001/*
002 * Portions of this software was developed by employees of the National Institute
003 * of Standards and Technology (NIST), an agency of the Federal Government and is
004 * being made available as a public service. Pursuant to title 17 United States
005 * Code Section 105, works of NIST employees are not subject to copyright
006 * protection in the United States. This software may be subject to foreign
007 * copyright. Permission in the United States and in foreign countries, to the
008 * extent that NIST may hold copyright, to use, copy, modify, create derivative
009 * works, and distribute this software and its documentation without fee is hereby
010 * granted on a non-exclusive basis, provided that this notice and disclaimer
011 * of warranty appears in all copies.
012 *
013 * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
014 * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
015 * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
016 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
017 * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
018 * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
019 * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
020 * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
021 * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
022 * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
023 * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
024 * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
025 */
026
027package gov.nist.secauto.metaschema.core.metapath.function.library;
028
029import gov.nist.secauto.metaschema.core.metapath.DynamicContext;
030import gov.nist.secauto.metaschema.core.metapath.ISequence;
031import gov.nist.secauto.metaschema.core.metapath.MetapathConstants;
032import gov.nist.secauto.metaschema.core.metapath.function.DocumentFunctionException;
033import gov.nist.secauto.metaschema.core.metapath.function.FunctionUtils;
034import gov.nist.secauto.metaschema.core.metapath.function.IArgument;
035import gov.nist.secauto.metaschema.core.metapath.function.IFunction;
036import gov.nist.secauto.metaschema.core.metapath.item.IItem;
037import gov.nist.secauto.metaschema.core.metapath.item.atomic.IStringItem;
038import gov.nist.secauto.metaschema.core.metapath.item.node.IDocumentNodeItem;
039import gov.nist.secauto.metaschema.core.util.ObjectUtils;
040
041import java.io.IOException;
042import java.net.URI;
043import java.util.List;
044
045import edu.umd.cs.findbugs.annotations.NonNull;
046
047public final class FnDoc {
048  // private static final Logger logger = LogManager.getLogger(FnDoc.class);
049
050  @NonNull
051  static final IFunction SIGNATURE = IFunction.builder()
052      .name("doc")
053      .namespace(MetapathConstants.NS_XPATH_FUNCTIONS)
054      .deterministic()
055      .contextDependent()
056      .focusIndependent()
057      .argument(IArgument.newBuilder()
058          .name("arg1")
059          .type(IStringItem.class)
060          .zeroOrOne()
061          .build())
062      .returnType(IDocumentNodeItem.class)
063      .returnOne()
064      .functionHandler(FnDoc::execute)
065      .build();
066
067  private FnDoc() {
068    // disable construction
069  }
070
071  @SuppressWarnings("unused")
072  @NonNull
073  private static ISequence<IDocumentNodeItem> execute(@NonNull IFunction function,
074      @NonNull List<ISequence<?>> arguments, @NonNull DynamicContext dynamicContext,
075      IItem focus) {
076    ISequence<? extends IStringItem> arg = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(0)));
077
078    IStringItem item = FunctionUtils.getFirstItem(arg, true);
079
080    return item == null ? ISequence.empty() : ISequence.of(fnDoc(item, dynamicContext));
081  }
082
083  /**
084   * Dynamically load the document associated with the URI, and return a
085   * {@link IDocumentNodeItem} containing the result.
086   * <p>
087   * Based on the XPath 3.1
088   * <a href="https://www.w3.org/TR/xpath-functions-31/#func-doc">fn:doc</a>
089   * function.
090   *
091   * @param uri
092   *          the resource to load the data from
093   * @param context
094   *          the Metapath dynamic context
095   * @return the loaded document node item
096   */
097  public static IDocumentNodeItem fnDoc(@NonNull IStringItem uri, @NonNull DynamicContext context) {
098    URI documentUri;
099    try {
100      documentUri = URI.create(uri.asString());
101    } catch (IllegalArgumentException ex) {
102      throw new DocumentFunctionException(DocumentFunctionException.INVALID_ARGUMENT,
103          String.format("Invalid URI argument '%s' to fn:doc or fn:doc-available.", uri.asString()), ex);
104    }
105
106    URI baseUri = context.getStaticContext().getBaseUri();
107    if (baseUri != null) {
108      // resolve if possible
109      documentUri = baseUri.resolve(documentUri);
110    } else {
111      if (!documentUri.isAbsolute() && !documentUri.isOpaque()) {
112        throw new DocumentFunctionException(DocumentFunctionException.ERROR_RETRIEVING_RESOURCE, String
113            .format("No base-uri is available in the static context to resolve the URI '%s'.", documentUri.toString()));
114      }
115    }
116
117    try {
118      return context.getDocumentLoader().loadAsNodeItem(ObjectUtils.notNull(documentUri));
119    } catch (IOException ex) {
120      throw new DocumentFunctionException(DocumentFunctionException.ERROR_RETRIEVING_RESOURCE, String
121          .format("Unable to retrieve the resource identified by the URI '%s'.", documentUri.toString()), ex);
122    }
123  }
124}