RE: [xsl] Style Sheet Guidelines

["Michael Kay" <mike@xxxxxxxxxxxx>]

I don't see why you consider xsl:attribute to be "more formal" or "stricter"
than an attribute in a literal result element. Being more long-winded
doesn't make it more formal; and just because an attribute value template is
more concise, that doesn't make it a "shorthand".

Go for readability.

In Saxon 8.x, the two forms generate identical run-time code.

Michael Kay
http://www.saxonica.com/

 

> -----Original Message-----
> From: Chris_Graham@xxxxxxxxxxx [mailto:Chris_Graham@xxxxxxxxxxx] 
> Sent: 31 December 2004 00:52
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject: [xsl] Style Sheet Guidelines
> 
> Hi All,
> 
> We have an issue of style guidelines to address when writing 
> XSL files.
> 
> Basically, it revolves around readability and performance.
> 
> We have the choice between the more formal form:
> 
> <!-- Format given value as a Product/Policy Type (HOM/MOT/CTP/CTQ) -->
> <xsl:template name="productOptions">
>         <xsl:param name="name"/>
> <select>
> <xsl:attribute name="name"><xsl:value-of 
> select="$name"/></xsl:attribute>
>     <option value=''></option>
>     <option value='MOT'>Motor</option>
>     <option value='HOM'>Home</option>
>     <option value='CTP'>CTP</option>
> </select>
> </xsl:template>
> 
> And a shorthand form:
> 
> <!-- Format given value as a Product/Policy Type (HOM/MOT/CTP/CTQ) -->
> <xsl:template name="productOptions">
>         <xsl:param name="name"/>
> <select name="{$name}">
>     <option value=''></option>
>     <option value='MOT'>Motor</option>
>     <option value='HOM'>Home</option>
>     <option value='CTP'>CTP</option>
> </select>
> </xsl:template>
> 
> The difference is in the formal declaration of the attribute 
> 'name' of the 
> 
> 'select' element.
> 
> The first way is the the stricter, the second is easier to 
> understand and 
> work with.
> 
> When we are working with templates, we call it the same way:
> 
> <xsl:call-template name="productOptions">
>   <xsl:with-param name="name">Product01</xsl:with-param>
> </xsl:call-template>
> 
> It outputs the same results.
> 
> Whilst these differences are relatively minor, in this 
> example, they do 
> become more profound when applied to every instance where 
> they should be.
> 
> Consider this shorthand example:
> 
> <FONT size="5">
> Good morning!<br/>
> </FONT>
> 
> This is easier to read, as it is standard HTML.
> 
> Compare it now to the formal example:
> 
> <FONT>
> <xsl:attribute name="size">5</xsl:attribute>
> Good morning!<br/>
> </FONT>
> 
> The output is identical:
> 
> <FONT size="5">
> Good morning!<br>
> </FONT>
> 
> and
> 
> <FONT size="5">
> Good morning!<br>
> </FONT>
> 
> 
> The only difference between the formal and the shorthand is that the 
> shorthand form shows up as a problem in the annotation 
> portion of each 
> page (the right hand column where you will see a small red 
> square). It 
> does not effect the SAX parsing of the file, WSAD just issues 
> some problem 
> 
> warnings. (You can always open the file in a text editor 
> inside WSAD and 
> you will not see these conditions).
> 
> The version that uses the <xsl:attribute> form takes about 
> 10-15% longer 
> to run, which is as expected (as it has extra parsing to do [and uses 
> slightly more memory as well]).
> 
> I prefer the shorthand form as it is easier to read and consumes less 
> resources at runtime.
> 
> I would appreciate some input from others more knowledable 
> than myself in 
> what works best for them (and why).
> 
> -Chris
> 
> 
> 
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