Manipulating xsl attributes before XSLT - html

Question

Given xsl file to change color
<xsl:if test="!colorChanges()">
<StaticLabel style="{StaticLabel/#style}">
<Caption>
<xsl:value-of select="$StaticLabel/Caption"/>
</Caption>
<PreviewCaption>
<xsl:value-of select="$StaticLabel/Caption"/>
</PreviewCaption>
</StaticLabel>
</xsl:if>
Given this xml data
<StaticLabel style="font-family:Arial;color:#000000;font-size:9pt">
<Caption><![CDATA[FoodType]]></Caption>
<Name><![CDATA[French]]></Name>
</StaticLabel>
</xsl:if>
Current result after xslt
<StaticLabel style="font-family:Arial;color:#000000;font-size:9pt">
<Caption>Food Type</Caption>
<PreviewCaption>French</PreviewCaption>
</StaticLabel>
Is there anyway to ONLY change the color while keeping other style attributes before xslt is performed without updating the xml file?
Expected result:
<StaticLabel style="font-family:Arial;color:#CCCCCC;font-size:9pt">
<Caption>Food Type</Caption>
<PreviewCaption>French</PreviewCaption>
</StaticLabel>
Possible XSL solution
<xsl:if test="colorChanges()">
<StaticLabel>
<xsl:attribute name="style">
//other style attributes stay same and ONLY edit color
<xsl:text>color:#CCCCCC"</xsl:text>
</xsl:attribute>
<Caption>
<xsl:value-of select="$StaticLabel/Caption"/>
</Caption>
<PreviewCaption>
<xsl:value-of select="$StaticLabel/Caption"/>
</PreviewCaption>
</StaticLabel>
</xsl:if>

Answer 1

I. XSLT 1.0 solution:
This generic transformation:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:param name="pStyle" select="'font-size:12pt'"/>
<xsl:variable name="vStyleName"
select="concat(';',substring-before($pStyle, ':'),':')"/>
<xsl:variable name="vCurrentStyleValue" select=
"substring-before(substring-after(concat(';', /*/#style, ';'), $vStyleName),
';')"/>
<xsl:variable name="vCurrentStyle"
select="concat($vStyleName,$vCurrentStyleValue)"/>
<xsl:template match="node()|#*" name="identiy">
<xsl:copy>
<xsl:apply-templates select="node()|#*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="/*/#style">
<xsl:attribute name="style">
<xsl:variable name="vprecStyles" select=
"substring-before(concat(';',., $vCurrentStyle), $vCurrentStyle)"/>
<xsl:value-of select="substring($vprecStyles, 2)"/>
<xsl:if test="$vprecStyles">;</xsl:if>
<xsl:value-of select="$pStyle"/>
<xsl:value-of select="substring-after(concat(';',.), $vCurrentStyle)"/>
</xsl:attribute>
</xsl:template>
</xsl:stylesheet>
when applied on the provided XML document:
<StaticLabel style="font-family:Arial;color:#000000;font-size:9pt">
<Caption>Food Type</Caption>
<PreviewCaption>French</PreviewCaption>
</StaticLabel>
produces the wanted, correct result:
<StaticLabel style="font-family:Arial;color:#CCCCCC;font-size:9pt">
<Caption>Food Type</Caption>
<PreviewCaption>French</PreviewCaption>
</StaticLabel>
When we change the $pStyle parameter to:
<xsl:param name="pStyle" select="'font-family:Courier'"/>
then again the wanted, correct result is produced:
<StaticLabel style="font-family:Courier;color:#000000;font-size:9pt">
<Caption>Food Type</Caption>
<PreviewCaption>French</PreviewCaption>
</StaticLabel>
If we change the $pStyle parameter to:
<xsl:param name="pStyle" select="'font-size:12pt'"/>
We again get the correct result:
<StaticLabel style="font-family:Arial;color:#000000;font-size:12pt">
<Caption>Food Type</Caption>
<PreviewCaption>French</PreviewCaption>
</StaticLabel>
Finally, if we change the $pStyle parameter to:
<xsl:param name="pStyle" select="'line-height:15pt'"/>
we again get the correct, desired result:
<StaticLabel style="font-family:Arial;color:#000000;font-size:9pt;line-height:15pt">
<Caption>Food Type</Caption>
<PreviewCaption>French</PreviewCaption>
</StaticLabel>
This is quite error-proof -- observe:
<StaticLabel style="font-family:Arial;background-color:#ffffff;color:#000000;font-size:9pt">
<Caption>Food Type</Caption>
<PreviewCaption>French</PreviewCaption>
</StaticLabel>
and we have the $pStyle parameter again as:
<xsl:param name="pStyle" select="'color:#CCCCCC'"/>
We still get the correct result (not confused by other CSS properties ending with "color"):
<StaticLabel style="font-family:Arial;background-color:#ffffff;color:#CCCCCC;font-size:9pt">
<Caption>Food Type</Caption>
<PreviewCaption>French</PreviewCaption>
</StaticLabel>
II. XSLT 2.0 solution -- much easier:
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:param name="pStyle" select="'color:#CCCCCC'"/>
<xsl:variable name="vStyleName" select=
"substring-before($pStyle, ':')"/>
<xsl:variable name="vcurStyles"
select="tokenize(/*/#style, ';')"/>
<xsl:variable name="vnewStyles" select=
"if($vcurStyles[substring-before(.,':') eq $vStyleName])
then ($vcurStyles[substring-before(.,':') ne $vStyleName],
$pStyle)
else ($vcurStyles, $pStyle)
"/>
<xsl:template match="node()|#*" name="identiy">
<xsl:copy>
<xsl:apply-templates select="node()|#*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="/*/#style">
<xsl:attribute name="style" select="string-join($vnewStyles, ';')">
</xsl:attribute>
</xsl:template>
</xsl:stylesheet>