ca.uhn.fhir.model.base.composite.BaseResourceReferenceDt.java Source code

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Here is the source code for ca.uhn.fhir.model.base.composite.BaseResourceReferenceDt.java

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package ca.uhn.fhir.model.base.composite;

/*
 * #%L
 * HAPI FHIR - Core Library
 * %%
 * Copyright (C) 2014 - 2016 University Health Network
 * %%
 * 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,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

import static org.apache.commons.lang3.StringUtils.isBlank;

import org.hl7.fhir.instance.model.api.IBaseDatatype;
import org.hl7.fhir.instance.model.api.IBaseReference;
import org.hl7.fhir.instance.model.api.IBaseResource;
import org.hl7.fhir.instance.model.api.IIdType;

import ca.uhn.fhir.context.RuntimeResourceDefinition;
import ca.uhn.fhir.model.api.BaseIdentifiableElement;
import ca.uhn.fhir.model.api.IResource;
import ca.uhn.fhir.model.primitive.IdDt;
import ca.uhn.fhir.model.primitive.StringDt;
import ca.uhn.fhir.rest.client.api.IRestfulClient;

public abstract class BaseResourceReferenceDt extends BaseIdentifiableElement
        implements IBaseDatatype, IBaseReference {

    private static final long serialVersionUID = 1L;

    private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(BaseResourceReferenceDt.class);
    private IBaseResource myResource;

    /**
     * Constructor
     */
    public BaseResourceReferenceDt() {
        // nothing
    }

    /**
     * Constructor
     * 
     * @param theResource
     *           The loaded resource itself
     */
    public BaseResourceReferenceDt(IResource theResource) {
        myResource = theResource;
        setReference(theResource.getId());
    }

    @Override
    public abstract StringDt getDisplayElement();

    public abstract IdDt getReference();

    /**
     * Gets the actual loaded and parsed resource instance, <b>if it is already present</b>. This method will return the
     * resource instance only if it has previously been loaded using {@link #loadResource(IRestfulClient)} or it was
     * contained within the resource containing this resource.
     *
     * See the FHIR specification section on <a
     * href="http://www.hl7.org/implement/standards/fhir/references.html#id">contained resources</a> for more
     * information.
     * 
     * @see #loadResource(IRestfulClient)
     */
    @Override
    public IBaseResource getResource() {
        return myResource;
    }

    @Override
    protected boolean isBaseEmpty() {
        return super.isBaseEmpty() && myResource == null;
    }

    /**
     * Returns the referenced resource, fetching it <b>if it has not already been loaded</b>. This method invokes the
     * HTTP client to retrieve the resource unless it has already been loaded, or was a contained resource in which case
     * it is simply returned.
     */
    public IBaseResource loadResource(IRestfulClient theClient) {
        if (myResource != null) {
            return myResource;
        }

        IdDt resourceId = getReference();
        if (resourceId == null || isBlank(resourceId.getValue())) {
            throw new IllegalStateException("Reference has no resource ID defined");
        }
        if (isBlank(resourceId.getBaseUrl()) || isBlank(resourceId.getResourceType())) {
            throw new IllegalStateException(
                    "Reference is not complete (must be in the form [baseUrl]/[resource type]/[resource ID]) - Reference is: "
                            + resourceId.getValue());
        }

        String resourceUrl = resourceId.getValue();

        ourLog.debug("Loading resource at URL: {}", resourceUrl);

        RuntimeResourceDefinition definition = theClient.getFhirContext()
                .getResourceDefinition(resourceId.getResourceType());
        Class<? extends IBaseResource> resourceType = definition.getImplementingClass();
        myResource = theClient.fetchResourceFromUrl(resourceType, resourceUrl);
        myResource.setId(resourceUrl);
        return myResource;
    }

    public abstract BaseResourceReferenceDt setReference(IdDt theReference);

    public BaseResourceReferenceDt setReference(IIdType theReference) {
        if (theReference instanceof IdDt) {
            setReference((IdDt) theReference);
        } else if (theReference != null) {
            setReference(new IdDt(theReference.getValue()));
        } else {
            setReference((IdDt) null);
        }
        return this;
    }

    @Override
    public void setResource(IBaseResource theResource) {
        myResource = theResource;
    }

    @Override
    public String toString() {
        org.apache.commons.lang3.builder.ToStringBuilder b = new org.apache.commons.lang3.builder.ToStringBuilder(
                this, org.apache.commons.lang3.builder.ToStringStyle.SHORT_PREFIX_STYLE);
        b.append("reference", getReference().getValueAsString());
        b.append("loaded", getResource() != null);
        return b.toString();
    }

}