I want to get the value of a specific node, specified by its id attribute. But the behaviour of my XSL parser, Saxon, is not how I expected it to work.
This is my XSL code:
<xsl:template match="synonyme">
<xsl:element name="corr">
<xsl:value-of select="#connecteur" />
<xsl:value-of select="/liste/connecteur[#id=#connecteur]/forme[1]" />
</xsl:element>
</xsl:template>
I just matched a tag named synonyme which has a connecteur attribute. My code outputs the value of this attribute.
I also want to output the value of another node which has an id attribute matching the connecteur attribute of my currently matched synonyme tag. But no results are ever found for this query, the second value-of always has empty output.
If I write, e.g. [#id='c160'], where c160 is the exact same thing that is output by the first value-of, it works! But not when comparing to the #attribute of my matched node. How can I fix this?
The XML is basically
<liste><connecteur id="c160"><forme>foo</forme></connecteur>
<connecteur id="c161"><synonyme connecteur="c160" /></connecteur>
</liste>
and the expected output in place of the synonyme is <corr>c160 foo</corr>.
The predicate you use:
[#id=#connecteur]
is looking for an element with two attributes - id and connecteur- with equal values. To look for an element with an id attribute whose value matches the value of the current element's connecteur value, you need to use:
[#id=current()/#connecteur]
See: https://www.w3.org/TR/xslt/#function-current
A better solution would be to define a key as:
<xsl:key name="ref" match="connecteur" use="#id" />
then use:
<xsl:value-of select="key('ref', #connecteur)/forme" />
to resolve the cross-reference.
See: https://www.w3.org/TR/xslt/#key
Related
I am outputting the name node of each property node in a ; delimited string as following:
<xsl:value-of select="properties/property/name" separator=";" />
I want to alter this such that each element is prefixed with _. An example output should be:
_alpha;_beta;_gamma
I tried the following:
<xsl:value-of select="concat('_', properties/property/name)" separator=";" />
I want to use this to create an output node containing that string:
<my_node>
<xsl:value-of select="concat('_', properties/property/name)" separator=";" />
</my_node>
This gives an error when there are multiple properties:
XPTY0004: A sequence of more than one item is not allowed
as the second argument of fn:concat() (<name>, <name>)
Is there a way to get this working in XSLT 2.0/3.0?
I could resort to the XSLT 1.0 for-each solution as given in https://stackoverflow.com/a/57856287/12042211 (in which we are manually adding the separator), but I am wondering if something elegant in XSLT 2.0/3.0 is possible.
The answer is yes. XSLT 2.0 allows you to write expressions like this...
<xsl:value-of select="properties/property/concat('_', name)" separator=";" />
So, for each property it selects the concatenation of "_" with the name element.
Such syntax is not valid in XSLT 1.0 though.
In XSLT 3.0 I would tend to write this as
<xsl:value-of select="properties/property ! ('_' || name)" separator=";" />
and perhaps use string-join() instead of xsl:value-of. You haven't shown the context, but try to use xsl:value-of only when you really want a text node, not when you just want a string.
More for reference than actual need: what is the XPath syntax to allow me to reference an element in a xsl:for-each block when the same element name is used elsewhere?
Please note, unfortunately this must be a 1.0 solution
For example, I have the following simple XML, and I want to match up the items with the same id value...
<data>
<block1>
<item><id>1</id><text>Hello</text></item>
<item><id>2</id><text>World</text></item>
</block1>
<block2>
<item><id>1</id><text>123</text></item>
<item><id>2</id><text>ABC</text></item>
</block2>
</data>
If I have a for-each on the block1, how can I reference both the id within the block1 and the id within the block2?
This will work, but I think it is messy...
<xsl:for-each select="//block1/item">
<xsl:variable name="id" select="id"/>
<xsl:value-of select="text"/> - <xsl:value-of select="//block2/item[id=$id]/text"/>
</xsl:for-each>
With the result of...
Hello - 123
World - ABC
Is there a simplified way of replacing the $id in select="//block2/item[id=$id]/text" so that it is referring to the id element from the for-each?
Another way to do it which you may find clearer, and will probably be faster, is to use keys:
<xsl:key name="b2" match="block2/item" use="id"/>
then
<xsl:value-of select="key('b2', id)/text"/>
What you have is correct and common as it is. There's no need to simplify it further; it's a standard idiom recognized and used by those working with XSLT.
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="$y/newValue" />
</xsl:when>
<xsl:otherwise>
<xsl:copy>
<xsl:apply-templates select="#*|*|text()" />
</xsl:copy>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
And to explain the transformation:
I'm writing down part that is static and then call apply-templates on the fragment I'm interested in, that has a liquid structure.
Then I'm using a slightly modified identity transformation that copies everything from source to target (starting from the /a:Root/a:Parent fragment), except when we position ourselves on the text I'm interested in changing.
The text() I'm interested in will have as parent (../.) the element referred by an xpath string found in the second fragment. Variable x means, in the context of the when, this element.
Variable y finds a field element that has as child an xpath element that if evaluated using xalan will refer to the same element that the x variable relates to.
Now I used generate-id() in order to compare the physical elements, otherwise it would have compared by the toString of the element (which is wrong). If variable y doesn't exist, it means that I have no xpath element for this element that could have changed, and I'm leaving it alone. If the y variable exists, I can get from it the newValue and I'm currently positioned on the element which text I want to update.
I have a variable from which I need to dynamically generate nodes
<xsl:template match="banner_discount_1 | banner_discount_2 | banner_discount_3">
<xsl:variable name="link">banner_discount_<xsl:value-of select="substring-after(name(.) ,'banner_discount_')" />_link</xsl:variable>
<xsl:value-of select="$link" />
</xsl:template>
<xsl:value-of> selects the string, but I want to be able to select the node which name matches the name of a variable.
In my case the node looks something like this:
<banner_discount_1_link />
<banner_discount_2_link />
...
Here is the xml I'm using
<banner_discount_1> 12 </banner_discount_1>
<banner_discount_2> 21 </banner_discount_2>
<banner_discount_3> 32 </banner_discount_3>
<banner_discount_1_link> link1 </banner_discount_1_link>
<banner_discount_2_link> link2 </banner_discount_2_link>
<banner_discount_3_link> link3 </banner_discount_3_link>
#MartinHonnen is on the right track, but you need to set the selection context as well.
Since you're in a template that's selecting the banner_discount_ nodes, that is your context. From your XML sample, it looks like the nodes you want to select are siblings, so this should work:
<xsl:value-of select="../*[local-name() = $link]"/>
It is preferable to target the nodes directly, but if they could be anywhere in the document, then you may resort to
<xsl:value-of select="//*[local-name() = $link]"/>
This is a last resort because it is potentially O(n) with respect to the number of nodes in the document.
Use <xsl:value-of select="*[local-name() = $link]"/>. If that does not help then consider to show a sample of the XML.
I want to select an element by index with the indexed number being passed in with a param, the param is being passed in via PHP. Here's what I am trying:
//PHP
$xslt->setParameter('','player',$player);
$xslt->importStylesheet( $XSL );
print $xslt->transformToXML( $data );
//xslt
<xsl:param name="player" data-type="number"/>
<template match="/">
<xsl:value-of select="result[$player]/#name" />
</template>
And I know the value of the param is being passed correctly because I can just output the value of the param ($player) and it will output the correct value. If I hard code the indexed number "$player" to any number of index I want like below:
<template match="/">
<xsl:value-of select="result[2]/#name" />
</template>
it works. So, what I am doing wrong here. Can you not use params/variables to select indexes?
It may be evaluating the value of your xsl:param as a string, rather than a number. You can try explicitly converting it to a number using the number() function.
<xsl:value-of select="result[number($player)]/#name" />
The predicate filter specifying a number is short-hand for [position()=$param]. You can use xsl:param inside the predicate filter, like this, and it will evaluate the xsl:param value as a number:
<xsl:value-of select="result[position()=$player]/#name" />
If I hard code the indexed number
"$player" to any number of index I
want like below:
<template match="/">
<xsl:value-of select="result[2]/#name" />
</template>
it works.
No, any compliant XSLT processor will not select anything.
result[2]/#name
is a relative expression against the current node, and the current node is the / -- document-node.
Any well-formed XML document has exactly one top element (never two), therefore
result[2]
is equivalent to:
/result[2]
and doesn't select anything.
Most probably you are dealing with another expression, which you haven't shown (or the template is not matching just /).
Also:
<xsl:param name="player" data-type="number"/>
this is invalid syntax. The <xsl:param> instruction doesn't have a data-type attribute.
In fact, in XSLT 1.0 there isn't any way to specify the type of variables or parameters.
This is why in:
result[$player]/#name
$player is treated as string -- not as an integer.
To achieve the "indexing" you want, use:
result[position()=$player]/#name
The position() function returns a number and this causes the other operand of the = operator to be converted to (and used as) number.