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Marc Mundt · Jun 13, 2022

Yes, the GenericService will send an EnsLib.HTTP.GenericMessage object to your business process. The GenericMessage includes the headers and content of the inbound HTTP request. Your DTL can use these fields to transform to another format.

Similarly, the GenericOperation accepts the same GenericMessage type and uses the values in it to issue an HTTP request to the downstream system.

So all together, this allows you to create a REST web service and/or call out to external REST services using only the GUI.

https://docs.intersystems.com/irisforhealth20221/csp/docbook/DocBook.UI....

Marc Mundt · Jun 6, 2022

Here's a sample class to Base64 encode a stream:

Class Example.B64.Util Extends %RegisteredObject
{

/// Be cautious if changing CHUNKSIZE. Incorrect values could cause the resulting encoded data to be invalid.
/// It should always be a multiple of 57 and needs to be less than ~2.4MB when MAXSTRING is 3641144
Parameter CHUNKSIZE = 2097144;

ClassMethod B64EncodeStream(pStream As %Stream.Object, pAddCRLF As %Boolean = 0) As %Stream.Object
{
    set tEncodedStream=##class(%Stream.GlobalCharacter).%New()
    
    do pStream.Rewind()
    
    while ('pStream.AtEnd) {
        set tReadLen=..#CHUNKSIZE
        set tChunk=pStream.Read(.tReadLen)
        
        do tEncodedStream.Write($System.Encryption.Base64Encode(tChunk,'pAddCRLF))
        if (pAddCRLF && 'pStream.AtEnd) {
            do tEncodedStream.Write($c(13,10))
        }
    }
    
    do tEncodedStream.Rewind()
    
    quit tEncodedStream
}
}
Marc Mundt · Apr 13, 2022

Just to add a bit of context to the above:
An example use case where you would want to return the operation's response back to the service would be in an HL7 integration where, instead of having the service generate an ACK to return to the upstream sending system, we want to return the ACK or NAK that we got back from the downstream receiving system.

Marc Mundt · Apr 13, 2022

What Response From does is control which responses from a call to an operation (or another component) are returned to the business service that called the router. By default the router won't return the response to the service, but setting Response From will enable responses to be returned from specific operations (or * for all operations). This is how you can control which response gets sent back to the service in a case when a router calls multiple operations. If multiple responses match the Response From setting, then only the first response will be returned to the service.

Response Target Config Names allows you to specify additional components (beyond the service that called the router) that should receive a copy of the response that came back from the operation. So you could send a copy of an ACK or other response to another operation for some reason.

All of this is probably moot, because I'm guessing your service doesn't need to receive a response.

In terms of the NULL responses, these shouldn't become orphans -- the fact that they appear in the message trace tells us that the production knows which session they belong to so they should get deleted along with the rest of the session.

Marc Mundt · Apr 12, 2022

Absolutely. You can do this with two assign actions:

First assign action moves the stream pointer to the end of the stream content:

The second assign action writes our new content to the end of the stream:

And an extra note of explanation: what we're actually doing with these assigns is calling a method in the request class, which returns a status code, and assigning that status code to a temporary variable. It would be best to check this status code to see if there was an error, but I haven't added that here to keep things simple.