Get current nodes xpath - xslt

I need to get the xpath of current node for which i have written an xsl function
<func:function name="fn:getXpath">
<xsl:variable name="xpath">
<xsl:for-each select="ancestor-or-self::*">
<xsl:value-of select="concat($xpath, name())" />
<xsl:if test="not(position()=last())">
<xsl:value-of select="concat('/', $xpath)" />
</xsl:if>
</xsl:for-each>
</xsl:variable>
<func:result select="$xpath" />
</func:function>
But when I run this, I'm getting the following error
file:///D:/test.xsl; Line #165; Column #63; Variable accessed before it is bound!
file:///D:/test.xsl; Line #165; Column #63; java.lang.NullPointerException
I'm using xalan 2.7.0. Please help.

In your example you are trying to use the variable in the definition itself, which is not valid.
It looks your intention is to try and modify the value of an existing value. However XSLT is a functional language, and as a result variables are immutable. This means you cannot change the value once defined.
In this case, you don't need to be so complicated. You can just remove the reference to the variable itself, and you will get the result you need
<func:function name="fn:getXpath">
<xsl:variable name="xpath">
<xsl:for-each select="ancestor-or-self::*">
<xsl:value-of select="name()"/>
<xsl:if test="not(position()=last())">
<xsl:value-of select="'/'"/>
</xsl:if>
</xsl:for-each>
</xsl:variable>
<func:result select="$xpath" />
</func:function>

You are using the variable $xpath inside the definition of the variable itself:
<func:function name="fn:getXpath">
<xsl:variable name="xpath">
<xsl:for-each select="ancestor-or-self::*">
<xsl:value-of select="concat($xpath, name())" /> <-------
<xsl:if test="not(position()=last())">
<xsl:value-of select="concat('/', $xpath)" /> <-------
</xsl:if>
</xsl:for-each>
</xsl:variable>
<func:result select="$xpath" />
</func:function>
The variable is not known at that point.

Related

Sum value of output of template in Apache FOP

I am using Apache FOP to generate a PDF document, and to display a certain value I have to iterate over a number of nodes to determine a total price value, then sum that value. So far I have a function that iterates over an array and then retrieves the intended value, but the issue occurs when I try to sum the results.
<xsl:function name="foo:buildTotalValue">
<xsl:param name="items" />
<xsl:variable name="totals">
<xsl:for-each select="$items/charge">
<xsl:call-template name="getTotalPriceNode">
<xsl:with-param name="itemParam" select="." />
</xsl:call-template>
</xsl:for-each>
</xsl:variable>
<xsl:value-of select="sum(exsl:node-set($totals))" />
</xsl:function>
<xsl:template name="getTotalPriceNode">
<xsl:param name="itemParam" />
<xsl:choose>
<xsl:when test="$itemParam/Recurrance = 'OnceOff'">
<xsl:value-of select="$itemParam/TotalValue" />
</xsl:when>
<xsl:when test="$itemParam/Recurrance = 'Monthly'">
<xsl:value-of select="$itemParam/TotalValue * $itemParam/Months"/>
</xsl:when>
<xsl:otherwise><xsl:value-of select="0" /></xsl:otherwise>
</xsl:choose>
</xsl:template>
I'm hoping that when I pass in foo:buildTotalValue with entries like this:
<Charges>
<Charge>
<Recurrance>OnceOff</Recurrance>
<TotalValue>50.00</TotalValue>
</Charge>
<Charge>
<Recurrance>Monthly</Recurrance>
<TotalValue>10.00</TotalValue>
<Months>6</Months>
</Charge>
</Charges>
would return with the value 110.00, but instead I get the error:
Cannot convert string "50.0060.00" to double
I've tried adding a <value> or something in the templates and then using that as a selector for the exsl:node-set function but it doesn't seem to make a difference.
AFAICT, the problem with your function is that it builds a concatenated string of values returned by the called template, instead of a tree of nodes that can be converted into a node-set and summed.
Try changing:
<xsl:for-each select="$items/charge">
<xsl:call-template name="getTotalPriceNode">
<xsl:with-param name="itemParam" select="." />
</xsl:call-template>
</xsl:for-each>
to:
<xsl:for-each select="$items/charge">
<total>
<xsl:call-template name="getTotalPriceNode">
<xsl:with-param name="itemParam" select="." />
</xsl:call-template>
</total>
</xsl:for-each>
and:
<xsl:value-of select="sum(exsl:node-set($totals))" />
to:
<xsl:value-of select="sum(exsl:node-set($totals)/total)" />
Untested, because (see comment to your question).
I ended up using the suggestion from Martin from the comment - the xpath 2+ expression along the line of:
sum(Charge[Recurrance = 'OnceOff']/TotalValue | Charge[Recurrance = 'Monthly']/(TotalValue * Months))
which was able to achieve what I needed without the use of functions / templates / node-set (And in a lot less code)

xsl declare variable and reassign/change value in for-each is not working

I'm declaring variable "flag" in for-each and reassigning value inner for-each. I'm getting error duplicate variable within the scope.
My code is:
<xsl:variable name="flag" select="'0'"/>
<xsl:template match="/">
<xsl:for-each select="Properties/Property">
<xsl:variable name="flag" select="'0'"/>
<xsl:choose>
<xsl:when test="$language='en-CA'">
<xsl:for-each select="Localization/[Key=$language]">
<xsl:value-of select="Value/Value"/>
<xsl:variable name="flag" select="'1'"/>
</xsl:for-each>
<xsl:if test="$flag ='0'">
<xsl:value-of select="$flag"/>
</xsl:if>
</xsl:when>
</xsl:choose>
</xsl:for-each>
</xsl:template>
Can we update/re-assign variable value? If not Do we have any other options?
Any help?
XSLT is not a procedural language and variables in XSLT don't behave like variables in procedural languages; they behave more like variables in mathematics. That is, they are names for values. The formula x=x+1 makes no sense in mathematics and it makes no sense in XSLT either.
It's always difficult to reverse-engineer a specification from procedural code, especially from incorrect procedural code. So tell us what you are trying to achieve, and we will tell you the XSLT way (that is, the declarative/functional way) of doing it.
XSLT variables are single-assignment.
you can create an xsl template and do xsl recursion.
for example:
<xsl:template name="IncrementUntil5">
<xsl:param name="counter" select="number(1)" />
<xsl:if test="$counter < 6">
<test><xsl:value-of select="$counter"/></test>
<xsl:call-template name="IncrementUntil5">
<xsl:with-param name="counter" select="$counter + 1"/>
</xsl:call-template>
</xsl:if>
</xsl:template>
then call it like this:
<xsl:template match="/">
<div>
<xsl:call-template name="IncrementUntil5"/>
</div>
</xsl:template>
Try this:
<xsl:template match="/">
<xsl:for-each select="Properties/Property">
<xsl:choose>
<xsl:when test="$language='en-CA' and Localization/Key='en-CA'">
<xsl:value-of select="Value/Value"/>
</xsl:when>
</xsl:choose>
</xsl:for-each>
</xsl:template>
You don't need to iterate through a collection to determine if something's present, the simple XPath Localization/Key='en-CA' will be true if there's any element matching it that exists.

XSLT tokenize nodeset

I'm trying to create a variable that stores the value of an input string (TypeInput) in init cap form. This new variable will be used in different places in my stylesheet. I created a template that I call to convert the input string to init cap form. However, when I run the stylesheet, the resulting variable TypeInputInitCap shows up as NodeSet(1) in the debugger and doesn't output text in my output. Any ideas why? See sample below.
<xsl:variable name="TypeInputInitCap">
<xsl:call-template name="ConvertToInitCapString">
<xsl:with-param name="str" select="$TypeInput"></xsl:with-param>
</xsl:call-template>
</xsl:variable>
<xsl:template name="ConvertToInitCapString">
<xsl:param name="str"></xsl:param>
<!-- Extract each component of the name delimited by . -->
<xsl:variable name="TokenNodeSet">
<xsl:for-each select="tokenize($str, '.')">
<!-- Init cap each component -->
<xsl:value-of select="concat(upper-case(substring(.,1,1)), lower-case(substring(.,2)))"></xsl:value-of>
</xsl:for-each>
</xsl:variable>
<xsl:for-each select="$TokenNodeSet">
<xsl:value-of select="."></xsl:value-of>
<xsl:if test="not(last())">
<xsl:text>.</xsl:text>
</xsl:if>
</xsl:for-each>
</xsl:template>
I think that the problem is that the $TokenNodeSet variable contains just a single string, and so the second for-each just loops once.
What about doing this instead:
<xsl:template name="ConvertToInitCapString">
<xsl:param name="str"></xsl:param>
<xsl:for-each select="tokenize($str, '\.')">
<xsl:value-of select="concat(upper-case(substring(.,1,1)), lower-case(substring(.,2)))"/>
<xsl:if test="not(last())">
<xsl:text>.</xsl:text>
</xsl:if>
</xsl:for-each>
EDIT
Fixed the tokenize() call above as suggested by LarsH in the comments
I would replace
<xsl:variable name="TokenNodeSet">
<xsl:for-each select="tokenize($str, '.')">
<!-- Init cap each component -->
<xsl:value-of select="concat(upper-case(substring(.,1,1)), lower-case(substring(.,2)))"></xsl:value-of>
</xsl:for-each>
</xsl:variable>
with
<xsl:variable name="TokenNodeSet" select="for $token in tokenize($str, '\.') return concat(upper-case(substring($token,1,1)), lower-case(substring($token,2)))" />
or better yet with
<xsl:variable name="TokenNodeSet" as="xs:string*" select="for $token in tokenize($str, '\.') return concat(upper-case(substring($token,1,1)), lower-case(substring($token,2)))" />
or finally as it is XSLT 2.0 where there are no nodesets I would rename the variable as e.g.
<xsl:variable name="TokenSequence" as="xs:string*" select="for $token in tokenize($str, '\.') return concat(upper-case(substring($token,1,1)), lower-case(substring($token,2)))" />
Thanks all for your help. The second part in my template was not necessary, so I'm now using this version, which works. It re-adds a '.' character between the tokens. (I didn't use the short version suggested in this thread because I will end up with an extra dot at the end if concatenated.):
<xsl:template name="ConvertToInitCapString">
<xsl:param name="str" select="."></xsl:param>
<!-- Extract each component of the name delimited by . -->
<xsl:for-each select="tokenize($str, '\.')">
<!-- Init cap each component -->
<xsl:value-of select="concat(upper-case(substring(.,1,1)), lower-case(substring(.,2)))"></xsl:value-of>
<xsl:if test="position() != last()">
<xsl:value-of select="'.'"></xsl:value-of>
</xsl:if>
</xsl:for-each>
</xsl:template>

XSLT: xsl:function won't work

The following works for me:
<xsl:variable name="core" select="document('CoreMain_v1.4.0.xsd')" />
<xsl:variable name="AcRec" select="document('AcademicRecord_v1.3.0.xsd')" />
<xsl:template match="xs:element">
<xsl:variable name="prefix" select="substring-before(#type, ':')" />
<xsl:variable name="name" select="substring-after(#type, ':')" />
<xsl:choose>
<xsl:when test="$prefix = 'AcRec'">
<xsl:apply-templates select="$AcRec//*[#name=$name]">
<xsl:with-param name="prefix" select="$prefix" />
</xsl:apply-templates>
</xsl:when>
<xsl:when test="$prefix = 'core'">
<xsl:apply-templates select="$core//*[#name=$name]">
<xsl:with-param name="prefix" select="$prefix" />
</xsl:apply-templates>
</xsl:when>
</xsl:choose>
</xsl:template>
But I use the same logic to handle the lookup of elements in the current or other documents based on the prefix, matching the node name in numerous places within the stylesheet. So, after changing the stylesheet version to 2.0, I tried:
<xsl:template match="xs:element">
<xsl:value-of select="my:lookup(#type)" />
</xsl:template>
<xsl:function name="my:lookup">
<xsl:param name="attribute" />
<!-- parse the attribute for the prefix & name values -->
<xsl:variable name="prefix" select="substring-before($attribute, ':')" />
<xsl:variable name="name" select="substring-after($attribute, ':')" />
<!-- Switch statement based on the prefix value -->
<xsl:choose>
<xsl:when test="$prefix = 'AcRec'">
<xsl:apply-templates select="$AcRec//*[#name=$name]">
<xsl:with-param name="prefix" select="$prefix" />
</xsl:apply-templates>
</xsl:when>
<xsl:when test="$prefix = 'core'">
<xsl:apply-templates select="$core//*[#name=$name]">
<xsl:with-param name="prefix" select="$prefix" />
</xsl:apply-templates>
</xsl:when>
</xsl:choose>
</xsl:function>
In my reading, I have only found examples of functions that return text - none call templates. I have the impression that an xsl:function should always return text/output...
After more investigation, it is entering the my:lookup function and the variables (prefix & name) are getting populated. So it does enter the xsl:choose statement, and the hits the appropriate when test. The issue appears to be with the apply-templates - value-of is displaying the child values; copy-of does as well, which I think is odd (shouldn't the output include the xml element declarations?). Why would there be a difference if code that works in a template declaration is moved to an xsl:function?
It's been a while since I did any serious XSLT, but IIRC your problem is not in the function, but in your template:
<xsl:template match="xs:element">
<xsl:value-of select="my:lookup(#type)" />
</xsl:template>
The value-of statement won't inline the result tree returned by your function. Instead, it's going to try and reduce that result tree down into some kind of string, and inline that instead. This is why you're seeing the child values and not the elements themselves.
To inline the result tree returned by your function, you'll need to use some templates to copy the result tree into place.
So, your main template will need to change to this:
<xsl:template match="xs:element">
<xsl:apply-templates select="my:lookup(#type)" />
</xsl:template>
and you'll need some templates to do the recursive call. A quick google found a good discussion of the identity template that should do what you need.
(Please forgive any syntax errors, as I said, it's been a while ...)

index in loop XSL

I have two nested loop in XSL like this, at this moment I use position() but it's not what I need.
<xsl:for-each select="abc">
<xsl:for-each select="def">
I wanna my variable in here increasing fluently 1,2,3,4,5.....n
not like 1,2,3,1,2,3
</xsl:for-each>
</xsl:for-each>
Can you give me some idea for this stub. Thank you very much!
With XSL, the problem is you cannot change a variable (it's more like a constant that you're setting). So incrementing a counter variable does not work.
A clumsy workaround to get a sequential count (1,2,3,4,...) would be to call position() to get the "abc" tag iteration, and another call to position() to get the nested "def" tag iteration. You would then need to multiply the "abc" iteration with the number of "def" tags it contains. That's why this is a "clumsy" workaround.
Assuming you have two nested "def" tags, the XSL would look as follows:
<xsl:for-each select="abc">
<xsl:variable name="level1Count" select="position() - 1"/>
<xsl:for-each select="def">
<xsl:variable name="level2Count" select="$level1Count * 2 + position()"/>
<xsl:value-of select="$level2Count" />
</xsl:for-each>
</xsl:for-each>
Just change the way to select the items to loop over:
<xsl:for-each select="abc/def">
<xsl:value-of select="position()"/>
</xsl:for-each>
Should you specifically need to keep the nested loops, consider adding yet another loop like this:
<xsl:variable name="items" select="//abc/def"/>
<xsl:for-each select="abc">
<xsl:for-each select="def">
<xsl:variable name="id" select="generate-id()"/>
<xsl:for-each select="$items">
<xsl:if test="generate-id()=$id">
<xsl:value-of select="position()"/>
</xsl:if>
</xsl:for-each>
</xsl:for-each>
</xsl:for-each>
<xsl:for-each select="abc">
<xsl:variable name="i" select="position()"/>
<xsl:for-each select="def">
<xsl:value-of select="$i" />
</xsl:for-each>
</xsl:for-each>
This is an extension of pythonquick's answer that handles different numbers of sub-elements:
<xsl:for-each select="abc">
<xsl:variable name="level1Position" select="position()"/>
<xsl:variable name="priorCount" select="count(../abc[position() < $level1Position]/def)"/>
<xsl:for-each select="def">
<xsl:variable name="level2Count" select="$priorCount + position()"/>
<xsl:value-of select="$level2Count" />
</xsl:for-each>
</xsl:for-each>
Input:
<root>
<abc>
<def>A</def>
<def>B</def>
<def>C</def>
</abc>
<abc>
<def>D</def>
<def>E</def>
</abc>
<abc>
<def>F</def>
</abc>
<abc>
<def>G</def>
<def>H</def>
<def>I</def>
</abc>
</root>