IPC communication

The first step is to add the ALIpcClient.dll to project references.

using ALIpcClient;

Create an object for the communciation and another one to receive commands from ARCHline.XP

private readonly ALIpcClient.ALIpcClient _ipcClient = new ALIpcClient.ALIpcClient();
private readonly ALIpcClient.IndirectClientFunction _functionForCommands;

At the initializaton phase set up the receive command hook function. 

//Register the command handler function
_functionForCommands = CommandHandler;
IntPtr intPtr = Marshal.GetFunctionPointerForDelegate(_functionForCommands);
_ipcClient.RegisterIndirectCommandQueue(intPtr);

You can decide to start a new embedded instance of ARCHline.XP or join into an existing one.

//Start a new ARCHLine.XP instance or join to an existing one?
bool startARCHline = true;

            //Create the IPC channel with a unique name

string ipcChannelId = startARCHline ? Guid.NewGuid().ToString() : string.Empty ;
bool archLineStarted = startARCHline ?_ipcClient.StartArchline(
          "c:\\Program Files\\ARCHline.XP 2021\\ARCHlineXP2021.bin",  //The path to the ARCHLine.XP executable
          $" -s -n -ipc {ipcChannelId}",    //ARCHLine.XP command parameters: (-s: start new project), (-n: no splash) and (-ipc name: The name of the IPC channel)
          25000,                                     //Max waiting time for ARCHLine.XP to start in msec
          alHostWnd.Handle,                 //Host control's handle
          Width, Height,                         //Host window's size
          out _archLineAppHwnd) : true;      //ARCHline.XP's main window handle

The ipcChannelId is the identifier of the communication channel. Every instance can create its own channel Id. By default it is an empty string. At ARCHline.XP start you can define it with the -ipc command.

//If ARCHLine.XP has started successfully then connect to it
if (archLineStarted && _ipcClient.Connect(ipcChannelId))
{
    //Handle successfull connection
    ;
}
else
{
    //Handle errors
    ;
}

Incoming commands

Incoming commands come from ARCHline.XP, the client can receive at the registered hook function. The command parameter describes the command name, the parameter is it's parameters and the clientCommandResult is the handler object for the command. It can reply to ARCHline.XP about the current command, set the result and close it. Closing it is mandatory.

public void CommandHandler(string command, string param, ALIpcClient.IClientCommandResult clientCommandResut)
{
     if (command == "on_selection_changed") //If the list of the selected items changed in ARCHLine.XP
     {
         //Process the incoming parameters
         ALIpcClient.Variables selectedARCHLineItems = new ALIpcClient.Variables.ItemIDArray();
         selectedARCHLineItems.FromStream(param);
     }
     //Always close commands even if the application cannot handle the specified command type
     clientCommandResut.SetFinished(true, string.Empty);
}

The command can be synchron or asynchron. The synchron command means the sender is waiting until the command is not closed at the receiver side.

Outgoing commands

The client can send commands to ARCHline.XP. The first parameter is the function code, the second one is the function's parameter, the third one is the mode that can be synchron and asynchron, and the last one is the result object.

It describes:

• if the command is finished or not,
• if the result was successful or not,
• the result parameters.

string msStream = ModStruct.CreateModstructStream(itemIdentifiers);
if(_ipcClient.SendCommand(ALServerCommandType.cSetProperties, msStream, true, out
ServerCommandResult setPropertiesCommandResult)) {
          Debug.Assert(setPropertiesCommandResult.IsFinished());
          bool ok = setPropertiesCommandResult.GetResult(out string resultValue);
          Debug.Assert(ok);
}

These are the avaliable commands:

• Kernel command
  It can execute all ARCHline.XP internal commands. The parameter contains the ARCHline.XP command itself.
• Get properties
  The parameter defines the items and the result value contains the properties in XML format.
• Set properties
  The parameter is an XML stream or file what contins a list of new properties for all items what reqires to change.