[XSL-LIST Mailing List Archive Home]
[By Thread]
[By Date]
[Recent Entries]
[Reply To This Message]
the joy of breaking out from procedural/imperative programmi
Subject: the joy of breaking out from procedural/imperative programming style (was: Re: Peculiar Problem in .xsl file
From: Gunther Schadow <gunther@xxxxxxxxxxxxxxxxxxxxxx>
Date: Fri, 06 Dec 2002 11:31:15 -0500
|
Hi, on Chandra's issue of month names, etc. I'd like to take
the oportunity to do some XSLT style-evangelism.
I think this case is a particular good example for how ugly
choices are and that one should deliberately try to find other
ways than using xsl:choose, (and xsl:call-template, xsl:for-each
for that matter.)
XSLT is much more fun if you use its own powers rather than
trying to cling on to the weak metaphors of imperative programming
(i.e., case, procedure call and loops.)
So, instead of this ugly choice, you could make tables:
<xsl:variable name="monthNames">
<month digits="01" name="January"/>
<month digits="02" name="February"/>
<month digits="03" name="March"/>
<month digits="04" name="April"/>
<month digits="05" name="May"/>
<month digits="06" name="June"/>
<month digits="07" name="July"/>
<month digits="08" name="August"/>
<month digits="09" name="September"/>
<month digits="10" name="October"/>
<month digits="11" name="November"/>
<month digits="12" name="December"/>
<xsl:variable>
and then you simply go:
<xsl:value-of
select="$monthNames/month[@digits=substring($date, 5, 2)]/@name"/>
just think of relational model for most of your data, the above
is same as the SQL form
SELECT name FROM monthNames WHERE digits='..'
The advantage: much cleaner code, much less ugly choose/when,
easily reuseable, easily EXTENSIBLE. For instance you could
easily support multi-lingual date representations either by
loading the month name table from an external resource:
<xsl:variable name="monthNames" select="document($monthnamesuri)"/>
or by adding another "column" for language code such as:
<month digits="01" name="January" xml:lang="en"/>
<month digits="01" name="Januar" xml:lang="dn"/>
<month digits="01" name="Janvier" xml:lang="fr"/>
etc.
Just indulge in the many possible ways you could read this data
from XML locale files.
XSLT is so much fun if you can break out of the imperative/
procedural progamming box. (And much pain and suffering if you
don't break out of that box.)
enjoy,
-Gunther
Gunther Schadow wrote:
What you should try is this:
<xsl:when test="$month='01'">
instead of <xsl:when test="$month=01">
that way you avoid the potentially buggy type casting behavior
of your XSLT processor to become manifest. Just leave the values
you compare both strings at all times (it's probably slightly
faster that way anyway :-). That way you are sure to hold on to
the leading zero.
In fact I wonder if it's really buggy type casting? It seem to
be reasonable for this machinery to cast the second operand to
of the = relation to the data type of the first operand. That
would cast the number 1 to a string, which would be '1', then
you compare '01'='1' and the answer is correctly false. XSLT
spec might make a ruling that clarifies that, but it's a subtle
problem, so, I'd expect that to go wrong somewhere. Luckily
your workaround is straight-forward.
regards,
-Gunther
Chandra - wrote:
Hi Guys,
I am trying to print out a html file with a date in words, given date
in a xml file in number format
XSL file:
<xsl:variable name='month' select='substring ($date, 5, 2)'/>
<xsl:choose>
<xsl:when test='$month=01'>
<xsl:text>January </xsl:text>
</xsl:when>
<xsl:when test='$month=02'>
<xsl:text>February </xsl:text>
</xsl:when>
<xsl:when test='$month=03'>
<xsl:text>March </xsl:text>
</xsl:when>
<xsl:when test='$month=04'>
<xsl:text>April </xsl:text>
</xsl:when>
<xsl:when test='$month=05'>
<xsl:text>May </xsl:text>
</xsl:when>
<xsl:when test='$month=06'>
<xsl:text>June </xsl:text>
</xsl:when>
<xsl:when test='$month=07'>
<xsl:text>July </xsl:text>
</xsl:when>
<xsl:when test='$month=08'>
<xsl:text>August </xsl:text>
</xsl:when>
<xsl:when test='$month=09'>
<xsl:text>September </xsl:text>
</xsl:when>
<xsl:when test='$month=10'>
<xsl:text>October </xsl:text>
</xsl:when>
<xsl:when test='$month=11'>
<xsl:text>November </xsl:text>
</xsl:when>
<xsl:when test='$month=12'>
<xsl:text>December </xsl:text>
</xsl:when>
</xsl:choose>
When valuepassed into the date variable is 20020516, I don't get a
month. Infact if the month is from 01 to 09, I dont get a month in
words. If the month is 10 to 12, I get a month displayed. Very very
peculiar. I am unable to find the solution. I tried and printed out
the value of the month variable. It seems to take the 2 digits
correctly. However it doesn't go into the appropraite month code when
the month starts with 0!! For example, if the month is 05, it doesnt
go into this part of the code:
<xsl:when test='$month=05'>
<xsl:text>May </xsl:text>
</xsl:when>
If the month were 10, 11 or 12, the code works fine.
Can anyone guess what the problem is...
Thanks in advance,
Chandra
_________________________________________________________________
The new MSN 8: advanced junk mail protection and 2 months FREE*
http://join.msn.com/?page=features/junkmail
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
--
Gunther Schadow, M.D., Ph.D. gschadow@xxxxxxxxxxxxxxx
Medical Information Scientist Regenstrief Institute for Health Care
Adjunct Assistant Professor Indiana University School of Medicine
tel:1(317)630-7960 http://aurora.regenstrief.org
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
|
PURCHASE STYLUS STUDIO ONLINE TODAY!
Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!
Download The World's Best XML IDE!
Accelerate XML development with our award-winning XML IDE - Download a free trial today!
Subscribe in XML format
RSS 2.0 |
|
Atom 0.3 |
|
|