Configuring an out-of-process OLEServer for DCOM

Introduction

When you register an out-of-process OLEServer using File/Export or OLERegister, Dyalog APL automatically updates the Windows registry so that your OLEServer is immediately accessible to an OLE client application running on the same computer.

If you wish to make the same object accessible to client applications running on different computers (using distributed COM, or DCOM) you have to install additional registry entries on the server and on each of the clients.

Once you have established these registries entries, you should be able to access the OLEServer from Windows 95 or NT client computers in exactly the same way as if it were local; the client applications need not know where the server is located. In most cases, these additional registry entries are sufficient. However, the NT and DCOM security considerations may require the use of dcomcnfg.exe (a Microsoft utility) to set additional values. For example, if you get E_ACCESSDENIED errors when connecting from the client you may need to run dcomcnfg.exe on the server computer to assign the appropriate launch and access permissions for the OLEServer object.

The additional registry entries are described below. You may add these to the registry directly (using regedit.exe) or by running the functions provided in the DCOMREG.DWS workspace.

DCOM Registry Entries for the Server

On the computer upon which you want the OLEServer to be run, you must add the following registry entries.

A key under HKEY_CLASSES_ROOT\AppID whose name corresponds to the CLSID of your OLEServer object as reported by the value of its ClassID property. The (Default) value of this key should be the name of the server object. In addition, you must define a RunAs entry which specifies the manner in which a client application runs your server. The simplest choice is Interactive User which specifies that the client application is treated like a normal user.

For example, if you had saved an OLEServer namespace called Loan (c.f. samples\loan.dws), whose ClassID property had the value {B80E9D40-2090-11D1-8F93-0020AFABD95D} the entries would be:
```
HKEY_CLASSES_ROOT\AppID\{B80E9D40-2090-11D1-8F93-0020AFABD95D}
(Default)=dyalog.Loan
RunAs=Interactive User
```
An AppID entry to the HKEY_CLASSES_ROOT**\**CLSID key. (Note that this key will itself have been created by Dyalog APL/W when you saved the workspace) Once again, CLSID refers to the value of your OLEServer's ClassID property. The value of the AppID entry is the (same) CLSID. Using the same example as above, the entry would be:
```
HKEY_CLASSES_ROOT\{B80E9D40-2090-11D1-8F93-0020AFABD95D}
AppID={B80E9D40-2090-11D1-8F93-0020AFABD95D}
```

DCOM Registry Entries for the Client

On each of the computers from which you wish to call the OLEServer object as a client, you must add the following entries.

Two keys under HKEY_CLASSES_ROOT that identify the object (locally) and associate it with your OLEServer Note that the local name of the object is arbitrary and may be different on each client.
```
HKEY_CLASSES_ROOT\dyalog.ServerName</p>
HKEY_CLASSES_ROOT\dyalog.ServerName\CLSID
```
CLSID is again the CLSID of the OLEServer object (this must be the same as that of the server machine). dyalog.ServerName can be replaced with whatever name you want clients to use to refer to this object.
Under HKEY_CLASSES_ROOT\AppID, a key whose name corresponds to the CLSID of your server object. The (Default) value of this key should be the name of the OLE server object (its name on the server computer). In addition, the key should contain a RemoteServerName entry whose value is the name of the server computer. For example:
```
HKEY_CLASSES_ROOT\AppID\{B80E9D40-2090-11D1-8F93-0020AFABD95D}
(Default)=dyalog.Loan
RemoteServerName=ntsvr
```

DCOMREG Workspace

The workspace DCOMREG.DWS contains a single namespace called reg that contains three functions to help register an out-of-process OLE Server for DCOM.

RegDCOMServer

This function should be run on the server computer and is called as follows:

      RegDCOMServer ServerName CLSID

Where ServerName is a character string containing the (full) name of the OLEServer (e.g. dyalog.Loan) and CLSID is a character string containing the CLSID of the server (the value of it ClassID property). For example:

      )LOAD LOAN
.\LOAN saved ...
      )COPY DCOMREG
DCOMREG saved ...

      CLSID ←('Loan' ⎕WG 'ClassID')
      reg.RegDCOMServer 'dyalog.Loan' CLSID

RegDCOMClient

This function should be run on each of the client computers and is called as follows:

      machine RegDCOMClient ServerName CLSID

Where machine is a character vector specifying the name of the (NT) server computer, ServerName is a character vector containing the (full) name of the OLEServer (e.g. dyalog.Loan) and CLSID is a character string containing the CLSID of the server (the value of it ClassID property). For example:

      CLSID←'{B80E9D40-2090-11D1-8F93-0020AFABD95D}'
      'NTSVR' reg.RegDCOMClient 'dyalog.Loan' CLSID

Config

This niladic function simply invokes the dcomcnfg.exe utility using ⎕CMD.