· Jul 5, 2020

How to add POST Body data to Net.HttpRequest

Hi, how do I add the POST body content to my Net.HttpRequest (It's not a key value pair, I am posting my own JSON to the remote server because it needs JSON in the body):

                set httpRequest=##class(%Net.HttpRequest).%New()

                set httpRequest.Https=1
                set httpRequest.Server=""
                set AbsolutePath="/api/redacted"
                set QueryString="?operation=redacted&id=redacted"
                 set status=httpRequest.Post(AbsolutePath_QueryString)
But how to add the Body to the request?
For the sake of this post, the body could be:
{ "MyKey":"MyValue" }
but in reality it's a highly nested, valid, JSON string.
Kind regards!
Discussion (7)0
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Hi Anthony,

Look at the doc for the property EntityBody, you can do something like :

Set body = { "MyKey":"MyValue" }
Do httpRequest.EntityBody.Write(  body.%ToJSON() )

 property EntityBody as %GlobalBinaryStream;

When an Entity-Body is included with a message, the data type of that body is determined via the header fields Content-Type and Content- Encoding. These define a two-layer, ordered encoding model.

This is a stream so to insert into this stream use:

	Do oref.EntityBody.Write("Data into stream")


Here is an example of a HTTP Operation POSTing HL7 messages. this HTTP request uses HTTPS and a Proxy Server. The lines I have highlighted in Yellow will be different in your case as you are sending JSON. Not clear if you are using FHIR. However your ContentType will most likely be application/json or application/json+fhir

    set tSC=$$$OK,pResponse=""
    try {
        set message=pRequest.OutputToString(,,.tSC) if 'tSC quit
        set tResponse = ##class(%Net.HttpResponse).%New(),tResponse.ContentType="application/hl7-v2"
        if '$IsObject(..HTTPRequest) {
            set pHttpRequest=##class(%Net.HttpRequest).%New()
            set pHttpRequest.Server=..Adapter.HTTPServer
            set pHttpRequest.Port=..Adapter.HTTPPort
            set pHttpRequest.ProxyServer=..Adapter.ProxyServer
            set pHttpRequest.ProxyPort=..Adapter.ProxyPort
            set pHttpRequest.ProxyTunnel=..Adapter.ProxyHttpTunnel
            set pHttpRequest.ProxyHTTPS=1
            set pHttpRequest.SSLConfiguration=..Adapter.SSLConfig
            set pHttpRequest.UserAgent="curl/7.29.0"
            set pHttpRequest.ContentEncoding="HL7-ER7"
            set pHttpRequest.ContentCharset="UTF-8"
            set pHttpRequest.ContentType="application/hl7-v2"
            set pHttpRequest.AcceptGzip=0
            set pHttpRequest.WriteRawMode=0
            set pHttpRequest.ReadRawMode=0
            set pHttpRequest.OpenTimeout=..Adapter.ConnectTimeout
            set pHttpRequest.Timeout=..Adapter.ResponseTimeout
            set pHttpRequest.WriteTimeout=..Adapter.WriteTimeout
            set pHttpRequest.SocketTimeout=115
            set ..HTTPRequest=pHttpRequest
        set ..HTTPRequest.HttpResponse=tResponse
        do ..HTTPRequest.EntityBody.Write(message)
        set tSC=..HTTPRequest.Post(..Adapter.URL,0,1) if 'tSC {
            set sc=$$$DebugLog("HTTP Write","Error: "_$$$GetErrorText(tSC))
        else {do $$$DebugLog("HTTP Write","Post Sucessful)}
        set response=..HTTPRequest.HttpResponse
        $$$TRACE("HTTP Response Status: "_response.StatusCode)
        if response.StatusCode=200 {
            if $IsObject(response.Data) {
                set message="" while 'response.Data.AtEnd {set message=message_response.Data.Read(,.tSC) if 'tSC quit}
                set pResponse=##class(EnsLib.HL7.Message).ImportFromString(message,.tSC) if 'tSC $$$TRACE("An error occurred creating Respnse Message: "_$system.Status.GetErrorText(tSC))
        else {
            set message="" if $IsObject(response.Data) {set message="" while 'response.Data.AtEnd {set message=message_response.Data.Read(,.tSC) if 'tSC quit}}
            set tSC=$$$ERROR(5001,"HTTP Response Status is "_response.StatusCode_" with Error Text: "_response.ReasonPhrase_" with Content: "_message) quit
    catch ex {
        set tSC=ex.AsStatus()
    if 'tSC,'$IsObject(pResponse) {

  // Here I create a NACK HL7 message if I didn't get a valid response from the remote server. Possibly because the server is down or the 

 //server has crashed. I have a DTL that takes the inbound HL7 request message and transforms it into an HL7 ACK message. I force the ACK 

// Code to "AE" and use the contents of tSC (error status) as the Error Message. Note I make use of the 3rd parameter in the Transform()

// method that allows you to pass in an object containing any properties you want. This is a useful way of getting data into the DTL that

// doesn't exist in either your sourse or target objects.

        set pResponse=##class(EnsLib.HL7.Message).%New(),aux=##class(HPRS.Transformations.CreateNACKDTL.AUX).%New()
        set aux.ACKCode="AE",aux.ACKMessage=$system.Status.GetErrorText(tSC)
        set sc=##class(HPRS.Transformations.CreateNACKDTL).Transform(pRequest,.pResponse,.aux) if 'sc $$$TRACE("Unable to Create NACK Response HL7 Message")
    $$$TRACE("Outcome of HTTP Operation: "_$s(tSC:"Ok",1:"Error: "_$$$GetErrorText(tSC)))
    quit $$$OK


Nigel Salm