Special thanks: Karl D. Swartzendruber and all participants of following discussion:
http://www.infopathdev.com/forums/p/10098/35969.aspx#35969
Other parts: 2, 3.
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Let me guess what might have brought you to that blog page about codeless programming in InfoPath. Any of you who developed at least one sophisticated InfoPath form sooner or later have been realized that writing forms with real complex behavior is impossible without some sort of coding in C# or VB.NET. So developers have no choice but to deal with mixed developing environment like Visual Studio, managing form security levels, security certificates and so on. But there are people who like to keep things simple. At least I do. And that’s why probably you are reading that page too:)
Anyway, lets get to the business. How to iterate an Infopath Repeating table?
Here is our scenario: we have a repeating group on the form which will be populated with wonderful (but often overlooked) Contact Selector Control with some user information. The control provides us all necessary information about user except his email.
But wait, that is outrageous! The email was the only reason why we decided to use that now not so awesome control! Well… at least we have access to the web service which able to return user email in exchange of account name. There are countless blogs describing how to utilize UserProfileService to get info of a single user in Contact Selector. Here I’ll try to demonstrate how to deal with multiple selection in Contact Selector. So now our task is clear – we have to construct a string acceptable in Email address field iterating through repeating group and submitting query to the web service on each cycle of iteration.
Let’s go.
The first things first – here using-the-contact-selector-control you will find detailed explanation how to utilize Contact Selector Control. The resulting data structure for the control in main data source should look like this

The Control also requires secondary data source

Add text field named HlinkToEmail. That field will hold result of our computations. Resulting Main Data Source:

When your new shiny control starts providing you users from your network that means we are ready for the web service part. Here we’ll use SharePoint GetUserProfileByName web method. You will need SharePoint Services running somewhere on your network. That part is pretty straightforward. Add secondary web service receive connection. Your link in connection settings should look like
http://<youservername>/_vti_bin/UserProfileService.asmx.
The results of that part:

“Programming” part
Place a button on the layout. At Rules and Merge tab create rule named setfCounter. Press “Set Conditon”. In the first area choose “The expression”. Here is string to paste in second area:
count(my:Person)>0
The only action will assign initial value to the HlinkToEmail field. Press fx button at new action form. Check “Edit XPath (advanced)” checkbox. To avoid too detailed instructions of choosing functions and form elements just copy paste the following expression:
xdMath:Eval(xdMath:Eval(my:Person, ‘concat(my:AccountId, "|")’), "..")

At main data source pane double click at HlinkToEmail field. At Rules and Merge tab create rule named fConterRule. It’s a conditional rule. In the Set Condition dialog in the first area: Choose The expression. Then paste this expression into second area:
contains(., "|")
The resulting set of actions:

The rule will consist of 3 actions. The fist action will be setting AccountName field of data source named GetUserProfileByName to the portion of HlinkToEmail field. Check “Edit XPath (advanced)” checkbox. Paste Xpath expression:
substring-before(., "|")
Next is self-explanatory action. Add action -> Query using data connection -> Choose GetUserProfileByName.
Add the last action to set HlinkToEmail field to the new value by assigning following XPath expression:
concat(substring-after(., "|"), ";", xdXDocument:GetDOM("GetUserProfileByName")/dfs:myFields/dfs:dataFields/s0:GetUserProfileByNameResponse/s0:GetUserProfileByNameResult/s0:PropertyData/s0:Values/s0:ValueData/s0:Value[../../../s0:Name = "WorkEmail"])
We done with actions of that rule. Make sure that check box “Stop processing rules then this rule finishes” is checked.
Add the last rule right after fConterRule. In Set Condition dialog choose The expression. In expression area copy paste:
substring-before(., ";") = "" and contains(.,";")

And finally, set the HlinkToEmail to the following XPath expression:
substring-after(., ";")
That’s it.
P.S. Now you know how to iterate and read repeating structures. But what if you need to write? Well, InfoPath doesn’t provide UI to parameterize repeating structures are assigned to new values. Still here you will find a workaround which overcomes this limitation.
Posted under tags: MOSS Contact Selector Control Infopath Sharepoint