I have following question, basically i just would like to create a custom array, something like
- Yellow | Red | Green
And after loop through this items using for-each and printing the values, i created something like this:
<xsl:variable name="Colors">
<m>Yellow</m>
<m>Red</m>
<m>Green</m>
</xsl:variable>
And then i try to loop on it:
<xsl:for-each select="$Colors">
<xsl:value-of select ="current()" />
</xsl:for-each>
But i get this error: Exrpession must evalutate to a node-set $Colors
Any idea, what could be wrong?
With XSLT 1.0 your variable contains a result tree fragment (RTF) and you can't do anything with it but use xsl:copy-of or xsl:value-of. Fortunately most XSLT 1.0 processor support exsl:node-set or similar to convert a result tree fragment to a node set so you can use <xsl:for-each select="exsl:node-set($Colors)/m">...</xsl:for-each>, where you then need to declare xmlns:exsl="http://exslt.org/common" in your stylesheet.
Related
I wish to construct an XSL node set variable using a contained for-each loop. It is important that the constructed node set is the original (a selected) node set, not a copy.
Here is a much simplified version of my problem (which could of course be solved with a select, but that's not the point of the question). I've used the <name> node to test that the constructed node set variable is in fact in the original tree and not a copy.
XSL version 1.0, processor is msxsl.
Non-working XSL:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text" encoding="iso-8859-1" omit-xml-declaration="yes" />
<xsl:template match="/">
<xsl:variable name="entries">
<xsl:for-each select="//entry">
<xsl:copy-of select="."/>
</xsl:for-each>
</xsl:variable>
<xsl:variable name="entryNodes" select="msxsl:node-set($entries)"/>
<xsl:for-each select="$entryNodes">
<xsl:value-of select="/root/name"/>
<xsl:value-of select="."/>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
XML input:
<?xml version="1.0" encoding="UTF-8"?>
<root>
<name>X</name>
<entry>1</entry>
<entry>2</entry>
</root>
Wanted output:
X1X2
Actual output:
12
Of course the (or a) problem is the copy-of, but I can't work out a way around this.
There isn't a "way around it" in XSLT 1.0 - it's exactly how this is supposed to work. When you have a variable that is declared with content rather than with a select then that content is a result tree fragment consisting of newly-created nodes (even if those nodes are a copy of nodes from the original tree). If you want to refer to the original nodes attached to the original tree then you must declare the variable using select. A better question would be to detail the actual problem and ask how you could write a suitable select expression to find the nodes you want without needing to use for-each - most uses of xsl:if or xsl:choose can be replaced with suitably constructed predicates, maybe involving judicious use of xsl:key, etc.
In XSLT 2.0 it's much more flexible. There's no distinction between node sets and result tree fragments, and the content of an xsl:variable is treated as a generic "sequence constructor" which can give you new nodes if you construct or copy them:
<xsl:variable name="example" as="node()*">
<xsl:copy-of select="//entry" />
</xsl:variable>
or the original nodes if you use xsl:sequence:
<xsl:variable name="example" as="node()*">
<xsl:sequence select="//entry" />
</xsl:variable>
I wish to construct an XSL node set variable using a contained
for-each loop.
I have no idea what that means.
It is important that the constructed node set is the original (a
selected) node set, not a copy.
This part I think I understand a little better. It seems you need to replace:
<xsl:variable name="entries">
<xsl:for-each select="//entry">
<xsl:copy-of select="."/>
</xsl:for-each>
</xsl:variable>
with:
<xsl:variable name="entries" select="//entry"/>
or, preferably:
<xsl:variable name="entries" select="root/entry"/>
The resulting variable is a node-set of the original entry nodes, so you can do simply:
<xsl:for-each select="$entries">
<xsl:value-of select="/root/name"/>
<xsl:value-of select="."/>
</xsl:for-each>
to get your expected result.
Of course, you could do the same thing by operating directly on the original nodes, in their original context - without requiring the variable.
In response to the comments you've made:
We obviously need a better example here, but I think I am getting a vague idea of where you want to go with this. But there are a few things you must understand first:
1.
In order to construct a variable which contains a node-set of nodes in their original context, you must use select. This does not place any limits whatsoever on what you can select. You can do your selection all at once, or in stages, or even in a loop (here I mean a real loop). You can combine the intermediate selections you have made in any way sets can be combined: union, intersection, or difference. But you must use select in all these steps, otherwise you will end up with a set of new nodes, no longer having the context they did in the source tree.
IOW, the only difference between using copy and select is that the former creates new nodes, which is precisely what you wish to avoid.
2.
xsl:for-each is not a loop. It has no hierarchy or chronology. All the nodes are processed in parallel, and there is no way to use the result of previous iteration in the current one - because no iteration is "previous" to another.
If you try to use xsl:for-each in order to add each of n processed nodes to a pre-existing node-set, you will end up with n results, each containing the pre-existing node-set joined with one of the processed nodes.
3.
I think you'll find the XPath language is quite powerful, and allows you to select the nodes you want without having to go through the complicated loops you hint at.
It might help if you showed us a problem that can't be trivially solved in XSLT 1.0. You can't solve your problem the way you are asking for: there is no equivalent of xsl:sequence in XSLT 1.0. But the problem you have shown us can be solved without such a construct. So please explain why you need what you are asking for.
I have an XML with 2 XML fragments, 1st one is a fragment where the new values must be applied (which can have pretty complex elements) like
... some static parents
<a:element1>
<a:subelement tag="someString">
<a:s1>a</a:s1>
</a:subelement>
</a:element1>
<a:element2>b</a:element2>
<a:element3>c</a:element3>
... lots of other elements like the above ones
and 2nd fragment that has XPaths generated from the first XML and a new value, like
<field>
<xpath>/Parent/element1/subelement[#tag="someString"]/s1</xpath>
<newValue>1</newValue>
</field>
<field>
<xpath>/Parent/element2</xpath>
<newValue>2</newValue>
</field>
We might not have new values to apply for all the elements in the first fragment.
I'm struggling to make an XSLT transformation that should apply the new values to the places indicated by the XPaths.
The output should be:
... some static parents
<a:element1>
<a:subelement tag="someString">
<a:s1>1</a:s1>
</a:subelement>
</a:element1>
<a:element2>2</a:element2>
... lots of other elements like the above ones
I have access to xalan:evaluate to evaluate the dynamic xpath. I'm trying different solutions, I will write them here when they will start to make sense.
Any ideas of approaches are well received. Thanks
Oki, I found out how, and I will write the answer here maybe someone sometime will need this:
<xsl:template match="/">
<!-- static parents -->
<a:Root>
<xsl:apply-templates select="/a:Root/a:Parent" />
</a:Root>
</xsl:template>
<xsl:template match="#*|*|text()">
<xsl:variable name="x" select="generate-id(../.)" />
<xsl:variable name="y" select="//field[generate-id(xalan:evaluate(xpath)) = $x]" />
<xsl:choose>
<xsl:when test="$y">
<xsl:value-of select="$y/newValue" />
</xsl:when>
<xsl:otherwise>
<xsl:copy>
<xsl:apply-templates select="#*|*|text()" />
</xsl:copy>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
And to explain the transformation:
I'm writing down part that is static and then call apply-templates on the fragment I'm interested in, that has a liquid structure.
Then I'm using a slightly modified identity transformation that copies everything from source to target (starting from the /a:Root/a:Parent fragment), except when we position ourselves on the text I'm interested in changing.
The text() I'm interested in will have as parent (../.) the element referred by an xpath string found in the second fragment. Variable x means, in the context of the when, this element.
Variable y finds a field element that has as child an xpath element that if evaluated using xalan will refer to the same element that the x variable relates to.
Now I used generate-id() in order to compare the physical elements, otherwise it would have compared by the toString of the element (which is wrong). If variable y doesn't exist, it means that I have no xpath element for this element that could have changed, and I'm leaving it alone. If the y variable exists, I can get from it the newValue and I'm currently positioned on the element which text I want to update.
I've got an xsl:variable that contains a pre-processed set (DoesNotContainChildElement). I think msxsl:node-set() is adding a root element so position is always 1. But what I need it the top 15 elements.
<xsl:variable name="Summary">
<xsl:for-each select="msxsl:node-set($DoesNotContainChildElement)">
<xsl:if test="position() < 16">
<xsl:copy-of select="."></xsl:copy-of>
</xsl:if>
</xsl:for-each>
No, the function msxsl:node-set does not add any root node, it is simply that with XSLT 1.0 a sample like
<xsl:variable name="rtf1">
<item>1</item>
<item>2</item>
<item>3</item>
</xsl:variable>
creates a result tree fragment and "A result tree fragment is treated equivalently to a node-set that contains just a single root node". So in the sample above we have a result tree fragment with a single root node containing three item child elements.
Applying the msxsl:node-set(rtf1) extension function then gives you a node-set instead of a result tree fragment where now the node-set contains a single root node with three item child elements. Thus if you want to access the item elements you need msxsl:node-set($rtf1)/* or more general msxsl:node-set($rtf1)/node() to access all child nodes.
You may try msxsl:node-set($DoesNotContainChildElement)/*. If it's true that msxsl:node-set() adds a root node, then adding /* to your path will iterate over the children, where you can test for position.
Alternatively you could simply use <xsl:apply-templates select="msxsl:node-set($DoesNotContainChildElement)/*" mode="testposition"/> and <xsl:template match="*" mode="testposition">….
There's only one variable $DoesNotContainChildElement so a for-each will only yield value 1 for position().
You can check that by running the following:
<xsl:for-each select="$x">
<pos1><xsl:value-of select="position()"/></pos1>
</xsl:for-each>
<xsl:for-each select="$x/*">
<pos2><xsl:value-of select="position()"/></pos2>
</xsl:for-each>
Where x is a (node-set type) variable.
The result will look something like
<pos1>1</pos1>
<pos2>1</pos2>
<pos2>2</pos2>
<pos2>3</pos2>
<pos2>...</pos2>
Adding <xsl:copy-of select="."/> will result in the output of the entire variable contents in case of the first for-each above, whereas for the second for-each it will result in the output of each sub-element of the variable one-by-one.
The second form is the one to use if you wish to output only selected sub-elements.
The same holds when you first apply the node-set function to change an rtf into a node-set.
As I have mentioned in this post:
dynamic multiple filters in xsl
Basically, I want to apply multiple filters to my xml using "for loop" and these filters are dynamic which are coming from some other xml
sth like this:
foreach(list/field[#ProgramCategory=$Country][not(contain(#Program,$State1][not(contain(#Program,$State2][not(contain(#Program,$State3][not(contain(#Program,$Staten])
The problem is that I can get n no. of states which I am getting through for loop of other xml.
I cannot use document() function as suggested by Dimitre so I was thinking of achieving it by:
<xsl:variable name="allprograms">
<xsl:for-each select="/list2/field2">
<xsl:text disable-output-escaping="yes">[not(contains(#Program,'</xsl:text><xsl:value-of select="#ProgramID"></xsl:value-of><xsl:text disable-output-escaping="yes">'))]</xsl:text>
</xsl:for-each>
</xsl:variable>
gives me something like this:
[not(contains(#Program,'Virginia'))][not(contains(#Program,'Texas'))][not(contains(#Program,'Florida'))]
I want to use this above value as a filter in the for loop below and I am not sure how to achieve that
<xsl:for-each="list/field[not(contains(#Program,'Virginia'))][not(contains(#Program,'Texas'))][not(contains(#Program,'Florida'))]">
Before this I also have a for loop to filter United States
xsl:for-each="list/field $allprograms">
<xsl:value-of select="#ows_ID" />
</xsl:for-each>
I want my answer to be 1082, 1088..
I can add the xml here too if there is any confusion..
Jack,
From the previous solution you just need to add to this:
<xsl:param name="pFilteredStates">
<state>Virginia</state>
<state>Texas</state>
<state>Florida</state>
</xsl:param>
the following (changing the current variable definition that relies on the document() function):
<xsl:variable name="vFiltered" select=
"ext:node-set($pFilteredStates)/*
"/>
Where the "ext:" prefix needs to be bound to this namespace (this is the EXSLT namespace -- if your XSLT processor doesn't implement exslt:node-set() then you need to find what xxx:node-set() extension it implements, or tell us what is your XSLT processor and people will provide this information):
"http://exslt.org/common"
So, your <xsl:stylesheet> may look like the following:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:ext="http://exslt.org/common" exclude-result-prefixes="ext">
I still recommend that the $pFilteredStates parameter should be passed by the initiator of the transformation -- in which case you can delete the definition of $vFiltered and replace every reference to it with $pFilteredStates` and the transformation should work OK.
I am using a variable say xpathvar in the XSLT whose value will be supplied at the time of call to XSLT. How can i achieve this?
My XSLT file looks like -
<xsl:param name="xpathvar"/>
<xsl:param name="keyxpath"/>
<xsl:template match="/">
<listofResults>
<xsl:for-each select="$xpathvar">
<keyvalues><xsl:value-of select="xalan:evaluate(substring-before($keyxpath,'||'))"/></keyvalues>
<keyvalues><xsl:value-of select="xalan:evaluate(substring-after($keyxpath,'||'))"/></keyvalues>
</xsl:for-each>
</listofResults>
</xsl:template>
</xsl:stylesheet>
If I mention the variable in the for-each, it throws error. Please guide how can I achieve this.
Thanks!
According to Global xsl:param containing xpath expression string it can't be done purely with plain old XSLT, you need to use the evaluate extension see: Xalan evaluate expression
I dont think this can be done like this you must use xpath so example would be
<template match="Node[name=$xpathvar]" />
<xsl:for-each select="*[name()=$xpathvar]">
</xsl:for-each>
I think it does not let you use the variable directly because it is not a nodeset.
If I mention the variable in the
for-each, it throws error
In XSLT 1.0 (it looks you are using Xalan), you can iterate over node sets, only. So $xpathvar should be an instance of node set data type.
In XSLT 2.0 you can iterate over sequence (including scalar values).
Also, if the string containing the "dynamic" XPath expression is simple enough (only QName test step, maybe positional predicates) this could be done (as is already answered in SO) with standar XSLT.