001package ca.uhn.fhir.fhirpath;
002
003/*
004 * #%L
005 * HAPI FHIR - Core Library
006 * %%
007 * Copyright (C) 2014 - 2021 Smile CDR, Inc.
008 * %%
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *      http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 * #L%
021 */
022
023import org.hl7.fhir.instance.model.api.IBase;
024
025import java.util.List;
026import java.util.Optional;
027
028public interface IFhirPath {
029
030        /**
031         * Apply the given FhirPath expression against the given input and return
032         * all results in a list
033         * 
034         * @param theInput The input object (generally a resource or datatype)
035         * @param thePath The fluent path expression
036         * @param theReturnType The type to return (in order to avoid casting)
037         */
038        <T extends IBase> List<T> evaluate(IBase theInput, String thePath, Class<T> theReturnType);
039
040        /**
041         * Apply the given FhirPath expression against the given input and return
042         * the first match (if any)
043         *
044         * @param theInput The input object (generally a resource or datatype)
045         * @param thePath The fluent path expression
046         * @param theReturnType The type to return (in order to avoid casting)
047         */
048        <T extends IBase> Optional<T> evaluateFirst(IBase theInput, String thePath, Class<T> theReturnType);
049
050
051        /**
052         * Parses the expression and throws an exception if it can not parse correctly
053         */
054        void parse(String theExpression) throws Exception;
055}