InfoPath Dev

Hi,

I have a repeating table with an "on changed" event handler for one of the fields in the table. Whenever the value changes, I want to modify the value of a different field in the same row. How can I reference a different field of the current row? (This needs to work in a browser-enabled form, if that makes any difference.) Thanks in advance!

Use a relative XPath... you should already have the object for the current node from the event handler parameters. Then you can use a relative XPath like "../OtherField" to get to the other field. The .. means to go up to the parent node.

The "field" that changes is actually an attribute within a node of an XmlDocument which is the datasource passed back from a web service. This attribute is the "sender" object when the "on changed" event fires. The other "field" that I need to update within the event handler is a different attribute of the same Xml element.

I tried "./@otherattribute" as the path for a SelectSingleNode on the datasource, but it complains of a null reference exception.

I think I'm having problems because the sender is just an attribute instead of a node. When I examine the XmlEventArgs it says that the OldParent is null.

I wonder if using the current() function my path might work better? I tried something like that, but it complained that it needs an XSLT context.

If your particular scenario current() is the same as ., so there's no advantage.

Did your XPath use "./" or "../"? Because that makes a difference. As stated above "." is the current node whereas ".." is the parent node (even for attributes).

Both "./" and "../" returned null references. Current() doesn't appear to be allowed in XPath expressions. It says it's an undefined function and asks for an XsltContext to provide a definition. I had hoped to be able to use current() in the context of an absolute XPath. Something along the lines of
"/dfs:myFields/dfs:dataFields/...record[current()]/@otherattribute"
I know there is a current() function in InfoPath, but I don't know how to get it to work in the code of an event handler.

This is getting pretty frustrating - it should be simple. This is a project with high visibility in the company and I'm at a complete standstill. Argh!

Have you tried just using a rule on the field in your form. When it changes it sets the value of the other form in the row? This might be a good work around solution until you get your syntax figured out. Since you are changing a field in the same row you do not have to use the current function. Typically it is a syntax issue in your xpath statement.

Good Luck

Thanks for your response.

I looked at using a rule. The problem with that approach is that the conditions on when to apply a rule appear to be limited to <some value> "is equal to" or "is not equal to" or "is less than" etc. <some other value>. I would need the rule to apply whenever the value is *changed*, regardless of how it compares to some other value or whether it matches a specific pattern. Also, I don't want to execute the rule if the value hasn't changed. None of the rule options seem to allow for this.

That confused me the first time I saw it too. The solution is to NOT use a condition. If there is no condition present on the rule, then it DOES fire each time a value is changed.

YEA!! That worked! Thanks for sticking with me on this, Greg. Thanks for your input as well, Clay. This should be documented somewhere...

Myles

Actually it kind of is--if you look at the rule dialog box, it says:

Condition:
None - This rule always applies.

Now, you might not understand exactly what that means right away--but I'm sure it makes total sense to you know that you've been through this!

Keep up the good work!