[BLACKBOX] foreign COM-objects part 2: inherit multiple interfaces

From: VDI <bernhardt.gunnar{([at]})nowhere.xy>
Date: Fri, 17 Dec 2010 09:36:26 +0100

----boundary-LibPST-iamunique-593318031_-_-
Content-type: text/plain

Dear all,

one thing I found to be quite confusing when trying to use MSXML from
 BB:

In principle you should be able to create a new xmlElement and append
 it to any kind of xmlNode, because IXMLDOMElement is derived from
 IXMLDOMNode.

TYPE
  IXMLDOMNode* = POINTER TO INTERFACE RECORD
                 END;
  IXMLDOMElement* = POINTER TO INTERFACE RECORD (ANYPTR + IXMLDOMNode)
                    END;
PROCEDURE (this:IXMLDocument) createElement*( <omitted> ) :
 IXMLElement,NEW,ABSTRACT;
PROCEDURE (this:IXMLDOMNode) appendChild*(p0 : IXMLDOMNode) :
 IXMLDOMNode,NEW,ABSTRACT;

Above code is taken from the gpcp interface module.


The code generated by (Dev)ComInterfaceGen looks like this:
TYPE
                IXMLDOMDocument = POINTER TO RECORD (CtlT.Object)
                        (this: IXMLDOMDocument) createElement (tagName: ARRAY OF CHAR):
 IXMLDOMElement, NEW;
                END;
                IXMLDOMNode = POINTER TO RECORD (CtlT.Object)
                        (this: IXMLDOMNode) appendChild (newChild: IXMLDOMNode):
 IXMLDOMNode, NEW;
                END;
                IXMLDOMElement = POINTER TO RECORD (CtlT.Object)
                        <omitted>
                END;
 
Am I correct that the reason is that Component Pascal as it is defined
 in the Language Report (by Oberon) does not allow to inherit from
 multiple interfaces so there is not easy way to circumvent this?
                
kind regards
gunnar

----
To unsubscribe, send a message with body "SIGNOFF BLACKBOX" to LISTSERV{([at]})nowhere.xy----boundary-LibPST-iamunique-593318031_-_-
Content-type: application/rtf
Content-transfer-encoding: base64
Content-Disposition: attachment; filename="rtf-body.rtf"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----boundary-LibPST-iamunique-593318031_-_---

Received on Fri Dec 17 2010 - 09:36:26 UTC