xsl inside for-each use different css class - css

Question

how can I display the text inside a for-each loop, in xslt, using each time a different css class? can I generate somehow the name of the css class based on some variable or something?? is it possible?
for example in the following code inside the foreach loop can I display the li with a different css class each time...such as in the first iteration li class="1"...second iteartion li class="2"...and obvious in css exists li.1{..}, li.2{...}
<xsl:output method="text" indent="no"/>
<xsl:variable name="newline">
<xsl:text>
</xsl:text>
</xsl:variable>
<xsl:template match="/">
<xsl:text>Collections of books</xsl:text>
<xsl:value-of select="$newline"/>
<xsl:variable name="index" select="0"/>
<xsl:for-each select="collection/book">
<xsl:sort select="category"/>
<xsl:variable name="lastCat" select="category"/>
<xsl:if test="not(preceding-sibling::book[category=$lastCat])">
<xsl:value-of select="$newline"/>
<xsl:value-of select="category"/>
<xsl:value-of select="$newline"/>
<xsl:value-of select="$newline"/>
</xsl:if>
<ul>
<li>
<xsl:value-of select="title"/>
<xsl:text> </xsl:text>
<xsl:value-of select="author"/>
<xsl:text> </xsl:text>
<xsl:value-of select="year"/>
<xsl:text> </xsl:text>
<xsl:value-of select="isbn"/>
</li>
</ul>
<xsl:value-of select="$newline"/>
</xsl:for-each>
</xsl:template>

Answer 1

You're XSLT is a little confusing as to whether you are outputting text or html. However, in answer to your immediate question you can easily add attributes to the exist li elements you are outputing in one of two ways.
Firstly, you can make use of the xsl:attribute statement, which should be added immediately following the li tag.
<li>
<xsl:attribute name="class">
<xsl:value-of select="position()" />
</xsl:attribute>
...
The better method though is to use 'attribute value templates' to specify attributes. (The curly brackets indicate an AVT to be evaluated in this case, as opposed to being a piece of text to be literally output)
<li class="{position()}">
...
In both cases the output will be similar to the following
<li class="1">...
<li class="2">...
In this example I am simply using the position() to demonstrate how you can set attributes, but you could easily use variables if required.
<li class="{$classname}">