XSL if test display content when it has values

Question

I have an if test where I want to display the content of the 'year' property with a comma when the property has values. This isn't working so I would be thankful for suggestions.

<xsl:if test="year != null">
     <xsl:value-of select="year"/>,
</xsl:if> 

Solution

You can check year element presence simply using this expression:

<xsl:if test="year">

If you want to check that year element isn't empty:

<xsl:if test="year != ''">