001/*
002 * #%L
003 * HAPI FHIR - Core Library
004 * %%
005 * Copyright (C) 2014 - 2023 Smile CDR, Inc.
006 * %%
007 * Licensed under the Apache License, Version 2.0 (the "License");
008 * you may not use this file except in compliance with the License.
009 * You may obtain a copy of the License at
010 *
011 *      http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 * #L%
019 */
020package ca.uhn.fhir.fhirpath;
021
022import org.hl7.fhir.instance.model.api.IBase;
023
024import javax.annotation.Nonnull;
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
056
057        /**
058         * This method can be used optionally to supply an evaluation context for the
059         * FHIRPath evaluator instance. The context can be used to supply data needed by
060         * specific functions, e.g. allowing the <code>resolve()</code> function to
061         * fetch referenced resources.
062         *
063         * @since 6.4.0
064         */
065        void setEvaluationContext(@Nonnull IFhirPathEvaluationContext theEvaluationContext);
066}