Validate IBAN using XSLT 2.0?
is it possible to write an XSLT function which can do the basic IBAN Mod-97 check?
From Wikipedia:
1. Move the four initial characters to the end of the string. 2. Replace each letter in the string with two digits, thereby expanding the string, where A=10, B=11, ..., Z=35. 3. Interpret the string as a decimal integer and compute the remainder of that number on division by 97.If the remainder is 1, the checks digits test is passed and the IBAN may be vali开发者_开发技巧d.
Thanks.
This transformation:
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:my="my:my">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:variable name="vCaps" select=
"'ABCDEFGHIJKLMNOPQRSTUVWXYZ'"/>
<xsl:template match="text()">
<xsl:sequence select="my:isIBAN(.)"/>
</xsl:template>
<xsl:function name="my:isIBAN" as="xs:boolean">
<xsl:param name="pString" as="xs:string"/>
<xsl:variable name="vDigits" select=
"string-join(
(for $vStarting4 in substring($pString, 1,4),
$vRest in substring($pString, 5),
$vNewString in concat($vRest,$vStarting4),
$vLen in string-length($vNewString),
$i in 1 to $vLen
return
my:code(substring($vNewString,$i,1))
),
''
)
"/>
<xsl:sequence select="xs:integer($vDigits) mod 97 eq 1"/>
</xsl:function>
<xsl:function name="my:code" as="xs:string">
<xsl:param name="pChar" as="xs:string"/>
<xsl:sequence select=
"if(string-length($pChar) ne 1 or not(contains($vCaps, $pChar)))
then $pChar
else
xs:string
(string-to-codepoints($pChar) - string-to-codepoints('A') +10)
"/>
</xsl:function>
</xsl:stylesheet>
when applied on this XML document:
<t>GB82WEST12345698765432</t>
produces the wanted, correct result:
true
Do note: The function my:isIBAN()
can be implemented as a single XPath 2.0 expression. I didn't provide it for reasons of readability.
Just for fun (I didn't see that @Dimitre have already answered it)
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:local="http://localhost/">
<xsl:template match="IBAN[local:validate(.)]">
<xsl:text>Validated IBAN</xsl:text>
</xsl:template>
<xsl:function name="local:validate">
<xsl:param name="pIBAN" as="xs:string"/>
<xsl:sequence select="xs:integer(
codepoints-to-string(
for $n in string-to-codepoints(
concat(
substring(
$pIBAN,
5
),
substring(
$pIBAN,
1,
4
)
)
)
return if ($n > 64)
then string-to-codepoints(
string(
$n - 55
)
)
else $n
)
) mod 97 eq 1"/>
</xsl:function>
</xsl:stylesheet>
With this input:
<IBAN>GB82WEST12345698765432</IBAN>
Output:
Validated IBAN
EDIT: Better one liner.
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