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FHIR – Feel the Fire - Part 1 Jayant Singh http://www.j4jayant.com 1

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Feel the FireFHIR provides very good specificationhttp://www.hl7.org/implement/standards/fhir/Hands on experience on any thing helpsunderstand it better.Connect FHIR test servers and explore FHIR -healthcare resources in RESTful environment. 2

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Connect Test ServersI will discuss two approaches to connect testserverFiddlerWrite your own client (in C#)I will connect Grahames test server available athttp://hl7connect.healthintersections.com.au/svc/fhir/ 3

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Connect using FiddlerFiddler is simple tool which we will use tocompose requests to RESTful FHIR test serversDownload and install Fiddler fromhttp://www.fiddler2.com/fiddler2/ 4

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Conformance Resource - RequestFirst step - request a conformance resource to know how anapplication or implementation supports FHIR.OPTIONShttp://hl7connect.healthintersections.com.au/svc/fhir/ 5

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Conformance Resource - ResponseRead the conformance carefully to understand supported FHIRresources 6

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Patient Resource Feed - RequestGEThttp://hl7connect.healthintersections.com.au/svc/fhir/patientIn this request we have specified “Accept” Http header to specifycontent type for this request as xml 7

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Patient Resource Feed - Responsefeed with collection of all the patient resources. Each patientresource will be inside “entry” element.Go through each element in this xml and understand it bycomparing with definition available in specification 8

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Patient Resource - RequestGEThttp://hl7connect.healthintersections.com.au/svc/fhir/patient/@1In this request we have specified “Accept” Http header to specifycontent type for this request as json 9

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Patient Resource - ResponsePatient ResourceGo through each element in this json and understand it bycomparing with definition available in specification 10

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Bad RequestTry to query a resource which is not availableGEThttp://hl7connect.healthintersections.com.au/svc/fhir/patient/@1123This will return HTTP 404 Not Found status code 11

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Write a Client in C#Writing your own client to query resources fromtest server will help you understand the FHIR &RESTful environment.Sample code provided here is written in C# anduses a library RestSharp to make RESTfulrequest/response. 12

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Sample Code//create a RestClientvar client = new RestClient();//Assign base url of RESTFul Serverclient.BaseUrl = txtUri.Text.Trim();//HTTP method(GET/POST etc) to use for this requestMethod method = (Method)Enum.Parse((typeof(Method)), cmbHttpOptions.Text);//Create RestRequestvar request = new RestRequest(method);//Add header "Accept" to request xml or json data formatif (cmbContentType.Text.Equals("xml")) request.AddHeader("Accept", "application/xml");else request.AddHeader("Accept", "application/json");//resource to query like patient, patient/@1, document etc.request.Resource = txtResource.Text.Trim();//Execute the request and get responseIRestResponse response = client.Execute(request);//display the raw response headertxtResult.Text = "************Response Header***********n";for (int i = 0; i < response.Headers.Count; i++) txtResult.Text += response.Headers[i].Name + ": " + response.Headers[i].Value + "n";txtResult.Text += "StatusCode: " + response.StatusCode + "n";//display the raw response contenttxtResult.Text += "nn************Raw Content**********n"; 13txtResult.Text += response.Content;

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Using this clientRequest Patient Resource with xml response 14

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Using this clientRequest Document Resource with json response 15

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ImportantTry more resource URIs on your own to exploreother resourceshttp://hl7connect.healthintersections.com.au/svc/fhir/ lists all the supported resources and theirprofilesNote that these servers are testing servers. Theymay be sporadically unavailable 16

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Thank You Jayant Singh http://www.j4jayant.com 17