[VIVO-1872] - Add download option to SPARQL Query page (#164)

* Add download option to SPARQL Query page

* Set SPARQL query results content type even if downloading

* Address pull request comments

api/src/main/java/edu/cornell/mannlib/vitro/webapp/controller/admin/SparqlQueryController.java

@@ -40,6 +40,8 @@ import edu.cornell.mannlib.vitro.webapp.rdfservice.RDFServiceException;
 import edu.cornell.mannlib.vitro.webapp.utils.http.AcceptHeaderParsingException;
 import edu.cornell.mannlib.vitro.webapp.utils.http.NotAcceptableException;
 import edu.cornell.mannlib.vitro.webapp.utils.sparql.SparqlQueryUtils;
+import edu.cornell.mannlib.vitro.webapp.controller.api.sparqlquery.RdfResultMediaType;
+import edu.cornell.mannlib.vitro.webapp.controller.api.sparqlquery.ResultSetMediaType;
 
 /**
  * Present the SPARQL Query form, and execute the queries.
@@ -110,11 +112,20 @@ public class SparqlQueryController extends FreemarkerHttpServlet {
 				.getRDFService();
 
 		String queryString = req.getParameter("query");
+		boolean download = Boolean.parseBoolean(req.getParameter("download"));
+		Query query = SparqlQueryUtils.create(queryString);
 		try {
-			String format = interpretRequestedFormats(req, queryString);
+			String format = interpretRequestedFormats(req, query);
 			SparqlQueryApiExecutor core = SparqlQueryApiExecutor.instance(
 					rdfService, queryString, format);
 			resp.setContentType(core.getMediaType());
+
+			if (download) {	
+				String extension = getFilenameExtension(req, query, format);
+				resp.setHeader("Content-Transfer-Encoding", "binary");
+				resp.setHeader("Content-disposition", "attachment; filename=query-results." + extension);
+			}
+
 			core.executeAndFormat(resp.getOutputStream());
 		} catch (InvalidQueryTypeException e) {
 			do400BadRequest("Query type is not SELECT, ASK, CONSTRUCT, "
@@ -132,8 +143,7 @@ public class SparqlQueryController extends FreemarkerHttpServlet {
 	}
 
 	private String interpretRequestedFormats(HttpServletRequest req,
-			String queryString) throws NotAcceptableException {
+			Query query) throws NotAcceptableException {
-		Query query = SparqlQueryUtils.create(queryString);
 		String parameterName = (query.isSelectType() || query.isAskType()) ? "resultFormat"
 				: "rdfResultFormat";
 		String parameterValue = req.getParameter(parameterName);
@@ -145,6 +155,20 @@ public class SparqlQueryController extends FreemarkerHttpServlet {
 		}
 	}
 
+	private String getFilenameExtension(HttpServletRequest req, 
+			Query query, String format) {
+		String extension;
+		if (query.isSelectType() || query.isAskType()) {
+			ResultSetMediaType mediaType = ResultSetMediaType.fromContentType(format);
+			extension = mediaType.getExtension();
+		}
+		else {
+			RdfResultMediaType mediaType = RdfResultMediaType.fromContentType(format);
+			extension = mediaType.getExtension();
+		}
+		return extension;
+	}
+
 	private void do400BadRequest(String message, HttpServletResponse resp)
 			throws IOException {
 		resp.setStatus(400);

api/src/main/java/edu/cornell/mannlib/vitro/webapp/controller/api/sparqlquery/RdfResultMediaType.java

@@ -12,17 +12,17 @@ import java.util.Map;
  * and DESCRIBE).
  */
 public enum RdfResultMediaType {
-	TEXT("text/plain", true, "NTRIPLE", "N-TRIPLE"),
+	TEXT("text/plain", true, "NTRIPLE", "N-TRIPLE", "nt"),
 
-	RDF_XML("application/rdf+xml", true, "RDFXML", "RDF/XML"),
+	RDF_XML("application/rdf+xml", true, "RDFXML", "RDF/XML", "rdf"),
 
-	N3("text/n3", true, "N3", "N3"),
+	N3("text/n3", true, "N3", "N3", "n3"),
 
-	TTL("text/turtle", false, "N3", "TTL"),
+	TTL("text/turtle", false, "N3", "TTL", "ttl"),
 
-	JSON("application/json", false, "N3", "JSON"),
+	JSON("application/json", false, "N3", "JSON", "json"),
 
-	JSON_LD("application/ld+json", false, "N3", "JSON");
+	JSON_LD("application/ld+json", false, "N3", "JSON", "jsonld");
 
 	// ----------------------------------------------------------------------
 	// Keep a map of content types, for easy conversion back and forth
@@ -79,12 +79,18 @@ public enum RdfResultMediaType {
 	 */
 	private final String jenaResponseFormat;
 
+	/**
+	 * What extension should be used if file is downloaded?
+	 */
+	private final String extension;
+
 	private RdfResultMediaType(String contentType, boolean nativeFormat,
-			String serializationFormat, String jenaResponseFormat) {
+			String serializationFormat, String jenaResponseFormat, String extension) {
 		this.contentType = contentType;
 		this.nativeFormat = nativeFormat;
 		this.serializationFormat = serializationFormat;
 		this.jenaResponseFormat = jenaResponseFormat;
+		this.extension = extension;
 	}
 
 	public String getContentType() {
@@ -103,4 +109,8 @@ public enum RdfResultMediaType {
 		return jenaResponseFormat;
 	}
 
+	public String getExtension() {
+		return extension;
+	}
+
 }

api/src/main/java/edu/cornell/mannlib/vitro/webapp/controller/api/sparqlquery/ResultSetMediaType.java

@@ -12,15 +12,15 @@ import java.util.Map;
  * SELECT and ASK).
  */
 public enum ResultSetMediaType {
-	TEXT("text/plain", true, "TEXT", null),
+	TEXT("text/plain", true, "TEXT", null, "txt"),
 
-	CSV("text/csv", true, "CSV", null),
+	CSV("text/csv", true, "CSV", null, "csv"),
 
-	TSV("text/tab-separated-values", false, "CSV", "tsv"),
+	TSV("text/tab-separated-values", false, "CSV", "tsv", "tsv"),
 
-	XML("application/sparql-results+xml", true, "XML", null),
+	XML("application/sparql-results+xml", true, "XML", null, "xml"),
 
-	JSON("application/sparql-results+json", true, "JSON", null);
+	JSON("application/sparql-results+json", true, "JSON", null, "json");
 
 	// ----------------------------------------------------------------------
 	// Keep a map of content types, for easy conversion back and forth
@@ -78,12 +78,18 @@ public enum ResultSetMediaType {
 	 */
 	private final String jenaResponseFormat;
 
+	/**
+	 * What extension should be used if file is downloaded?
+	 */
+	private final String extension;
+
 	private ResultSetMediaType(String contentType, boolean nativeFormat,
-			String rdfServiceFormat, String jenaResponseFormat) {
+			String rdfServiceFormat, String jenaResponseFormat, String extension) {
 		this.contentType = contentType;
 		this.nativeFormat = nativeFormat;
 		this.rdfServiceFormat = rdfServiceFormat;
 		this.jenaResponseFormat = jenaResponseFormat;
+		this.extension = extension;
 	}
 
 	public String getContentType() {
@@ -102,4 +108,8 @@ public enum ResultSetMediaType {
 		return jenaResponseFormat;
 	}
 
+	public String getExtension() {
+		return extension;
+	}
+
 }

webapp/src/main/webapp/templates/freemarker/body/admin/admin-sparqlQueryForm.ftl

@@ -27,6 +27,11 @@
         	 <label><input type='radio' name='rdfResultFormat' value='application/json'>JSON-LD</label>
         </div>
 
+		<div class="options">
+			<input type="checkbox" id="download" name="download" value="true">
+			<label for="download"> Save results to file</label><br>		
+		</div>
+
         <input class="submit" type="submit" value="Run Query" />
     </form>
 </div><!-- content -->