/**
* OLAT - Online Learning and Training<br>
* http://www.olat.org
* <p>
* Licensed under the Apache License, Version 2.0 (the "License"); <br>
* you may not use this file except in compliance with the License.<br>
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing,<br>
* software distributed under the License is distributed on an "AS IS" BASIS, <br>
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br>
* See the License for the specific language governing permissions and <br>
* limitations under the License.
* <p>
* Copyright (c) since 2004 at Multimedia- & E-Learning Services (MELS),<br>
* University of Zurich, Switzerland.
* <hr>
* <a href="http://www.openolat.org">
* OpenOLAT - Online Learning and Training</a><br>
* This file has been modified by the OpenOLAT community. Changes are licensed
* under the Apache 2.0 license as the original file.
*/
package org.olat.fileresource.types;
import java.io.File;
import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Namespace;
import org.dom4j.XPath;
import org.olat.core.logging.OLog;
import org.olat.core.logging.Tracing;
import org.olat.core.util.PathUtils;
import org.olat.ims.resources.IMSLoader;
/**
* Initial Date: Apr 6, 2004
*
* @author Mike Stock
*/
public class ScormCPFileResource extends FileResource {
private static final OLog log = Tracing.createLoggerFor(ScormCPFileResource.class);
private static final String IMS_MANIFEST = "imsmanifest.xml";
/**
* SCORM IMS CP file resource identifier.
*/
public static final String TYPE_NAME = "FileResource.SCORMCP";
public ScormCPFileResource() {
super(TYPE_NAME);
}
public static ResourceEvaluation evaluate(File file, String filename) {
ResourceEvaluation eval = new ResourceEvaluation();
try {
ImsManifestFileFilter visitor = new ImsManifestFileFilter();
Path fPath = PathUtils.visit(file, filename, visitor);
if(visitor.isValid()) {
Path realManifestPath = visitor.getManifestPath();
Path manifestPath = fPath.resolve(realManifestPath);
RootSearcher rootSearcher = new RootSearcher();
Files.walkFileTree(fPath, rootSearcher);
if(rootSearcher.foundRoot()) {
manifestPath = rootSearcher.getRoot().resolve(IMS_MANIFEST);
} else {
manifestPath = fPath.resolve(IMS_MANIFEST);
}
Document doc = IMSLoader.loadIMSDocument(manifestPath);
if(validateImsManifest(doc)) {
eval.setValid(true);
} else {
eval.setValid(false);
}
} else {
eval.setValid(false);
}
} catch (IOException | IllegalArgumentException e) {
log.error("", e);
eval.setValid(false);
}
return eval;
}
public static boolean validateImsManifest(Document doc) {
try {
//do not throw exception already here, as it might be only a generic zip file
if (doc == null) return false;
String adluri = null;
String seqencingUri = null;
String simpleSeqencingUri = null;
// get all organization elements. need to set namespace
Element rootElement = doc.getRootElement();
String nsuri = rootElement.getNamespace().getURI();
// look for the adl cp namespace that differs a scorm package from a normal cp package
Namespace nsADL = rootElement.getNamespaceForPrefix("adlcp");
if (nsADL != null ) adluri = nsADL.getURI();
Namespace nsADLSeq = rootElement.getNamespaceForPrefix("adlseq");
if (nsADLSeq != null ) seqencingUri = nsADLSeq.getURI();
Namespace nsADLSS = rootElement.getNamespaceForPrefix("imsss");
if (nsADLSS != null ) simpleSeqencingUri = nsADLSS.getURI();
// we can only support scorm 1.2 so far.
if (adluri != null && !((adluri.indexOf("adlcp_rootv1p2") != -1) || (adluri.indexOf("adlcp_rootv1p3") != -1))){
//we dont have have scorm 1.2 or 1.3 namespace so it can't be a scorm package
return false;
}
Map<String, Object> nsuris = new HashMap<>(5);
nsuris.put("ns", nsuri);
//nsuris.put("adluri", adluri);
//we might have a scorm 2004 which we do not yet support
if (seqencingUri != null) nsuris.put("adlseq", seqencingUri);
if (simpleSeqencingUri != null) nsuris.put("imsss", simpleSeqencingUri);
// Check for organization element. Must provide at least one... title gets extracted from either
// the (optional) <title> element or the mandatory identifier attribute.
// This makes sure, at least a root node gets created in CPManifestTreeModel.
XPath meta = rootElement.createXPath("//ns:organization");
meta.setNamespaceURIs(nsuris);
Element orgaEl = (Element) meta.selectSingleNode(rootElement); // TODO: accept several organizations?
if (orgaEl == null) {
return false;
}
// Check for at least one <item> element referencing a <resource> of adlcp:scormtype="sco" or "asset",
// which will serve as an entry point.
XPath resourcesXPath = rootElement.createXPath("//ns:resources");
resourcesXPath.setNamespaceURIs(nsuris);
Element elResources = (Element)resourcesXPath.selectSingleNode(rootElement);
if (elResources == null) {
return false;
}
XPath itemsXPath = rootElement.createXPath("//ns:item");
itemsXPath.setNamespaceURIs(nsuris);
List items = itemsXPath.selectNodes(rootElement);
if (items.size() == 0) {
return false; // no <item> element.
}
// check for scorm 2004 simple sequencing stuff which we do not yet support
if (seqencingUri != null) {
XPath seqencingXPath = rootElement.createXPath("//ns:imsss");
List sequences = seqencingXPath.selectNodes(rootElement);
if (sequences.size() > 0) {
return false; // seqencing elements found -> scorm 2004
}
}
Set<String> set = new HashSet<String>();
for (Iterator iter = items.iterator(); iter.hasNext();) {
Element item = (Element) iter.next();
String identifier = item.attributeValue("identifier");
//check if identifiers are unique, reject if not so
if (!set.add(identifier)) {
return false;//TODO:create special error message for non unique ids
}
}
for (Iterator iter = items.iterator(); iter.hasNext();) {
Element item = (Element) iter.next();
String identifierref = item.attributeValue("identifierref");
if (identifierref == null) continue;
XPath resourceXPath = rootElement.createXPath("//ns:resource[@identifier='" + identifierref + "']");
resourceXPath.setNamespaceURIs(nsuris);
Element elResource = (Element)resourceXPath.selectSingleNode(elResources);
if (elResource == null) {
return false;
}
//check for scorm attribute
Attribute scormAttr = elResource.attribute("scormtype");
//some packages have attribute written like "scormType"
Attribute scormAttrUpper = elResource.attribute("scormType");
if (scormAttr == null && scormAttrUpper == null) {
return false;
}
String attr = "";
if (scormAttr != null) attr = scormAttr.getStringValue();
if (scormAttrUpper != null) attr = scormAttrUpper.getStringValue();
if (attr == null) {
return false;
}
if (elResource.attributeValue("href") != null && (attr.equalsIgnoreCase("sco") || attr.equalsIgnoreCase("asset"))) {
return true; // success.
}
}
return false;
} catch (Exception e) {
log.warn("Not a valid SCORM package", e);
return false;
}
}
private static class ImsManifestFileFilter extends SimpleFileVisitor<Path> {
private boolean manifestFile;
private Path manifestPath;
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
throws IOException {
String filename = file.getFileName().toString();
if(IMS_MANIFEST.equals(filename)) {
manifestFile = true;
manifestPath = file;
}
return manifestFile ? FileVisitResult.TERMINATE : FileVisitResult.CONTINUE;
}
public boolean isValid() {
return manifestFile;
}
public Path getManifestPath() {
return manifestPath;
}
}
}