InfoPath Dev

I have secondary data source "workers.xml".And i have a textbox field1 on my form. Now, i want to use a field1 value to get from workers.xml a person with id=field1 value.How can i do that in c#?

Ok, solved it(thanks forhttp://infopathdev.com/forums/topic.asp?TOPIC_ID=88).
But now,i cant get any data.My code looks like that:
-----------------------------------------------------------
DataObject obj = thisXDocument.DataObjects["workers.xml"];
IXMLDOMDocument3 domXML = (IXMLDOMDocument3) obj.DOM;
domXML.setProperty("SelectionNamespaces","xmlns:my=\"http://schemas.microsoft.com/office/infopath/2003/myXSD/2005-12-01T19:27:12\"");
IXMLDOMNode worker = obj.DOM.selectSingleNode("/my:myFields/my:workers/my:worker[my:id=1]/child..login");
[...]
row.selectSingleNode("my:pracownik").nodeTypedValue=worker.text;
------------------------
And im getting
"System.NullReferenceException: Object reference not set to an instance of an object"
on this last line of code (row.selected...).I have field 'pracownik' on my form and my 'workers.xml' file looks like that:
[..]
<my:workers>
<my:worker>
<my:id>1</my:id>
<my:name>john</my:name>
</my:worker>
<my:worker>
<my:id>2</my:id>
<my:name>tod</my:name>
</my:worker>
[...]
</my:workers>

Where is a mistake?

--------------------------------------------------------

The XPath in this statement looks really weird:

IXMLDOMNode worker = obj.DOM.selectSingleNode("/my:myFields/my:workers/my:worker[my:id=1]/child..login");

What is "child..login" at the end? If you want the name, change it to "my:name". The reason your getting an error on the line that you're getting them on is because the line listed above is initializing the 'worker' variable to null because your XPath does not return any nodes.

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Matt Faus
InfoPath Dev Texas

Doesnt matter what is written here,
IXMLDOMNode worker = obj.DOM.selectSingleNode("/my:myFields/my:workers/my:worker[my:id=1]/my:name");
or
IXMLDOMNode worker = obj.DOM.selectSingleNode("/my:myFields/my:workers/my:worker/my:name");
i cant make this work. I want to get name with id from my primary source,from textbox on my form.But now i just want to know, that it works and gets anything from this workers.xml...

Maby there is another way of getting a data from secondary data source file?im really frustrated...

You need the goo to select the namespaces.

Patrick Halstead [InfoPath MVP]
InfoPathDev

Forgive me, but..whats 'goo'?:)

http://en.wikipedia.org/wiki/Goo_%28Gumby_character%29

Sorry, couldn't resist! Anyway, I'm not sure - in InfoPath if you double-click on the node that you are trying to access and go the to the Details tab there is information about the namespace there.

---------------
Matt Faus
InfoPath Dev Texas

goo,well...ok ;)
I solved my problem, i had to use /ns3:..../ns3:..... instead of /my:....,for my secondary data source. I dont know why, but it works now.