Developing a FHIR Server

Using C# and MongoDb, Xml and Json

Ewout Kramer,

Furore (e.kramer@furore.com)

Architectural context

CDR

FHIR REST

Comm.Service

v3

v2

PHR

FHIR

VNA

FHIR

ETL

HIS LIMS PACS

FHIR Msg

Comm.Service

DB

Solution scenarios

StorageStorage

ProcessingProcessing

FHIR Resource

FHIR REST

JSON/XML

POCO/POJO

DBMS

ORM

FHIR Parser

JSON/XML

POCO/POJO

NoSql(Xml/Json)

FHIR Parser

JSON/XML

JSON/XML

NoSql(Json/Xml)

FHIR Validator

JSON/XML

XML

NoSql(Json)

FHIR Validator

Json and Xml Roundtrip?

<XXX xmlns=“urn:foo”> <B a=“c” /> <C>One</C> <C>Two</C> <D>One</D> <div>Not <b>so</b></div></XXX>

{ “B”: { “@a” : “c” }, “C”: [ “One”, “Two” ], “D” : “One”, “div” : { “#text” : “Not ”,

“b” : “so”}

}

FHIR Xml and JSon guidelines

<Person xmlns="http://www.hl7.org/fhir"> <identifiers> <identifier> <type> <code>MR</code> <system>urn:hl7-org:sid/v2-0203</system> </type> <identifier> <system>oid:1.2.36.146.595.217.0.1</system> <id>12345</id> </identifier> <assigner> <text>Acme Healthcare</text> </assigner> <period> <low>2001-05-06</low> </period> </identifier> </identifiers> <text> <status>generated</status> <xhtml xmlns="http://www.w3.org/1999/xhtml"> <table> <tbody> <tr>

"Person" : { "identifiers" : [ { "identifier" : { "type" : { "code" : "MR",

"system" : "urn:hl7-org:sid/v2-0203“ }

} } ], "text" : { "status" : "generated", "xhtml" : "<table><tbody><tr><td>Name</td>

<td>Peter James <b>Chalmers</b> </table></tbody></table>"

} }

Two ways of storing in MongoDb

var database = server.GetDatabase("test");

var collection = database.GetCollection<Entity>("entities");

var entity = new Entity { Name = "Tom" }; collection.Insert(entity); var id = entity.Id;

BsonDocument nested = new BsonDocument {

{ "name", "John Doe" }, { "address", new BsonDocument

{ { "street", "123 Main St." }, { "city", "Centerville" }, { "zip", 12345 }

}}

};collection.Insert(nested);

What a detour….

Json -> XML -> Json -> Bson

ResourceRecord-RecordId, Version -State-CreationDate, Author

ResourceRecord-RecordId, Version -State-CreationDate, Author

ResourceRecord-RecordId, Version -State-CreationDate, Author

Storing a resource as a record

ResourceInstance-AsJson(), ToJson(), …-GetElement(), ReplaceElement()-ResourceId, Location, Type

FHIR ResourceData (XML)

How do I do transactions/locking?MongoDB does not use traditional locking or complex transactions with rollback, as it is designed to be lightweight and fast and predictable in its performance. It can be thought of as analogous to the MySQL MyISAM autocommit model. By keeping transaction support extremely simple, performance is enhanced, especially in a system that may run across many servers.

Brewer’s CAP theorem

Consistency, Availability and Partition tolerance

Pick any two…

C

A P

http://fhir.apphb.com/fhir/help

26th Annual Plenary & Working Group MeetingSep 9, 2012 to Sep 14, 2012 - Baltimore, MD

(Dutchies take note: September 12th general elections!)

SATURDAY SEPTEMBER 8th

FIRST FHIR CONNECTATHON