Hey Bing,

Assuming you have the functions.xml file in your package, you can use SLNet messages to import it and set it active.

To upload a functions.xml file, use the 'AddFunctionsXmlRequestMessage'

var xmlContents = File.ReadAllText("..."); // The xml contents of the function file
var protocolName = "...";
var fileName = "..."; // The file name for the functions file.
var addReq = new AddFunctionsXmlRequestMessage()
{
File = xmlContents,
ProtocolName = protocolName,
FileName = fileName
};

var response = _engine.SendSLNetSingleResponseMessage(addReq) as AddFunctionsXmlResponseMessage;

if (response == null || !response.Success || !response.TraceData.HasSucceeded())
{
// Something went wrong, response.TraceData might contain more information
// and can be 'ToStringed'
}

Setting a functions.xml active can be done with the 'SetCurrentFunctionsXmlRequestMessage'
var setReq = new SetCurrentFunctionsXmlRequestMessage()
{
File = fileName,
ProtocolName = protocolName,
};

var setResp = _engine.SendSLNetSingleResponseMessage(setReq) as SetCurrentFunctionsXmlResponseMessage;
if (setResp == null || !setResp.Success || !setResp.TraceData.HasSucceeded())
{
// Something went wrong
}

Activating a functions.xml can fail in case there is already a different file active and in use (by service definitions, resources…) and the update is not considered 'safe'. The following changes are considered unsafe:

• Removing a function definition
• Lowering the max instances of a function definition
• Change name of a function definition to a name that is not unique within the protocol function version
• Change the profile of function definition
• Change parent of a function definition
• Changes to the entrypoints of a function definition
• Remove an interface of a function definition
• Remove a parameter of a function definition

If there are any unsafe changes between the function versions the call will fail unless you force it, which will skip these checks. Forcing can be done with a property on the 'SetCurrentFunctionsXmlRequestMessage',but is of course not recommended to do by default.

Note that using SLNet messages directly is not recommended. I do think the relevant method in the SRMInstaller should cover your use case as well, so if you encounter an issue with that, it's best to get in touch with the A&O domain.