Problem with MSXML DOM Parser

[lenny wintfeld]

Hi

I'd like to use the MSXML15 libraries from sourceforge to parse an XML configuration file, but so far, no luck. I tried dropping the sample vi that came with the MSXML15 package "Database editor.vi" onto a blank block diagram, but it generates tons of errors. The example's block diagram is clean, but vi's that it uses have lots of error messages in them. I can provide specific examples if it would help. Most (possibly all) of the errors are because of type mismatches on wires that connect XML invoke node methods or properties with Labview objects. The methods/properties invariably are of type void and the LabVIEW objects have some other (evidently) incompatible type.

I suspect that this either has to do with my version of LabVIEW (8.0) or with a LabVIEW setup option. The reason is, I have the same problem with the very nice example program posted here by Randy on 7/19/06. His vi is MSXML_save_XML.vi and its block diagram yields similar type mismatches.

I also tried using DEMO_XML_File_Read.zip by jlokanis from his post here of 8/25/08, but it is Labview 8.5 specific and 8.0 won't load it.

Can someone give me some hints on how to get the sample programs to run?

And more generally, are there some resources I can look at that would help me get at MSXML methods directly? I've done quite a bit of DOM parser access to XML in Java and while it's tedious to do, you can accomplish quite a bit with it.

Any advice greatly appreciated!

Lenny Wintfeld

[lenny wintfeld]

I was able to fix the problem, though I'm not exactly sure why what I did fixed it. I post what I did here in the hope that someone else will find it useful at some point.

1. My computer had MSXML 6 installed in it. I downloaded and installed MSXML4 Service Pack 3 from the MS web site. This installs in parallel with MSXML6. Shutting down and reloading LabVIEW and then loading the sample program was then enough to eliminate about 70% of the errors.

2. The remaining dependent vi's with errors were fixed by a) going to each of the MSXML Invoke Nodes that had broken wires leading in or out of them in each vi with errors, b) selecting a method or property that is shown on the invoke node (which caused LabVIEW to make that node a lighter color and also caused LabVIEW to display a list of all valid methods/properties), c) selecting from the list the exact same attribute or property. Doing this for only one property/attribute fixed all bad wires on that particular Invoke node!

I'm not sure why doing this fixed the problem. I speculate that it caused LabVIEW to re-load the reference to the node from a different typelib on my computer. But that's for somone much more knowledgeable than myself to answer.

Thanks to forum participants who helped in the past. I hope this will aid somone, some time.

Lenny Wintfeld