ca.uhn.fhir.fhirpath.IFhirPath Maven / Gradle / Ivy
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* HAPI FHIR - Core Library
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* Copyright (C) 2014 - 2024 Smile CDR, Inc.
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* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* See the License for the specific language governing permissions and
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package ca.uhn.fhir.fhirpath;
import jakarta.annotation.Nonnull;
import org.hl7.fhir.instance.model.api.IBase;
import java.util.List;
import java.util.Optional;
public interface IFhirPath {
/**
* Apply the given FhirPath expression against the given input and return
* all results in a list
*
* @param theInput The input object (generally a resource or datatype)
* @param thePath The fluent path expression
* @param theReturnType The type to return (in order to avoid casting)
*/
List evaluate(IBase theInput, String thePath, Class theReturnType);
/**
* Apply the given FhirPath expression against the given input and return
* all results in a list. Unlike the {@link #evaluate(IBase, String, Class)} method which
* uses a String containing a FHIRPath expression, this method takes a parsed FHIRPath
* expression returned by the {@link #parse(String)} method. This has the advantage
* of avoiding re-parsing expressions if the same expression will be evaluated
* repeatedly.
*
* @param theInput The input object (generally a resource or datatype)
* @param theParsedExpression A parsed FHIRPath expression returned by {@link #parse(String)}
* @param theReturnType The type to return (in order to avoid casting)
* @since 6.8.0
*/
List evaluate(IBase theInput, IParsedExpression theParsedExpression, Class theReturnType);
/**
* Apply the given FhirPath expression against the given input and return
* the first match (if any)
*
* @param theInput The input object (generally a resource or datatype)
* @param thePath The fluent path expression
* @param theReturnType The type to return (in order to avoid casting)
*/
Optional evaluateFirst(IBase theInput, String thePath, Class theReturnType);
/**
* Apply the given FhirPath expression against the given input and return
* the first match (if any). Unlike the {@link #evaluateFirst(IBase, String, Class)} method which
* uses a String containing a FHIRPath expression, this method takes a parsed FHIRPath
* expression returned by the {@link #parse(String)} method. This has the advantage
* of avoiding re-parsing expressions if the same expression will be evaluated
* repeatedly.
*
* @param theInput The input object (generally a resource or datatype)
* @param theParsedExpression A parsed FHIRPath expression returned by {@link #parse(String)}
* @param theReturnType The type to return (in order to avoid casting)
* @since 6.8.0
*/
Optional evaluateFirst(
IBase theInput, IParsedExpression theParsedExpression, Class theReturnType);
/**
* Parses the expression and throws an exception if it can not parse correctly.
* Note that the return type from this method is intended to be a "black box". It can
* be passed back into the {@link #evaluate(IBase, IParsedExpression, Class)}
* method on any FHIRPath instance that comes from the same {@link ca.uhn.fhir.context.FhirContext}
* instance. Any other use will produce unspecified results.
*/
IParsedExpression parse(String theExpression) throws Exception;
/**
* This method can be used optionally to supply an evaluation context for the
* FHIRPath evaluator instance. The context can be used to supply data needed by
* specific functions, e.g. allowing the resolve() function to
* fetch referenced resources.
*
* @since 6.4.0
*/
void setEvaluationContext(@Nonnull IFhirPathEvaluationContext theEvaluationContext);
/**
* This interface is a marker interface representing a parsed FHIRPath expression.
* Instances of this class will be returned by {@link #parse(String)} and can be
* passed to {@link #evaluate(IBase, IParsedExpression, Class)} and
* {@link #evaluateFirst(IBase, IParsedExpression, Class)}. Using a pre-parsed
* FHIRPath expression can perform much faster in some situations where an
* identical expression will be evaluated many times against different targets,
* since the parsing step doesn't need to be repeated.
*
* Instances of this interface should be treated as a "black box". There are no
* methods that can be used to manipulate parsed FHIRPath expressions.
*
*
* @since 6.8.0
*/
interface IParsedExpression {
// no methods
}
}