Quick question

swicks · November 29th, 2012, 12:57 PM

Relatively new to Xpath and XSLT - reading another developers code and don't quite understand what is happening.

To give context, XML file looks basically like this:

<root>
<BrowserBarTitle></BrowserBarTitle>
<Title>Random Title</Title>
</root>

I don't understand the second part of the union |

<xsl:value-of select="/*/BrowserBarTitle[string(.)] | /*/Title[not(string(/*/BrowserBarTitle))]" disable-output-escaping="yes"/>

Thanks,
Shannon

Martin Honnen · November 29th, 2012, 02:34 PM

With XSLT 1.0 an xsl: value-of creates a text node with the string value of the first node of the selected node set. I think the posted snippet is an attempt to output either BrowserBarTitle or Title, depending on whether one of them is empty.

swicks · November 29th, 2012, 02:44 PM

Hi Martin, thanks for the response.

I am still not clear on this part:

/*/Title[not(string(/*/BrowserBarTitle))

From the output, I can see it selects the value of Title but don't understand how not(string(/*/BrowserBarTitle) fits into the picture.

mhkay · November 30th, 2012, 05:57 AM

Read it as

Code:

if (string(/*/BrowserBarTitle))
then ""
else /*/Title

and it might be clearer. Note that there is no need for the value of the predicate in a filter expression to depend on the node being filtered.

In XSLT 2.0 you could write this as an "if" expression, but in XSLT 1.0 the filter expression is your only option (and you might prefer it anyway, since it's shorter).