hapi-fhir/hapi-fhir-base/src/site/xdoc/doc_rest_operations.xml
2014-04-15 08:50:42 -04:00

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<?xml version="1.0" encoding="UTF-8"?>
<document xmlns="http://maven.apache.org/XDOC/2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/XDOC/2.0 http://maven.apache.org/xsd/xdoc-2.0.xsd">
<properties>
<title>RESTful Operations - HAPI FHIR</title>
<author email="jamesagnew@users.sourceforge.net">James Agnew</author>
</properties>
<body>
<section name="Implementing Resource Provider Operations">
<p>
RESTful Clients and Servers both share the same
method pattern, with one key difference: A client
is defined using annotated methods on an interface
which are used to retrieve resources,
whereas a server requires concrete method implementations
to actually provide those resources.
</p>
<p>
Unless otherwise specified, the examples below show <b>server</b>
implementations, but client methods will follow the same patterns.
</p>
<p>
The following table lists the operations supported by
HAPI FHIR RESTful Servers and Clients.
</p>
<table>
<thead>
<tr style="font-weight: bold; font-size: 1.2em;">
<td>Operation</td>
<td>Definition</td>
</tr>
</thead>
<tbody>
<tr>
<td>
<a href="#instance_read">Instance - Read</a>
</td>
<td>
Read the current state of the resource
</td>
</tr>
<tr>
<td>
<a href="#instance_vread">Instance - VRead</a>
</td>
<td>
Read the state of a specific version of the resource
</td>
</tr>
<tr>
<td>
<a href="#instance_update">Instance - Update</a>
</td>
<td>
Read the state of a specific version of the resource
</td>
</tr>
<tr>
<td>
<a href="#instance_delete">Instance - Delete</a>
</td>
<td>
Delete a resource
</td>
</tr>
<tr>
<td>
<a href="#history">Instance - History</a>
</td>
<td>
Retrieve the update history for a particular resource
</td>
</tr>
<tr>
<td>
<a href="#type_create">Type - Create</a>
</td>
<td>
Create a new resource with a server assigned id
</td>
</tr>
<tr>
<td>
<a href="#instance_update">Type - Search</a>
<macro name="toc">
<param name="section" value="7"/>
<param name="fromDepth" value="2"/>
</macro>
</td>
<td>
Search the resource type based on some filter criteria
</td>
</tr>
<tr>
<td>
<a href="#type_search">Type - Search</a>
</td>
<td>
Search the resource type based on some filter criteria
</td>
</tr>
<tr>
<td>
<a href="#history">Type - History</a>
</td>
<td>
Retrieve the update history for a particular resource type
</td>
</tr>
<tr>
<td>
<a href="#type_validate">Type - Validate</a>
</td>
<td>
Check that the content would be acceptable as an update
</td>
</tr>
<tr>
<td>
<a href="#system_conformance">System - Conformance</a>
</td>
<td>
Get a conformance statement for the system
</td>
</tr>
<tr>
<td>
<a href="#system_transaction">System - Transaction</a>
</td>
<td>
Update, create or delete a set of resources as a single transaction
</td>
</tr>
<tr>
<td>
<a href="#history">System - History</a>
</td>
<td>
Retrieve the update history for all resources
</td>
</tr>
<tr>
<td>
<a href="#system_search">System - Search</a>
</td>
<td>
Search across all resource types based on some filter criteria
</td>
</tr>
</tbody>
</table>
<a name="instance_read"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="Instance Level - Read">
<p>
The
<a href="http://hl7.org/implement/standards/fhir/http.html#read"><b>read</b></a>
operation retrieves a resource by ID. It is annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/Read.html">@Read</a>
annotation, and has a single parameter annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/IdParam.html">@IdParam</a>
annotation.
</p>
<macro name="snippet">
<param name="id" value="read" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/Patient/111</code>
</p>
<a name="instance_vread"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="Instance Level - VRead">
<p>
The
<a href="http://hl7.org/implement/standards/fhir/http.html#vread"><b>vread</b></a>
operation retrieves a specific version of a resource with a given ID. It looks exactly
like a "read" operation, but with a second
parameter annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/VersionIdParam.html">@VersionIdParam</a>
annotation.
</p>
<macro name="snippet">
<param name="id" value="vread" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/Patient/111/_history/2</code>
</p>
<a name="instance_update"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="Instance Level - Update">
<p>
The
<a href="http://hl7.org/implement/standards/fhir/http.html#update"><b>update</b></a>
operation updates a specific resource instance (using its ID), and optionally
accepts a version ID as well (which can be used to detect version conflicts).
</p>
<p>
Update methods must be annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/Update.html">@Update</a>
annotation, and have a parameter annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/ResourceParam.html">@Resource</a>
annotation. This parameter contains the resource instance to be created.
</p>
<p>
In addition, the method must have a parameter annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/IdParam.html">@IdParam</a>
annotation, and optionally may have a parameter annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/VersionIdParam.html">@VersionIdParam</a>
</p>
<p>
Update methods must return an object of type
<a href="./apidocs/ca/uhn/fhir/rest/api/MethodOutcome.html">MethodOutcome</a>. This
object contains the identity of the created resource.
</p>
<p>
The following snippet shows how to define an update method on a server:
</p>
<macro name="snippet">
<param name="id" value="update" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method (this would be invoked using an HTTP PUT,
with the resource in the PUT body):<br/>
<code>http://fhir.example.com/Patient</code>
</p>
<p>
The following snippet shows how the corresponding client interface
would look:
</p>
<macro name="snippet">
<param name="id" value="updateClient" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
In the case of a server which is able to do version conflict checking, an
extra parameter would be added:
</p>
<macro name="snippet">
<param name="id" value="updateVersion" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<a name="instance_delete"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="Instance Level - Delete">
<p>
The
<a href="http://hl7.org/implement/standards/fhir/http.html#delete"><b>delete</b></a>
operation retrieves a specific version of a resource with a given ID. It takes a single
ID parameter annotated with an
<a href="./apidocs/ca/uhn/fhir/rest/annotation/IdParam.html">@IdParam</a>
annotation, which supplies the ID of the resource to delete.
</p>
<macro name="snippet">
<param name="id" value="delete" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Delete methods are allowed to return the following types:
</p>
<ul>
<li>
<b>void</b>: This method may return <code>void</code>, in which case
the server will return an empty response and the client will ignore
any successful response from the server (failure responses will still throw
an exception)
</li>
<li>
<b><a href="./apidocs/ca/uhn/fhir/rest/api/MethodOutcome.html">MethodOutcome</a></b>:
This method may return <code>MethodOutcome</code>,
which is a wrapper for the FHIR OperationOutcome resource, which may optionally be returned
by the server according to the FHIR specification.
</li>
</ul>
<p>
Example URL to invoke this method (HTTP DELETE):<br/>
<code>http://fhir.example.com/Patient/111</code>
</p>
<a name="type_create"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="Type Level - Create">
<p>
The
<a href="http://hl7.org/implement/standards/fhir/http.html#create"><b>create</b></a>
operation saves a new resource to the server, allowing the server to
give that resource an ID and version ID.
</p>
<p>
Create methods must be annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/Create.html">@Create</a>
annotation, and have a single parameter annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/ResourceParam.html">@Resource</a>
annotation. This parameter contains the resource instance to be created.
</p>
<p>
Create methods must return an object of type
<a href="./apidocs/ca/uhn/fhir/rest/api/MethodOutcome.html">MethodOutcome</a>. This
object contains the identity of the created resource.
</p>
<p>
The following snippet shows how to define a server create method:
</p>
<macro name="snippet">
<param name="id" value="create" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method (this would be invoked using an HTTP POST,
with the resource in the POST body):<br/>
<code>http://fhir.example.com/Patient</code>
</p>
<p>
The following snippet shows how the corresponding client interface
would look:
</p>
<macro name="snippet">
<param name="id" value="createClient" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<a name="type_search"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="Type Level - Search">
<p>
The
<a href="http://hl7.org/implement/standards/fhir/http.html#search"><b>search</b></a> operation returns a bundle
with zero-to-many resources of a given type, matching a given set of parameters.
</p>
<subsection name="Search with No Parameters">
<p>
The following example shows a search with no parameters. This operation
should return all resources of a given type (this obviously doesn't make
sense in all contexts, but does for some resource types).
</p>
<macro name="snippet">
<param name="id" value="searchAll" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/Patient</code>
</p>
</subsection>
<subsection name="Search with a String Parameter">
<p>
To allow a search using given search parameters, add one or more parameters
to your search method and tag these parameters as either
<a href="./apidocs/ca/uhn/fhir/rest/server/parameters/RequiredParam.html">@RequiredParam</a>
or
<a href="./apidocs/ca/uhn/fhir/rest/server/parameters/OptionalParam.html">@OptionalParam</a>.
</p>
<p>
This annotation takes a "name" parameter which specifies the parameter's
name (as it will appear in the search URL). FHIR defines standardized parameter
names for each resource, and these are available as constants on the
individual HAPI resource classes.
</p>
<macro name="snippet">
<param name="id" value="searchStringParam" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/Patient?family=SMITH</code>
</p>
</subsection>
<subsection name="Search By Identifier">
<p>
Searches method parameters may be of any type that implements the
<a href="./apidocs/ca/uhn/fhir/model/api/IQueryParameterType.html">IQueryParameterType</a>
interface. For example, the search below can be used to search by
identifier (e.g. search for an MRN).
</p>
<macro name="snippet">
<param name="id" value="searchIdentifierParam" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/Patient?identifier=urn:foo|7000135</code>
</p>
</subsection>
<subsection name="Multiple Parameters">
<p>
Search methods may take multiple parameters, and these parameters
may be optional. To add a second required parameter, annotate the
parameter with
<a href="./apidocs/ca/uhn/fhir/rest/server/parameters/RequiredParam.html">@RequiredParam</a>.
To add an optional parameter (which will be passed in as <code>null</code> if no value
is supplied), annotate the method with
<a href="./apidocs/ca/uhn/fhir/rest/server/parameters/OptionalParam.html">@OptionalParam</a>.
</p>
<p>
You may annotate a method with any combination of as many @RequiredParam and as many @OptionalParam
parameters as you want. It is valid to have only @RequiredParam parameters, or
only @OptionalParam parameters, or any combination of the two.
</p>
<macro name="snippet">
<param name="id" value="searchOptionalParam" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URLs to invoke this method:<br/>
<code>http://fhir.example.com/Patient?family=SMITH</code><br/>
<code>http://fhir.example.com/Patient?family=SMITH&amp;given=JOHN</code>
</p>
</subsection>
<subsection name="Composite (Multi-Valued) Parameters">
<p>
It is possible to accept multiple values of a single parameter
as well. This is useful in cases when you want to return a list
of resources with criteria matching a list of possible values.
See the <a href="http://www.hl7.org/implement/standards/fhir/search.html#combining">FHIR Specification</a>
for more information.
</p>
<p>
The FHIR specification allows two types of composite parameters:
</p>
<ul>
<li>
Where a parameter may accept multiple comma separated values within a single value string
(e.g. <code>?language=FR,NL</code>) this is treated as an <b>OR</b> relationship, and
the search should return elements matching either one or the other.
</li>
<li>
Where a parameter may accept multiple value strings for the same parameter name
(e.g. <code>?language=FR&amp;language=NL</code>) this is treated as an <b>AND</b> relationship,
and the search should return only elements matching both.
</li>
</ul>
<h4>OR Relationship Query Parameters</h4>
<p>
To accept a composite parameter, use a parameter type which implements the
<a href="./apidocs/ca/uhn/fhir/model/api/IQueryParameterOr.html">IQueryParameterOr</a>
interface. For example, to accept searches for
Observations matching any of a collection of names:
</p>
<macro name="snippet">
<param name="id" value="searchMultiple" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/Observation?name=urn:fakenames|123,urn:fakenames|456</code>
</p>
<h4>AND Relationship Query Parameters</h4>
<p>
To accept a composite parameter, use a parameter type which implements the
<a href="./apidocs/ca/uhn/fhir/model/api/IQueryParameterAnd.html">IQueryParameterAnd</a>
interface.
</p>
<p>
See the section below on <a href="#DATE_RANGES">date ranges</a> for
one example of an AND parameter.
</p>
</subsection>
<subsection name="Date Parameters - Simple">
<p>
The FHIR specification provides a sytax for specifying
dates (and date/times as well, but for simplicity we will just say dates here)
as search criteria.
</p>
<p>
Dates may be optionally prefixed with a qualifier. For example, the
string <code>&gt;=2011-01-02</code> means any date on or after 2011-01-02.
</p>
<p>
To accept a qualified date parameter, use the
QualifiedDateParam
parameter type.
</p>
<macro name="snippet">
<param name="id" value="dates" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/Observation?birthdate=&gt;=2011-01-02</code>
</p>
<p>
Invoking a client of thie type involves the following syntax:
</p>
<macro name="snippet">
<param name="id" value="dateClient" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
</subsection>
<a name="DATE_RANGES"/>
<subsection name="Date Parameters - Ranges">
<p>
A common scenario in searches is to allow searching for resources
with values (i.e timestamps) within a range of dates.
</p>
<p>
FHIR allows for multiple parameters with the same key, and interprets
these as being an "AND" set. So, for example, a range of<br/>
<code>DATE &gt;= 2011-01-01</code> and <code>DATE &lt; 2011-02-01</code><br/>
can be interpreted as any date within January 2011.
</p>
<p>
The following snippet shows how to accept such a range, and combines it
with a specific identifier, which is a common scenario. (i.e. Give me a list
of observations for a specific patient within a given date range)
</p>
<macro name="snippet">
<param name="id" value="dateRange" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/Observation?subject.identifier=7000135&amp;date=&gt;=2011-01-01&amp;date=&lt;2011-02-01</code>
</p>
<p>
Invoking a client of this type involves the following syntax:
</p>
<macro name="snippet">
<param name="id" value="dateClient" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
</subsection>
<subsection name="Resource Includes (_include)">
<p>
FHIR allows clients to request that specific linked resources be included
as contained resources, which means that they will be "embedded" in a special
container called "contained" within the parent resource.
</p>
<p>
HAPI allows you to add a parameter for accepting includes if you wish
to support them for specific search methods.
</p>
<macro name="snippet">
<param name="id" value="pathSpec" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/DiagnosticReport?subject.identifier=7000135&amp;_include=DiagnosticReport.subject</code>
</p>
</subsection>
<subsection name="Named Queries (_query)">
<p>
FHIR supports <a href="http://www.hl7.org/implement/standards/fhir/search.html#advanced">named queries</a>,
which may have specific behaviour defined. The following example shows how to create a Search
operation with a name.
</p>
<p>
This operation can only be invoked by explicitly specifying the given query name
in the request URL. Note that the query does not need to take any parameters.
</p>
<macro name="snippet">
<param name="id" value="searchNamedQuery" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Example URL to invoke this method:<br/>
<code>http://fhir.example.com/Patient?_query=namedQuery1&amp;someparam=value</code>
</p>
</subsection>
<a name="type_validate"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="Type Level - Validate">
<p>
Not yet implemented
</p>
<a name="system_conformance"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="System Level - Conformance">
<p>
FHIR defines that a FHIR Server must be able to export a conformance statement,
which is an instance of the
<a href="http://hl7.org/implement/standards/fhir/conformance.html">Conformance</a>
resource describing the server itself.
</p>
<p>
The HAPI FHIR RESTful server will automatically export such
a conformance statement. See the
<a href="./doc_rest_server.html">RESTful Server</a>
documentation for more information.
</p>
<p>
If you wish to override this default behaviour by creating
your own metadata provider, you simply need to define a class
with a method annotated using the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/Metadata.html">@Metadata</a>
annotation.
</p>
<macro name="snippet">
<param name="id" value="metadataProvider" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
To create a Client which can retrieve a Server's conformance
statement is simple. First, define your Client Interface, using
the @Metadata annotation:
</p>
<macro name="snippet">
<param name="id" value="metadataClient" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
Then use the standard
<a href="doc_rest_client.html">RESTful Client</a> mechanism for instantiating
a client:
</p>
<macro name="snippet">
<param name="id" value="metadataClientUsage" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<a name="system_transaction"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="System Level - Transaction">
<p>
Not yet implemented
</p>
<a name="system_search"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="System Level - Search">
<p>
Not yet implemented
</p>
<a name="history"/>
</section>
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<!-- ****************************************************************** -->
<section name="History (Instance, Type, Server)">
<p>
The
<a href="http://hl7.org/implement/standards/fhir/http.html#history"><b>history</b></a>
operation retrieves a historical collection of all versions of a single resource
<i>(instance history)</i>, all resources of a given type <i>(type history)</i>,
or all resources of any type on a server <i>(server history)</i>.
</p>
<p>
History methods must be annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/History.html">@History</a>
annotation, and will have additional requirements depending on the kind
of history method intended:
</p>
<ul>
<li>
For an <b>Instance History</b> method, the method must have a parameter
annotated with the
<a href="./apidocs/ca/uhn/fhir/rest/annotation/IdParam.html">@IdParam</a>
annotation, indicating the ID of the resource for which to return history.
</li>
<li>
For an <b>Type History</b> method, the method must not have any @IdParam parameter.
</li>
<li>
For an <b>Server History</b> method, the method must not have any @IdParam parameter
and must not be found in a ResourceProvider definition.
<!-- TODO: make ResourceProvider a link to a defintion of these on the RESTFul server page -->
</li>
</ul>
<p>
The following snippet shows how to define a history method on a server:
</p>
<macro name="snippet">
<param name="id" value="history" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
<p>
The following snippet shows how to define various history methods in a client.
</p>
<macro name="snippet">
<param name="id" value="historyClient" />
<param name="file" value="src/site/example/java/example/RestfulPatientResourceProviderMore.java" />
</macro>
</section>
</body>
</document>