Question

Given the following XML:

<root>
    Pacman <format bold="1" italic="1">rules</format>!
</root>

What is a better implementation than the following, which results in 2ⁿ-1 possible conditional statements?

<xsl:template match="format">
    <xsl:choose>
        <xsl:when test="@bold='1' and @italic='1'">
            <b><i><xsl:value-of-select="."/></i></b>
        </xsl:when>
        <xsl:when test="@bold='1'">
            <b><xsl:value-of-select="."/></b>
        </xsl:when>
        <xsl:when test="@italic='1'">
            <i><xsl:value-of-select="."/></i>
        </xsl:when>
    </xsl:choose>
</xsl:template>

You can see there is a huge problem if I want to add a new possible attribute such as underline="1", which will result in 4 new conditionals here.

Edit: Also assume that I cannot use CSS classes and must use HTML tags for styling.

Answer 1

My XSLT is so rusty, the hinges won’t budge, but I think you can use <xsl:call-template … /> to process one attribute at a time using one template per attribute.

The following probably has some very obvious mistakes, but hopefully it gives you the vibe.

<xsl:template name="bold">
    <xsl:choose>
        <xsl:when test="@bold='1'">
            <b><xsl:call-template name="italics" /></b>
        </xsl:when>
        <xsl:otherwise>
            <xsl:call-template name="italics" />
        </xsl:otherwise>
    </xsl:choose>
</xsl:template>

<xsl:template name="italics">
    …
</xsl:template>