Mark, Our axscript host implementation is based around the old "ActiveScriptHost" class by Ernest Laurentin. Our base collection class is a template class implements _NewEnum, Count and other functions as per this dispatch map:
DISP_PROPERTY_EX_ID(C##BaseName, "_NewEnum", DISPID_NEWENUM, _NewEnum, SetNotSupported, VT_UNKNOWN) DISP_PROPERTY_EX_ID(C##BaseName, "Count", DISP_ID_COUNT, GetCount, SetNotSupported, VT_I2) DISP_FUNCTION(C##BaseName, "Add", Add, VT_DISPATCH, VTS_VARIANT VTS_VARIANT) DISP_FUNCTION(C##BaseName, "Item", GetItem, VT_DISPATCH, VTS_VARIANT) DISP_FUNCTION(C##BaseName, "Remove", Remove, VT_EMPTY, VTS_VARIANT) DISP_DEFVALUE(C##BaseName, "Item") I'm not sure where this came from now, probably from one of the MS MFC samples, possibly XRTFrame. The implementation of Next does "return ResultFromScode(S_FALSE)" on reaching the end of the list of available items. The debug tracing inside our app shows that all the expected objects are being created and destroyed, so it may be something wrong in our internal 'wiring' that relates the scriptable objects to our internal data model objects that is not properly tidying up. We have yet to prove that it really is the absence of a StopIteration exception that is causing the app crash, so we are continuing to unpick the code. Best regards, David. -----Original Message----- From: Mark Hammond [mailto:skippy.hamm...@gmail.com] Sent: 17 April 2012 02:15 To: supp...@pulsonix.com Cc: python-win32@python.org Subject: Re: [python-win32] Need advice on iterator implementation in scripting host On 13/04/2012 9:14 PM, Pulsonix Tech Support wrote: > We have an ActiveX scripting host implementation in our application > (written in C++), so that users can run scripts to access our data > from inside the application. > > Current problem is that iterating from Python script doesn't work right. > You can iterate through a collection, but attempts to do this a second > time cause application crashes or unexpected behaviour. Seems to work > okay from VBscript though. > > This may be because we are not raising StopIteration exception when > iterator.Next() has no items left. But I can't find any information > about how to do this from a C++ scripting host implementation. win32com has some iterator support built in, but was done way before Python itself had proper iterators so probably isn't ideal. The most basic support is enabled when the object has a "Count" property and an Item() method. Some support for IEnumVARIANT also exists, but it requires you to wrap the object in win32com.client.util.Iterator - which I should possibly revisit as we might be able to make that seamless. How are you attempting to expose iteration? Mark _______________________________________________ python-win32 mailing list python-win32@python.org http://mail.python.org/mailman/listinfo/python-win32
