this.format == OutputFormat.ATOM) {
+                    response.setContentType(XMLMIME_ATOM);
+                    feed.generateAtom(writer, this.service.getExtensionProfile());
+                } else {
+                    response.setContentType(XMLMIME_RSS);
+                    feed.generateRss(writer, this.service.getExtensionProfile());
+                }
+                }finally{
+                    if(writer != null)
+                        writer.close();
+                }
+            }
+
+            @Override
+            void generateOutputFormat(final BaseEntry entry, final HttpServletResponse response) throws IOException {
+                XmlWriter writer = null;
+                try{
+                 writer = createWriter(response.getWriter());
+                if (this.format == OutputFormat.ATOM) {
+                    response.setContentType(XMLMIME_ATOM);
+                    entry.generateAtom(writer, this.service.getExtensionProfile());
+                } else {
+                    response.setContentType(XMLMIME_RSS);
+                    entry.generateRss(writer, this.service.getExtensionProfile());
+                }
+                }finally{
+                    if(writer != null)
+                        writer.close();
+                }
+            }
+            private XmlWriter createWriter(final Writer target) throws IOException {
+                XmlWriter writer = new XmlWriter(target, this.encoding);
+                // set the default namespace to Atom if Atom is the response format
+                if (this.format == OutputFormat.ATOM)
+                    writer.setDefaultNamespace(DEFAULT_NAMESPACE);
+                return writer;
+            }
+        }
+    }
+    
+    
+    
 }

contrib/gdata-server/src/java/org/apache/lucene/gdata/server/registry/ProvidedService.java

@@ -15,6 +15,8 @@
  */ 
 package org.apache.lucene.gdata.server.registry;
 
+import javax.xml.transform.Templates;
+
 import org.apache.lucene.gdata.search.config.IndexSchema;
 
 import com.google.gdata.data.ExtensionProfile;
@@ -55,4 +57,9 @@ public interface ProvidedService {
      * @return the index schema configuration for this service
      */
     public abstract IndexSchema getIndexSchema();
+    /**
+     * @return the compiled xslt stylesheet to transform the feed / entry for preview
+     */
+    public abstract Templates getTransformTemplate();
+    
 }

contrib/gdata-server/src/java/org/apache/lucene/gdata/server/registry/ProvidedServiceConfig.java

@@ -17,6 +17,11 @@ package org.apache.lucene.gdata.server.registry;
 
 import java.lang.reflect.Constructor;
 
+import javax.xml.transform.Templates;
+import javax.xml.transform.TransformerConfigurationException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.stream.StreamSource;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.lucene.gdata.search.config.IndexSchema;
@@ -26,9 +31,7 @@ import org.apache.lucene.gdata.utils.SimpleObjectPool;
 
 import com.google.gdata.data.BaseEntry;
 import com.google.gdata.data.BaseFeed;
-import com.google.gdata.data.Entry;
 import com.google.gdata.data.ExtensionProfile;
-import com.google.gdata.data.Feed;
 
 /**
  * Standard implementation of
@@ -78,6 +81,9 @@ public class ProvidedServiceConfig implements ProvidedService, ScopeVisitor {
     private ExtensionProfile extensionProfile;
 
     private int poolSize = DEFAULT_POOL_SIZE;
+    
+    private Templates transformerTemplate;
+    
 
     /**
      * @return Returns the poolSize.
@@ -326,4 +332,33 @@ public class ProvidedServiceConfig implements ProvidedService, ScopeVisitor {
             this.indexSchema.setName(this.serviceName);
     }
 
+    /**
+     * @see org.apache.lucene.gdata.server.registry.ProvidedService#getTransformTemplate()
+     */
+    public Templates getTransformTemplate() {
+        
+        return this.transformerTemplate;
+    }
+    
+    /**
+     * Sets and creates the preview transformer xslt template to provide a html formate for feeds and entries.
+     * The given file name must be available in the classpath. 
+     * @param filename - the name of the file in the classpath
+     */
+    public void setXsltStylesheet(String filename){
+        if(filename == null || filename.length() == 0){
+            LOG.info("No preview stylesheet configured for service "+this.serviceName);
+            return;
+        }
+        
+        TransformerFactory factory = TransformerFactory.newInstance();
+        
+        try {
+            this.transformerTemplate = factory.newTemplates(new StreamSource(ProvidedServiceConfig.class.getResourceAsStream(filename.startsWith("/")?filename:"/"+filename)));
+        } catch (TransformerConfigurationException e) {
+            throw new RuntimeException("Can not compile xslt stylesheet path: "+filename,e);
+        }
+        
+    }
+    
 }

contrib/gdata-server/src/java/org/apache/lucene/gdata/server/registry/RegistryBuilder.java

@@ -77,6 +77,7 @@ class RegistryBuilder {
         digester.addBeanPropertySetter("gdata/service/entry-class", "entryType");
         digester.addBeanPropertySetter("gdata/service/extension-profile",
                 "extensionProfileClass");
+        digester.addBeanPropertySetter("gdata/service/previewStyleSheet","xsltStylesheet");
         addIndexRule(digester);
         /*
          * load components and configurations

contrib/gdata-server/src/java/org/apache/lucene/gdata/servlet/handler/DefaultGetHandler.java

@@ -90,12 +90,12 @@ public class DefaultGetHandler extends AbstractGdataRequestHandler {
                         this.feedResponse);
 
                 this.feedResponse.sendResponse(feed, this.feedRequest
-                        .getConfigurator().getExtensionProfile());
+                        .getConfigurator());
             } else {
                 BaseEntry entry = this.service.getSingleEntry(this.feedRequest,
                         this.feedResponse);
                 this.feedResponse.sendResponse(entry, this.feedRequest
-                        .getConfigurator().getExtensionProfile());
+                        .getConfigurator());
             }
 
         } catch (ServiceException e) {

contrib/gdata-server/src/java/org/apache/lucene/gdata/servlet/handler/DefaultInsertHandler.java

@@ -74,7 +74,7 @@ public class DefaultInsertHandler extends AbstractGdataRequestHandler {
         BaseEntry entry = this.service.createEntry(this.feedRequest,this.feedResponse);
         setFeedResponseFormat();
         setFeedResponseStatus(GDataResponse.CREATED);        
-        this.feedResponse.sendResponse(entry, this.feedRequest.getConfigurator().getExtensionProfile());
+        this.feedResponse.sendResponse(entry, this.feedRequest.getConfigurator());
         
         }catch (ServiceException e) {
            LOG.error("Could not process GetFeed request - "+e.getMessage(),e);

contrib/gdata-server/src/java/org/apache/lucene/gdata/servlet/handler/DefaultUpdateHandler.java

@@ -75,7 +75,7 @@ public class DefaultUpdateHandler extends AbstractGdataRequestHandler {
 			BaseEntry entry = this.service.updateEntry(this.feedRequest,
 					this.feedResponse);
 			setFeedResponseFormat();
-			this.feedResponse.sendResponse(entry, this.feedRequest.getConfigurator().getExtensionProfile());
+			this.feedResponse.sendResponse(entry, this.feedRequest.getConfigurator());
 		
 		}
 		catch (ServiceException e) {

contrib/gdata-server/src/test/org/apache/lucene/gdata/server/TestGDataResponse.java

@@ -24,6 +24,7 @@ import javax.servlet.http.HttpServletResponse;
 import junit.framework.TestCase; 
  
 import org.apache.lucene.gdata.server.GDataRequest.OutputFormat; 
+import org.apache.lucene.gdata.utils.ProvidedServiceStub;
 import org.easymock.MockControl; 
  
 import com.google.gdata.data.Entry; 
@@ -69,7 +70,7 @@ public class TestGDataResponse extends TestCase {
     public void testSendResponseBaseFeedExtensionProfile() throws IOException { 
         try{ 
             Feed f = null; 
-            this.response.sendResponse(f,new ExtensionProfile()); 
+            this.response.sendResponse(f, new ProvidedServiceStub()); 
             fail("Exception expected"); 
         }catch (IllegalArgumentException e) { 
             // 
@@ -90,7 +91,7 @@ public class TestGDataResponse extends TestCase {
         this.response.setOutputFormat(OutputFormat.ATOM); 
         this.control.replay(); 
          
-        this.response.sendResponse(createFeed(),new ExtensionProfile()); 
+        this.response.sendResponse(createFeed(), new ProvidedServiceStub()); 
         assertEquals("Simple XML representation",stringWriter.toString(),generatedFeedAtom); 
         this.control.reset(); 
          
@@ -102,8 +103,7 @@ public class TestGDataResponse extends TestCase {
         this.httpResponse.setContentType(GDataResponse.XMLMIME_RSS);
         this.control.replay(); 
          
-        this.response.sendResponse(createFeed(),new ExtensionProfile 
+        this.response.sendResponse(createFeed(), new ProvidedServiceStub()); 
-                ()); 
         assertEquals("Simple XML representation",stringWriter.toString(),generatedFeedRSS); 
          
          
@@ -117,7 +117,7 @@ public class TestGDataResponse extends TestCase {
     public void testSendResponseBaseEntryExtensionProfile() throws IOException { 
         try{ 
             Entry e = null; 
-            this.response.sendResponse(e,new ExtensionProfile()); 
+            this.response.sendResponse(e, new ProvidedServiceStub()); 
             fail("Exception expected"); 
         }catch (IllegalArgumentException e) { 
             // 
@@ -134,11 +134,11 @@ public class TestGDataResponse extends TestCase {
         PrintWriter writer = new PrintWriter(stringWriter); 
          
         this.control.expectAndReturn(this.httpResponse.getWriter(),writer); 
+        this.httpResponse.setContentType(GDataResponse.XMLMIME_ATOM);
         this.response.setOutputFormat(OutputFormat.ATOM); 
         this.control.replay(); 
          
-        this.response.sendResponse(createEntry(),new ExtensionProfile 
+        this.response.sendResponse(createEntry(), new ProvidedServiceStub()); 
-                ()); 
         assertEquals("Simple XML representation ATOM",stringWriter.toString(),generatedEntryAtom); 
          
         // test rss output 
@@ -147,11 +147,11 @@ public class TestGDataResponse extends TestCase {
         writer = new PrintWriter(stringWriter); 
          
         this.control.expectAndReturn(this.httpResponse.getWriter(),writer); 
+        this.httpResponse.setContentType(GDataResponse.XMLMIME_RSS);
         this.response.setOutputFormat(OutputFormat.RSS); 
         this.control.replay(); 
          
-        this.response.sendResponse(createEntry(),new ExtensionProfile 
+        this.response.sendResponse(createEntry(), new ProvidedServiceStub()); 
-                ()); 
          
         assertEquals("Simple XML representation RSS",stringWriter.toString(),generatedEntryRSS); 
          

contrib/gdata-server/src/test/org/apache/lucene/gdata/utils/ProvidedServiceStub.java

@@ -15,6 +15,8 @@
  */
 package org.apache.lucene.gdata.utils;
 
+import javax.xml.transform.Templates;
+
 import org.apache.lucene.gdata.search.config.IndexSchema;
 import org.apache.lucene.gdata.server.registry.ProvidedService;
 
@@ -63,4 +65,11 @@ public class ProvidedServiceStub implements ProvidedService {
         return this.indexSchema;
     }
 
+    public Templates getTransformTemplate() {
+        
+        return null;
+    }
+
+  
+
 }

contrib/gdata-server/webroot/WEB-INF/classes/gdata-config.xml

@@ -6,6 +6,7 @@
 		<extension-profile>
 			com.google.gdata.data.ExtensionProfile
 		</extension-profile>
+		<previewStyleSheet>transform.xslt</previewStyleSheet>
 		<index-schema defaultSearchField="content">
 			<index useTimedIndexer="true" indexerIdleTime="120" optimizeAfterCommit="5" commitAfterDocuments="10">
 				<defaultAnalyzer>

contrib/gdata-server/webroot/WEB-INF/classes/gdata-config.xsd

@@ -3,6 +3,7 @@
 	<xs:element name="feed-class" type="xs:string" />
 	<xs:element name="entry-class" type="xs:string" />
 	<xs:element name="extension-profile" type="xs:string" />
+		<xs:element name="previewStyleSheet" type="xs:string" />
 	<xs:element name="class" type="xs:string" />
 	<xs:annotation>
 		<xs:documentation xml:lang="en">
@@ -27,6 +28,8 @@
 					minOccurs="1" />
 				<xs:element ref="extension-profile" maxOccurs="1"
 					minOccurs="1" />
+				<xs:element ref="previewStyleSheet" maxOccurs="1"
+					minOccurs="0" />
 				<xs:element ref="index-schema" maxOccurs="1"
 					minOccurs="1" />
 			</xs:sequence>