Unlocking the Mysteries of Data View Web Part XSL Tags – Part 12 – Miscellaneous: Person or Group Columns

Cross-posted from EndUserSharePoint.com…

As I got into writing this “last” article in the series, I realized that between the things people have asked me over the course of the series and the things I think might be useful, I have far more than one more article to write. I think I’ll keep this series going for a while (Mark willing) and try to cover more of the things that you can do in Data View Web Parts (DVWPs), XSL-based or not.

Person or Group columns are pretty unique in that they contain a big blob of markup which represents a sort of “person object”. They look like a big mess, but they actually contain a great deal of information. Here’s what a typical Person or Group column might contain.

<xsl:value-of select="@Author"/>

renders something like

<nobr><span><A HREF="/_layouts/userdisp.aspx?ID=15">Rufus T. Farnsworth</A><img border="0" height="1" width="3" src="/_layouts/images/blank.gif"/><a href='javascript:' onclick='IMNImageOnClick();return false;' class='ms-imnlink'><img name='imnmark' title='' border='0' height='12' width='12' src='/_layouts/images/blank.gif' alt='No presence information' sip='[email protected]' id='imn_1,type=smtp'/></a></span></nobr> 

There will be some variation based on whether you’ve got presence turned on, what type of authentication you are using, etc., but as you can see, it’s messy. Since the column value contains markup, when you display it using the <xsl:value> tag, you should also use the disable-output-escaping=”yes” attribute.

<xsl:value-of select="@Author" disable-output-escaping=”yes”/> 

renders as

Rufus T. Farnsworth

which is a link to the user profile page (_layouts/userdisp.aspx) for this user.

Even worse, if the same user is displayed multiple times in the DVWP, the markup won’t usually even match! Here’s the same user displayed from a different item in the same list:

<nobr><span><A HREF="/_layouts/userdisp.aspx?ID=15">Rufus T. Farnsworth</A><img border="0" height="1" width="3" src="/_layouts/images/blank.gif"/><a href='javascript:' onclick='IMNImageOnClick();return false;' class='ms-imnlink'><img name='imnmark' title='' border='0' height='12' width='12' src='/_layouts/images/blank.gif' alt='No presence information' sip='[email protected]' id='imn_4,type=smtp'/></a></span></nobr>

As you can see, id='imn_1,type=smtp' and id='imn_4,type=smtp' don’t match. So if you try to do sorting or grouping by a Person or Group column, you get “unexpected” results. (Most of us just call this the “wrong answer”).

One way to deal with the variations in the Person or Group column values is to substring out the user’s unique ID and use that for your sorting or grouping column:

<xsl:variable name=”UserID” select="substring-before(substring-after(@Author, ‘ID=’), ‘&quot;’)"/>

The variable $UserID will now contain 15 for both versions of this same user.

If you don’t want to display the user’s name as a hyperlink, you can do the same sort of substring trick. Simply substring out the actual name:

<xsl:variable name="UserAccount" select="substring-after(substring-before(substring-after(@Author, ‘ID=’), ‘&lt;’), ‘&gt;’)"/>

In this example, the variable $UserAccount = "Rufus T. Farnsworth".

I’ve been asked many, many questions about Person or Group columns over the years, but these two tips address the majority of the questions.

I’ve used some of the XSL string functions above, and those functions can be really useful in many other ways as well. In my next article, I’ll go over what string functions are available and how you might use them in your DVWP’s XSL.