/* The contents of this file are subject to the license and copyright terms
* detailed in the license directory at the root of the source tree (also
* available online at http://fedora-commons.org/license/).
*/
package org.fcrepo.client.utility.validate;
import java.util.Collection;
import org.fcrepo.client.utility.validate.types.BasicObjectInfo;
import org.fcrepo.client.utility.validate.types.ContentModelInfo;
import org.fcrepo.client.utility.validate.types.DatastreamInfo;
import org.fcrepo.client.utility.validate.types.ObjectInfo;
import org.fcrepo.client.utility.validate.types.RelationshipInfo;
import org.fcrepo.client.utility.validate.types.ContentModelInfo.DsTypeModel;
import org.fcrepo.client.utility.validate.types.ContentModelInfo.Form;
import org.fcrepo.common.Constants;
/**
* This is the actual validation engine, performing validation tests on an
* {@link ObjectInfo}. The engine is provided with an {@link ObjectSource} at
* instantiation time, in case additional objects are required to complete the
* validation.
*
* @author Jim Blake
*/
public class ObjectValidator {
private final ObjectSource objectSource;
public ObjectValidator(ObjectSource objectSource) {
if (objectSource == null) {
throw new NullPointerException("objectSource may not be null.");
}
this.objectSource = objectSource;
}
/**
* If we only have a PID, we can get the object from the
* {@link ObjectSource}. But if that fails, we need to mock up an object
* for the result.
*/
public ValidationResult validate(String pid) {
if (pid == null) {
throw new NullPointerException("pid may not be null.");
}
ObjectInfo object = null;
try {
object = objectSource.getValidationObject(pid);
} catch (ObjectSourceException e) {
// This falls into the case of object==null.
}
if (object == null) {
ValidationResult result =
new ValidationResult(new BasicObjectInfo(pid));
result.addNote(ValidationResultNotation.objectNotFound(pid));
return result;
} else {
return validate(object);
}
}
/**
* Each object is expected to have at least one content model. Validate each
* of the content models.
*/
public ValidationResult validate(ObjectInfo object) {
if (object == null) {
throw new NullPointerException("object may not be null.");
}
ValidationResult result = new ValidationResult(object);
Collection<String> contentmodels = object.getContentModels();
if (contentmodels.size() == 0){
result.addNote(ValidationResultNotation.noContentModel());
return result;
}
for (String contentmodel:contentmodels){
validateAgainstContentModel(result, contentmodel, object);
}
return result;
}
/**
* <p>
* Validate each content model relation.
* </p>
* <p>
* If the content model relation doesn't point to an object PID, note that
* and give up. Same if no object is found at that PID.
* </p>
* <p>
* If we find an actual content model object, verify that the original
* object satisfies the content model.
* </p>
*/
private void validateAgainstContentModel(ValidationResult result,
String cm,
ObjectInfo object) {
String contentModelPid;
if (cm.startsWith("info:fedora/")){
contentModelPid = cm.substring(12);
} else{
result.addNote(ValidationResultNotation
.unrecognizedContentModelUri(cm));
return;
}
try {
ContentModelInfo contentModel =
objectSource.getContentModelInfo(contentModelPid);
if (contentModel == null) {
result.addNote(ValidationResultNotation
.contentModelNotFound(contentModelPid));
} else {
for (DsTypeModel typeModel : contentModel.getTypeModels()) {
confirmMatchForDsTypeModel(result,
typeModel,
contentModelPid,
object);
}
}
} catch (ObjectSourceException e) {
result.addNote(ValidationResultNotation
.errorFetchingContentModel(contentModelPid, e));
return;
} catch (InvalidContentModelException e) {
result.addNote(ValidationResultNotation.contentModelNotValid(e));
}
}
/**
* The object must have a datastream to match each dsTypeModel in the
* content model. Matching a dsTypeModel means equal IDs and an acceptable
* form.
*/
private void confirmMatchForDsTypeModel(ValidationResult result,
DsTypeModel typeModel,
String contentModelPid,
ObjectInfo object) {
String id = typeModel.getId();
DatastreamInfo dsInfo = object.getDatastreamInfo(id);
if (dsInfo == null) {
// If there is no datastream by that name, nothing to check.
result.addNote(ValidationResultNotation
.noMatchingDatastreamId(contentModelPid, id));
return;
}
Collection<Form> forms = typeModel.getForms();
if (forms.isEmpty()) {
// If the type model has no forms, it's an automatic match.
return;
}
// Otherwise, the datastream must meet the constraints of at least one form.
for (Form form : forms) {
if (meetsConstraint(dsInfo.getMimeType(), form.getMimeType())
&& meetsConstraint(dsInfo.getFormatUri(), form
.getFormatUri())) {
return;
}
}
result.addNote(ValidationResultNotation
.datastreamDoesNotMatchForms(contentModelPid, id));
}
/**
* If the constraint is not null, the value must match it.
*/
private boolean meetsConstraint(String value, String constraint) {
return (constraint == null) || constraint.equals(value);
}
}