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.FunctionUtils; 033import gov.nist.secauto.metaschema.core.metapath.function.IArgument; 034import gov.nist.secauto.metaschema.core.metapath.function.IFunction; 035import gov.nist.secauto.metaschema.core.metapath.item.IItem; 036import gov.nist.secauto.metaschema.core.metapath.item.atomic.IBooleanItem; 037import gov.nist.secauto.metaschema.core.metapath.item.atomic.IStringItem; 038import gov.nist.secauto.metaschema.core.util.ObjectUtils; 039 040import java.util.List; 041 042import edu.umd.cs.findbugs.annotations.NonNull; 043import edu.umd.cs.findbugs.annotations.Nullable; 044 045public final class FnStartsWith { 046 047 @NonNull 048 static final IFunction SIGNATURE = IFunction.builder() 049 .name("starts-with") 050 .namespace(MetapathConstants.NS_XPATH_FUNCTIONS) 051 .argument(IArgument.newBuilder() 052 .name("arg1").type(IStringItem.class) 053 .zeroOrOne() 054 .build()) 055 .argument(IArgument.newBuilder() 056 .name("arg2") 057 .type(IStringItem.class) 058 .zeroOrOne() 059 .build()) 060 .returnType(IBooleanItem.class) 061 .returnOne() 062 .functionHandler(FnStartsWith::execute) 063 .build(); 064 065 @SuppressWarnings("unused") 066 @NonNull 067 private static ISequence<IBooleanItem> execute(@NonNull IFunction function, 068 @NonNull List<ISequence<?>> arguments, 069 @NonNull DynamicContext dynamicContext, 070 IItem focus) { 071 IStringItem arg1 = FunctionUtils.getFirstItem( 072 FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(0))), true); 073 IStringItem arg2 = FunctionUtils.getFirstItem( 074 FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(1))), true); 075 076 return ISequence.of(fnStartsWith(arg1, arg2)); 077 } 078 079 private FnStartsWith() { 080 // disable construction 081 } 082 083 /** 084 * Determine if the string provided in the first argument contains the string in 085 * the second argument as a leading substring. 086 * <p> 087 * Based on the XPath 3.1 <a href= 088 * "https://www.w3.org/TR/xpath-functions-31/#func-starts-with">fn:starts-with</a> 089 * function. 090 * 091 * @param arg1 092 * the string to examine 093 * @param arg2 094 * the string to check as the leading substring 095 * @return {@link IBooleanItem#TRUE} if {@code arg1} starts with {@code arg2}, 096 * or {@link IBooleanItem#FALSE} otherwise 097 */ 098 public static IBooleanItem fnStartsWith(@Nullable IStringItem arg1, @Nullable IStringItem arg2) { 099 String arg2String = arg2 == null ? "" : arg2.asString(); 100 101 boolean retval; 102 if (arg2String.isEmpty()) { 103 retval = true; 104 } else { 105 String arg1String = arg1 == null ? "" : arg1.asString(); 106 retval = arg1String.contains(arg2String); 107 } 108 return IBooleanItem.valueOf(retval); 109 } 110}