Ok, let me take some time to look this over. I'm sure I'll have more questions.

Thanks

Kevin




>No I didn't mean that. ToXML() parameter does that.
>Cetin
>
>>The IsDiffGram causes only changes to be sent to the XML file?
>>
>>
>>
>>>Kevin,
>>>I don't know really. Probably it means attached XML stays as is but only the ToXML(...,lChangesOnly) outputs diffgram.
>>>Cetin
>>>
>>>>Thanks! This example is exactly what I was looking for.
>>>>
>>>>The help file says "Setting the IsDiffGram property does not actually
>>>>alter the associated XML document."
>>>>
>>>>I'm not sure I understand this property. Can you elaborate?
>>>>
>>>>Thanks Cetin!
>>>>
>>>>
>>>>
>>>>
>>>>>Yes and no. Depends on version. Under VFP9 you have the luxury doing this with XMLAdpater class. The diffgram I pasted is from VFP7. Here is a sample for VFP9 that both creates the diffgram (might be your COM1) and updates from XML diffgram (might be your COM2):
>>>>>

>>>>>LOCAL lcDiffXML
>>>>>lcDiffXML = GetDiffGram() && COM1 creates diff.
>>>>>UpdateFromDiffgram(m.lcDiffXML) && COM2 gets XML
>>>>>
>>>>>
>>>>>PROCEDURE GetDiffGram
>>>>>USE _samples+"\data\customer"
>>>>>CURSORSETPROP("Buffering",5,'customer')
>>>>>BROWSE TITLE "Modify on site 1"
>>>>>
>>>>>* Create diffgram xml
>>>>>LOCAL lcChanges, oAdapter
>>>>>oAdapter = CREATEOBJECT('xmlAdapter')
>>>>>oAdapter.AddTableSchema('customer')
>>>>>oAdapter.IsDiffgram = .T.
>>>>>oAdapter.ToXML('lcChanges','',.f.,.t.,.t.)
>>>>>* Closing data just for sampling
>>>>>USE IN 'customer'
>>>>>RETURN m.lcChanges
>>>>>
>>>>>PROCEDURE UpdateFromDiffgram(tcDiffGram)
>>>>>LOCAL oAdapter
>>>>>* just for sampling using a different alias
>>>>>USE _samples+'data\customer' ALIAS myCustomer
>>>>>* we don't want to save when we are sampling only
>>>>>CURSORSETPROP("Buffering",5,'myCustomer')
>>>>>BROWSE TITLE 'Before applying diffgram'
>>>>>
>>>>>oAdapter = CREATEOBJECT('xmlAdapter')
>>>>>oAdapter.LoadXML(m.tcDiffGram,.f.)
>>>>>oAdapter.Tables(1).Alias = 'myCustomer'
>>>>>oAdapter.Tables(1).ApplyDiffgram()
>>>>>BROWSE TITLE 'After applying diffgram'
>>>>>

Too much hardcoding in there but this is a sample:)
>>>>>PS: AFAIK you also work with .Net and you would like to know XMLAdapter is friendly with .Net datasets and diffgrams (also VFPOLEDB have as added support).
>>>>>Cetin
>>>>>
>>>>>>Do I understand that I must store the changes back to the database myself? How is this
>>>>>>done? There could be any number of records and field changed. Is there any way to do
>>>>>>this automatically?
>>>>>>
>>>>>>
>>>>>>
>>>>>>>XmlUpdateGram() function creates an updategram (needs multilocks and buffering). That is it only includes updated/inserted/deleted records as updgram:before and after records. Suppose you updated customer table and changed company field, deleted ANATR and inserted NEWCUS. XmlUpdateGram('customer') produces an output like:
>>>>>>>

>>>>>>><?xml version = "1.0" encoding="Windows-1252" standalone="yes"?>
>>>>>>><root xmlns:updg="urn:schemas-microsoft-com:xml-updategram">
>>>>>>>	<updg:sync>
>>>>>>>		<updg:before>
>>>>>>>			<customer>
>>>>>>>				<cust_id>ALFKI</cust_id>
>>>>>>>				<company>Alfreds Futterkiste</company>
>>>>>>>* other fields here
>>>>>>>			</customer>
>>>>>>>		</updg:before>
>>>>>>>		<updg:after>
>>>>>>>			<customer>
>>>>>>>				<cust_id>ALFKI</cust_id>
>>>>>>>				<company>Alfreds Futterkiste-Updated</company>
>>>>>>>* other fields here
>>>>>>>			</customer>
>>>>>>>		</updg:after>
>>>>>>>		<updg:before>
>>>>>>>			<customer>
>>>>>>>* all fields here - unmodified
>>>>>>>			</customer>
>>>>>>>		</updg:before>
>>>>>>>		<updg:after/>
>>>>>>>		<updg:before/>
>>>>>>>		<updg:after>
>>>>>>>			<customer>
>>>>>>>				<cust_id>NEWCUS</cust_id>
>>>>>>>* other fields here
>>>>>>>			</customer>
>>>>>>>		</updg:after>
>>>>>>>	</updg:sync>
>>>>>>></root>
>>>>>>>

Instead of receiving the whole table diffgram approach only gets 'differences' IOW. On receving side you have to process this yourself however (ie: XMLDocument). VFP9 CA and XMLAdapter might help you to work with them in an easier way. Check www.prenia.com for samples.
>>>>>>>Cetin
>>>>>>>
>>>>>>>
>>>>>>>>The reason I'm using COM is because I will need to update the
>>>>>>>>application piece by piece. I don't want everything compiled
>>>>>>>>into one big EXE.
>>>>>>>>
>>>>>>>>Can you elaborate on the DiffGram option?
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>Hmm that in turn would bring up other questions. Ways to go are more than one and which one to choose depends. ie: One scenario:
>>>>>>>>>
>>>>>>>>>Instead of CursorToXml and XmlTocursor you might choose ADO and pass an ADO recordset instead.
>>>>>>>>>Another one is to pass a diffgram instead of all rows using CursorToXML and XMLToCursor.
>>>>>>>>>Yet another one might be passing just an array of records that are updated/added/deleted with flags.
>>>>>>>>>
>>>>>>>>>Actually first I would think of "do I really want to talk between COM objects or even do I want a single COM object in my application" - sounds like I don't like COM objects:) Really I don't, too much problems with them for me (call it DLL hell, security etc etc).
>>>>>>>>>
>>>>>>>>>If one of them can connect to data why would other one cannot and a need for 2 evils?
>>>>>>>>>Cetin
>>>>>>>>>
>>>>>>>>>>Thanks. This brings up another question.
>>>>>>>>>>
>>>>>>>>>>I want to use CURSORTOXML() and XMLTOCURSOR() to pass data to and
>>>>>>>>>>from COM objects.
>>>>>>>>>>
>>>>>>>>>>Once I make changes to data and convert it to XML, and after I use
>>>>>>>>>>XMLTOCURSOR() to create a cursor, whats the best way to update the
>>>>>>>>>>database?
>>>>>>>>>>
>>>>>>>>>>I am using a VFP database now, with possible plans later to convert
>>>>>>>>>>to SQL Server.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>>>For the 'nOutputFormat', 'nFlags', 'cSchemaName', 'cSchemaLocation', and 'cNameSpace'
>>>>>>>>>>>>parameters, are there any standards as far as what settings I should use?
>>>>>>>>>>>>
>>>>>>>>>>>>I am only using the command to pass data back & forth between COM objects.
>>>>>>>>>>>
>>>>>>>>>>>If there were standards there wouldn't be flags;)
>>>>>>>>>>>nOutputFormat: 2 or 3 are my favorites. More compact.
>>>>>>>>>>>nFlags: 1 to make it compact.
>>>>>>>>>>>For others it depends. Probably "1" inline schema would be good.
>>>>>>>>>>>
>>>>>>>>>>>With these settings:
>>>>>>>>>>>CursorToXml('myAlias','myMemvar',2,1,0,"1")
>>>>>>>>>>>would create a compact XML with inline schema and store in m.myMemvar and IMHO is good for your need.
>>>>>>>>>>>Cetin